What is the definition of operative dentistry?
Operative dentistry is the art and science of the diagnosis, treatment, and prognosis of defects of teeth that do not require full coverage restorations for correction.
What are the indications for operative procedures?
What is the significance of high-speed handpieces in operative dentistry?
They allow more conservative and efficient removal of tooth structure for restorative procedures.
What concept was introduced alongside high-speed instrumentation in dentistry?
The concept of four-handed dentistry.
What advancements have influenced the dynamics of operative dentistry?
Advances in treatment techniques, philosophies, and materials.
What has the bonding of restorations to tooth structure led to?
The development of new composite restorative materials and conservative bonding techniques.
What is essential for a restorative dentist to understand?
Dental anatomy, histology, physiology, and occlusion.
What structures protect the pulp in teeth?
Dentin, enamel, and cementum.
What are the major determinants of function in teeth?
The form of a tooth and the contour/contact relationships with adjacent and opposing teeth.
What are the primary treatment needs in operative dentistry?
What role does the pulp cavity position and form play in dentistry?
It is mandatory during preparation and caries removal.
What is the purpose of understanding tooth anatomy and histology?
To ensure proper function in mastication, esthetics, speech, and protection.
What are the classes of human teeth?
What does tooth form predict?
The function of teeth.
What is the hardest substance in the human body?
Enamel
What cells form enamel?
Ameloblasts
From which embryonic layer do ameloblasts originate?
Ectoderm
What are the Tomes processes?
Short extensions of ameloblasts toward the dentinoenamel junction (DEJ).
What percentage of enamel is inorganic matter?
95% to 98% by weight.
What is the largest mineral constituent of enamel?
Hydroxyapatite (90% to 92% by volume).
What is the organic content of tooth enamel?
About 1% to 2% by weight.
What is the water content of tooth enamel?
About 4% by weight.
What are the structural components of enamel?
How many enamel rods are in a mandibular incisor?
Approximately 5 million.
How many enamel rods are in a maxillary molar?
About 12 million.
How are the enamel rods oriented relative to the DEJ?
They are aligned perpendicularly to the DEJ and tooth surface.
What is the orientation of the rods in the cervical region of permanent teeth?
They are oriented outward in a slightly apical direction.
What is the function of fissures at the junction of lobes?
They act as food traps.
What is the function of fissures at the junction of lobes in teeth?
Acts as a food trap, predisposing tooth to dental caries.
What tissues make up the Pulp-Dentin Complex?
Dentin and pulp tissues, specialized connective tissues of mesodermal origin.
What is the origin of dentin and pulp tissues?
Formed from the dental papilla of the tooth bud.
How do many investigators view dentin and pulp tissues?
As a single tissue forming the pulp-dentin complex.
What are odontoblasts?
Cells that form dentin, located in the pulp cavity with processes extending into dentin.
What are Tomes fibers?
Long, slender cytoplasmic processes of odontoblasts extending into dentinal tubules.
Why is dentin considered living tissue?
It can react to physiological and pathological stimuli, leading to changes like secondary and reparative dentin.
What are the types of dentin changes throughout life?
What does dentin cover in the tooth structure?
Externally covered by enamel on the crown and cementum on the root; forms walls of pulp cavity internally.
What is the function of odontoblastic processes?
Extend from odontoblasts into dentin, lying in dentinal tubules.
What happens to dentinal tubules when acid etched?
The tubule apertures are opened and widened by acid application.
What is the composition of cementum?
About 45% to 50% inorganic material (hydroxyapatite) and 50% to 55% organic matter and water.
What is the color of cementum compared to dentin?
Light yellow and slightly lighter in color than dentin.
What is unique about the fluoride content of cementum?
It has the highest fluoride content of all mineralized tissue.
How does cementum change throughout life?
New layers are deposited continuously to maintain attachment as the superficial layer ages.
What is the difference between acellular and cellular cementum?
Acellular cementum predominates on the coronal half, while cellular cementum occurs more frequently on the apical half.
What surrounds the apical foramen in teeth?
Cementum on the root end surrounds the apical foramen.
What predominates on the coronal half of the root?
Acellular cementum
Where does cellular cementum occur more frequently?
On the apical half of the root
What surrounds the apical foramen?
Cementum on the root end
What compensates for attritional wear of the occlusal surface?
Increase in cementum thickness on the root end
What do principal fibers of periodontal ligament continue into?
Surface of cementum as Sharpey’s fibers
What is dental caries?
An infectious microbiologic disease of the teeth causing localized dissolution and destruction of calcified tissues
What percentage of children (age 5-17) are caries-free?
Approximately 55%
By age 17, what fraction of adolescents have experienced caries?
Three out of four
What is the caries rate in adults older than 55 years?
Higher than in children
What are signs of bacterial infection in teeth?
Cavitations (destruction creating a 'cavity')
What is essential to understand in clinical practice regarding caries?
Focus on treating the underlying cause of the disease
What is the evidence for the role of bacteria in caries genesis?
Overwhelming; studies show bacteria cause caries
What happens to teeth free from bacterial infection?
They do not develop caries
What can reduce caries in animals and humans?
Antibiotics
What can oral bacteria do to enamel in vitro?
Demineralize enamel and produce lesions
What is the earliest evidence of caries on smooth enamel?
A white spot
Where are white spots usually observed?
On the facial and lingual surfaces of the teeth
What is the earliest evidence of caries on the smooth enamel surface of a crown?
A white spot
Where are white spots usually observed on teeth?
On the facial and lingual surfaces
What are white spots described as?
Chalky white, opaque areas revealed when the tooth surface is desiccated
What term is used for areas of enamel that lose translucency due to demineralization?
Incipient caries
What must be distinguished from white spots of incipient caries?
Developmental white spot hypocalcifications of enamel
What does the restoration of a carious lesion not do?
It does not cure the carious process
What eliminates the potential for caries formation?
Implementation of appropriate caries-preventive measures
What do tooth restorations primarily do?
Repair the tooth damage caused by caries
What are the three basic principles of Operative Dentistry?
What is the definition of tooth preparation?
Mechanical alteration of a defective, injured, or diseased tooth to receive restorative material
What must be removed during tooth preparation?
All defective or friable tooth structure
What are the objectives of tooth preparation?
Who presented much of the scientific foundations on tooth preparation objectives?
G. V. Black
How are tooth preparations classified according to G. V. Black?
What are Class I restorations?
All pit-and-fissure restorations
What types are included in Class I restorations?
What are Class II restorations?
Restorations on the proximal surfaces of posterior teeth
What are the types of Class II preparations?
What are the types of Class II preparations?
What is the difference between MO and DO preparations?
The distal wall in MO is a mesial wall in DO.
What is an MOD preparation?
An MOD preparation has similar walls, line angles, and point angles, but lacks mesial and distal walls.
What are Class III restorations?
Restorations on the proximal surfaces of anterior teeth that do not involve the incisal angle.
What are Class IV restorations?
Restorations on the proximal surfaces of anterior teeth that do involve the incisal edge.
What are Class V restorations?
Restorations on the gingival third of the facial or lingual surfaces of all teeth, excluding pit-and-fissure lesions.
What are Class VI restorations?
Restorations on the incisal edge of anterior teeth or the occlusal cusp heights of posterior teeth.
What defines a Simple tooth preparation?
A Simple preparation involves only one tooth surface.
What defines a Compound tooth preparation?
A Compound preparation involves two tooth surfaces.
What defines a Complex tooth preparation?
A Complex preparation involves three or more tooth surfaces.
What is an Internal Wall in tooth preparation?
A prepared (cut) surface that does not extend to the external tooth surface.
What is an Axial Wall?
An internal wall parallel with the long axis of the tooth.
What is a Pulpal Wall?
An internal wall that is perpendicular to the long axis of the tooth and occlusal of the pulp.
What is an External Wall?
A prepared surface that extends to the external tooth surface, named after the tooth surface it faces.
What is a Floor (or Seat) in cavity preparation?
A prepared wall that is flat and perpendicular to occlusal forces, e.g. pulpal and gingival walls.
What is an Enamel Wall?
The portion of a prepared external wall consisting of enamel.
What is a Dentinal Wall?
The portion of a prepared external wall consisting of dentin, where mechanical retention features may be located.
What is a Line Angle?
The junction of two planal surfaces of different orientation along a line.
What is a Point Angle?
The junction of three planal surfaces of different orientation.
What is a Cavosurface Angle?
The angle formed by the junction of a prepared wall and the external surface of the tooth.
What is the Cavosurface Margin?
The actual junction between the prepared wall and the external surface of the tooth.
What surfaces are illustrated in the tooth preparation walls schema?
What are the walls of tooth preparation?
What are the line angles in tooth preparation?
What are the point angles in tooth preparation?
What are the two stages of the tooth preparation procedure?
What are the steps in the initial tooth preparation stage?
What are the steps in the final tooth preparation stage?
What is essential in the evaluation of masticatory forces?
Evaluation of location, direction, and area of tooth contacts during mandibular movements.
What type of teeth support gliding contacts?
Anterior teeth support gliding contacts.
What type of teeth support heavy forces during chewing?
Posterior teeth support heavy forces.
What is the main holding contact area for opposing supporting cusp?
Fossa or marginal ridge contact area.
What happens during anterior movement of the mandible?
Lower anterior teeth glide along the lingual surfaces of maxillary anterior teeth.
What is the purpose of multiple contacts during protrusion?
To prevent excessive force on any individual pair of gliding teeth.
What is a handpiece used for in cavity preparation?
A device for holding rotating instruments, transmitting power, and positioning them intraorally.
What are the two basic types of handpieces?
What are the two basic types of handpieces in dentistry?
When did most development of methods for preparing teeth occur?
In the last 100 years
What is the term used for rotary cutting instruments with bladed cutting heads?
Bur
What are carbide burs used for?
Cutting dentin with slow speed handpieces
What are diamond instruments used for?
Cutting enamel with high speed handpieces
What are the three parts of diamond instruments?
What does laser stand for in dentistry?
Light amplification by stimulated emission of radiation
What are the types of lasers that have shown promise in dentistry?
What are the four common categories of material properties?
What are some examples of physical properties of materials?
What is the process called when restoring a tooth directly in the intraoral environment?
Direct restorative dentistry
What materials are used for direct restorations?
What is crucial to know in restorative dentistry regarding materials?
The structures and properties involved
What is the significance of selecting the correct wavelength for lasers in dentistry?
To ensure absorption of energy and prevent side effects from heat generation
What is direct restorative dentistry?
It is accomplished directly in the intraoral environment.
What are the materials for direct restorations?
What are the traditional stages of fabricating dental restorations by indirect techniques?
What are the materials for indirect restorations?
What is the definition of Class I restorations?
All pit-and-fissure restorations are Class I, assigned to three groups.
What are the types of Class I restorations?
What is amalgam in restorative dentistry?
A metal-like restorative material composed of a mixture of silver/tin/copper alloy and mercury.
How is amalgam applied to teeth?
The unset mixture is pressed into a specifically prepared undercut tooth form and contoured to restore the tooth’s form and function.
What is the current status of amalgam as a restorative material?
Its popularity has decreased due to concerns about safety and environmental effects, and the benefits of composites.
What concerns exist regarding amalgam restorations?
Concerns relate to poor esthetics, weakening of the tooth by removal of more tooth structure, and recurrent issues.
What are the concerns about amalgam restorations?
What are amalgam restorations suited for?
Restoring many defects in teeth economically and simply.
What factor may lead to a reduction in amalgam use?
Concern about disposal of amalgam from dental offices.
What environmental concern is associated with amalgam?
Mercury contamination of municipal water supplies.
What regulations have some communities passed regarding amalgam?
Defined limits of allowable mercury in wastewater from dental offices.
What can be costly for dental offices in relation to mercury?
Monitoring mercury levels and installing reduction equipment.
In which countries has legislation restricting amalgam use been implemented?
Japan, Denmark, Canada, Sweden, Germany.
What is the function of amalgam as a restorative material?
Easily inserted into a tooth preparation to restore form and function.
What types of amalgam restorations exist?
Bonded and nonbonded amalgam restorations.
What is required for the tooth preparation form for amalgam?
What are the requirements for amalgam thickness?
Must possess a uniform specified minimum thickness for strength.
What angle must the amalgam margin be formed at?
90-degree amalgam angle (butt joint form).
What are the clinical indications for direct amalgam restorations?
Moderate to large Class I and Class II restorations, especially under heavy occlusion.
Why is amalgam avoided in prominent esthetic areas?
Most patients find the appearance objectionable compared to composites.
What is a disadvantage of amalgam compared to composite?
Tooth preparation for amalgam is larger, leading to more tooth structure removal.
What are the advantages of amalgam restorations?
What are the primary advantages of amalgam restorations?
What are the primary disadvantages of amalgam restorations?
What is the required restoration angle for amalgam placement?
A 90-degree or greater restoration angle at the cavosurface margin.
What is the minimum thickness for amalgam to ensure adequate compressive strength?
0.75 to 2 mm
What type of form must amalgam be placed into for retention?
An undercut form in the tooth for mechanical retention.
What are the initial stages of tooth preparation for amalgam?
What is the initial depth for tooth preparation in amalgam restorations?
0.2 mm inside the DEJ or 1.5 mm from the central groove, whichever is greater.
What are the principles of Conservative Class I Amalgam Restorations?
How can you eliminate a weak wall of enamel in amalgam restorations?
By joining two outlines that are <0.5 mm apart.
What should the outline form of a Conservative Class I preparation look like?
Gently flowing curves with distinct cavosurface margins.
What is the ideal faciolingual width for conservative Class I tooth preparation?
1 to 1.5 mm
What is the ideal depth for conservative Class I tooth preparation?
1.5 to 2 mm
Where is the pulpal floor usually located in conservative Class I preparation?
In dentin, depending on enamel thickness
What does convenience form in tooth preparation require?
Adequate access and visibility
What should be included in the outline of conservative Class I preparations?
Remaining occlusal enamel defects
What is the strongest enamel margin composed of?
Full-length enamel rods on sound dentin
What should be ensured during the initial tooth preparation for Class I amalgam?
All caries is removed from the peripheral DEJ
What is the ideal depth for the pulpal floor during initial tooth preparation?
Remain at 1.5 mm
What are the components of primary resistance form?
What provides the primary retention form in conservative Class I restorations?
Parallelism or slight occlusal convergence of external walls
What should the cavosurface angle not exceed?
100 degrees
What should the marginal-amalgam angle not be less than?
80 degrees
What does final tooth preparation include?
How is the removal of remaining infected dentin best accomplished?
Using a discoid-type spoon excavator or a round carbide bur
What should not affect resistance form during carious dentin removal?
The periphery should not need further extension
What should the flat floor be at in terms of depth?
At the initial pulpal floor depth of 1.5 to 2 mm
When should the external walls have been finished?
During earlier steps in conservative tooth preparation
What is the thickness range for sound enamel or dentin?
1.5 to 2 mm
What is contraindicated in the tooth preparation for an amalgam restoration?
An occlusal cavosurface bevel
What angle should the cavosurface angle be for amalgam restoration?
90 to 100 degrees
What is the ideal amalgam angle at the margins?
80 to 90 degrees
What type of joint is the strongest for enamel and amalgam?
Butt joint margin
What is the nature of amalgam as a material?
Brittle with low edge strength
What should be done before the restoration of a completed tooth preparation?
Inspect and clean
What are examples of Conservative Class I Amalgam Preparations?
What is the bur tilt for entry in tooth preparation?
Long axis parallel with bisector of angle formed by long axis of tooth and perpendicular line to plane through facial and lingual cusp points
What is the initial tooth preparation step for extensive caries?
Excavation of infected dentin and insertion of a liner if necessary
When is caries considered extensive?
When the distance between infected dentin and pulp is less than 1 mm or when the defect extends up the cuspal inclines
What is the benefit of using amalgam in large Class I restorations?
Good wear resistance and occlusal contact relationships
What is the preparation design for mandibular first premolar?
Includes cutting instrument held parallel to bisector of angle formed by tooth's long axis and perpendicular line to facial and lingual cusp points
What should be included in the outline for maxillary first molar preparation?
Mesial and central pits connected by fissure
What is necessary for extension in mandibular second premolar preparation?
Extension through lingual ridge enamel when enameloplasty does not eliminate lingual fissure
What is the initial depth for Class I Amalgam restorations?
1.5 to 2 mm - 1.5 mm at pits or fissures - 2 mm on external walls
How should the preparation be extended for Class I Amalgam restorations?
Laterally to remove all enamel undermined by caries, alternating cutting and examining.
What is the cavosurface angle for caries extending up cuspal inclines?
90- to 100-degree angle while maintaining initial depth.
When is cusp capping indicated in Class I Amalgam restorations?
When the defect extends to: - Half the distance between primary groove and cusp tip - Two thirds distance, usually required due to fracture risk.
What is the method for removing infected dentin in Class I Amalgam restorations?
Same as for conservative preparation.
What should be done if pulp exposure occurs during Class I Amalgam restoration?
Decide to apply a direct pulp cap of calcium hydroxide or treat endodontically.
Are secondary resistance or retention forms necessary for extensive Class I amalgam preparations?
Usually not necessary; primary resistance form obtained by outlining tooth preparation.
What is secondary resistance form in Class I Amalgam preparations?
Flat seats in dentin (0.2 mm inside DEJ) if flat pulpal floor is removed.
How is primary retention achieved in Class I Amalgam restorations?
By occlusal convergence of enamel walls; secondary retention may come from undercuts.
What are Class I Occlusolingual Amalgam restorations used for?
On maxillary molars with a lingual fissure connecting to distal oblique fissure and distal pit.
What is the initial tooth preparation for Class I Occlusolingual restorations?
Establish outline, primary resistance, primary retention forms, and initial preparation depth.
What is the maximum width for the mesiodistal width of the lingual extension in Class I Occlusolingual restorations?
Should not exceed 1 mm, except for carious or undermined enamel removal.
How should the tooth preparation be adjusted when indicated in Class I Occlusolingual restorations?
Cut more at the expense of the oblique ridge rather than centering over the fissure.
What should be done when preparing tooth for Class II Amalgam Restorations?
What is the occlusal outline form for Class II Amalgam Restoration?
Similar to Class I tooth preparation
What is the depth of the occlusal step in Class II preparations?
1.5 to 2 mm (1.5 mm at fissure)
What are the objectives for the proximal margins in Class II restorations?
What is the bur position for beginning the proximal ditch cut?
Bur positioned to create initial proximal ditch
What should be ensured regarding the gingival margin when preparing small lesions?
Gingival margin should clear adjacent tooth by only 0.5 mm
What happens to the pulpal depth if the gingival margin is extended into cementum?
Pulpal depth is 0.75 to 0.8 mm
What should be done to weaken proximal enamel during preparation?
Bur is moved toward and perpendicular to proximal surface
What is the effect of the faciolingual dimension of the proximal ditch?
Greater at gingival than at occlusal level
What tool is used to remove isolated enamel?
Spoon excavator
What is the purpose of moving isolated enamel?
To prepare the tooth for restoration by removing weakened enamel.
What tool is used to fracture weakened proximal enamel?
Spoon excavator.
What is observed in the occlusal view after removing proximal enamel?
Proximal enamel is removed, showing the internal preparation.
What is the definition of initial Class II tooth preparation?
Extension of external walls to reach sound tooth structure, resist fracture, and retain restorative material.
What should be the condition of pulpal and axial line angles in proper outline form?
They should be in sound dentin.
What is the ideal depth for axial and pulpal walls?
To be prepared to a specified limited depth.
What is the proper direction for proximal walls?
To achieve full-length enamel rods and 90-degree amalgam at preparation margin.
Where are retention locks cut in tooth preparation?
0.2 mm inside DEJ, parallel to DEJ.
How is infected carious dentin removed from Class II preparations?
Using a slowly revolving round bur of appropriate size.
Does the presence of infected carious dentin require deepening the entire wall?
No, it does not indicate deepening the entire wall.
What does secondary resistance form involve?
Resistance of remaining tooth structure against fracture from oblique forces.
How is the fracture resistance of the amalgam restoration enhanced?
Using a gingival margin trimmer to bevel or round the axiopulpal line angle.
What are the four characteristics of retentive locks?
Occlusal view, proximal view, position, and orientation.
What should be corrected in preparation walls and margins?
Unsupported enamel and marginal irregularities.
Is an occlusal cavosurface bevel indicated in amalgam preparation?
No, it is not indicated.
What is the ideal cavosurface angle at the proximal margin?
90 degrees (maximum of 100 degrees).
What should the occlusal line angle be in tooth preparation?
90 to 100 degrees or greater.
What is compared when looking at variations of one proximal surface tooth preparations?
Differences in size of pulp chambers, lingual cusps, and direction of pulpal walls.
What is the occlusal outline form for a mandibular first premolar with sound transverse ridge?
Two-surface preparation that does not include opposite pit.
What type of preparation is shown for a maxillary first molar?
Conventional mesio-occlusal preparation and extended to include distal pit.
What is the maxillary first molar preparation type A?
Conventional mesio-occlusal preparation.
What is the maxillary first molar preparation type B?
Mesioocclusal preparation extended to include distal pit.
What is the maxillary first molar preparation type C?
Mesio-occlusolingual preparation, including distal pit and distal oblique and lingual fissures.
What is the maxillary first molar preparation type D?
Mesio-occlusal preparation with facial fissure extension.
What is a simple box restoration?
Restoration without occlusal step for small proximal lesion without occlusal fissures or prior restoration.
What do proximal locks extend to?
Proximal locks extend to occlusal surface.
What is illustrated in a slot preparation?
A, Mesiodistal longitudinal section illustrating carious lesion; B, Initial tooth preparation; C, Preparation with infected carious dentin removed.
What do retention grooves show in a slot preparation?
They are shown in longitudinal section, illustrating contour of axial wall and direction of facial and lingual walls.
What is the purpose of a wedged matrix in slot preparation?
To assist in the preparation by providing support and maintaining contour.
What is the mandibular second premolar preparation type?
Mesio-occlusodistal preparation.
What is the mandibular first premolar preparation modification?
Lingual cusp reduced for capping.
What is involved in the reduction of distolingual cusp of maxillary molar?
A, Cutting depth gauge groove with side of bur; B, Completed depth gauge groove; C and D, Completed cusp reduction.
What is the ideal distofacial extension for mandibular first molar preparation?
Entire distal cusp included in preparation outline form.
When is capping of distal cusp indicated?
When occlusal margin crosses cuspal eminence.
What is the necessary reduction for amalgam thickness in distal cusp?
Reduction of 2 mm is necessary to provide for minimal 2-mm thickness of amalgam.
What is the purpose of cast metal restoration?
Versatile and especially applicable to Class II onlay preparations.
What does the Class II inlay involve?
Involves the occlusal and proximal surfaces.
What is typically involved in the dental restoration process?
A dental laboratory is involved, and the dentist and laboratory technician must be devoted to perfection.
What does a Class II inlay involve?
The occlusal and proximal surfaces of a posterior tooth; may cap one or more, but not all, of the cusps.
What does a Class II onlay involve?
The proximal surfaces of a posterior tooth; caps all of the cusps.
What does a Class II overlay involve?
The proximal surfaces of a posterior tooth; caps all of the cusps and covers three-fourths of the tooth crown.
What is the fabrication process for dental restorations referred to?
An indirect procedure because the casting is made on a replica of the prepared tooth in a dental laboratory.
What are the major advantages of cast metal restorations?
High compressive and tensile strengths, valuable for restoring most of or the entire occlusal surface.
When is a cast metal inlay indicated?
For large restorations needing higher strength or superior control of contours and contacts.
When is a cast metal onlay an excellent alternative?
For teeth greatly weakened by caries or large, failing restorations, where facial and lingual surfaces are relatively unaffected.
What are the benefits of using a cast metal onlay for weakened teeth?
Superior physical properties to withstand occlusal loads and designed to distribute loads to decrease fracture risk.
Why is preserving intact facial and lingual enamel important?
It maintains the health of contiguous soft tissues.
What should be considered when proximal surface caries is extensive?
Favorable consideration should be given to the cast inlay or onlay.
How can endodontically treated teeth be restored?
With a cast metal onlay, designed to distribute occlusal loads to reduce fracture risk.
What should be recognized in teeth with fracture lines?
Fracture lines in enamel and dentin are cleavage planes for possible future fracture.
What may be warranted for teeth at risk for fracture?
Restoration with cast onlays (with skirting) and crowns to brace the tooth against fracture injury.
What is important in dental rehabilitation with cast metal alloys?
Using cast metal restorations to restore adjacent or opposing teeth.
What are the indications for dental rehabilitation with cast metal alloys?
What are the advantages of cast metal restorations?
What are the contraindications for cast metal restorations?
What is the advantage of using cast metal restorations for abutment teeth?
What should be controlled before using cast metal restorations in patients with a high caries rate?
What are the direct restorative materials indicated for young patients?
Why might esthetics limit the use of cast metal restorations?
What is a common alternative to cast metal restorations in esthetically sensitive areas?
What is a disadvantage of cast metal restorations regarding appointments?
What are the restorative uses of cast metal alloys?
What is the first disadvantage of cast inlays?
Requires at least two appointments and more time than direct restorations.
What is the second disadvantage of cast inlays?
Patients must have temporary restorations between appointments.
What is the third disadvantage of cast inlays?
Indirect cast restorations are more expensive due to materials and lab costs.
What is the fourth disadvantage of cast inlays?
Every step requires diligence; errors can lead to poor fits.
What is the fifth disadvantage of cast inlays?
Small inlays may cause a wedging effect, increasing tooth splitting risk.
What type of burs are used for initial preparation of cast metal inlays?
Parallel burs that are plane cut and tapered fissure burs.
What is the purpose of plane cut burs in preparation?
To ensure vertical walls are smooth and straight.
What is the draw path orientation during preparation?
Oriented to a single path, usually the long axis of the tooth crown.
What is the gingival-to-occlusal divergence range for preparation walls?
May range from 2 to 5 degrees per wall from the line of draw.
What is the maximum occlusal divergence for short vertical walls?
A maximum of 2 degrees is desirable to increase retention.
What is the depth of the occlusal box punch cut?
1.5 mm.
How should the long axis of the bur be oriented for maxillary posterior teeth?
Parallel to the long axis of the tooth crown.
How should the bur be oriented for mandibular molar and second premolar teeth?
Tilt slightly lingually to parallel the long axis of the tooth crown.
What is important to conserve during the extension of the mesial wall?
Conserve dentin that supports the marginal ridge.
What can a marginal bevel provide during preparation?
Additional extension.
What is the result of improper extension during preparation?
It can weaken the marginal ridge.
What does the dovetail retention form ensure?
The inlay fits into the preparation only in an occlusal-to-gingival direction.
What is the purpose of extending the proximal ditch facially and lingually?
To reach the desired position of the facioaxial and linguoaxial line angles.
What should be the gingival clearance with the adjacent tooth for minimal lesions?
0.5 mm clearance with the unbeveled gingival margin.
What does moderate to extensive caries dictate for the proximal ditch extension?
Continued extension to the extent of the caries at the dentinoenamel junction.
How should the axial wall follow during preparation?
It should follow the contour of the tooth faciolingually.
What should the axial wall follow during initial preparation?
The contour of the tooth faciolingually.
Should carious dentin on the axial wall be removed at the initial preparation stage?
No, it should not be removed.
What is indicated if minimal extension is needed for esthetic objectives?
Planing the distofacial, distolingual, and gingival walls by parallel burs.
How deep should the retention grooves be cut during initial preparation?
Shallow, 0.3 mm deep.
Where should the retention grooves be positioned?
In sound dentin, near but not contacting the DEJ.
What should be done if carious dentin is judged to be infected?
Apply a rubber dam before removal of infected dentin.
What is used to bevel the occlusal and gingival margins?
A slender, flame-shaped, fine-grit diamond instrument.
What angle should the marginal metal be on the inlay after beveling?
45-degree marginal metal.
What is the result of failing to bevel the gingival margin?
Weak margin formed by undermined rods and 110-degree marginal metal.
What is the desired width of the cavosurface bevel on the occlusal margin?
Approximately one fourth the depth of the respective wall.
What is the resulting occlusal marginal metal of the inlay?
40-degree metal; the occlusal marginal enamel is 140-degree enamel.
What should be done after the cement base is completed?
Prepare bevels and flares using a flame-shaped diamond instrument.
What is the purpose of the cavosurface design?
Helps seal and protect the margins and results in a strong enamel margin.
What is indicated if the prepared tooth is short?
Cut shallow retention grooves in the facioaxial and linguoaxial line angles.
What is the direction of the instrument when beveling the gingival margin?
Move the instrument facially along the gingival margin, tilted mesially.
What is the effect of a properly directed gingival bevel?
Results in 30-degree marginal metal.
What happens if a wider bevel is desired?
Include an enamel defect in the preparation.
What is the view of the completed disto-occlusal preparation for inlay?
Disto-occlusal view of maxillary right first premolar.
What type of preparation is completed for inlay?
Disto-occlusal preparation
What is the preparation type for the maxillary right first premolar?
Mesio-occlusodistal preparation for inlay
What is desired for the mesiofacial proximal wall in Class II cast metal preparations?
Minimal flare for esthetic reasons
What may require extension of the preparation outline?
Faulty facial groove or faulty distal oblique groove
What is the purpose of extending facial, lingual, and gingival margins on abutments?
To increase surface area for guiding planes
What must the occlusal outline form accommodate for removable partial dentures?
Rest preparation without involving restoration margins
What is necessary when extending the occlusal outline up the cusp slopes?
Consider capping the cusp
Why should undermined occlusal enamel be removed?
To provide access for proper excavation of caries
What is the recommended depth increase for the pulpal floor?
Increase from 1.5 mm to 2 mm
What treatment may be applied when smooth surfaces are affected by caries?
Large inlay, onlay, three-quarter crown, full crown, or multiple restorations
What determines the choice of cast metal restorations for extensive carious portions?
Degree of tooth circumference involved
What is modified in Inlay Tooth Preparations?
What instrument is used for shallow decalcification of the distofacial cusp?
Flame-shaped diamond instrument
What is the purpose of facial or lingual surface groove extensions in Onlay Tooth Preparations?
To provide additional retention form
What is the recommended taper for vertical walls in tooth preparation?
Minimal amount of taper (2 degrees per wall)
What are the three retention features in tooth preparation?
What are skirts in tooth preparation?
Thin extensions of facial or lingual proximal margins of cast metal onlay
What is the purpose of skirt extensions?
Improve retention and resistance form of the preparation
When is a collar provided in tooth preparation?
When preparing a weakened tooth for mesio-occlusodistal onlay capping all cusps
What is the depth of the shoulder prepared for a collar?
0.8 mm deep
What should the occlusal 1 mm of reduction follow?
The original contour of the tooth
What is the use of a slot in the dentin?
To provide necessary retention form
What is the purpose of using a slot in dentin?
To provide necessary retention form.
Which tooth is an example where a slot in dentin may be helpful?
Mandibular second molar.
What type of restoration is required for the mandibular second molar?
Mesioocclusal onlay restoration capping all cusps.
Who is the author of the lecture on tooth preparation?
Associate Professor Vesela Stefanova, PhD.
When were posterior composite restorations introduced?
In the mid-1960s.
What improvements have been reported for composite use in posterior teeth?
Successful results due to improved physical properties and bonding systems.
What is the expected lifetime of resin-based composites compared to amalgam?
Comparable in Class I and Class II restorations.
What are the material qualities of composite?
Sufficient strength for Class I and II restorations; insulative; conservative tooth preparation.
What are the indications for using composites?
What are the contraindications for using composites?
What are the advantages of using composites?
What is an advantage of tooth structure removal?
What are the bonding benefits of tooth structure removal?
What are the disadvantages related to material in tooth structure removal?
What is a disadvantage of tooth structure removal regarding placement?
What makes tooth structure removal more technique sensitive?
How does the cost of tooth structure removal compare to amalgam restorations?
What are the three typical composite preparations?
When is the amalgam-like conventional preparation form indicated?
What do the conventional beveled and conventional preparation designs provide?
What characterizes modified tooth preparations?
What cutting instruments are used for Class I and II preparations?
What is a benefit of using diamond instruments in tooth preparation?
What is a challenge when using diamond instruments?
What preparation design is preferred for extensive occlusal restorations?
What are the characteristics of inverted cone burs?
How is the tooth prepared for a large or moderate restoration?
What is the objective of tooth preparation for Class I amalgam?
To remove all caries or faults as conservatively as possible.
What can be sealed during conservative preparation techniques?
Other less involved or at-risk areas.
Where does one enter for a large Class I composite tooth preparation?
In the distal pit area of the faulty occlusal surface.
What is the initial pulpal floor depth for Class I preparation?
1.5 mm, measured from the central groove.
What is the facial or lingual wall height usually after removing the central groove?
Approximately 1.75 to 2 mm.
What dictates the facial and lingual extension and width?
Caries, old restorative material, or fault.
How should the strength of cuspal and marginal ridge areas be preserved?
As much as possible during preparation.
What is the recommended thickness of remaining tooth structure for premolars?
Approximately 1.6 mm.
What is the recommended thickness of remaining tooth structure for molars?
Approximately 2 mm.
What happens to the pulpal floor when extending toward cusp tips?
The same approximate 1.5-mm depth is maintained.
What is the axial depth for preparing a groove extension through the cusp ridge?
0.2 mm inside the DEJ and gingivally to include all of the fault.
What should be done if caries or old restorative material remains on the pulpal floor?
It should be removed with the appropriate instrument.
How is the occlusal margin left after preparation?
As prepared, without beveling or flaring.
What is the purpose of additional beveling on the occlusal margin?
It may result in thin composite in areas of heavy occlusal contact.
What shape do occlusal walls take when using an inverted cone instrument?
They converge occlusally, enhancing retention form.
Why is there a reduced need for occlusal bevels?
The ends of the enamel rods are already exposed by the preparation.
What is the width of the bevel when beveling a groove extension?
0.25- to 0.5-mm width at a 45-degree angle to the prepared wall.
What design characterizes a larger Class I composite tooth preparation?
It is primarily a conventional design, often with beveled facial or lingual grooves.
What should be done after removing a cavitated carious lesion?
Adjacent less involved areas should be treated conservatively with sealants or minimally invasive preparations.
How do modified Class I tooth preparations appear?
They have a scooped out appearance and are prepared with a small round or inverted cone diamond bur.
What is the initial pulpal depth for modified Class I preparations?
1.5 mm or approximately 0.2 mm inside the DEJ.
What is the advantage of using indirect techniques for restorations?
Restorations are fabricated outside of the mouth, allowing for better esthetics and durability.
What materials are used for tooth-colored indirect restorations?
Laboratory processed composites and ceramics, such as porcelain and hot pressed glasses.
When are indirect tooth-colored restorations indicated?
For Class I and II restorations in areas of esthetic importance or for large defects.
What is an advantage of using indirect techniques for large restorations?
Contours of large restorations are more easily developed.
Why are indirect materials preferred for large posterior restorations?
They are more durable and maintain occlusal surfaces and contacts better than direct composites.
What is a contraindication for ceramic restorations?
Heavy occlusal forces can cause fractures.
What is especially important in large posterior restorations?
Occlusal contacts
What can cause ceramic restorations to fracture?
Heavy occlusal forces
What are indicators of bruxing and clenching habits?
What is a requirement for adhesive techniques to ensure success?
Near-perfect moisture control
What should be avoided in deep subgingival preparations?
Recording impressions and finishing
What is a preferred bonding location for indirect restorations?
Enamel margins, especially along gingival margins of proximal boxes
What are the advantages of indirect restorations?
How do indirect restorations compare to direct composites in terms of physical properties?
Better physical properties due to ideal laboratory conditions
What is the wear resistance of ceramic restorations compared to direct composites?
More wear resistant
What is a major shortcoming of direct composite restorations?
Polymerization shrinkage
What reduces stress during cementation of indirect restorations?
Little composite cement is used
What can indirect tooth-colored restorations strengthen?
Remaining tooth structure weakened by caries, trauma, or preparation
What do indirect techniques provide better control over?
What is the biocompatibility of ceramics related to?
Chemical inertness and soft tissue response
What are ceramics considered in terms of tissue response?
Chemically inert materials with excellent biocompatibility and soft tissue response.
What influences pulpal biocompatibility in indirect techniques?
Related more to adhesive composite cements than to the ceramic materials used.
What is an advantage of indirect techniques regarding support?
They allow the fabrication of restorations to be delegated to dental laboratory technicians.
What is a disadvantage of indirect techniques regarding cost and time?
They usually require two patient appointments and fabrication of a temporary restoration, leading to higher costs.
How do indirect tooth-colored inlays and onlays compare to direct restorations?
They are more expensive than direct restorations but less costly than more invasive esthetic alternatives.
What is required for restorations made using indirect techniques?
A high level of operator skill and diligence during all stages of the process.
What is a potential issue with the brittleness of ceramics?
Ceramic restorations can fracture if not adequately supported or if preparation thickness is insufficient.
What problem can ceramic materials cause to opposing dentition?
Excessive wear of opposing enamel or restorations, especially if rough and unpolished.
What bonding difficulties are associated with resin-to-resin in indirect restorations?
Laboratory-processed resins have few double bonds for chemical adhesion, requiring mechanical abrasion or chemical treatment.
What is the issue with the clinical track record of indirect bonded restorations?
They have a short clinical track record with few controlled clinical trials available.
What is the potential for repair in indirect restorations?
Low potential for repair, particularly for ceramic inlays/onlays.
What happens when a partial fracture occurs in a ceramic inlay/onlay?
Repair is usually not definitive; it involves mechanical roughening, etching, and applying a silane coupling agent.
Why might direct composite repairs not be suitable for some ceramic inlays/onlays?
Because they are indicated in areas where occlusal wear, esthetics, and resistance are important.
What are ceramic inlays/onlays indicated for?
Why are direct composite repairs often unsuitable?
The composite might be exposed to a challenging environment.
What is a disadvantage of ceramic restorations during try-in?
Difficult try-in and delivery due to polishing challenges.
How can indirect composite restorations be polished?
With the same instruments and materials used for direct composites.
What improves the physical properties of composite restorations?
Being free of voids and having a maximally polymerized resin matrix.
What techniques are used in the dental laboratory for composites?
How do laboratory-processed composite inlays/onlays compare to direct composites?
More resistant to occlusal wear, especially in contact areas.
What are some advantages of laboratory-processed composites?
When are processed composite restorations indicated?
Why have ceramic inlays and onlays become popular?
Due to patient demand for esthetic, durable materials and improvements in techniques.
What types of ceramic materials are used?
How do the properties of ceramics compare to composites?
Ceramics match enamel properties better than composites.
What is the thermal expansion property of ceramics?
Close to that of tooth structure.
What may vary in tooth preparation for indirect restorations?
Differences in fabrication steps and physical properties of materials.
What should a dentist decide before starting a restoration procedure?
What type of restoration is indicated based on specific factors.
What should a dentist decide before beginning any procedure?
The type of restoration indicated, according to the factors.
What should a clinician consult if unfamiliar with a technique?
Manufacturer’s literature and possibly the dental laboratory.
What is the design requirement for indirect tooth-colored inlays and onlays?
Provide adequate thickness and a passive insertion pattern with rounded internal angles and well-defined margins.
What angle should all margins have for restoration strength?
A 90 degree butt-joint cavosurface angle.
Why should all angles be rounded in tooth preparation?
To avoid stress concentrations, reducing the potential for fractures.
What is the minimum isthmus width for a mesio-occlusal inlay preparation?
At least 2 mm wide.
What is the recommended depth for a pulpal floor in inlay preparation?
1.5 to 2 mm in depth.
What should interproximal margins allow for in tooth preparation?
At least 0.5 mm clearance of contact with neighboring tooth.
What is preferred for gingival margins in tooth preparation?
Gingival margins in enamel are greatly preferred.
What should be done if caries affect the facial or lingual surface?
Extend the preparation with a gingival shoulder around the transitional line angle.
What is the requirement for capping a cusp during preparation?
Cusp should be capped if the extension is two thirds or greater than the distance from any primary groove to the cusp tip.
How much should cusps be reduced if they must be capped?
Reduced by 1.5 to 2 mm.
When should a tooth be capped?
If the extension is two thirds or greater than the distance from any primary groove to the cusp tip.
How much should cusps be reduced when capped?
1.5 to 2 mm with a 90-degree cavosurface angle.
What is necessary when capping centric holding cusps?
Prepare a shoulder to move the facial or lingual cavosurface margin away from contact with opposing tooth.
What can happen if there are contacts directly on margins?
It can lead to premature deterioration of marginal integrity.
What must tooth preparations for CAD/CAM inlays reflect?
The capabilities of the CAD software, hardware, and CAM milling devices.
How long does it take to prepare a tooth and deliver an inlay using CAD/CAM?
Approximately 1 hour.
What does the CAD/CAM system eliminate?
The need for a conventional impression, temporary restoration, and multiple patient appointments.
What is required for laboratory-fabricated indirect systems?
Preparation must have a path of draw for insertion and removal without interferences from undercuts.
What do some CAD/CAM systems do during the optical impression?
Automatically 'block out' any undercuts.
What is a mesio-occlusodistofacial inlay preparation?
Preparation for ceramic inlay on maxillary first molar.
What is a Class III preparation?
Preparations on the proximal surfaces of anterior teeth that do not involve the incisal angle.
What is the term for the faciolingual line angle at the incisal in Class III preparations?
Incisal line angle.
What are the line angles in Class III preparations?
Axiolingual (al), linguogingival (lg), axiogingival (ag), faciogingival (fg), axiofacial (af), incisal (i).
What are the point angles in Class III preparations?
Axiolinguogingival (alg), axiofaciogingival (afg), axioincisal (ai).
What are Class IV Preparations?
Preparations on the proximal surfaces of anterior teeth that do involve the incisal edge.
What are the tooth preparation walls in Class IV?
What are the line angles in tooth preparation?
What are the point angles in tooth preparation?
What are the two stages of tooth preparation?
What are the steps in the initial tooth preparation stage?
What are the steps in the final tooth preparation stage?
What are the indications for Class III and IV restorations?
Almost all Class III and IV restorations are restored with composites, requiring adequate isolation for effective bonding.
What are the contraindications for using composite in Class III and IV restorations?
What is a contraction gap in composite restorations?
A V-shaped gap formed between the root and composite due to polymerization shrinkage.
What defines Class III tooth preparations?
Located on the proximal surfaces of anterior teeth.
What is the definition of Class III tooth preparations?
Located on the proximal surfaces of anterior teeth.
Why are Class III tooth preparations predominantly for composite restorations?
Typical need for esthetic restorations in anterior teeth.
What type of bond retains most Class III composite restorations?
Micromechanical bond from acid etching and resin bonding.
What is the effect of using diamond burs in tooth preparation?
Leaves surfaces rougher, increasing surface area and micromechanical retention.
What negative effect can a thick smear layer have?
Can negatively affect self-etching bonding systems.
What is the operator's role in selecting rotary preparation instruments?
Selection is operator dependent based on knowledge and technique.
When might a groove or cove be necessary in Class III restorations?
When restorations extend onto the root surface or are very large.
What is a common method to achieve additional retention form in Class III preparations?
Increasing surface area with a wider enamel bevel or flare along the margin.
Which approach is preferable when restoring a proximal surface of an anterior tooth?
Lingual approach is preferable unless excessive cutting is needed.
What are the advantages of restoring from the lingual approach?
What indicates a facial approach for restoration?
What should be done when both facial and lingual surfaces are involved?
Use the approach that provides the best access for instrumentation.
What is the primary indication for conventional Class III preparation?
Restoration of root surfaces.
Is it common to have an entire Class III preparation of the conventional type?
No, it would be unusual.
What is the purpose of a Class III preparation?
To restore root surfaces of a tooth.
Is it common to have an entire Class III preparation of the conventional type?
No, it's unusual.
What part of the tooth is most likely prepared in a Class III preparation?
The root surface without enamel margin.
What is the design of the Class III preparation?
Combination of modified or beveled conventional preparation with conventionally prepared root-surface area.
What type of preparation design is used for the root-surface portion?
Conventional tooth preparation design with butt joint marginal configuration and retention groove in dentin.
What is the design for the coronal portion of a Class III preparation?
Beveled conventional tooth preparation design, could also be modified.
What happens when a lesion is entirely on the root surface?
The entire preparation is a conventional type with butt joint margins.
What does the conventional Class III preparation for a root surface lesion include?
Preparation identical to the slot preparation for amalgam.
What is illustrated in the mesiodistal longitudinal section of a Class III preparation?
Carious lesion, initial tooth preparation, infected carious dentin removal, retention grooves, axial wall contour.
What is the angle of the cavosurface margins in a conventional Class III preparation?
90-degree cavosurface angle.
What materials are the external walls of the conventional Class III preparation composed of?
Entirely of dentin and cementum.
How deep should the walls be prepared in a Class III preparation?
Approximately 0.75 mm into dentin.
What may be necessary in non-enamel root-surface preparations?
Groove retention form to increase retention of the material.
What is the marginal configuration for the crown areas of the preparation?
Beveled or flared marginal configuration.
What dictates the pulpal depth of the crown portion in a Class III preparation?
Extent of existing restoration or extent of infected carious lesion.
How is retention of restorative material typically provided in the crown portion?
By bonding.
What is the initial depth for Class III tooth preparation?
0.75 mm
What should be done if retention grooves are not anticipated?
Remove caries to a depth of 0.75 mm.
What angle should the external walls form during preparation?
90-degree cavosurface angle
What tool can be used to remove remaining infected dentin?
Round burs or spoon excavators
When should old restorative material be removed?
If it is amalgam, shows caries, pulp was symptomatic, or is not intact.
What is the purpose of groove retention in root-surface preparations?
To ensure restorative material is retained.
How does a retention groove help with polymerization shrinkage?
It minimizes the negative effects of shrinkage when inserting composite.
Where is a continuous retention groove located?
0.25 mm from the root surface
What is the depth of the continuous retention groove?
0.25 mm
What is used for external walls in tooth preparation?
A round bur is used for external walls.
When is a continuous groove used in tooth preparation?
A continuous groove is used when maximum retention is anticipated.
Where is the groove located in tooth preparation?
The groove is located 0.25 mm from the root surface.
What is the depth of the groove in tooth preparation?
The groove is prepared to a depth of 0.25 mm.
How should the groove be directed in tooth preparation?
The groove should be directed as the bisector of the angle formed by the junction of the axial wall and the external wall.
What should the groove be parallel to in tooth preparation?
For its entire length, the groove should be parallel to the root surface.
What is the purpose of beveled conventional tooth preparation?
It is primarily indicated for replacing an existing defective restoration in the crown portion of the tooth.
When else can beveled conventional tooth preparation be used?
It may be used when restoring a large carious lesion for increased retention or resistance form.
What shape does the tooth preparation take for replacements?
The tooth preparation takes the shape of the existing restoration along with extensions for recurrent caries or defects.
What characterizes the beveled conventional preparation?
The preparation is characterized by external walls that are perpendicular to the enamel surface, with the enamel margin beveled.
How do the axial line angles vary in tooth preparation?
The axial line angles may or may not be of uniform pulpal depth, varying with the thickness of the enamel portion.
What should be used if part of the tooth is on the root surface?
A conventional cavosurface configuration should be used in this area.
What is the general form of the replacement restoration?
The replacement restoration has the same general form as the previous (old) tooth preparation.
How is retention usually obtained in tooth restorations?
Retention is usually obtained by bonding to the enamel and dentin.
When might groove retention be necessary?
Groove retention may be necessary when replacing a large restoration or restoring a large Class III lesion.
What is recommended for lingual access in tooth preparation?
A clean, unscratched front surface mirror is recommended for a clear view.
How can direct vision be used in tooth preparation?
Direct vision may be used by tilting the patient’s head.
What does the dotted line indicate in lingual access?
The dotted line indicates the normal outline form dictated by the shape of the carious lesion.
What is the initial step in Class III conventional tooth preparation?
A bur or diamond is held perpendicular to the enamel surface for the initial opening.
What is the correct angle of entry for Class III preparation?
The correct angle of entry is parallel to the enamel rods on the mesiolingual angle of the tooth.
What happens during incorrect entry in tooth preparation?
Incorrect entry overextends the lingual outline.
What is done to enlarge the opening for caries removal?
The same bur or diamond is used to enlarge the opening while establishing initial axial wall depth.
What is the purpose of extending the external walls during tooth preparation?
To sound tooth structure at a limited prescribed depth, dictated by caries or old restorative material.
What areas should not be included in the extension during tooth preparation?
What is the initial axial wall depth in tooth preparation?
0.2 mm inside the dentinoenamel junction (DEJ), approximately 0.75 to 1.25 mm deep.
What is the axial wall's contour during preparation?
Outwardly convex, following the external tooth contour and DEJ.
What is the axial wall depth if a retention groove is used?
0.5 mm into dentin at retention locations.
How are the enamel walls prepared in tooth preparation?
They are prepared perpendicular to the external tooth surface.
What instruments are used to finish the gingival floor and lingual wall?
The same round cutting instrument used for the outline form.
What is completed after establishing the outline form and initial axial wall depth?
The initial tooth preparation stage is completed.
What is done during the final preparation of Class III restorations?
Remove infected dentin, old restorative material, and apply liners if indicated.
What is the bevel or flare in Class III preparations?
A cavosurface bevel or flare of enamel instead of a butt joint.
What angle should the cavosurface bevel be prepared at?
Approximately 45 degrees to the external tooth surface.
What is the recommended bevel width for tooth preparation?
0.25 to 0.5 mm.
When is a margin not beveled during preparation?
If little or no enamel is present or access for finishing is difficult.
What should be done if the preparation extends onto root structure?
No bevel is placed on cementum, prepared as a conventional preparation.
When may bevels not be recommended on lingual surface margins?
In areas of centric contact or heavy masticatory forces.
What are the margins of a tooth preparation subjected to?
Why is composite less effective for heavy attritional forces?
Composite has less wear resistance than enamel.
What is a large beveled conventional Class III preparation?
It includes beveled enamel walls and retention grooves.
What is the approach for facial access in tooth preparation?
Follow the same stages as for lingual access; direct vision is used.
What is simplified in the facial access procedure?
It is simplified due to direct vision and usually larger lesions.
What are the steps in Class III initial preparation?
What is the most used type of Class III tooth preparation?
The modified tooth preparation is most commonly used.
When is a modified Class III preparation indicated?
For small and moderate lesions or faults.
What is the design goal of a modified Class III preparation?
To be as conservative as possible.
What dictates the preparation design of a modified Class III preparation?
The extent of the fault or defect.
What angle is aimed for in modified Class III preparation walls?
External angles of 90 degrees or greater.
What is the typical depth of initial axial wall in modified preparations?
Usually 0.2 mm into dentin.
What shape do the walls of small preparations in modified Class III take?
Walls may diverge externally in a scoop shape.
What is the objective of a modified Class III preparation?
To include carious area as conservatively as possible.
What should be minimized in tooth extensions during preparation?
Extensions should include only necessary tooth structure due to caries or defect.
What can be left in nonstress areas during preparation?
Some undermined enamel can be left.
What should tooth structure removal be based on?
Extent of caries or defect.
What type of enamel can be left in nonstress areas?
Some undermined enamel.
What should be removed at the margins?
Very friable enamel.
What should the outline form of tooth preparation avoid?
What is a characteristic of Modified Class III Tooth Preparation?
Larger preparations may require additional beveling or flaring.
What angle should the bevel be prepared at?
45-degree angle to the external surface.
What is the width range for the bevel?
0.25 to 0.5 mm.
What may preclude a bevel on the lingual enamel margin of a maxillary incisor?
Presence of occlusal contact.
What are the final steps for a modified tooth preparation?
What is the purpose of a Class IV composite restoration?
To restore fractured, defective, or cariously involved anterior teeth.
What is the conventional tooth preparation design for Class IV?
Minimal clinical application, except on root surfaces.
When is pin retention necessary in composite restorations?
When a large amount of tooth structure is missing.
What are the risks of using pins in anterior teeth?
What is the bevel angle for Class IV beveled conventional tooth preparation?
45-degree angle to the external tooth surface.
What is the width range for the bevel in Class IV preparation?
0.25 to 2 mm.
What is a veneer?
A layer of tooth-colored material applied to restore defects and discolorations.
What materials can veneers be made of?
Composite, porcelain, or pressed ceramic materials.
What are common indications for veneers?
Teeth with malformed, discolored, abraded surfaces or faulty restorations.
What are the two types of esthetic veneers?
What are partial veneers indicated for?
Restoration of localized defects or intrinsic discoloration.
What are full veneers indicated for?
Restoration of generalized defects or discolorations.
What are partial veneers indicated for?
Restoration of localized defects or areas of intrinsic discoloration.
What are full veneers indicated for?
Restoration of generalized defects or areas of intrinsic staining involving most of the facial surface of the tooth.
Describe the facial view of a partial veneer.
Partial veneer does not extend subgingivally or involve the incisal angle.
What is a window preparation design in full veneers?
It extends to the gingival crest and terminates at the facioincisal angle.
What does the incisal-lapping preparation design in full veneers include?
It extends subgingivally and includes all of the incisal surface.
When is subgingival extension indicated?
For preparation of darkly stained teeth and is not considered routine.
What do the cross-sections of veneers illustrate?
The three types of veneers: A through C.
What is shown after the removal of old direct full veneers?
Localized white spots are evident.
What do the models illustrate in relation to direct partial veneers?
Fault (x) and cavity preparation (y) with irregular chamfered margins.
What is the result of intraenamel preparations for partial veneers?
Conservative esthetic result of completed partial veneers.
What is the condition of the maxillary anterior teeth in direct full veneers?
Enamel hypoplasia.
What is the purpose of etching in full veneers?
To prepare the facial surface for direct full veneer application.
What design is used for tetracycline-stained anterior teeth?
Etched porcelain veneers with window preparation design on canines.
What is the purpose of soft wax in porcelain veneers preparation?
To block out lingual embrasures to facilitate impression making.
What are the key topics covered in Lecture 6?
Class V Restorations, Material Qualities, Indications/Contraindications, Aesthetic Materials, Tooth Preparation techniques.
What does Class V Tooth Preparation involve?
Conventional, Baveled, Modified, and preparations for abrasion and erosion lesions.
What are the indications/contraindications for Class V restorations?
Specific criteria determining when to use or avoid Class V restorations.
What are the advantages/disadvantages of Class V restorations?
Benefits and drawbacks associated with Class V restorations.
What are the steps in initial and final tooth preparation?
Processes involved in preparing the tooth for Class V restoration.
What is the topic of the document?
Dental Caries
What is the department mentioned?
The Department
What is the title of the book referenced?
Sturdevant’s Art and Science of Operative Dentistry
What are the main topics covered in the document?
What are the three main numbering systems in dentistry?
What is the FDI two-digit tooth numbering system used for?
To identify adult teeth by quadrants and tooth positions.
What is the definition of dental caries?
A disease characterized by the demineralization of tooth structure.
What are the classification methods of dental caries?
What are the methods of treatment for dental caries?
Where can dental caries originate?
What is the histopathology of dental caries?
Involves necrotic dentin and reparative dentin formation.
What happens to odontoblasts in response to dental caries?
They die, leaving empty tubules called dead tracts.
What occurs during the reaction of pulp-dentin to caries?
Formation of reparative dentin and sclerosis of tubules.
What does the occlusal enamel look like in dental caries?
Intact with a small opening in the fissure, darkened due to demineralization.
What is a key feature of the lesion in dental caries?
Filled with a bacterial plug containing high numbers of MS and lactobacilli.
What is the basic principle of treatment for dental caries?
Cavity preparations.
What are the elements involved in cavity preparations?
What are the elements of cavity preparations?
What are masticatory forces?
Forces involved in chewing and grinding food.
What is the speed of hand-rotated instruments?
300 RPM
What is the speed of the foot engine?
700 RPM
What is the speed of the electric engine?
1000 RPM
What is the speed of the dental unit?
5000 RPM
What is the speed of diamond cutting instruments?
5000 RPM
What is the speed of tungsten carbide burs?
12,000 RPM
What is the speed of ball bearing handpieces?
25,000 RPM
What is the speed of water turbine angle handpiece?
50,000 RPM
What is the speed of belt-driven angle handpiece?
150,000 RPM
What is the speed of air turbine angle handpiece?
250,000 RPM
What is the speed of air turbine straight handpiece?
25,000 RPM
What is the speed of experimental air bearing handpiece?
800,000 RPM
What is the speed of contemporary air turbine handpiece?
300,000 RPM
What are the characteristics of restorative materials?
Short and specific properties related to dental restorations.
What is the definition of Class I restorations?
Restorations involving pits and fissures.
What is the definition of Class II restorations?
Restorations involving proximal surfaces of posterior teeth.
What is the principle of initial tooth preparation depth for amalgam restorations?
Depth should be sufficient to remove caries.
What is the difference between conservative and extensive Class I amalgam restorations?
Conservative involves minimal tooth structure removal; extensive involves more significant removal.
What is the occlusal outline form for Class II amalgam restorations?
Shape defined by the occlusal surface and proximal areas.
What is the proximal outline form in cavity preparation?
Shape of the cavity in the proximal box area.
What is the occlusal step in tooth preparation?
The occlusal step is a part of tooth preparation that involves creating a flat surface on the top of the tooth to accommodate a restoration.
What does proximal outline form refer to?
Proximal outline form refers to the shape and boundaries of the cavity preparation on the proximal surfaces of teeth.
What is the final tooth preparation?
Final tooth preparation is the last stage in preparing a tooth for a restoration, ensuring all required dimensions and forms are achieved.
What are the variations of one proximal surface tooth preparations?
Variations of one proximal surface tooth preparations include different techniques and designs based on clinical situations.
What are Class I and II tooth preparations for cast metal restorations?
Class I and II tooth preparations are specific cavity designs for restoring teeth with cast metal materials, focusing on proper outline and retention.
What is the introduction in Sturdevant's Art and Science of Operative Dentistry?
The introduction covers foundational concepts and the significance of operative dentistry in clinical practice.
What are the material qualities discussed in the textbook?
Material qualities refer to the properties of dental materials that influence their performance and suitability for restorations.
What is a conventional Class I tooth preparation?
A conventional Class I tooth preparation is a cavity design for occlusal surfaces of posterior teeth, focusing on minimal invasion.
What does 'prevention of extension' mean in tooth preparation?
'Prevention of extension' refers to designing cavity preparations that minimize the risk of further decay or damage to the tooth.
What are the indications for Class I and II indirect restorations?
Indications include significant tooth structure loss, esthetic concerns, and the need for enhanced strength and durability.
What are the advantages of laboratory processed composite inlays and onlays?
Advantages include superior fit, strength, and esthetics compared to direct restorations.
What are the disadvantages of ceramic inlays and onlays?
Disadvantages may include higher cost, potential brittleness, and the need for more extensive tooth preparation.
What is the quote by Mahatma Gandhi?
Live as if you were to die tomorrow. Learn as if you were to live forever.
What are Class III and Class IV tooth preparations for?
Aesthetic materials
What is the title of the book mentioned?
Sturdevant's Art and Science Operative Dentistry
What is included in the Class III and IV tooth preparation outline?
What are the indications for amalgam in tooth preparation?
What are the characteristics of composite in tooth preparation?
What is the pulpal depth for amalgam preparation?
Uniform 0.2-0.5 mm inside DEJ
What is the recommended distance between pulp and amalgam?
Provide 2 mm between pulp and amalgam
What is the recommended treatment for a root surface lesion?
Conventional Class III tooth preparation for a lesion entirely on root surface
What are the instruments used in Class III tooth preparation?
Access instruments for Class III tooth preparation
What is the purpose of GLUMA desensitizer in tooth preparation?
Used when not bonding
What is a lesion entirely on the root surface?
What is a Conventional Class III Tooth Preparation?
What is a Beveled Conventional Class III Tooth Preparation?
What is involved in Lingual Access?
What does Final Preparation refer to?
What is a Large Beveled Conventional Class III Preparation?
What is Facial Access in dentistry?
What is a Modified Class III Tooth Preparation?
What is a Class IV Tooth Preparation?
What is a Class IV Beveled Conventional Tooth Preparation?
What is a Class IV Modified Tooth Preparation?
What are Veneers in dentistry?
What are Direct Partial Veneers?
What are Direct Full Veneers?
What are Porcelain Veneers?
What is Class V Tooth Preparation?
What is Sturdevant's Art and Science of Operative Dentistry?
Where can you find the Table of Contents for Sturdevant's textbook?
What is the definition of operative dentistry?
Operative dentistry is the art and science of the diagnosis, treatment, and prognosis of defects of teeth that do not require full coverage restorations for correction.
What are the indications for operative procedures?
What is the significance of high-speed handpieces in operative dentistry?
They allow more conservative and efficient removal of tooth structure for restorative procedures.
What concept was introduced alongside high-speed instrumentation in dentistry?
The concept of four-handed dentistry.
What advancements have influenced the dynamics of operative dentistry?
Advances in treatment techniques, philosophies, and materials.
What has the bonding of restorations to tooth structure led to?
The development of new composite restorative materials and conservative bonding techniques.
What is essential for a restorative dentist to understand?
Dental anatomy, histology, physiology, and occlusion.
What are the major determinants of function in teeth?
The form of a tooth and the contour/contact relationships with adjacent and opposing teeth.
What are the primary treatment needs in operative dentistry?
What role does the pulp cavity position and form play in dentistry?
It is mandatory during preparation and caries removal.
What is the purpose of understanding tooth anatomy and histology?
To ensure proper function in mastication, esthetics, speech, and protection.
What are the Tomes processes?
Short extensions of ameloblasts toward the dentinoenamel junction (DEJ).
What are the structural components of enamel?
How are the enamel rods oriented relative to the DEJ?
They are aligned perpendicularly to the DEJ and tooth surface.
What is the orientation of the rods in the cervical region of permanent teeth?
They are oriented outward in a slightly apical direction.
What is the function of fissures at the junction of lobes in teeth?
Acts as a food trap, predisposing tooth to dental caries.
What tissues make up the Pulp-Dentin Complex?
Dentin and pulp tissues, specialized connective tissues of mesodermal origin.
How do many investigators view dentin and pulp tissues?
As a single tissue forming the pulp-dentin complex.
What are odontoblasts?
Cells that form dentin, located in the pulp cavity with processes extending into dentin.
What are Tomes fibers?
Long, slender cytoplasmic processes of odontoblasts extending into dentinal tubules.
Why is dentin considered living tissue?
It can react to physiological and pathological stimuli, leading to changes like secondary and reparative dentin.
What are the types of dentin changes throughout life?
What does dentin cover in the tooth structure?
Externally covered by enamel on the crown and cementum on the root; forms walls of pulp cavity internally.
What is the function of odontoblastic processes?
Extend from odontoblasts into dentin, lying in dentinal tubules.
What happens to dentinal tubules when acid etched?
The tubule apertures are opened and widened by acid application.
What is the composition of cementum?
About 45% to 50% inorganic material (hydroxyapatite) and 50% to 55% organic matter and water.
What is the color of cementum compared to dentin?
Light yellow and slightly lighter in color than dentin.
What is unique about the fluoride content of cementum?
It has the highest fluoride content of all mineralized tissue.
How does cementum change throughout life?
New layers are deposited continuously to maintain attachment as the superficial layer ages.
What is the difference between acellular and cellular cementum?
Acellular cementum predominates on the coronal half, while cellular cementum occurs more frequently on the apical half.
What compensates for attritional wear of the occlusal surface?
Increase in cementum thickness on the root end
What do principal fibers of periodontal ligament continue into?
Surface of cementum as Sharpey’s fibers
What is dental caries?
An infectious microbiologic disease of the teeth causing localized dissolution and destruction of calcified tissues
What is essential to understand in clinical practice regarding caries?
Focus on treating the underlying cause of the disease
What is the evidence for the role of bacteria in caries genesis?
Overwhelming; studies show bacteria cause caries
What are white spots described as?
Chalky white, opaque areas revealed when the tooth surface is desiccated
What term is used for areas of enamel that lose translucency due to demineralization?
Incipient caries
What must be distinguished from white spots of incipient caries?
Developmental white spot hypocalcifications of enamel
What eliminates the potential for caries formation?
Implementation of appropriate caries-preventive measures
What is the definition of tooth preparation?
Mechanical alteration of a defective, injured, or diseased tooth to receive restorative material
What are the objectives of tooth preparation?
How are tooth preparations classified according to G. V. Black?
What types are included in Class I restorations?
What are the types of Class II preparations?
What is the difference between MO and DO preparations?
The distal wall in MO is a mesial wall in DO.
What is an MOD preparation?
An MOD preparation has similar walls, line angles, and point angles, but lacks mesial and distal walls.
What are Class III restorations?
Restorations on the proximal surfaces of anterior teeth that do not involve the incisal angle.
What are Class IV restorations?
Restorations on the proximal surfaces of anterior teeth that do involve the incisal edge.
What are Class V restorations?
Restorations on the gingival third of the facial or lingual surfaces of all teeth, excluding pit-and-fissure lesions.
What are Class VI restorations?
Restorations on the incisal edge of anterior teeth or the occlusal cusp heights of posterior teeth.
What defines a Complex tooth preparation?
A Complex preparation involves three or more tooth surfaces.
What is an Internal Wall in tooth preparation?
A prepared (cut) surface that does not extend to the external tooth surface.
What is a Pulpal Wall?
An internal wall that is perpendicular to the long axis of the tooth and occlusal of the pulp.
What is an External Wall?
A prepared surface that extends to the external tooth surface, named after the tooth surface it faces.
What is a Floor (or Seat) in cavity preparation?
A prepared wall that is flat and perpendicular to occlusal forces, e.g. pulpal and gingival walls.
What is a Dentinal Wall?
The portion of a prepared external wall consisting of dentin, where mechanical retention features may be located.
What is a Cavosurface Angle?
The angle formed by the junction of a prepared wall and the external surface of the tooth.
What is the Cavosurface Margin?
The actual junction between the prepared wall and the external surface of the tooth.
What surfaces are illustrated in the tooth preparation walls schema?
What are the walls of tooth preparation?
What are the line angles in tooth preparation?
What are the point angles in tooth preparation?
What are the two stages of the tooth preparation procedure?
What are the steps in the initial tooth preparation stage?
What are the steps in the final tooth preparation stage?
What is essential in the evaluation of masticatory forces?
Evaluation of location, direction, and area of tooth contacts during mandibular movements.
What is the main holding contact area for opposing supporting cusp?
Fossa or marginal ridge contact area.
What happens during anterior movement of the mandible?
Lower anterior teeth glide along the lingual surfaces of maxillary anterior teeth.
What is the purpose of multiple contacts during protrusion?
To prevent excessive force on any individual pair of gliding teeth.
What is a handpiece used for in cavity preparation?
A device for holding rotating instruments, transmitting power, and positioning them intraorally.
What are the three parts of diamond instruments?
What are some examples of physical properties of materials?
What is the process called when restoring a tooth directly in the intraoral environment?
Direct restorative dentistry
What is crucial to know in restorative dentistry regarding materials?
The structures and properties involved
What is the significance of selecting the correct wavelength for lasers in dentistry?
To ensure absorption of energy and prevent side effects from heat generation
What are the traditional stages of fabricating dental restorations by indirect techniques?
What is the definition of Class I restorations?
All pit-and-fissure restorations are Class I, assigned to three groups.
What are the types of Class I restorations?
What is amalgam in restorative dentistry?
A metal-like restorative material composed of a mixture of silver/tin/copper alloy and mercury.
How is amalgam applied to teeth?
The unset mixture is pressed into a specifically prepared undercut tooth form and contoured to restore the tooth’s form and function.
What is the current status of amalgam as a restorative material?
Its popularity has decreased due to concerns about safety and environmental effects, and the benefits of composites.
What concerns exist regarding amalgam restorations?
Concerns relate to poor esthetics, weakening of the tooth by removal of more tooth structure, and recurrent issues.
What are the concerns about amalgam restorations?
What factor may lead to a reduction in amalgam use?
Concern about disposal of amalgam from dental offices.
What environmental concern is associated with amalgam?
Mercury contamination of municipal water supplies.
What regulations have some communities passed regarding amalgam?
Defined limits of allowable mercury in wastewater from dental offices.
What can be costly for dental offices in relation to mercury?
Monitoring mercury levels and installing reduction equipment.
In which countries has legislation restricting amalgam use been implemented?
Japan, Denmark, Canada, Sweden, Germany.
What is the function of amalgam as a restorative material?
Easily inserted into a tooth preparation to restore form and function.
What is required for the tooth preparation form for amalgam?
What are the requirements for amalgam thickness?
Must possess a uniform specified minimum thickness for strength.
What are the clinical indications for direct amalgam restorations?
Moderate to large Class I and Class II restorations, especially under heavy occlusion.
Why is amalgam avoided in prominent esthetic areas?
Most patients find the appearance objectionable compared to composites.
What is a disadvantage of amalgam compared to composite?
Tooth preparation for amalgam is larger, leading to more tooth structure removal.
What are the primary advantages of amalgam restorations?
What are the primary disadvantages of amalgam restorations?
What is the required restoration angle for amalgam placement?
A 90-degree or greater restoration angle at the cavosurface margin.
What type of form must amalgam be placed into for retention?
An undercut form in the tooth for mechanical retention.
What are the initial stages of tooth preparation for amalgam?
What is the initial depth for tooth preparation in amalgam restorations?
0.2 mm inside the DEJ or 1.5 mm from the central groove, whichever is greater.
What are the principles of Conservative Class I Amalgam Restorations?
How can you eliminate a weak wall of enamel in amalgam restorations?
By joining two outlines that are <0.5 mm apart.
What should the outline form of a Conservative Class I preparation look like?
Gently flowing curves with distinct cavosurface margins.
Where is the pulpal floor usually located in conservative Class I preparation?
In dentin, depending on enamel thickness
What should be included in the outline of conservative Class I preparations?
Remaining occlusal enamel defects
What should be ensured during the initial tooth preparation for Class I amalgam?
All caries is removed from the peripheral DEJ
What are the components of primary resistance form?
What provides the primary retention form in conservative Class I restorations?
Parallelism or slight occlusal convergence of external walls
What does final tooth preparation include?
How is the removal of remaining infected dentin best accomplished?
Using a discoid-type spoon excavator or a round carbide bur
What should not affect resistance form during carious dentin removal?
The periphery should not need further extension
What should the flat floor be at in terms of depth?
At the initial pulpal floor depth of 1.5 to 2 mm
When should the external walls have been finished?
During earlier steps in conservative tooth preparation
What is contraindicated in the tooth preparation for an amalgam restoration?
An occlusal cavosurface bevel
What are examples of Conservative Class I Amalgam Preparations?
What is the bur tilt for entry in tooth preparation?
Long axis parallel with bisector of angle formed by long axis of tooth and perpendicular line to plane through facial and lingual cusp points
What is the initial tooth preparation step for extensive caries?
Excavation of infected dentin and insertion of a liner if necessary
When is caries considered extensive?
When the distance between infected dentin and pulp is less than 1 mm or when the defect extends up the cuspal inclines
What is the benefit of using amalgam in large Class I restorations?
Good wear resistance and occlusal contact relationships
What is the preparation design for mandibular first premolar?
Includes cutting instrument held parallel to bisector of angle formed by tooth's long axis and perpendicular line to facial and lingual cusp points
What should be included in the outline for maxillary first molar preparation?
Mesial and central pits connected by fissure
What is necessary for extension in mandibular second premolar preparation?
Extension through lingual ridge enamel when enameloplasty does not eliminate lingual fissure
What is the initial depth for Class I Amalgam restorations?
1.5 to 2 mm - 1.5 mm at pits or fissures - 2 mm on external walls
How should the preparation be extended for Class I Amalgam restorations?
Laterally to remove all enamel undermined by caries, alternating cutting and examining.
What is the cavosurface angle for caries extending up cuspal inclines?
90- to 100-degree angle while maintaining initial depth.
When is cusp capping indicated in Class I Amalgam restorations?
When the defect extends to: - Half the distance between primary groove and cusp tip - Two thirds distance, usually required due to fracture risk.
What is the method for removing infected dentin in Class I Amalgam restorations?
Same as for conservative preparation.
What should be done if pulp exposure occurs during Class I Amalgam restoration?
Decide to apply a direct pulp cap of calcium hydroxide or treat endodontically.
Are secondary resistance or retention forms necessary for extensive Class I amalgam preparations?
Usually not necessary; primary resistance form obtained by outlining tooth preparation.
What is secondary resistance form in Class I Amalgam preparations?
Flat seats in dentin (0.2 mm inside DEJ) if flat pulpal floor is removed.
How is primary retention achieved in Class I Amalgam restorations?
By occlusal convergence of enamel walls; secondary retention may come from undercuts.
What are Class I Occlusolingual Amalgam restorations used for?
On maxillary molars with a lingual fissure connecting to distal oblique fissure and distal pit.
What is the initial tooth preparation for Class I Occlusolingual restorations?
Establish outline, primary resistance, primary retention forms, and initial preparation depth.
What is the maximum width for the mesiodistal width of the lingual extension in Class I Occlusolingual restorations?
Should not exceed 1 mm, except for carious or undermined enamel removal.
How should the tooth preparation be adjusted when indicated in Class I Occlusolingual restorations?
Cut more at the expense of the oblique ridge rather than centering over the fissure.
What should be done when preparing tooth for Class II Amalgam Restorations?
What is the occlusal outline form for Class II Amalgam Restoration?
Similar to Class I tooth preparation
What are the objectives for the proximal margins in Class II restorations?
What is the bur position for beginning the proximal ditch cut?
Bur positioned to create initial proximal ditch
What should be ensured regarding the gingival margin when preparing small lesions?
Gingival margin should clear adjacent tooth by only 0.5 mm
What happens to the pulpal depth if the gingival margin is extended into cementum?
Pulpal depth is 0.75 to 0.8 mm
What should be done to weaken proximal enamel during preparation?
Bur is moved toward and perpendicular to proximal surface
What is the effect of the faciolingual dimension of the proximal ditch?
Greater at gingival than at occlusal level
What is the purpose of moving isolated enamel?
To prepare the tooth for restoration by removing weakened enamel.
What is observed in the occlusal view after removing proximal enamel?
Proximal enamel is removed, showing the internal preparation.
What is the definition of initial Class II tooth preparation?
Extension of external walls to reach sound tooth structure, resist fracture, and retain restorative material.
What should be the condition of pulpal and axial line angles in proper outline form?
They should be in sound dentin.
What is the proper direction for proximal walls?
To achieve full-length enamel rods and 90-degree amalgam at preparation margin.
How is infected carious dentin removed from Class II preparations?
Using a slowly revolving round bur of appropriate size.
Does the presence of infected carious dentin require deepening the entire wall?
No, it does not indicate deepening the entire wall.
What does secondary resistance form involve?
Resistance of remaining tooth structure against fracture from oblique forces.
How is the fracture resistance of the amalgam restoration enhanced?
Using a gingival margin trimmer to bevel or round the axiopulpal line angle.
What are the four characteristics of retentive locks?
Occlusal view, proximal view, position, and orientation.
What should be corrected in preparation walls and margins?
Unsupported enamel and marginal irregularities.
What is compared when looking at variations of one proximal surface tooth preparations?
Differences in size of pulp chambers, lingual cusps, and direction of pulpal walls.
What is the occlusal outline form for a mandibular first premolar with sound transverse ridge?
Two-surface preparation that does not include opposite pit.
What type of preparation is shown for a maxillary first molar?
Conventional mesio-occlusal preparation and extended to include distal pit.
What is the maxillary first molar preparation type B?
Mesioocclusal preparation extended to include distal pit.
What is the maxillary first molar preparation type C?
Mesio-occlusolingual preparation, including distal pit and distal oblique and lingual fissures.
What is the maxillary first molar preparation type D?
Mesio-occlusal preparation with facial fissure extension.
What is a simple box restoration?
Restoration without occlusal step for small proximal lesion without occlusal fissures or prior restoration.
What is illustrated in a slot preparation?
A, Mesiodistal longitudinal section illustrating carious lesion; B, Initial tooth preparation; C, Preparation with infected carious dentin removed.
What do retention grooves show in a slot preparation?
They are shown in longitudinal section, illustrating contour of axial wall and direction of facial and lingual walls.
What is the purpose of a wedged matrix in slot preparation?
To assist in the preparation by providing support and maintaining contour.
What is involved in the reduction of distolingual cusp of maxillary molar?
A, Cutting depth gauge groove with side of bur; B, Completed depth gauge groove; C and D, Completed cusp reduction.
What is the ideal distofacial extension for mandibular first molar preparation?
Entire distal cusp included in preparation outline form.
What is the necessary reduction for amalgam thickness in distal cusp?
Reduction of 2 mm is necessary to provide for minimal 2-mm thickness of amalgam.
What is the purpose of cast metal restoration?
Versatile and especially applicable to Class II onlay preparations.
What is typically involved in the dental restoration process?
A dental laboratory is involved, and the dentist and laboratory technician must be devoted to perfection.
What does a Class II inlay involve?
The occlusal and proximal surfaces of a posterior tooth; may cap one or more, but not all, of the cusps.
What does a Class II onlay involve?
The proximal surfaces of a posterior tooth; caps all of the cusps.
What does a Class II overlay involve?
The proximal surfaces of a posterior tooth; caps all of the cusps and covers three-fourths of the tooth crown.
What is the fabrication process for dental restorations referred to?
An indirect procedure because the casting is made on a replica of the prepared tooth in a dental laboratory.
What are the major advantages of cast metal restorations?
High compressive and tensile strengths, valuable for restoring most of or the entire occlusal surface.
When is a cast metal inlay indicated?
For large restorations needing higher strength or superior control of contours and contacts.
When is a cast metal onlay an excellent alternative?
For teeth greatly weakened by caries or large, failing restorations, where facial and lingual surfaces are relatively unaffected.
What are the benefits of using a cast metal onlay for weakened teeth?
Superior physical properties to withstand occlusal loads and designed to distribute loads to decrease fracture risk.
Why is preserving intact facial and lingual enamel important?
It maintains the health of contiguous soft tissues.
What should be considered when proximal surface caries is extensive?
Favorable consideration should be given to the cast inlay or onlay.
How can endodontically treated teeth be restored?
With a cast metal onlay, designed to distribute occlusal loads to reduce fracture risk.
What should be recognized in teeth with fracture lines?
Fracture lines in enamel and dentin are cleavage planes for possible future fracture.
What may be warranted for teeth at risk for fracture?
Restoration with cast onlays (with skirting) and crowns to brace the tooth against fracture injury.
What is important in dental rehabilitation with cast metal alloys?
Using cast metal restorations to restore adjacent or opposing teeth.
What are the indications for dental rehabilitation with cast metal alloys?
What are the advantages of cast metal restorations?
What are the contraindications for cast metal restorations?
What is the advantage of using cast metal restorations for abutment teeth?
What should be controlled before using cast metal restorations in patients with a high caries rate?
What is a common alternative to cast metal restorations in esthetically sensitive areas?
What is a disadvantage of cast metal restorations regarding appointments?
What is the first disadvantage of cast inlays?
Requires at least two appointments and more time than direct restorations.
What is the second disadvantage of cast inlays?
Patients must have temporary restorations between appointments.
What is the third disadvantage of cast inlays?
Indirect cast restorations are more expensive due to materials and lab costs.
What is the fourth disadvantage of cast inlays?
Every step requires diligence; errors can lead to poor fits.
What is the fifth disadvantage of cast inlays?
Small inlays may cause a wedging effect, increasing tooth splitting risk.
What type of burs are used for initial preparation of cast metal inlays?
Parallel burs that are plane cut and tapered fissure burs.
What is the purpose of plane cut burs in preparation?
To ensure vertical walls are smooth and straight.
What is the draw path orientation during preparation?
Oriented to a single path, usually the long axis of the tooth crown.
What is the gingival-to-occlusal divergence range for preparation walls?
May range from 2 to 5 degrees per wall from the line of draw.
What is the maximum occlusal divergence for short vertical walls?
A maximum of 2 degrees is desirable to increase retention.
How should the long axis of the bur be oriented for maxillary posterior teeth?
Parallel to the long axis of the tooth crown.
How should the bur be oriented for mandibular molar and second premolar teeth?
Tilt slightly lingually to parallel the long axis of the tooth crown.
What is important to conserve during the extension of the mesial wall?
Conserve dentin that supports the marginal ridge.
What does the dovetail retention form ensure?
The inlay fits into the preparation only in an occlusal-to-gingival direction.
What is the purpose of extending the proximal ditch facially and lingually?
To reach the desired position of the facioaxial and linguoaxial line angles.
What should be the gingival clearance with the adjacent tooth for minimal lesions?
0.5 mm clearance with the unbeveled gingival margin.
What does moderate to extensive caries dictate for the proximal ditch extension?
Continued extension to the extent of the caries at the dentinoenamel junction.
How should the axial wall follow during preparation?
It should follow the contour of the tooth faciolingually.
What should the axial wall follow during initial preparation?
The contour of the tooth faciolingually.
Should carious dentin on the axial wall be removed at the initial preparation stage?
No, it should not be removed.
What is indicated if minimal extension is needed for esthetic objectives?
Planing the distofacial, distolingual, and gingival walls by parallel burs.
What should be done if carious dentin is judged to be infected?
Apply a rubber dam before removal of infected dentin.
What is used to bevel the occlusal and gingival margins?
A slender, flame-shaped, fine-grit diamond instrument.
What is the result of failing to bevel the gingival margin?
Weak margin formed by undermined rods and 110-degree marginal metal.
What is the desired width of the cavosurface bevel on the occlusal margin?
Approximately one fourth the depth of the respective wall.
What is the resulting occlusal marginal metal of the inlay?
40-degree metal; the occlusal marginal enamel is 140-degree enamel.
What should be done after the cement base is completed?
Prepare bevels and flares using a flame-shaped diamond instrument.
What is the purpose of the cavosurface design?
Helps seal and protect the margins and results in a strong enamel margin.
What is indicated if the prepared tooth is short?
Cut shallow retention grooves in the facioaxial and linguoaxial line angles.
What is the direction of the instrument when beveling the gingival margin?
Move the instrument facially along the gingival margin, tilted mesially.
What is the view of the completed disto-occlusal preparation for inlay?
Disto-occlusal view of maxillary right first premolar.
What is the preparation type for the maxillary right first premolar?
Mesio-occlusodistal preparation for inlay
What is desired for the mesiofacial proximal wall in Class II cast metal preparations?
Minimal flare for esthetic reasons
What may require extension of the preparation outline?
Faulty facial groove or faulty distal oblique groove
What is the purpose of extending facial, lingual, and gingival margins on abutments?
To increase surface area for guiding planes
What must the occlusal outline form accommodate for removable partial dentures?
Rest preparation without involving restoration margins
What treatment may be applied when smooth surfaces are affected by caries?
Large inlay, onlay, three-quarter crown, full crown, or multiple restorations
What determines the choice of cast metal restorations for extensive carious portions?
Degree of tooth circumference involved
What is modified in Inlay Tooth Preparations?
What instrument is used for shallow decalcification of the distofacial cusp?
Flame-shaped diamond instrument
What is the purpose of facial or lingual surface groove extensions in Onlay Tooth Preparations?
To provide additional retention form
What is the recommended taper for vertical walls in tooth preparation?
Minimal amount of taper (2 degrees per wall)
What are the three retention features in tooth preparation?
What are skirts in tooth preparation?
Thin extensions of facial or lingual proximal margins of cast metal onlay
When is a collar provided in tooth preparation?
When preparing a weakened tooth for mesio-occlusodistal onlay capping all cusps
What type of restoration is required for the mandibular second molar?
Mesioocclusal onlay restoration capping all cusps.
What improvements have been reported for composite use in posterior teeth?
Successful results due to improved physical properties and bonding systems.
What is the expected lifetime of resin-based composites compared to amalgam?
Comparable in Class I and Class II restorations.
What are the material qualities of composite?
Sufficient strength for Class I and II restorations; insulative; conservative tooth preparation.
What are the indications for using composites?
What are the contraindications for using composites?
What are the advantages of using composites?
What is an advantage of tooth structure removal?
What are the bonding benefits of tooth structure removal?
What are the disadvantages related to material in tooth structure removal?
What makes tooth structure removal more technique sensitive?
How does the cost of tooth structure removal compare to amalgam restorations?
When is the amalgam-like conventional preparation form indicated?
What do the conventional beveled and conventional preparation designs provide?
What characterizes modified tooth preparations?
What cutting instruments are used for Class I and II preparations?
What is a benefit of using diamond instruments in tooth preparation?
What is a challenge when using diamond instruments?
What preparation design is preferred for extensive occlusal restorations?
What are the characteristics of inverted cone burs?
How is the tooth prepared for a large or moderate restoration?
What is the objective of tooth preparation for Class I amalgam?
To remove all caries or faults as conservatively as possible.
What can be sealed during conservative preparation techniques?
Other less involved or at-risk areas.
Where does one enter for a large Class I composite tooth preparation?
In the distal pit area of the faulty occlusal surface.
What is the initial pulpal floor depth for Class I preparation?
1.5 mm, measured from the central groove.
What is the facial or lingual wall height usually after removing the central groove?
Approximately 1.75 to 2 mm.
What dictates the facial and lingual extension and width?
Caries, old restorative material, or fault.
How should the strength of cuspal and marginal ridge areas be preserved?
As much as possible during preparation.
What happens to the pulpal floor when extending toward cusp tips?
The same approximate 1.5-mm depth is maintained.
What is the axial depth for preparing a groove extension through the cusp ridge?
0.2 mm inside the DEJ and gingivally to include all of the fault.
What should be done if caries or old restorative material remains on the pulpal floor?
It should be removed with the appropriate instrument.
What is the purpose of additional beveling on the occlusal margin?
It may result in thin composite in areas of heavy occlusal contact.
What shape do occlusal walls take when using an inverted cone instrument?
They converge occlusally, enhancing retention form.
Why is there a reduced need for occlusal bevels?
The ends of the enamel rods are already exposed by the preparation.
What is the width of the bevel when beveling a groove extension?
0.25- to 0.5-mm width at a 45-degree angle to the prepared wall.
What design characterizes a larger Class I composite tooth preparation?
It is primarily a conventional design, often with beveled facial or lingual grooves.
What should be done after removing a cavitated carious lesion?
Adjacent less involved areas should be treated conservatively with sealants or minimally invasive preparations.
How do modified Class I tooth preparations appear?
They have a scooped out appearance and are prepared with a small round or inverted cone diamond bur.
What is the initial pulpal depth for modified Class I preparations?
1.5 mm or approximately 0.2 mm inside the DEJ.
What is the advantage of using indirect techniques for restorations?
Restorations are fabricated outside of the mouth, allowing for better esthetics and durability.
What materials are used for tooth-colored indirect restorations?
Laboratory processed composites and ceramics, such as porcelain and hot pressed glasses.
When are indirect tooth-colored restorations indicated?
For Class I and II restorations in areas of esthetic importance or for large defects.
What is an advantage of using indirect techniques for large restorations?
Contours of large restorations are more easily developed.
Why are indirect materials preferred for large posterior restorations?
They are more durable and maintain occlusal surfaces and contacts better than direct composites.
What is a preferred bonding location for indirect restorations?
Enamel margins, especially along gingival margins of proximal boxes
What are the advantages of indirect restorations?
How do indirect restorations compare to direct composites in terms of physical properties?
Better physical properties due to ideal laboratory conditions
What is the wear resistance of ceramic restorations compared to direct composites?
More wear resistant
What can indirect tooth-colored restorations strengthen?
Remaining tooth structure weakened by caries, trauma, or preparation
What are ceramics considered in terms of tissue response?
Chemically inert materials with excellent biocompatibility and soft tissue response.
What influences pulpal biocompatibility in indirect techniques?
Related more to adhesive composite cements than to the ceramic materials used.
What is an advantage of indirect techniques regarding support?
They allow the fabrication of restorations to be delegated to dental laboratory technicians.
What is a disadvantage of indirect techniques regarding cost and time?
They usually require two patient appointments and fabrication of a temporary restoration, leading to higher costs.
How do indirect tooth-colored inlays and onlays compare to direct restorations?
They are more expensive than direct restorations but less costly than more invasive esthetic alternatives.
What is required for restorations made using indirect techniques?
A high level of operator skill and diligence during all stages of the process.
What is a potential issue with the brittleness of ceramics?
Ceramic restorations can fracture if not adequately supported or if preparation thickness is insufficient.
What problem can ceramic materials cause to opposing dentition?
Excessive wear of opposing enamel or restorations, especially if rough and unpolished.
What bonding difficulties are associated with resin-to-resin in indirect restorations?
Laboratory-processed resins have few double bonds for chemical adhesion, requiring mechanical abrasion or chemical treatment.
What is the issue with the clinical track record of indirect bonded restorations?
They have a short clinical track record with few controlled clinical trials available.
What is the potential for repair in indirect restorations?
Low potential for repair, particularly for ceramic inlays/onlays.
What happens when a partial fracture occurs in a ceramic inlay/onlay?
Repair is usually not definitive; it involves mechanical roughening, etching, and applying a silane coupling agent.
Why might direct composite repairs not be suitable for some ceramic inlays/onlays?
Because they are indicated in areas where occlusal wear, esthetics, and resistance are important.
Why are direct composite repairs often unsuitable?
The composite might be exposed to a challenging environment.
What is a disadvantage of ceramic restorations during try-in?
Difficult try-in and delivery due to polishing challenges.
How can indirect composite restorations be polished?
With the same instruments and materials used for direct composites.
What improves the physical properties of composite restorations?
Being free of voids and having a maximally polymerized resin matrix.
What techniques are used in the dental laboratory for composites?
How do laboratory-processed composite inlays/onlays compare to direct composites?
More resistant to occlusal wear, especially in contact areas.
What are some advantages of laboratory-processed composites?
When are processed composite restorations indicated?
Why have ceramic inlays and onlays become popular?
Due to patient demand for esthetic, durable materials and improvements in techniques.
What types of ceramic materials are used?
How do the properties of ceramics compare to composites?
Ceramics match enamel properties better than composites.
What may vary in tooth preparation for indirect restorations?
Differences in fabrication steps and physical properties of materials.
What should a dentist decide before starting a restoration procedure?
What type of restoration is indicated based on specific factors.
What should a dentist decide before beginning any procedure?
The type of restoration indicated, according to the factors.
What should a clinician consult if unfamiliar with a technique?
Manufacturer’s literature and possibly the dental laboratory.
What is the design requirement for indirect tooth-colored inlays and onlays?
Provide adequate thickness and a passive insertion pattern with rounded internal angles and well-defined margins.
What angle should all margins have for restoration strength?
A 90 degree butt-joint cavosurface angle.
Why should all angles be rounded in tooth preparation?
To avoid stress concentrations, reducing the potential for fractures.
What should interproximal margins allow for in tooth preparation?
At least 0.5 mm clearance of contact with neighboring tooth.
What is preferred for gingival margins in tooth preparation?
Gingival margins in enamel are greatly preferred.
What should be done if caries affect the facial or lingual surface?
Extend the preparation with a gingival shoulder around the transitional line angle.
What is the requirement for capping a cusp during preparation?
Cusp should be capped if the extension is two thirds or greater than the distance from any primary groove to the cusp tip.
When should a tooth be capped?
If the extension is two thirds or greater than the distance from any primary groove to the cusp tip.
What is necessary when capping centric holding cusps?
Prepare a shoulder to move the facial or lingual cavosurface margin away from contact with opposing tooth.
What can happen if there are contacts directly on margins?
It can lead to premature deterioration of marginal integrity.
What must tooth preparations for CAD/CAM inlays reflect?
The capabilities of the CAD software, hardware, and CAM milling devices.
What does the CAD/CAM system eliminate?
The need for a conventional impression, temporary restoration, and multiple patient appointments.
What is required for laboratory-fabricated indirect systems?
Preparation must have a path of draw for insertion and removal without interferences from undercuts.
What do some CAD/CAM systems do during the optical impression?
Automatically 'block out' any undercuts.
What is a mesio-occlusodistofacial inlay preparation?
Preparation for ceramic inlay on maxillary first molar.
What is a Class III preparation?
Preparations on the proximal surfaces of anterior teeth that do not involve the incisal angle.
What is the term for the faciolingual line angle at the incisal in Class III preparations?
Incisal line angle.
What are the line angles in Class III preparations?
Axiolingual (al), linguogingival (lg), axiogingival (ag), faciogingival (fg), axiofacial (af), incisal (i).
What are the point angles in Class III preparations?
Axiolinguogingival (alg), axiofaciogingival (afg), axioincisal (ai).
What are Class IV Preparations?
Preparations on the proximal surfaces of anterior teeth that do involve the incisal edge.
What are the tooth preparation walls in Class IV?
What are the line angles in tooth preparation?
What are the point angles in tooth preparation?
What are the two stages of tooth preparation?
What are the steps in the initial tooth preparation stage?
What are the steps in the final tooth preparation stage?
What are the indications for Class III and IV restorations?
Almost all Class III and IV restorations are restored with composites, requiring adequate isolation for effective bonding.
What are the contraindications for using composite in Class III and IV restorations?
What is a contraction gap in composite restorations?
A V-shaped gap formed between the root and composite due to polymerization shrinkage.
What is the definition of Class III tooth preparations?
Located on the proximal surfaces of anterior teeth.
Why are Class III tooth preparations predominantly for composite restorations?
Typical need for esthetic restorations in anterior teeth.
What type of bond retains most Class III composite restorations?
Micromechanical bond from acid etching and resin bonding.
What is the effect of using diamond burs in tooth preparation?
Leaves surfaces rougher, increasing surface area and micromechanical retention.
What negative effect can a thick smear layer have?
Can negatively affect self-etching bonding systems.
What is the operator's role in selecting rotary preparation instruments?
Selection is operator dependent based on knowledge and technique.
When might a groove or cove be necessary in Class III restorations?
When restorations extend onto the root surface or are very large.
What is a common method to achieve additional retention form in Class III preparations?
Increasing surface area with a wider enamel bevel or flare along the margin.
Which approach is preferable when restoring a proximal surface of an anterior tooth?
Lingual approach is preferable unless excessive cutting is needed.
What are the advantages of restoring from the lingual approach?
What indicates a facial approach for restoration?
What should be done when both facial and lingual surfaces are involved?
Use the approach that provides the best access for instrumentation.
What is the primary indication for conventional Class III preparation?
Restoration of root surfaces.
Is it common to have an entire Class III preparation of the conventional type?
No, it would be unusual.
What part of the tooth is most likely prepared in a Class III preparation?
The root surface without enamel margin.
What is the design of the Class III preparation?
Combination of modified or beveled conventional preparation with conventionally prepared root-surface area.
What type of preparation design is used for the root-surface portion?
Conventional tooth preparation design with butt joint marginal configuration and retention groove in dentin.
What is the design for the coronal portion of a Class III preparation?
Beveled conventional tooth preparation design, could also be modified.
What happens when a lesion is entirely on the root surface?
The entire preparation is a conventional type with butt joint margins.
What does the conventional Class III preparation for a root surface lesion include?
Preparation identical to the slot preparation for amalgam.
What is illustrated in the mesiodistal longitudinal section of a Class III preparation?
Carious lesion, initial tooth preparation, infected carious dentin removal, retention grooves, axial wall contour.
What is the angle of the cavosurface margins in a conventional Class III preparation?
90-degree cavosurface angle.
What materials are the external walls of the conventional Class III preparation composed of?
Entirely of dentin and cementum.
How deep should the walls be prepared in a Class III preparation?
Approximately 0.75 mm into dentin.
What may be necessary in non-enamel root-surface preparations?
Groove retention form to increase retention of the material.
What is the marginal configuration for the crown areas of the preparation?
Beveled or flared marginal configuration.
What dictates the pulpal depth of the crown portion in a Class III preparation?
Extent of existing restoration or extent of infected carious lesion.
When should old restorative material be removed?
If it is amalgam, shows caries, pulp was symptomatic, or is not intact.
What is the purpose of groove retention in root-surface preparations?
To ensure restorative material is retained.
How does a retention groove help with polymerization shrinkage?
It minimizes the negative effects of shrinkage when inserting composite.
When is a continuous groove used in tooth preparation?
A continuous groove is used when maximum retention is anticipated.
Where is the groove located in tooth preparation?
The groove is located 0.25 mm from the root surface.
How should the groove be directed in tooth preparation?
The groove should be directed as the bisector of the angle formed by the junction of the axial wall and the external wall.
What should the groove be parallel to in tooth preparation?
For its entire length, the groove should be parallel to the root surface.
What is the purpose of beveled conventional tooth preparation?
It is primarily indicated for replacing an existing defective restoration in the crown portion of the tooth.
When else can beveled conventional tooth preparation be used?
It may be used when restoring a large carious lesion for increased retention or resistance form.
What shape does the tooth preparation take for replacements?
The tooth preparation takes the shape of the existing restoration along with extensions for recurrent caries or defects.
What characterizes the beveled conventional preparation?
The preparation is characterized by external walls that are perpendicular to the enamel surface, with the enamel margin beveled.
How do the axial line angles vary in tooth preparation?
The axial line angles may or may not be of uniform pulpal depth, varying with the thickness of the enamel portion.
What should be used if part of the tooth is on the root surface?
A conventional cavosurface configuration should be used in this area.
What is the general form of the replacement restoration?
The replacement restoration has the same general form as the previous (old) tooth preparation.
How is retention usually obtained in tooth restorations?
Retention is usually obtained by bonding to the enamel and dentin.
When might groove retention be necessary?
Groove retention may be necessary when replacing a large restoration or restoring a large Class III lesion.
What is recommended for lingual access in tooth preparation?
A clean, unscratched front surface mirror is recommended for a clear view.
How can direct vision be used in tooth preparation?
Direct vision may be used by tilting the patient’s head.
What does the dotted line indicate in lingual access?
The dotted line indicates the normal outline form dictated by the shape of the carious lesion.
What is the initial step in Class III conventional tooth preparation?
A bur or diamond is held perpendicular to the enamel surface for the initial opening.
What is the correct angle of entry for Class III preparation?
The correct angle of entry is parallel to the enamel rods on the mesiolingual angle of the tooth.
What happens during incorrect entry in tooth preparation?
Incorrect entry overextends the lingual outline.
What is done to enlarge the opening for caries removal?
The same bur or diamond is used to enlarge the opening while establishing initial axial wall depth.
What is the purpose of extending the external walls during tooth preparation?
To sound tooth structure at a limited prescribed depth, dictated by caries or old restorative material.
What areas should not be included in the extension during tooth preparation?
What is the initial axial wall depth in tooth preparation?
0.2 mm inside the dentinoenamel junction (DEJ), approximately 0.75 to 1.25 mm deep.
What is the axial wall's contour during preparation?
Outwardly convex, following the external tooth contour and DEJ.
What is the axial wall depth if a retention groove is used?
0.5 mm into dentin at retention locations.
How are the enamel walls prepared in tooth preparation?
They are prepared perpendicular to the external tooth surface.
What instruments are used to finish the gingival floor and lingual wall?
The same round cutting instrument used for the outline form.
What is completed after establishing the outline form and initial axial wall depth?
The initial tooth preparation stage is completed.
What is done during the final preparation of Class III restorations?
Remove infected dentin, old restorative material, and apply liners if indicated.
What is the bevel or flare in Class III preparations?
A cavosurface bevel or flare of enamel instead of a butt joint.
What angle should the cavosurface bevel be prepared at?
Approximately 45 degrees to the external tooth surface.
When is a margin not beveled during preparation?
If little or no enamel is present or access for finishing is difficult.
What should be done if the preparation extends onto root structure?
No bevel is placed on cementum, prepared as a conventional preparation.
When may bevels not be recommended on lingual surface margins?
In areas of centric contact or heavy masticatory forces.
Why is composite less effective for heavy attritional forces?
Composite has less wear resistance than enamel.
What is a large beveled conventional Class III preparation?
It includes beveled enamel walls and retention grooves.
What is the approach for facial access in tooth preparation?
Follow the same stages as for lingual access; direct vision is used.
What is simplified in the facial access procedure?
It is simplified due to direct vision and usually larger lesions.
What are the steps in Class III initial preparation?
What is the most used type of Class III tooth preparation?
The modified tooth preparation is most commonly used.
What dictates the preparation design of a modified Class III preparation?
The extent of the fault or defect.
What angle is aimed for in modified Class III preparation walls?
External angles of 90 degrees or greater.
What is the typical depth of initial axial wall in modified preparations?
Usually 0.2 mm into dentin.
What shape do the walls of small preparations in modified Class III take?
Walls may diverge externally in a scoop shape.
What is the objective of a modified Class III preparation?
To include carious area as conservatively as possible.
What should be minimized in tooth extensions during preparation?
Extensions should include only necessary tooth structure due to caries or defect.
What should the outline form of tooth preparation avoid?
What is a characteristic of Modified Class III Tooth Preparation?
Larger preparations may require additional beveling or flaring.
What may preclude a bevel on the lingual enamel margin of a maxillary incisor?
Presence of occlusal contact.
What are the final steps for a modified tooth preparation?
What is the purpose of a Class IV composite restoration?
To restore fractured, defective, or cariously involved anterior teeth.
What is the conventional tooth preparation design for Class IV?
Minimal clinical application, except on root surfaces.
When is pin retention necessary in composite restorations?
When a large amount of tooth structure is missing.
What are the risks of using pins in anterior teeth?
What is the bevel angle for Class IV beveled conventional tooth preparation?
45-degree angle to the external tooth surface.
What are common indications for veneers?
Teeth with malformed, discolored, abraded surfaces or faulty restorations.
What are partial veneers indicated for?
Restoration of localized defects or intrinsic discoloration.
What are partial veneers indicated for?
Restoration of localized defects or areas of intrinsic discoloration.
What are full veneers indicated for?
Restoration of generalized defects or areas of intrinsic staining involving most of the facial surface of the tooth.
Describe the facial view of a partial veneer.
Partial veneer does not extend subgingivally or involve the incisal angle.
What is a window preparation design in full veneers?
It extends to the gingival crest and terminates at the facioincisal angle.
What does the incisal-lapping preparation design in full veneers include?
It extends subgingivally and includes all of the incisal surface.
When is subgingival extension indicated?
For preparation of darkly stained teeth and is not considered routine.
What do the models illustrate in relation to direct partial veneers?
Fault (x) and cavity preparation (y) with irregular chamfered margins.
What is the result of intraenamel preparations for partial veneers?
Conservative esthetic result of completed partial veneers.
What is the purpose of etching in full veneers?
To prepare the facial surface for direct full veneer application.
What design is used for tetracycline-stained anterior teeth?
Etched porcelain veneers with window preparation design on canines.
What is the purpose of soft wax in porcelain veneers preparation?
To block out lingual embrasures to facilitate impression making.
What are the key topics covered in Lecture 6?
Class V Restorations, Material Qualities, Indications/Contraindications, Aesthetic Materials, Tooth Preparation techniques.
What does Class V Tooth Preparation involve?
Conventional, Baveled, Modified, and preparations for abrasion and erosion lesions.
What are the indications/contraindications for Class V restorations?
Specific criteria determining when to use or avoid Class V restorations.
What are the advantages/disadvantages of Class V restorations?
Benefits and drawbacks associated with Class V restorations.
What are the steps in initial and final tooth preparation?
Processes involved in preparing the tooth for Class V restoration.
What are the main topics covered in the document?
What are the three main numbering systems in dentistry?
What is the FDI two-digit tooth numbering system used for?
To identify adult teeth by quadrants and tooth positions.
What is the definition of dental caries?
A disease characterized by the demineralization of tooth structure.
What are the classification methods of dental caries?
What is the histopathology of dental caries?
Involves necrotic dentin and reparative dentin formation.
What happens to odontoblasts in response to dental caries?
They die, leaving empty tubules called dead tracts.
What occurs during the reaction of pulp-dentin to caries?
Formation of reparative dentin and sclerosis of tubules.
What does the occlusal enamel look like in dental caries?
Intact with a small opening in the fissure, darkened due to demineralization.
What is a key feature of the lesion in dental caries?
Filled with a bacterial plug containing high numbers of MS and lactobacilli.
What are the characteristics of restorative materials?
Short and specific properties related to dental restorations.
What is the definition of Class II restorations?
Restorations involving proximal surfaces of posterior teeth.
What is the principle of initial tooth preparation depth for amalgam restorations?
Depth should be sufficient to remove caries.
What is the difference between conservative and extensive Class I amalgam restorations?
Conservative involves minimal tooth structure removal; extensive involves more significant removal.
What is the occlusal outline form for Class II amalgam restorations?
Shape defined by the occlusal surface and proximal areas.
What is the proximal outline form in cavity preparation?
Shape of the cavity in the proximal box area.
What is the occlusal step in tooth preparation?
The occlusal step is a part of tooth preparation that involves creating a flat surface on the top of the tooth to accommodate a restoration.
What does proximal outline form refer to?
Proximal outline form refers to the shape and boundaries of the cavity preparation on the proximal surfaces of teeth.
What is the final tooth preparation?
Final tooth preparation is the last stage in preparing a tooth for a restoration, ensuring all required dimensions and forms are achieved.
What are the variations of one proximal surface tooth preparations?
Variations of one proximal surface tooth preparations include different techniques and designs based on clinical situations.
What are Class I and II tooth preparations for cast metal restorations?
Class I and II tooth preparations are specific cavity designs for restoring teeth with cast metal materials, focusing on proper outline and retention.
What is the introduction in Sturdevant's Art and Science of Operative Dentistry?
The introduction covers foundational concepts and the significance of operative dentistry in clinical practice.
What are the material qualities discussed in the textbook?
Material qualities refer to the properties of dental materials that influence their performance and suitability for restorations.
What is a conventional Class I tooth preparation?
A conventional Class I tooth preparation is a cavity design for occlusal surfaces of posterior teeth, focusing on minimal invasion.
What does 'prevention of extension' mean in tooth preparation?
'Prevention of extension' refers to designing cavity preparations that minimize the risk of further decay or damage to the tooth.
What are the indications for Class I and II indirect restorations?
Indications include significant tooth structure loss, esthetic concerns, and the need for enhanced strength and durability.
What are the advantages of laboratory processed composite inlays and onlays?
Advantages include superior fit, strength, and esthetics compared to direct restorations.
What are the disadvantages of ceramic inlays and onlays?
Disadvantages may include higher cost, potential brittleness, and the need for more extensive tooth preparation.
What is the quote by Mahatma Gandhi?
Live as if you were to die tomorrow. Learn as if you were to live forever.
What is included in the Class III and IV tooth preparation outline?
What are the indications for amalgam in tooth preparation?
What are the characteristics of composite in tooth preparation?
What is the recommended treatment for a root surface lesion?
Conventional Class III tooth preparation for a lesion entirely on root surface
What are the instruments used in Class III tooth preparation?
Access instruments for Class III tooth preparation
What is a Beveled Conventional Class III Tooth Preparation?
What is a Large Beveled Conventional Class III Preparation?
What is a Class IV Beveled Conventional Tooth Preparation?
What is Sturdevant's Art and Science of Operative Dentistry?
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