Composites / dental implant courses

TOOTHTOOTH
PREPARATIONSPREPARATIONS
FOR COMPOSITEFOR COMPOSITE
RESTORATIONSRESTORATIONS
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CONTENTSCONTENTS
 INTRODUCTIONINTRODUCTION
 POLYMERIZATION OF COMPOSITEPOLYMERIZATION OF COMPOSITE
 TYPES OF COMPOSTIE PREPARATIONTYPES OF COMPOSTIE PREPARATION
 INDICATIONS AND CONTRAINDICATIONS OFINDICATIONS AND CONTRAINDICATIONS OF
COMPOSITESCOMPOSITES
 CLASS I COMPOSITESCLASS I COMPOSITES
 CLASS II COMPOSITESCLASS II COMPOSITES
 CLASS III COMPOSTIESCLASS III COMPOSTIES
 CLASS IV COMPOSITESCLASS IV COMPOSITES
 CLASS V COMPOSITESCLASS V COMPOSITES
 CLASS VI COMPOSITESCLASS VI COMPOSITES
 PIT AND FISSURE SEALANTSPIT AND FISSURE SEALANTS
 CONCLUSIONCONCLUSION www.indiandentalacademy.com

INTRODUCTIONINTRODUCTION
““ WHO WOULD NOT LIKE TO HAVE A BEAUTIFIC MILLIONWHO WOULD NOT LIKE TO HAVE A BEAUTIFIC MILLION
DOLLAR SMILE WITH PEARLY WHITE DAZZLING TEETH,DOLLAR SMILE WITH PEARLY WHITE DAZZLING TEETH,
WELL SUCH SMILES ARE NOT MILES AWAY ANYMOREWELL SUCH SMILES ARE NOT MILES AWAY ANYMORE”.”.
Esthetic dentistry has evolved at a rapid rate in the past fewEsthetic dentistry has evolved at a rapid rate in the past few
decades when Buonocore in 1955, applied acid to teeth todecades when Buonocore in 1955, applied acid to teeth to
render the surface more receptive to adhesion.render the surface more receptive to adhesion.
Buonocore’s pioneering work led to major changes in theBuonocore’s pioneering work led to major changes in the
practise of dentistry. Today we are in the age of adhesivepractise of dentistry. Today we are in the age of adhesive
dentistry.dentistry.

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Traditional mechanical methods of retainingTraditional mechanical methods of retaining
restorative materials have been replaced to arestorative materials have been replaced to a
large extent, by tooth conserving adhesivelarge extent, by tooth conserving adhesive
methods.methods.
The concepts of large preparations and extensionThe concepts of large preparations and extension
for prevention proposed by Black in 1917,havefor prevention proposed by Black in 1917,have
gradually been replaced by concepts of smallergradually been replaced by concepts of smaller
preparations and more conservative techniques.preparations and more conservative techniques.

POLYMERIZATION OFPOLYMERIZATION OF
COMPOSITECOMPOSITE
 POLYMERIZATION SHRINKAGE:POLYMERIZATION SHRINKAGE:
Composite materials shrink whileComposite materials shrink while
hardening. This is known ashardening. This is known as
polymerization shrinkage.polymerization shrinkage.
usually does not cause significantusually does not cause significant
problems with restorations cured inproblems with restorations cured in
preparations having all enamel margins.preparations having all enamel margins.

Tooth preparation hasTooth preparation has
extended on to the rootextended on to the root
surface polymerizationsurface polymerization
shrinkage may cause gapshrinkage may cause gap
formation at the junction offormation at the junction of
the composite and rootthe composite and root
surface.surface.
V-shaped gap occursV-shaped gap occurs
because the force ofbecause the force of
polymerization of thepolymerization of the
composite is greater thancomposite is greater than
the initial bond strength ofthe initial bond strength of
the composite to the dentinthe composite to the dentin
of the root.of the root.

 Important clinical consideration regardingImportant clinical consideration regarding
polymerization shrinkage is the configuration factorpolymerization shrinkage is the configuration factor
( C-factor ).( C-factor ).
 C-factor is the ratio of bonded surfaces to theC-factor is the ratio of bonded surfaces to the
unbonded or free surfaces in a tooth preparation.unbonded or free surfaces in a tooth preparation.
 The higher the C-factor the greater is the potentialThe higher the C-factor the greater is the potential
for bond disruption from polymerization shrinkage.for bond disruption from polymerization shrinkage.

 For example class IVFor example class IV
restoration ( one bondedrestoration ( one bonded
surface and foursurface and four
unbonded surfaces) withunbonded surfaces) with
a C-factor of 0.25 is ata C-factor of 0.25 is at
low risk for adverselow risk for adverse
polymerization shrinkagepolymerization shrinkage
effects. however for aeffects. however for a
class I restoration with aclass I restoration with a
C-factor of five ( fiveC-factor of five ( five
bonded surfaces andbonded surfaces and
one unbonded surface )one unbonded surface )
is at much higher risk ofis at much higher risk of
bond disruptionbond disruption
associated withassociated with
polymerizationpolymerization
shrinkage, particularlyshrinkage, particularly
along the pulpal floor.along the pulpal floor.

TOOTH PREPARATIONS FOR COMPOSITETOOTH PREPARATIONS FOR COMPOSITE
RESTORATIONRESTORATION
 Basically the tooth preparation for a compositeBasically the tooth preparation for a composite
restoration includes:restoration includes:
 Removing the fault, defect, old material, or friableRemoving the fault, defect, old material, or friable
tooth structure.tooth structure.
 Creating prepared enamel margins of 90 degreesCreating prepared enamel margins of 90 degrees
or greater (greater than 90 degrees usually preferable)or greater (greater than 90 degrees usually preferable)
 Creating 90-degree ( or butt joint ) cavosurfaceCreating 90-degree ( or butt joint ) cavosurface
margins on root surfaces.margins on root surfaces.
 Roughening the prepared tooth structureRoughening the prepared tooth structure
( enamel and dentin) with a diamond stone.( enamel and dentin) with a diamond stone.

 These objectives can be met by producing a toothThese objectives can be met by producing a tooth
preparation form significantly different from that for anpreparation form significantly different from that for an
amalgam restoration. Differences include:amalgam restoration. Differences include:
Less outline extension ( adjacent suspicious or at –riskLess outline extension ( adjacent suspicious or at –risk
areas [grooves or pits] may be sealed rather thanareas [grooves or pits] may be sealed rather than
restored).restored).
An axial and / or pulpal wall of varying depth ( notAn axial and / or pulpal wall of varying depth ( not
uniform )uniform )
Incorporation of an enamel bevel at some areas ( theIncorporation of an enamel bevel at some areas ( the
width of which is dictated by the need for secondarywidth of which is dictated by the need for secondary
retention)retention)
Tooth preparation walls being rough ( to increase theTooth preparation walls being rough ( to increase the
surface area for bonding)surface area for bonding)
Use of a diamond stone ( to increase the roughness ofUse of a diamond stone ( to increase the roughness of
the tooth preparation walls )the tooth preparation walls )

TYPES OF COMPOSITE TOOTHTYPES OF COMPOSITE TOOTH
PREPARATIONSPREPARATIONS
 Five designs of tooth preparations for compositeFive designs of tooth preparations for composite
restorations are presented here and sometimes they willrestorations are presented here and sometimes they will
be used in combination. The designs include:be used in combination. The designs include:
 ConventionalConventional
 Beveled conventionalBeveled conventional
 ModifiedModified
 Box onlyBox only
 Slot preparation designsSlot preparation designs

CONVENTIONAL PREPARATIONCONVENTIONAL PREPARATION
Conventional tooth preparations are those typical forConventional tooth preparations are those typical for
amalgam restorations.amalgam restorations.
Primary indications for conventional tooth preparation inPrimary indications for conventional tooth preparation in
composite restoration are:composite restoration are:
 Preparations located on root surfaces ( non enamelPreparations located on root surfaces ( non enamel
areas)areas)
 Moderate to large class I or class II restorationsModerate to large class I or class II restorations

This design facilitates a better seal between the compositeThis design facilitates a better seal between the composite
and the dentin or cementum surfaces and enhancesand the dentin or cementum surfaces and enhances
retention of the compostie material in the tooth.retention of the compostie material in the tooth.
In moderate to large class I or class II compositeIn moderate to large class I or class II composite
restorations there may be increased need for resistancerestorations there may be increased need for resistance
form which the conventional amalgam like preparationform which the conventional amalgam like preparation
design provides.design provides.
An inverted cone diamond ( similar in shape to a No.245An inverted cone diamond ( similar in shape to a No.245
bur ) is used to prepare the tooth resulting in abur ) is used to prepare the tooth resulting in a
preparation design similar to that for amalgam, butpreparation design similar to that for amalgam, but
usually smaller in width and extensions and withoutusually smaller in width and extensions and without
prepared secondary retention forms.prepared secondary retention forms.
The inverted cone diamond not only leaves theThe inverted cone diamond not only leaves the
prepared tooth structure roughened, but also isprepared tooth structure roughened, but also is
conservative of the occlusal faciolingual extensionconservative of the occlusal faciolingual extension

..
The butt joint marginal configuration betweenThe butt joint marginal configuration between
the tooth and the composite is not required. thusthe tooth and the composite is not required. thus
the cavosurface angle in areas on the preparationthe cavosurface angle in areas on the preparation
periphery can be more flared ( obtuse ) than 90periphery can be more flared ( obtuse ) than 90
degrees.degrees.
Because of the similarity of the class I or class IIBecause of the similarity of the class I or class II
conventional composite preparation to anconventional composite preparation to an
amalgam tooth preparation, many operatorsamalgam tooth preparation, many operators
prefer its use whether the class I or class IIprefer its use whether the class I or class II
preparation is for a large posterior composite orpreparation is for a large posterior composite or
for restoring a new, smaller carious lesion.for restoring a new, smaller carious lesion.

 However conservation of tooth structure is of paramountHowever conservation of tooth structure is of paramount
importance.importance.
Class I or Class II conventional composite restorationsClass I or Class II conventional composite restorations
should be prepared as little as faciolingual extension asshould be prepared as little as faciolingual extension as
possible and should not routinely be extended into all pitspossible and should not routinely be extended into all pits
and fissures on the occulsal surface where sealants mayand fissures on the occulsal surface where sealants may
be indicated.be indicated.
It should be remembered that box like forms increaseIt should be remembered that box like forms increase
the negative effects of the C-factor.the negative effects of the C-factor.
It is usually advantageous to use a diamond stone forIt is usually advantageous to use a diamond stone for
preparing the tooth for a composite restoration. Thispreparing the tooth for a composite restoration. This
results in a roughened prepared surface, which increasesresults in a roughened prepared surface, which increases
the surface for bonding.the surface for bonding.

BEVELED CONVENTIONALBEVELED CONVENTIONAL
 Similar to conventional preparations in thatSimilar to conventional preparations in that
the outline form has external boxlike walls,the outline form has external boxlike walls,
but with some beveled enamel margins.but with some beveled enamel margins.
 Typically indicated when a compositeTypically indicated when a composite
restoration is being used to replace anrestoration is being used to replace an
existing restoration ( usually amalgam )existing restoration ( usually amalgam )
exhibiting a conventional tooth preparationexhibiting a conventional tooth preparation
design with enamel margins or to restore adesign with enamel margins or to restore a
large area.large area.
 Most typical for classes III,IV and VMost typical for classes III,IV and V
restorations.restorations.

ADVANTAGES OF ENAMELADVANTAGES OF ENAMEL
BEVELBEVEL
 The ends of the rods are moreThe ends of the rods are more
effectively etched thaneffectively etched than
otherwise only the sides of theotherwise only the sides of the
enamel rods are exposed.enamel rods are exposed.
 Increase in etched surfaceIncrease in etched surface
area results in a strongerarea results in a stronger
enamel to resin bond, whichenamel to resin bond, which
increases retention of theincreases retention of the
restoration and reducesrestoration and reduces
marginal leakage and marginalmarginal leakage and marginal
discoloration.discoloration.
 Incorporation of cavosurfaceIncorporation of cavosurface
bevel may enable thebevel may enable the
restoration to blend morerestoration to blend more
esthetically with the colorationesthetically with the coloration
of the surrounding toothof the surrounding tooth
structure.structure.

Even recognizing theseEven recognizing these
advantages, bevels are notadvantages, bevels are not
usually placed on theusually placed on the
occlusal surfaces ofocclusal surfaces of
posterior teeth or other areasposterior teeth or other areas
of potential heavy contactof potential heavy contact
because a conventionalbecause a conventional
preparation design alreadypreparation design already
produces end on etching ofproduces end on etching of
the enamel rods by virtue ofthe enamel rods by virtue of
the enamel rod direction onthe enamel rod direction on
occlusal surfacesocclusal surfaces
 Bevels are not placed onBevels are not placed on
proximal margins if suchproximal margins if such
beveling results in excessivebeveling results in excessive
extension of the cavosurfaceextension of the cavosurface
margins.margins.
 Therefore this design is rarelyTherefore this design is rarely
used for posterior compositeused for posterior composite
restorationsrestorations..

MODIFIEDMODIFIED
 Primarily indicated for the initial restoration of smaller,Primarily indicated for the initial restoration of smaller,
cavitated, carious lesion usually surrounded by enamelcavitated, carious lesion usually surrounded by enamel
and for correcting enamel defects.and for correcting enamel defects.
 This preparation has neither specified wall configurationsThis preparation has neither specified wall configurations
nor specified pulpal or axial depths; preferably they havenor specified pulpal or axial depths; preferably they have
enamel margins.enamel margins.
 The extension of the margins and the depth of thisThe extension of the margins and the depth of this
preparation are dictated solely by the extent and thepreparation are dictated solely by the extent and the
depth of the carious lesion or other defects.depth of the carious lesion or other defects.
 Preparations appears to have been “ scooped out “Preparations appears to have been “ scooped out “
rather than having the distinct internal line angles .rather than having the distinct internal line angles .

 This preparation conserveThis preparation conserve
more tooth structure becausemore tooth structure because
retention is obtained primarilyretention is obtained primarily
by micromechanical adhesionby micromechanical adhesion
to the surrounding enamel andto the surrounding enamel and
underlying dentin, rather thanunderlying dentin, rather than
by preparation of retentionby preparation of retention
grooves or coves in dentin.grooves or coves in dentin.
 Successful for largerSuccessful for larger
restorations as well.restorations as well.
 For restoration of large cariousFor restoration of large carious
lesions, wider bevels or flareslesions, wider bevels or flares
and retention grooves, coves orand retention grooves, coves or
locks may be indicated inlocks may be indicated in
addition to the retentionaddition to the retention
afforded by the adhesiveafforded by the adhesive
procedures.procedures.

BOX ONLYBOX ONLY
 Primarily indicated when only the proximal surface isPrimarily indicated when only the proximal surface is
faulty, with no lesions present on the occlusal surface.faulty, with no lesions present on the occlusal surface.
 A proximal box is prepared with either inverted cone orA proximal box is prepared with either inverted cone or
round diamond stone held parallel to the long axis of theround diamond stone held parallel to the long axis of the
tooth crown.tooth crown.
 Initial proximal axial depth is prepared 0.2 mm inside theInitial proximal axial depth is prepared 0.2 mm inside the
DEJ.DEJ.
 Form of the box is dependent on which diamond is usedForm of the box is dependent on which diamond is used
–more box like with the inverted diamond, more scooped–more box like with the inverted diamond, more scooped
with the round diamond.with the round diamond.
 Neither beveling nor secondary retention is usuallyNeither beveling nor secondary retention is usually
indicated.indicated.

FACIAL /LINGUAL SLOTFACIAL /LINGUAL SLOT
 Third modified design for restoring proximal lesions onThird modified design for restoring proximal lesions on
posterior teeth is the facial or lingual slot preparation.posterior teeth is the facial or lingual slot preparation.
 Lesion is detected on the proximal surface but theLesion is detected on the proximal surface but the
operator believes that access to the lesion can beoperator believes that access to the lesion can be
obtained from either a facial or lingual direction ratherobtained from either a facial or lingual direction rather
than through the marginal ridge from an occlusalthan through the marginal ridge from an occlusal
direction.direction.
 The preparation is extended occlusogingivally andThe preparation is extended occlusogingivally and
faciolingually enough to remove the lesion.faciolingually enough to remove the lesion.

INDICATIONS FOR COMPOSITEINDICATIONS FOR COMPOSITE
o Classes I, II, III, IV, V and VI restorations.Classes I, II, III, IV, V and VI restorations.
o Foundations or core build ups.Foundations or core build ups.
o Sealants and conservative composite restorations.Sealants and conservative composite restorations.
o Esthetic enhancement proceduresEsthetic enhancement procedures
 Partial veneersPartial veneers
 Full veneersFull veneers
 Tooth contour modificationsTooth contour modifications
 Diastema closuresDiastema closures
o Cements ( for indirect restorations )Cements ( for indirect restorations )
o Temporary restorationsTemporary restorations
o Periodontal splintingPeriodontal splinting

 The ADA has indicated the appropriateness of compositesThe ADA has indicated the appropriateness of composites
for use as pit and fissure sealants, preventive resins, initialfor use as pit and fissure sealants, preventive resins, initial
classes I and II lesions using modified conservative toothclasses I and II lesions using modified conservative tooth
preparations, moderate-sized classes I and II restorations,preparations, moderate-sized classes I and II restorations,
class V restorations , restorations of esthetically importantclass V restorations , restorations of esthetically important
areas and restorations in patients allergic or sensitive toareas and restorations in patients allergic or sensitive to
metals.metals.
 ADA does not support the use of composites in teeth withADA does not support the use of composites in teeth with
heavy occlusal stresses, sites that cannot be isolated orheavy occlusal stresses, sites that cannot be isolated or
patients who are allergic or sensitive to compositepatients who are allergic or sensitive to composite
materials.materials.
 If composites are used as indicated , the ADA furtherIf composites are used as indicated , the ADA further
states that “when used correctly in the primary andstates that “when used correctly in the primary and
permanent dentition, the expected lifetime of resin – basedpermanent dentition, the expected lifetime of resin – based
composites can be comparable to that of amalgam incomposites can be comparable to that of amalgam in
class I, class II, and class V restorations.”class I, class II, and class V restorations.”

CONTRAINDICATIONS OF COMPOSITESCONTRAINDICATIONS OF COMPOSITES
 IsolationIsolation
 Occlusal factorsOcclusal factors
 Operator ability and commitment factorsOperator ability and commitment factors

ADVANTAGESADVANTAGES
 EstheticEsthetic
 Conservative of tooth structure removalConservative of tooth structure removal
 Less complex when preparing the toothLess complex when preparing the tooth
 Insulative, having low thermal conductivityInsulative, having low thermal conductivity
 Used almost universallyUsed almost universally
 Bonded to tooth structure, resulting in good retention,Bonded to tooth structure, resulting in good retention,
low microleakage, minimal interfacial staining, andlow microleakage, minimal interfacial staining, and
increase strength of remaining tooth structure.increase strength of remaining tooth structure.
 RepairableRepairable

DISADVANTAGESDISADVANTAGES
 May have a gap formation, usually occuring on rootMay have a gap formation, usually occuring on root
surfaces as a result of the forces of polymerizationsurfaces as a result of the forces of polymerization
shrinkage of the composite material being greater thanshrinkage of the composite material being greater than
the initial early bond strength of the material to dentin.the initial early bond strength of the material to dentin.
 Are more difficult, time consuming, and costlyAre more difficult, time consuming, and costly
( compared to amalgam restorations ) because :( compared to amalgam restorations ) because :
 Tooth treatment usually multiple stepsTooth treatment usually multiple steps
 Insertion is more difficultInsertion is more difficult
 Establishing proximal contacts, axial contours,Establishing proximal contacts, axial contours,
embrasures, and occlusal contacts may be more difficult.embrasures, and occlusal contacts may be more difficult.
 Finishing and polishing procedures are more difficultFinishing and polishing procedures are more difficult

 Are more technique sensitive because the operating siteAre more technique sensitive because the operating site
must be appropriately isolated and the placement ofmust be appropriately isolated and the placement of
etchant, primer, and adhesive on the tooth structure isetchant, primer, and adhesive on the tooth structure is
very demanding of proper technique.very demanding of proper technique.
 May exhibit greater occlusal wear in areas of highMay exhibit greater occlusal wear in areas of high
occlusal stress or when all of the tooth’s occlusalocclusal stress or when all of the tooth’s occlusal
contacts are on the composite material.contacts are on the composite material.
 Have a higher linear coefficient of thermal expansionHave a higher linear coefficient of thermal expansion
resulting in potential marginal percolation if anresulting in potential marginal percolation if an
inadequate bonding techinque is utilized.inadequate bonding techinque is utilized.

ARMAMENTARIUM FOR COMPOSITEARMAMENTARIUM FOR COMPOSITE
 Standard dental set upStandard dental set up
Explorer Rubber dam setupExplorer Rubber dam setup
Mouth mirror High-speed handpieceMouth mirror High-speed handpiece
Cotton forceps Slow-speed handpieceCotton forceps Slow-speed handpiece
AnesthesiaAnesthesia
 Burs: Carbide ( no 557, no 330, no 4 S.S. White Inc )Burs: Carbide ( no 557, no 330, no 4 S.S. White Inc )
 Diamond: Coarse and medium gritDiamond: Coarse and medium grit
 37% phosphoric acid37% phosphoric acid
 Placement and carving instrumentsPlacement and carving instruments
 Suitable liner ( if necessary )Suitable liner ( if necessary )
 Suitable base ( if necessary )Suitable base ( if necessary )
 Articulating paper or waxArticulating paper or wax
 Radio opaque composite resinRadio opaque composite resin

 Oil free pumiceOil free pumice
 Cavity disinfectantCavity disinfectant
 Composite resin placement syringeComposite resin placement syringe
 Glycerin gelGlycerin gel
 Finishing instrumentsFinishing instruments
 Polishing instrumentsPolishing instruments
 Polishing paste materials.Polishing paste materials.

CLINICAL TECHNIQUE FOR DIRECT CLASS IIICLINICAL TECHNIQUE FOR DIRECT CLASS III
COMPOSITE RESTORATIONSCOMPOSITE RESTORATIONS
 TOOTH PREPARATION:TOOTH PREPARATION: Two approaches of toothTwo approaches of tooth
preparation are present for class III restorations. Theypreparation are present for class III restorations. They
areare
Facial approachFacial approach
Lingual approach.Lingual approach.
Lingual approach is usually preferable.Lingual approach is usually preferable.
Advantages of restoring the proximal lesion from lingualAdvantages of restoring the proximal lesion from lingual
approach include:approach include:
1) Facial enamel is conserved for enhanced esthetics.1) Facial enamel is conserved for enhanced esthetics.
2) some unsupported but not friable enamel may be left2) some unsupported but not friable enamel may be left
on the facial wall of a class III or class IV preparationon the facial wall of a class III or class IV preparation
3) Color matching is not critical.3) Color matching is not critical.
4) discoloration or deterioration of the restoration is less4) discoloration or deterioration of the restoration is less
visible.visible. www.indiandentalacademy.com

 INDICATIONS FOR FACIAL APPROACHINDICATIONS FOR FACIAL APPROACH::
1) The carious lesion is positioned facially such that facial1) The carious lesion is positioned facially such that facial
access would significantly conserve tooth structureaccess would significantly conserve tooth structure
2) The teeth are irregularly aligned, making lingual2) The teeth are irregularly aligned, making lingual
access undesirable.access undesirable.
3) Extensive caries extend onto the facial surface.3) Extensive caries extend onto the facial surface.
4) A faulty restoration that was originally placed from4) A faulty restoration that was originally placed from
facial approach needs to be replaced.facial approach needs to be replaced.
When both the facial and lingual surfaces are involved , useWhen both the facial and lingual surfaces are involved , use
the approach that provides the best access forthe approach that provides the best access for
instrumentation.instrumentation.
Prepare and restore approximating carious lesion or faultyPrepare and restore approximating carious lesion or faulty
restorations on adjacent teeth at the same appointmentrestorations on adjacent teeth at the same appointment

 Usually one of the preparations will be larger than theUsually one of the preparations will be larger than the
other.other.
 When the larger outline form is developed first, theWhen the larger outline form is developed first, the
second preparation usually can be more conservativesecond preparation usually can be more conservative
because of the improved access provided by the largerbecause of the improved access provided by the larger
restoration.restoration.
 The reverse order would be followed when the restorativeThe reverse order would be followed when the restorative
material is inserted.material is inserted.

CONVENTIONAL CLASS III TOOTH PREPARATIONCONVENTIONAL CLASS III TOOTH PREPARATION ::
Primary indication for this type of tooth preparation is for thePrimary indication for this type of tooth preparation is for the
restoration of root surfaces.restoration of root surfaces.
When preparing the conventional portion of a preparation theWhen preparing the conventional portion of a preparation the
form of the preparation walls is the same as that of anform of the preparation walls is the same as that of an
amalgam.amalgam.
Cavaosurface margins exhibit a 90-degree cavosurfaceCavaosurface margins exhibit a 90-degree cavosurface
angle and provide butt joints between the tooth and theangle and provide butt joints between the tooth and the
composite material. External walls are preparedcomposite material. External walls are prepared
perpendiular to root surface.perpendiular to root surface.
STAGES AND STEPS OF ROOT SURFACE TOOTHSTAGES AND STEPS OF ROOT SURFACE TOOTH
PREPARATIONPREPARATION
Using no ½ ,1 or 2 round bur or diamond, prepare the outlineUsing no ½ ,1 or 2 round bur or diamond, prepare the outline
form on the root surface, extending the external walls toform on the root surface, extending the external walls to
sound tooth structure while extending pulpally to an initialsound tooth structure while extending pulpally to an initial
depth of 0.75mm.depth of 0.75mm.

 Initial depth will be no more than 0.75mm at this depth theInitial depth will be no more than 0.75mm at this depth the
bur or diamond may be touching dentin, previousbur or diamond may be touching dentin, previous
restorative material , carious tooth structure or air.restorative material , carious tooth structure or air.
 Prepare the external walls perpendicular to the rootPrepare the external walls perpendicular to the root
surface thus forming a 90-degree cavosurface angle.surface thus forming a 90-degree cavosurface angle.
 The boxlike design is considered a part of retention form.The boxlike design is considered a part of retention form.
however at this stage of tooth preparation the externalhowever at this stage of tooth preparation the external
walls may be retentive because of opposing wallwalls may be retentive because of opposing wall
parallelism or slight undercuts or nonretentive because ofparallelism or slight undercuts or nonretentive because of
slight divergence outwardly.slight divergence outwardly.
 Remaining old restorative material should be removed.Remaining old restorative material should be removed.
 Groove retention may be necessary in root surfaceGroove retention may be necessary in root surface
preparations to better ensure that the restorative materialpreparations to better ensure that the restorative material
is retained in the tooth.is retained in the tooth.
 Retention groove created also may help in minimizing theRetention groove created also may help in minimizing the
potential negative effects of polymerization shrinkage.potential negative effects of polymerization shrinkage.

 Additionally this groove will enhance the marginal seal byAdditionally this groove will enhance the marginal seal by
resisting flexural forces ( from tooth flexure ) placed onresisting flexural forces ( from tooth flexure ) placed on
the cervical portion of the restoration.the cervical portion of the restoration.
 A continuous retention groove can be prepared in theA continuous retention groove can be prepared in the
internal portion of the external walls using a no ¼ roundinternal portion of the external walls using a no ¼ round
bur. This groove is utilized when maximum retention isbur. This groove is utilized when maximum retention is
anticipated.anticipated.
 Groove is located 0.25 mm from the root surface and isGroove is located 0.25 mm from the root surface and is
prepared to a depth of 0.25 mm.prepared to a depth of 0.25 mm.
 Groove is directed as the bisector of the angle formed byGroove is directed as the bisector of the angle formed by
the junction of the axial wall and the external wall.the junction of the axial wall and the external wall.
 For its entire length the groove should be parallel to theFor its entire length the groove should be parallel to the
root surface.root surface.

BEVELED CONVENTIONAL CLASS IIIBEVELED CONVENTIONAL CLASS III
TOOTH PREPARATIONTOOTH PREPARATION::
 Indicated primarily for replacing an existing defectiveIndicated primarily for replacing an existing defective
restoration in the crown portion of the tooth.restoration in the crown portion of the tooth.
 Also used when restoring a large carious lesion for whichAlso used when restoring a large carious lesion for which
the need for increased retention and or resistance form isthe need for increased retention and or resistance form is
anticipated.anticipated.
 This preparation is characterized by external walls that areThis preparation is characterized by external walls that are
perpendicular to the enamel surface with the enamelperpendicular to the enamel surface with the enamel
margin beveledmargin beveled..

 The axial line angles may or may not be of uniform pulpalThe axial line angles may or may not be of uniform pulpal
depth varying as the thickness of the enamel portion ofdepth varying as the thickness of the enamel portion of
the external wall varies.the external wall varies.
 The tooth preparation for the replacement restoration willThe tooth preparation for the replacement restoration will
have the dame general form of the previous (old) toothhave the dame general form of the previous (old) tooth
preparationpreparation
 Usually retention is obtained by bonding to the enamelUsually retention is obtained by bonding to the enamel
and dentin and no groove retention is necessaryand dentin and no groove retention is necessary

However when replacing a large restoration orHowever when replacing a large restoration or
restoring a large class III lesion the operator mayrestoring a large class III lesion the operator may
decide that retention form should be enhanced bydecide that retention form should be enhanced by
placing groove (at gingival) and or cove (at incisal)placing groove (at gingival) and or cove (at incisal)
retention features in addition to the bonded toothretention features in addition to the bonded tooth
structurestructure
LINGUAL ACCESS:LINGUAL ACCESS:
Use a round carbide bur ( no ½ ,1,or 2) or diamondUse a round carbide bur ( no ½ ,1,or 2) or diamond
stone, the size depending on the extent of thestone, the size depending on the extent of the
caries or defective restoration to prepare the outlinecaries or defective restoration to prepare the outline
form.form.
The point of entry is within the incisogingivalThe point of entry is within the incisogingival
dimensiondimension
of the carious lesion or defective restoration and asof the carious lesion or defective restoration and as
close to the adjacent tooth as possible withoutclose to the adjacent tooth as possible without
contacting it.contacting it.

 Extend the external walls to sound tooth structure duringExtend the external walls to sound tooth structure during
preparation of the outline form but only to the initialpreparation of the outline form but only to the initial
limited prescribed depth.limited prescribed depth.
 This extension should be as minimal as possible dictatedThis extension should be as minimal as possible dictated
by the extent of caries and or old restorative material onby the extent of caries and or old restorative material on
these wallsthese walls

Unless absolutely necessary do not:Unless absolutely necessary do not:
1) include the proximal contact area1) include the proximal contact area
2) extend on to the facial surface2) extend on to the facial surface
3) extend subgingivally3) extend subgingivally
 The axial wall depth at this initial stage toothThe axial wall depth at this initial stage tooth
preparation is limited to 0.2mm inside the DEJ whichpreparation is limited to 0.2mm inside the DEJ which
means it will be approximately 0.75 to 1.25mm deep ( themeans it will be approximately 0.75 to 1.25mm deep ( the
larger being incisally where enamel is thicker ).larger being incisally where enamel is thicker ).
 The axial wall will be outwardly convex following normalThe axial wall will be outwardly convex following normal
external tooth contour and the DEJ both incisogingivallyexternal tooth contour and the DEJ both incisogingivally
and faciolinguallyand faciolingually..
 The axial line angles should be placed at an initial depthThe axial line angles should be placed at an initial depth
of 0.2mm into dentinof 0.2mm into dentin

 If a retention groove is to be placed the axial wall shouldIf a retention groove is to be placed the axial wall should
be 0.5 mm into dentin at retention locations to preventbe 0.5 mm into dentin at retention locations to prevent
undermining enamel where the retention form isundermining enamel where the retention form is
prepared.prepared.
 Prepare the enamel walls perpendicular to the externalPrepare the enamel walls perpendicular to the external
tooth surface. The gingival and lingual wall usually aretooth surface. The gingival and lingual wall usually are
finished with same round cutting instrument that wasfinished with same round cutting instrument that was
used to prepare the outline form.used to prepare the outline form.
 Once the outline form and initial axiall wall depth haveOnce the outline form and initial axiall wall depth have
been established, the initial tooth preparation stage isbeen established, the initial tooth preparation stage is
completed and the final stage of tooth preparation begins.completed and the final stage of tooth preparation begins.
 For most class III restorations using the beveledFor most class III restorations using the beveled
conventional preparation the preparation would beconventional preparation the preparation would be
complete at this time except for placing an enamel bevelcomplete at this time except for placing an enamel bevel
or flare.or flare.

 If retention features( grooves or coves ) are indicatedIf retention features( grooves or coves ) are indicated
(and usually they are not) prepare them along the(and usually they are not) prepare them along the
gingivoaxial line angle and sometimes the incisoaxial linegingivoaxial line angle and sometimes the incisoaxial line
angle with a no ¼ bur. Occasionally retention may beangle with a no ¼ bur. Occasionally retention may be
provided by undercuts left from caries removal.provided by undercuts left from caries removal.
 No purposeful attempt is made to provide retentiveNo purposeful attempt is made to provide retentive
undercuts along the linguoaxial and facioaxial line anglesundercuts along the linguoaxial and facioaxial line angles
because these areas usually are not needed to retainbecause these areas usually are not needed to retain
composites and might unnecessarily weaken the lingualcomposites and might unnecessarily weaken the lingual
and facial enamel walls and margins.and facial enamel walls and margins.
 If deemed necessary prepare a gingival retention grooveIf deemed necessary prepare a gingival retention groove
along the gingivoaxial line angle. Care should bealong the gingivoaxial line angle. Care should be
exercised to prepare this groove approximately 0.2mmexercised to prepare this groove approximately 0.2mm
inside the DEJ to a depth of 0.25mm so as not toinside the DEJ to a depth of 0.25mm so as not to
undermine the enamel portion of the gingival wall.undermine the enamel portion of the gingival wall.

 Prepare any necessary incisal retention cove with thePrepare any necessary incisal retention cove with the
no.1/4 bur at the axioincisal point angle with the burno.1/4 bur at the axioincisal point angle with the bur
oriented in a similar angle,0.2 mm inside the DEJ andoriented in a similar angle,0.2 mm inside the DEJ and
0.25mm deep.0.25mm deep.
 Class III beveled conventional tooth preparation areClass III beveled conventional tooth preparation are
prepared as conventional preparations with the addition ofprepared as conventional preparations with the addition of
a cavosurface bevel or flare of the enamel rather than aa cavosurface bevel or flare of the enamel rather than a
butt joint margin.butt joint margin.
MODIFIED CLASS III TOOTH PREPARATIONMODIFIED CLASS III TOOTH PREPARATION::
 Most used type of class III tooth preparationMost used type of class III tooth preparation
 Indicated for small and moderate lesions or faults and isIndicated for small and moderate lesions or faults and is
designed to be as conservative as possible.designed to be as conservative as possible.
 The preparation is dictated b the extent of the fault orThe preparation is dictated b the extent of the fault or
defect and is prepared from a lingual approach whendefect and is prepared from a lingual approach when
possible with an appropriate size round bur or diamondpossible with an appropriate size round bur or diamond
instrument.instrument.

 No effort is made to produce preparation walls that haveNo effort is made to produce preparation walls that have
specific shapes or forms other than external angles of 90specific shapes or forms other than external angles of 90
degrees or greater.degrees or greater.
 Usually no groove (or cove) retention form is indicatedUsually no groove (or cove) retention form is indicated
because the retention of the material in the tooth willbecause the retention of the material in the tooth will
result from the bond created between the compositeresult from the bond created between the composite
material and the etched peripheral enamel.material and the etched peripheral enamel.
 The preparation design appears to be “scooped” orThe preparation design appears to be “scooped” or
concave .concave .
 Begin the preparation from a lingual approach ( ifBegin the preparation from a lingual approach ( if
possible) by making an opening using a round carbidepossible) by making an opening using a round carbide
bur ( no.1/2, 1, or 2) or diamond instrument the sizebur ( no.1/2, 1, or 2) or diamond instrument the size
depending on the extent of the lesion.depending on the extent of the lesion.
 The point of entry is within the incisogingival dimension ofThe point of entry is within the incisogingival dimension of
the lesion or defect and as close to the adjacent tooth asthe lesion or defect and as close to the adjacent tooth as
possible without contacting it.possible without contacting it.

 No effort is made to prepare walls that are perpendicularNo effort is made to prepare walls that are perpendicular
to the enamel surface; In fact, for small preparations theto the enamel surface; In fact, for small preparations the
walls may diverge externally form the axial depth in awalls may diverge externally form the axial depth in a
scoop shape resulting in bothscoop shape resulting in both
1) a beveled or flared marginal design1) a beveled or flared marginal design
2) conservation of internal tooth structure2) conservation of internal tooth structure
For larger modified preparations the initial tooth preparationFor larger modified preparations the initial tooth preparation
will still be prepared as conservatively as possible but thewill still be prepared as conservatively as possible but the
preparation walls may not be as divergent from the axialpreparation walls may not be as divergent from the axial
wall.wall.
Axial wall should be of limited depth 0.2mm inside the DEJAxial wall should be of limited depth 0.2mm inside the DEJ

CLINICAL TECHNIQUE FOR DIRECT CLASS IVCLINICAL TECHNIQUE FOR DIRECT CLASS IV
 TOOTH PREPARATION:TOOTH PREPARATION: The class IV compositeThe class IV composite
restoration has provided the profession with arestoration has provided the profession with a
conservative treatment to restore fractured, defective, orconservative treatment to restore fractured, defective, or
cariously involved anterior teeth when previously, acariously involved anterior teeth when previously, a
porcelain crown may have been the treatment of choice.porcelain crown may have been the treatment of choice.
 Conventional tooth preparation design has minimalConventional tooth preparation design has minimal
clinical class IV application except in those areas thatclinical class IV application except in those areas that
have margins located on root surfaces.have margins located on root surfaces.
 Beveled conventional tooth preparation is indicated forBeveled conventional tooth preparation is indicated for
large class IV restorationslarge class IV restorations
 Modified tooth preparation is indicated for smallerModified tooth preparation is indicated for smaller
class IVclass IV

 If a large amount of tooth structure is missing, grooveIf a large amount of tooth structure is missing, groove
retention form may be indicated even when theretention form may be indicated even when the
preparation periphery is entirely in enamel.preparation periphery is entirely in enamel.
 To provide additional retention in high stress areas, theTo provide additional retention in high stress areas, the
enamel bevels may be increased in width to provideenamel bevels may be increased in width to provide
greater surface area for etching, resulting in a strongergreater surface area for etching, resulting in a stronger
bond between the composite and the tooth.bond between the composite and the tooth.
 To provide appropriate resistance form the preparationTo provide appropriate resistance form the preparation
walls may need to be prepared in such a way as to resistwalls may need to be prepared in such a way as to resist
occlusal forces. This often requires proximal facial andocclusal forces. This often requires proximal facial and
lingual preparation walls that form 90-degree cavosurfacelingual preparation walls that form 90-degree cavosurface
angles, which are subsequently beveled and a gingivalangles, which are subsequently beveled and a gingival
floor prepared perpendicular to the long axis of the tooth.floor prepared perpendicular to the long axis of the tooth.
 This box like form may provide greater resistance toThis box like form may provide greater resistance to
fracture of the restoration and tooth from masticatoryfracture of the restoration and tooth from masticatory
forcesforces

CONVENTIONAL CLASS IV TOOTH PREPARATION:CONVENTIONAL CLASS IV TOOTH PREPARATION:
 Any portion of any calss IV restoration that extendsAny portion of any calss IV restoration that extends
onto the root requires a 90-degree cavosurface marginonto the root requires a 90-degree cavosurface margin
and possible groove retention form regardless whetherand possible groove retention form regardless whether
either a beveled conventional or modified preparationeither a beveled conventional or modified preparation
design is used for the portion of the preparation in thedesign is used for the portion of the preparation in the
crown of the tooth.crown of the tooth.
BEVELED CONVENTIONAL CLASS IV TOOTHBEVELED CONVENTIONAL CLASS IV TOOTH
PREPARATION:PREPARATION:
 Indicated for restoring large proximal areas that alsoIndicated for restoring large proximal areas that also
include the incisal surface of an anterior tooth.include the incisal surface of an anterior tooth.
 In addition to the etched enamel margin, retention ofIn addition to the etched enamel margin, retention of
the composite restorative material in beveled conventionalthe composite restorative material in beveled conventional
class IV tooth preparations may be obtained by groove orclass IV tooth preparations may be obtained by groove or
other shaped undercuts, dovetail extensions, threadedother shaped undercuts, dovetail extensions, threaded
pins, or a combination of these.pins, or a combination of these.

 Gingival and incisalGingival and incisal
retentive undercuts mayretentive undercuts may
be indicated in large classbe indicated in large class
IV preparations in whichIV preparations in which
rounded undercuts arerounded undercuts are
placed in the dentin alongplaced in the dentin along
line angles and into pointline angles and into point
angles whereverangles wherever
possible.possible.

 Using an appropriate sizeUsing an appropriate size
round carbide bur orround carbide bur or
diamond instrument atdiamond instrument at
high speed with air-waterhigh speed with air-water
coolant prepare thecoolant prepare the
outline form.outline form.
 Remove all weakenedRemove all weakened
enamel and establish theenamel and establish the
initial axial wall depth atinitial axial wall depth at
0.5mm into dentin.0.5mm into dentin.
Prepare the walls asPrepare the walls as
much as possible parallelmuch as possible parallel
and perpendicular to theand perpendicular to the
long axis of the tooth.long axis of the tooth.
 Excavate any remainingExcavate any remaining
infected dentin as the firstinfected dentin as the first
step of final toothstep of final tooth
preparation.preparation.

 Bevel the cavosurface margin of all accessible enamelBevel the cavosurface margin of all accessible enamel
margins of the preparation.margins of the preparation.
 The bevel is prepared at a 45-degree angle to theThe bevel is prepared at a 45-degree angle to the
external tooth surface with a flame-shaped or roundexternal tooth surface with a flame-shaped or round
diamond instrument.diamond instrument.
 Width of the bevel should be 0.25 to 2 mm depending onWidth of the bevel should be 0.25 to 2 mm depending on
the amount of tooth structure missing and the retentionthe amount of tooth structure missing and the retention
perceived necessaryperceived necessary

 Retention form is provided primarilyRetention form is provided primarily
by the micromechanical bonding ofby the micromechanical bonding of
the composite to the enamel andthe composite to the enamel and
dentin.dentin.
 Additional retention may beAdditional retention may be
obtained by increasing the width ofobtained by increasing the width of
the enamel bevels or placingthe enamel bevels or placing
retention undercuts.retention undercuts.
 If retention undercuts are deemedIf retention undercuts are deemed
necessary prepare a gingivalnecessary prepare a gingival
retention groove using a no ¼retention groove using a no ¼
round bur. It is prepared 0.2mmround bur. It is prepared 0.2mm
inside the DEJ at a depth of 0.25inside the DEJ at a depth of 0.25
mm and at angle bisecting themm and at angle bisecting the
junction of the axial wall andjunction of the axial wall and
gingival wall.gingival wall.

 MODIFIED CLASS IVMODIFIED CLASS IV
TOOTHTOOTH
PREPARATION:PREPARATION:
 Is indicated for smallIs indicated for small
or moderate class IVor moderate class IV
lesions or traumaticlesions or traumatic
defects.defects.
 The objective of toothThe objective of tooth
preparation is topreparation is to
remove as little toothremove as little tooth
structure as possiblestructure as possible
while removing the faultwhile removing the fault
and providing forand providing for
appropriate retentionappropriate retention
and resistance forms.and resistance forms.


 Remove any existing lesion or defectiveRemove any existing lesion or defective
restoration with a suitable size round bur orrestoration with a suitable size round bur or
diamond instrument and prepare the outline formdiamond instrument and prepare the outline form
to include weakened friable enamelto include weakened friable enamel
 Usually little or no initial tooth preparation isUsually little or no initial tooth preparation is
indicated for fractured incisal corners, other thanindicated for fractured incisal corners, other than
roughening the fractured tooth structure.roughening the fractured tooth structure.
 The cavosurface margins are prepared with aThe cavosurface margins are prepared with a
beveled or flared configuration.beveled or flared configuration.
 The axial depth is dependent on the extent ofThe axial depth is dependent on the extent of
the lesion, previous restoration, or fracture, butthe lesion, previous restoration, or fracture, but
initially no deeper than 0.2mm inside the DEJinitially no deeper than 0.2mm inside the DEJ

CLINICAL TECHNIQUE FOR CLASS VCLINICAL TECHNIQUE FOR CLASS V
 TOOTH PREPARATIONTOOTH PREPARATION: composite materials most: composite materials most
frequently are used for the restoration of class V lesionsfrequently are used for the restoration of class V lesions
in anterior teeth.in anterior teeth.
 CONVENTIONAL CLASS V TOOTH PREPARATION: isCONVENTIONAL CLASS V TOOTH PREPARATION: is
indicated for that portion of a carious lesion or defectindicated for that portion of a carious lesion or defect
entirely or partially on the facial or lingual root surfacesentirely or partially on the facial or lingual root surfaces
of a tooth.of a tooth.
 Features of the preparation include a 90-degreeFeatures of the preparation include a 90-degree
cavosurface angle; uniform depth of the axial line angles;cavosurface angle; uniform depth of the axial line angles;
and sometimes, groove retention form.and sometimes, groove retention form.

 Many class V lesions or defects will have some enamel atMany class V lesions or defects will have some enamel at
the incisal (occlusal) and possibly the mesial and or distalthe incisal (occlusal) and possibly the mesial and or distal
margins, the conventional composite tooth preparationmargins, the conventional composite tooth preparation
design is indicated only for the portion of the lesion ordesign is indicated only for the portion of the lesion or
defect extending onto the root surface.defect extending onto the root surface.
 The enamel marginal areas are prepared using either aThe enamel marginal areas are prepared using either a
beveled conventional or modified preparation design.beveled conventional or modified preparation design.
 Occasionally a class V lesion /defect is located entirelyOccasionally a class V lesion /defect is located entirely
on the root of the tooth requiring the use of aon the root of the tooth requiring the use of a
conventional preparation design exclusivelyconventional preparation design exclusively..

 DESCRIPTION OF A CONVENTIONAL TOOTHDESCRIPTION OF A CONVENTIONAL TOOTH
PREPATATION LOCATED ENTIRELY ON ROOTPREPATATION LOCATED ENTIRELY ON ROOT
SURFACE: A tapered fissure carbide bur ( noSURFACE: A tapered fissure carbide bur ( no
700,701,702 ) or similarly shaped diamond is used at high700,701,702 ) or similarly shaped diamond is used at high
speed with air water spray.speed with air water spray.
 When a tapered fissure bur or diamond is used makeWhen a tapered fissure bur or diamond is used make
entry at a 45 degree angle to the tooth surface by tiltingentry at a 45 degree angle to the tooth surface by tilting
the hand piece distallythe hand piece distally
 During preparation of the outline form the bur’s long axisDuring preparation of the outline form the bur’s long axis
should be maintained perpendicular to the externalshould be maintained perpendicular to the external
surface of the toothsurface of the tooth

 At this initial tooth preparation stage, the extensions inAt this initial tooth preparation stage, the extensions in
every direction are to sound tooth structure except theevery direction are to sound tooth structure except the
axial depth should only be 0.75mm.axial depth should only be 0.75mm.
 The 0.75mm axial wall depth will provide adequateThe 0.75mm axial wall depth will provide adequate
external wall width for :external wall width for :
1) Strength of the preparation wall1) Strength of the preparation wall
2) Strength of the composite2) Strength of the composite
3) Placement of a retention groove.3) Placement of a retention groove.
 If retention grooves are necessary they are prepared withIf retention grooves are necessary they are prepared with
a no.1/4 bur along the full length of the gingivoaxial anda no.1/4 bur along the full length of the gingivoaxial and
incisoaxial line angles.incisoaxial line angles.

 These grooves are prepared 0.25mm in depth into theThese grooves are prepared 0.25mm in depth into the
external walls and next to the axial wall at an angle thatexternal walls and next to the axial wall at an angle that
bisects the junction between the axial wall and thebisects the junction between the axial wall and the
gingival or occlusal wall.gingival or occlusal wall.
 This should leave, between the groove and the marginThis should leave, between the groove and the margin
sufficient remaining wall dimension(0.25mm) to preventsufficient remaining wall dimension(0.25mm) to prevent
fracture. it is helpful while preparing the grooves tofracture. it is helpful while preparing the grooves to
observe that this remaining wall dimensions is equal toobserve that this remaining wall dimensions is equal to
half the diameter or the bur head ( which is 0.5mm).half the diameter or the bur head ( which is 0.5mm).

BEVELEDBEVELED
CONVENTIONAL CLASSCONVENTIONAL CLASS
V TOOTH PREPARATION:V TOOTH PREPARATION:
is indicated either for :is indicated either for :
1) the replacement of an1) the replacement of an
existing ,defective class Vexisting ,defective class V
restoration that initiallyrestoration that initially
used a conventionalused a conventional
preparation orpreparation or
2) for a large, new carious2) for a large, new carious
lesionlesion
The beveled conventionalThe beveled conventional
class V preparation intiallyclass V preparation intially
will exhibit 90-degreewill exhibit 90-degree
cavosurface margins (thatcavosurface margins (that
subsequently will besubsequently will be
beveled) and an axial wallbeveled) and an axial wall
that is uniform in depththat is uniform in depth

 The axial depth into dentin is only 0.2mm when retentionThe axial depth into dentin is only 0.2mm when retention
groove is judged unnecessary and 0.5mm when agroove is judged unnecessary and 0.5mm when a
retention groove is planned and the margin is still inretention groove is planned and the margin is still in
enamel.enamel.
 Groove retention usually is not indicated when theGroove retention usually is not indicated when the
periphery of the tooth preparation is located in enamel.periphery of the tooth preparation is located in enamel.
Many of these larger preparations will be a combinationMany of these larger preparations will be a combination
of beveled enamel margins and 90-degree root-surfaceof beveled enamel margins and 90-degree root-surface
(non enamel) margins, with the root surface areas having(non enamel) margins, with the root surface areas having
groove retention .groove retention .

 Advantages of beveled conventional preparation are :Advantages of beveled conventional preparation are :
1) Increase retention due to the greater surface area of1) Increase retention due to the greater surface area of
etched enamel afforded by the beveletched enamel afforded by the bevel
2) Decreased microleakage due to enhanced bond2) Decreased microleakage due to enhanced bond
between the composite and the toothbetween the composite and the tooth
3) Decreased need for groove retention form.3) Decreased need for groove retention form.

MODIFIED CLASS V TOOTH PREPARATIONMODIFIED CLASS V TOOTH PREPARATION
 Indicated for theIndicated for the
restoration of small andrestoration of small and
moderate class V lesionsmoderate class V lesions
or defects. The objectiveor defects. The objective
is to restore the lesion oris to restore the lesion or
defect as conservativelydefect as conservatively
as possible.as possible.
 The lesion or defect isThe lesion or defect is
“scooped out” resulting in“scooped out” resulting in
a preparation form thata preparation form that
may have a divergent wallmay have a divergent wall
configuration and an axialconfiguration and an axial
surface that usually in notsurface that usually in not
uniform in depthuniform in depth

CLASS V TOOTH PREPARATION FORCLASS V TOOTH PREPARATION FOR
ABRASION/EROSION LESIONSABRASION/EROSION LESIONS
 Also are used to restored abraded or eroded cervicalAlso are used to restored abraded or eroded cervical
areas.areas.
 Abrasion in the form of a notch, often V-shaped is a lossAbrasion in the form of a notch, often V-shaped is a loss
or wearing away of tooth structure due to mechanicalor wearing away of tooth structure due to mechanical
forces, such as strenous tooth brushing with a hardforces, such as strenous tooth brushing with a hard
bristle toothbrush or abrasive tooth paste.bristle toothbrush or abrasive tooth paste.

 Erosion often a saucer-Erosion often a saucer-
shaped notch occursshaped notch occurs
primarily as a result ofprimarily as a result of
chemical dissolution.chemical dissolution.
 Idiopathic erosion orIdiopathic erosion or
abfracture may occur asabfracture may occur as
a result of flexure of thea result of flexure of the
cervical area under heavycervical area under heavy
occlusal stresses,occlusal stresses,
beginning withbeginning with
microfracture of the thinmicrofracture of the thin
enamel tooth structureenamel tooth structure
occlusal of theocclusal of the
cementoenamel junctioncementoenamel junction
which when combinedwhich when combined
with abrasive toothwith abrasive tooth
brushing, could produce abrushing, could produce a
“notched” defect.“notched” defect.

 When notching occurs the operator first must decide, withWhen notching occurs the operator first must decide, with
input from the patient whether or not the area need to beinput from the patient whether or not the area need to be
restored. This decision is based on the considerationsrestored. This decision is based on the considerations
discussed in the following points:discussed in the following points:
1) Caries1) Caries
2) Gingival health2) Gingival health
3) Esthetics3) Esthetics
4) Sensitivity4) Sensitivity
5) Pulp protection5) Pulp protection
6) Tooth strength6) Tooth strength

PIT AND FISSURE SEALANTS, PREVENTIVE RESINPIT AND FISSURE SEALANTS, PREVENTIVE RESIN
AND CONSERVATIVE COMPOSITE RESTORATIONSAND CONSERVATIVE COMPOSITE RESTORATIONS
AND CLASS VI COMPOSITE RESTORATIONSAND CLASS VI COMPOSITE RESTORATIONS
 When no cavitated carious lesion is diagnosed, theWhen no cavitated carious lesion is diagnosed, the
treatment decision is either to pursue no treatment ortreatment decision is either to pursue no treatment or
place a pit-and-fissure sealant, particularly if the surfaceplace a pit-and-fissure sealant, particularly if the surface
is a high risk for future caries.is a high risk for future caries.
 If a small carious lesion is detected and the adjacentIf a small carious lesion is detected and the adjacent
grooves and pits, although sound at the present time,grooves and pits, although sound at the present time,
are at risk to caries in the future, a preventive fesinare at risk to caries in the future, a preventive fesin
restoration (PRR) or conservative composite restorationrestoration (PRR) or conservative composite restoration
(CCR) ( which combines a small class I composite with a(CCR) ( which combines a small class I composite with a
sealant) may be the treatment recommendation.sealant) may be the treatment recommendation.
 Before any of these treatment are initiated, the operatorBefore any of these treatment are initiated, the operator
must be certain that no interproximal (class II) caries ormust be certain that no interproximal (class II) caries or
fault exists.fault exists.

PIT-AND-FISSURE SEALANTSPIT-AND-FISSURE SEALANTS
 Pit and fissures typically result from an incompletePit and fissures typically result from an incomplete
coalescence of enamel and are particularly prone tocoalescence of enamel and are particularly prone to
caries. By using a low-viscosity fluid resin, these areascaries. By using a low-viscosity fluid resin, these areas
can be sealed, following acid-etching of the walls of thecan be sealed, following acid-etching of the walls of the
pits and fissures and a few millimeters of surface enamelpits and fissures and a few millimeters of surface enamel
bordering these faults.bordering these faults.
 Sealants are most effective in children when they areSealants are most effective in children when they are
applied to the pits and fissures of permanent posteriorapplied to the pits and fissures of permanent posterior
teeth immediately upon eruption of the clinical crowns.teeth immediately upon eruption of the clinical crowns.
Adults also can benefit form the use of sealants if theAdults also can benefit form the use of sealants if the
individual experiences a change in caries susceptibilityindividual experiences a change in caries susceptibility
because of a change in their diet or medical condition.because of a change in their diet or medical condition.

 Sealant materials are based on urethaneSealant materials are based on urethane
dimethacrylate or Bis-GMA resins. Tintsdimethacrylate or Bis-GMA resins. Tints
frequently are added to sealants to produce colorfrequently are added to sealants to produce color
contrast for visual assessment.contrast for visual assessment.
 Clinical studies also show that sealants can beClinical studies also show that sealants can be
applied even over small, cavitated lesions withapplied even over small, cavitated lesions with
no subsequent progression of caries. However itno subsequent progression of caries. However it
is recommended that sealants be used for theis recommended that sealants be used for the
prevention of caries rather than for the treatmentprevention of caries rather than for the treatment
of existing carious lesion.of existing carious lesion.
 Only caries-free pits and fissures or incipientOnly caries-free pits and fissures or incipient
lesions in enamel not extending to the DEJlesions in enamel not extending to the DEJ
currently are recommended for treatment withcurrently are recommended for treatment with
pit-and-fissure sealantspit-and-fissure sealants

 INDICATIONS FOR SEALANTS:INDICATIONS FOR SEALANTS:
The indications for sealants have been presented in ADAThe indications for sealants have been presented in ADA
and public health publications. Both sources indicate thatand public health publications. Both sources indicate that
regardless of age, caries risk of an individual should beregardless of age, caries risk of an individual should be
the major factor for selecting teeth for sealant applicationthe major factor for selecting teeth for sealant application
Sealants may be indicated for either preventive orSealants may be indicated for either preventive or
therapeutic uses, depending on the patient’s caries risk,therapeutic uses, depending on the patient’s caries risk,
tooth morphology, or presence of incipient enameltooth morphology, or presence of incipient enamel
caries.caries.
 CLINICAL TECHNIQUE: The isolation of the area isCLINICAL TECHNIQUE: The isolation of the area is
critical to the success of the sealant. Because sealantcritical to the success of the sealant. Because sealant
placement in younger patients is more common, theplacement in younger patients is more common, the
molar teeth are often not fully erupted, and thereforemolar teeth are often not fully erupted, and therefore
isolation is difficultisolation is difficult

 If proper isolation cannot be obtained the bond of theIf proper isolation cannot be obtained the bond of the
sealant material to the occlusal surface will besealant material to the occlusal surface will be
compromised, resulting in either loss of the sealant orcompromised, resulting in either loss of the sealant or
recurrent caries under the sealant.recurrent caries under the sealant.
 The tooth is rinsed thoroughly while the explorer tip isThe tooth is rinsed thoroughly while the explorer tip is
used carefully to help remove residual pumice orused carefully to help remove residual pumice or
additional debris.additional debris.
 After the area is dried, a liquid etchant (35% to 50%After the area is dried, a liquid etchant (35% to 50%
Phosphoric acid) may be placed on the occlusal surfacePhosphoric acid) may be placed on the occlusal surface
with a small sponge, brush, or applicator tip for 30with a small sponge, brush, or applicator tip for 30
seconds.seconds.
 Gel etchants, traditionally used for most restorativeGel etchants, traditionally used for most restorative
procedures, may have less ability to effectively penetrateprocedures, may have less ability to effectively penetrate
into the pits and fissuresinto the pits and fissures

Laser cleaning and etching is an alternative to traditionalLaser cleaning and etching is an alternative to traditional
techniques, but lasing units are not yet widely available intechniques, but lasing units are not yet widely available in
general practice.general practice.
 Next the tooth is rinsed with water for 20 seconds whileNext the tooth is rinsed with water for 20 seconds while
the area is evacuated and then dried of all visiblethe area is evacuated and then dried of all visible
moisture.moisture.
 The properly acid-etched enamel surface has a lightlyThe properly acid-etched enamel surface has a lightly
frosted appearancefrosted appearance
 Fluoride rich resistant enamel may need to be etchedFluoride rich resistant enamel may need to be etched
longer.longer.
 Any brown stains that originally may have been in theAny brown stains that originally may have been in the
pits/fissures may still be present and should be allowed topits/fissures may still be present and should be allowed to
remain.remain. www.indiandentalacademy.com

 The self-cured sealant is mixed and applied with a smallThe self-cured sealant is mixed and applied with a small
applicator provided in the sealant kit.applicator provided in the sealant kit.
 After the polymerization of the sealant the rubber dam isAfter the polymerization of the sealant the rubber dam is
removed and the occlusion is evaluated using articulatingremoved and the occlusion is evaluated using articulating
paper.paper.
 If necessary a round 12-bladed carbide finishing bur orIf necessary a round 12-bladed carbide finishing bur or
white stone is used to remove the excess.white stone is used to remove the excess.

CONSERVATIVE COMPOSITE ANDCONSERVATIVE COMPOSITE AND
PREVENTIVE RESIN RESTORATIONSPREVENTIVE RESIN RESTORATIONS
 When restoring small pits and fissures on an unrestoredWhen restoring small pits and fissures on an unrestored
tooth, an ultraconservative, modified preparation designtooth, an ultraconservative, modified preparation design
is recommended.is recommended.
 This design allows for restoration of the lesion or defectThis design allows for restoration of the lesion or defect
with minimal removal of tooth structure and often may bewith minimal removal of tooth structure and often may be
combined with the use of composite or sealant to sealcombined with the use of composite or sealant to seal
radiating noncarious fissures or pits that are at high riskradiating noncarious fissures or pits that are at high risk
for subsequent caries activity.for subsequent caries activity.
 Originally referred to as a preventive resin restoration,Originally referred to as a preventive resin restoration,
this type of ultraconservative restoration is termed athis type of ultraconservative restoration is termed a
conservative composite restoration ( CCR ) at theconservative composite restoration ( CCR ) at the
University of North Carolina.University of North Carolina.

 The critical factor in this clinical assessment isThe critical factor in this clinical assessment is
whether or not the suspicious pit or fissure iswhether or not the suspicious pit or fissure is
cavitated, therefore requiring restorativecavitated, therefore requiring restorative
intervention.intervention.
 After deciding that cavitation has occurred, itAfter deciding that cavitation has occurred, it
usually determined whether to use amalgam orusually determined whether to use amalgam or
composite.composite.
 Important factors realted to this decisionsImportant factors realted to this decisions
include:include:
1) ability to isolate the tooth or teeth1) ability to isolate the tooth or teeth
2) Occlusal relationship2) Occlusal relationship
3) Esthetics3) Esthetics
4) Operator ability4) Operator ability

Usually a CCR is the treatment of choice for the smallUsually a CCR is the treatment of choice for the small
occlusal restoration. The advantages of composite overocclusal restoration. The advantages of composite over
amalgam for such restorations are:amalgam for such restorations are:
1) conserving tooth structure1) conserving tooth structure
2) Enhancing esthetics2) Enhancing esthetics
3) Bonding tooth structure together3) Bonding tooth structure together
4) Sealing the prepared tooth structure4) Sealing the prepared tooth structure
 Including other suspicious areas on the occlusal surfaceIncluding other suspicious areas on the occlusal surface
with either the composite restorative material or a sealantwith either the composite restorative material or a sealant
materialmaterial..

CLASS VI COMPOSITE RESTORATIONSCLASS VI COMPOSITE RESTORATIONS
 One of the most conservativeOne of the most conservative
indications for a directlyindications for a directly
placed posterior composite isplaced posterior composite is
a small faulty developmentala small faulty developmental
pit located on a cusp tip.pit located on a cusp tip.
 The typical class VI toothThe typical class VI tooth
preparation should be aspreparation should be as
small in diameter and assmall in diameter and as
shallow in depth as possible.shallow in depth as possible.
 Enter the faulty pit with aEnter the faulty pit with a
small, round bur (no.1/4 orsmall, round bur (no.1/4 or
no.1/2) or diamond orientedno.1/2) or diamond oriented
perpendicular to the surfaceperpendicular to the surface
and extend pulpally toand extend pulpally to
eliminate the lesion.eliminate the lesion.

 Visual examination and probing with an explorer oftenVisual examination and probing with an explorer often
reveals that the fault is limited to enamel because thereveals that the fault is limited to enamel because the
enamel in this area is quite thick.enamel in this area is quite thick.
 If the preparation is not already completed at this stage,If the preparation is not already completed at this stage,
complete the preparation using either a flame-shaped orcomplete the preparation using either a flame-shaped or
round diamond instrument to roughen the preparedround diamond instrument to roughen the prepared
surfacessurfaces
 If a faulty restoration or extensive caries is present onIf a faulty restoration or extensive caries is present on
the cusp tip, a round bur of appropriate size is used forthe cusp tip, a round bur of appropriate size is used for
excavating remaining infected dentin.excavating remaining infected dentin.

INDICATIONS FOR COMPOSITEINDICATIONS FOR COMPOSITE
RESTORATIONS IN CLASSES I AND IIRESTORATIONS IN CLASSES I AND II
 Small and moderate restorations, preferably with enamelSmall and moderate restorations, preferably with enamel
margins.margins.
 Most premolar or first molar restorations, particularlyMost premolar or first molar restorations, particularly
when esthetics is considered.when esthetics is considered.
 A restoration that does not provide all of the occlusalA restoration that does not provide all of the occlusal
contacts.contacts.
 A restoration that does not have heavy occlusal contacts.A restoration that does not have heavy occlusal contacts.
 A restoration that can be appropriately isolated during theA restoration that can be appropriately isolated during the
procedure.procedure.
 Some restorations that may serve as foundations forSome restorations that may serve as foundations for
crownscrowns
 Some very large restorations that are used to strengthenSome very large restorations that are used to strengthen
remaining weakened tooth structure( for economic orremaining weakened tooth structure( for economic or
interim use reasons)interim use reasons)

CONTRAINDICATIONS FOR CLASS I AND IICONTRAINDICATIONS FOR CLASS I AND II
 When the operating site cannot be appropriately isolatedWhen the operating site cannot be appropriately isolated
 With heavy occlusal stressesWith heavy occlusal stresses
 With all the occlusal contacts only on compostiesWith all the occlusal contacts only on composties
 In restorations that extend onto the root surfaceIn restorations that extend onto the root surface

 CONVENTIONAL CLASS I TOOTH PREPARTION: forCONVENTIONAL CLASS I TOOTH PREPARTION: for
the large class I tooth preparation, enter the tooth in thethe large class I tooth preparation, enter the tooth in the
distal pit area of the faulty occlusal surface, with thedistal pit area of the faulty occlusal surface, with the
inverted cone diamond, positioned parallel to the longinverted cone diamond, positioned parallel to the long
axis of the crown.axis of the crown.
 Prepare the pulpal floor to an initial depth of 1.5mm asPrepare the pulpal floor to an initial depth of 1.5mm as
measured from the central groove. Once the centralmeasured from the central groove. Once the central
groove area is removed, the facial or lingualgroove area is removed, the facial or lingual
measurement of this depth will be greater, usually aboutmeasurement of this depth will be greater, usually about
1.75 mm but this depends on the steepness of the1.75 mm but this depends on the steepness of the
cuspal inclinescuspal inclines..

 Preserve the strength of the cuspal and marginal ridge areas asPreserve the strength of the cuspal and marginal ridge areas as
much as possible. Even though the final bonded compositemuch as possible. Even though the final bonded composite
restoration will help restore some of the strength of weakened,restoration will help restore some of the strength of weakened,
unprepared facial, lingual, mesial, or distal tooth structure, theunprepared facial, lingual, mesial, or distal tooth structure, the
outline form should be as conservative as possible in theseoutline form should be as conservative as possible in these
areas.areas.
 Extensions into marginal ridges should result in approximately aExtensions into marginal ridges should result in approximately a
1.6mm thickness of remaining tooth structure (measured form1.6mm thickness of remaining tooth structure (measured form
the internal extension to the proximal height of contour) forthe internal extension to the proximal height of contour) for
premolars and approximately 2 mm for molarspremolars and approximately 2 mm for molars

As the diamond is moved along the central groove, theAs the diamond is moved along the central groove, the
resulting pulpal floor is usually flat and follows the riseresulting pulpal floor is usually flat and follows the rise
and fall of the DEJ. If extension is required toward theand fall of the DEJ. If extension is required toward the
cusp tips, the same approximate 1.5mm depth iscusp tips, the same approximate 1.5mm depth is
maintained, usually resulting in the pulpal floor risingmaintained, usually resulting in the pulpal floor rising
occlusally.occlusally.
 Once a groove extension is through the cusp ridge, theOnce a groove extension is through the cusp ridge, the
diamond prepares the facial (or lingual) portion of thediamond prepares the facial (or lingual) portion of the
faulty groove at an axial depth of 0.2 mm inside the DEJ,faulty groove at an axial depth of 0.2 mm inside the DEJ,
and gingivally to include all of the fault. Either the side orand gingivally to include all of the fault. Either the side or
the tip of the diamond may be used for the facial orthe tip of the diamond may be used for the facial or
lingual surfaced extension.lingual surfaced extension.

 After extending the outline form to sound tooth structure,After extending the outline form to sound tooth structure,
if any caries or old restorative material remains on theif any caries or old restorative material remains on the
pulpal floor, it should be removed with the diamond or apulpal floor, it should be removed with the diamond or a
round bur.round bur.
 Even though the occlusal margin does not have aEven though the occlusal margin does not have a
beveled or flared form it is left as prepared. No attempt isbeveled or flared form it is left as prepared. No attempt is
made to place additional beveling on the occlusal marginmade to place additional beveling on the occlusal margin
because it may result in thin composite in areas of heavybecause it may result in thin composite in areas of heavy
occlusal contact.occlusal contact.
 Also the inverted cone diamond results in occlusal wallsAlso the inverted cone diamond results in occlusal walls
that converge occlusally, thereby enhancing retentionthat converge occlusally, thereby enhancing retention
form. Because of the occlusal surface enamel rodform. Because of the occlusal surface enamel rod
direction, the ends of the enamel rods are alreadydirection, the ends of the enamel rods are already
exposed by the preparation which further reduces theexposed by the preparation which further reduces the
need for occlusal bevels. The marginal form of a grooveneed for occlusal bevels. The marginal form of a groove
extension on the facial or lingual surcace, may beextension on the facial or lingual surcace, may be
beveled with the diamond resulting in a 0.25 to 0.5mmbeveled with the diamond resulting in a 0.25 to 0.5mm
width bevel at a45-degree angle to the prepared wall.width bevel at a45-degree angle to the prepared wall.

 MODIFIED CLASS I TOOTH PREPARATION: minimallyMODIFIED CLASS I TOOTH PREPARATION: minimally
involved class I lesions or faults may be restored withinvolved class I lesions or faults may be restored with
composite using modified tooth preparations.composite using modified tooth preparations.
 These preparations are less specific in form, having aThese preparations are less specific in form, having a
scooped out appearance. Typically they are preparedscooped out appearance. Typically they are prepared
with a small round or inverted cone diamond.with a small round or inverted cone diamond.
 The initial depth is still 1.5mm or approximately 0.2 mmThe initial depth is still 1.5mm or approximately 0.2 mm
inside the DEJ but may not be uniform.inside the DEJ but may not be uniform.
 If a round diamond is used the resulting cavosurfaceIf a round diamond is used the resulting cavosurface
margin angle may be more flared than if an invertedmargin angle may be more flared than if an inverted
cone diamond were used.cone diamond were used.

CLINICAL TECHNIQUE FOR DIRECT CLASS IICLINICAL TECHNIQUE FOR DIRECT CLASS II
 TOOTH PREPARATION: the tooth preparation for aTOOTH PREPARATION: the tooth preparation for a
class II composite restoration may be either aclass II composite restoration may be either a
conventional or modified preparation design.conventional or modified preparation design.
 The modified design is for small restorations, generallyThe modified design is for small restorations, generally
using smaller diamond instruments and resulting in ausing smaller diamond instruments and resulting in a
preparation form that is more rounded less box like, andpreparation form that is more rounded less box like, and
less uniform extension in extension or depth.less uniform extension in extension or depth.
 The other predominant preparation design is similar toThe other predominant preparation design is similar to
the conventional preparation for an amalgam restoration.the conventional preparation for an amalgam restoration.
 The design results in a preparation form that is moreThe design results in a preparation form that is more
boxlike, has uniform pulpal and axial depths, and hasboxlike, has uniform pulpal and axial depths, and has
some preparation walls prepared perpendicular tosome preparation walls prepared perpendicular to
occlusal forcesocclusal forces www.indiandentalacademy.com

 CONVENTIONAL CLASS IICONVENTIONAL CLASS II
TOOTH PREPARATION:TOOTH PREPARATION:
OCCLUSAL STEP: theOCCLUSAL STEP: the
occlusal portion of theocclusal portion of the
class II preparation isclass II preparation is
prepared similarly asprepared similarly as
described for the class Idescribed for the class I
prepartionprepartion
PROXIMAL BOX: ThePROXIMAL BOX: The
extent of the carious lesionextent of the carious lesion
or amount of old restorativeor amount of old restorative
material are two factorsmaterial are two factors
that dictate the facial,that dictate the facial,
lingual, and gingivallingual, and gingival
extension of the proximalextension of the proximal
box of the preparationbox of the preparationwww.indiandentalacademy.com

Although it is not required to extend the proximal boxAlthough it is not required to extend the proximal box
beyond contact with the adjacent tooth (i.e providebeyond contact with the adjacent tooth (i.e provide
clearance with the adjacent tooth), it may simplify theclearance with the adjacent tooth), it may simplify the
preparation, matrix, composite insertion, and contouringpreparation, matrix, composite insertion, and contouring
procedures. However if all of the fault can be removedprocedures. However if all of the fault can be removed
without extending the proximal preparation beyond thewithout extending the proximal preparation beyond the
contact, the restoration of the proximal contact with thecontact, the restoration of the proximal contact with the
composite will be simplifiedcomposite will be simplified
 Once the diamond has extended through the marginalOnce the diamond has extended through the marginal
ridge be careful not to cut the adjacent tooth, theridge be careful not to cut the adjacent tooth, the
proximal ditch cut is initiated.proximal ditch cut is initiated.
 Hold the diamond over the DEJ with the tip of theHold the diamond over the DEJ with the tip of the
diamond positioned to create a gingivally directed cut thatdiamond positioned to create a gingivally directed cut that
will be 0.2mm inside the DEJ.will be 0.2mm inside the DEJ.

For a no.245 diamond instrument with a tip diameter ofFor a no.245 diamond instrument with a tip diameter of
0.8mm this would require one fourth of the diamond’s tip0.8mm this would require one fourth of the diamond’s tip
positioned over the dentin side of the DEJ (the otherpositioned over the dentin side of the DEJ (the other
three fourths of the tip over the enamel).three fourths of the tip over the enamel).
 The diamond is then extended facially lingually andThe diamond is then extended facially lingually and
gingivally to include all the faults, caries, old restorativegingivally to include all the faults, caries, old restorative
material.material.
 During this entire cutting the diamond is held parallel toDuring this entire cutting the diamond is held parallel to
the long axis of the tooth crown.the long axis of the tooth crown.
 The facial and lingual margins are extended asThe facial and lingual margins are extended as
necessary and should result in at least a 90-degreenecessary and should result in at least a 90-degree
margin, more obtuse being acceptable as well.margin, more obtuse being acceptable as well.

 If the preparation is conservative use a smaller, thinnerIf the preparation is conservative use a smaller, thinner
diamond instrument to complete the facial and lingualdiamond instrument to complete the facial and lingual
wall formation avoiding contact with the adjacent tooth.wall formation avoiding contact with the adjacent tooth.
 The gingival floor is prepared flat with an approximatelyThe gingival floor is prepared flat with an approximately
90-degree cavosurface margin. Gingival extension should90-degree cavosurface margin. Gingival extension should
be as minimal as possible trying to maintain an enamelbe as minimal as possible trying to maintain an enamel
margin.margin.
 The axial wall should be 0.2mm inside the DEJ and hav aThe axial wall should be 0.2mm inside the DEJ and hav a
slight outward convexity.slight outward convexity.
 For large carious lesions, additional axial wall cariesFor large carious lesions, additional axial wall caries
excavation may be necessary later during final toothexcavation may be necessary later during final tooth
preparationpreparation

 At this point the initial tooth preparation is complete. If noAt this point the initial tooth preparation is complete. If no
infected dentin remains and no proximal beveling isinfected dentin remains and no proximal beveling is
indicated the final preparation also is consideredindicated the final preparation also is considered
complete at this time.complete at this time.
 Because the composite will be retained byBecause the composite will be retained by
micromechanical retention, no secondary preparationmicromechanical retention, no secondary preparation
retention features are necessary.retention features are necessary.
 If an inverted cone diamond has been used, the facialIf an inverted cone diamond has been used, the facial
and lingual occlusal walls will be convergent occlusallyand lingual occlusal walls will be convergent occlusally
adding to retention form.adding to retention form.
 No bevels are placed on the cavosurface marginNo bevels are placed on the cavosurface margin
especially the occlusal margins.especially the occlusal margins.
 Bevels are not placed on facial and lingual walls of theBevels are not placed on facial and lingual walls of the
proximal box .proximal box .

However bevels can be placed on the proximal facial andHowever bevels can be placed on the proximal facial and
lingual margins if the proximal box is already widelingual margins if the proximal box is already wide
faciolingually and if it is determinde that additionalfaciolingually and if it is determinde that additional
retention form may be necessary.retention form may be necessary.
 Such bevels will increase the surface area and exposeSuch bevels will increase the surface area and expose
enamel rod ends, thereby improving retention.enamel rod ends, thereby improving retention.
 Proximal bevels should not be placed if excessiveProximal bevels should not be placed if excessive
extension of the margins is required.extension of the margins is required.
 A bevel is not usually placed on the gingival cavosurfaceA bevel is not usually placed on the gingival cavosurface
margin although it may be necessary to remove anymargin although it may be necessary to remove any
unsupported enamel rods at the margin because of theunsupported enamel rods at the margin because of the
ginigival orientation of the enamel rods.ginigival orientation of the enamel rods.

 For most class IIFor most class II
preparations this margin ispreparations this margin is
already approaching thealready approaching the
DEJ and therefore theDEJ and therefore the
enamel is thin.enamel is thin.
 Care is taken to maintainCare is taken to maintain
any enamel in this area toany enamel in this area to
result in a preparation withresult in a preparation with
all enamel margins.all enamel margins.
 Usually the only remainingUsually the only remaining
final tooth preparationfinal tooth preparation
procedure that may beprocedure that may be
necessary is additionalnecessary is additional
excavation of infectedexcavation of infected
dentin on either the pulpaldentin on either the pulpal
floor or axial wall.floor or axial wall.

 Thus the conventional class II composite toothThus the conventional class II composite tooth
preparation is similar to that for amalgam except nopreparation is similar to that for amalgam except no
secondary retention features are incorporated, thesecondary retention features are incorporated, the
extensions are less, and there is no requirement for aextensions are less, and there is no requirement for a
90-degree composite margin, unless the preparation is90-degree composite margin, unless the preparation is
extended onto the root surface.extended onto the root surface.
 MODIFIED CLASS II TOOTH PREPARATION: a smallMODIFIED CLASS II TOOTH PREPARATION: a small
round or inverted cone diamond may be used for thisround or inverted cone diamond may be used for this
preparation to scoop out the carious or faulty material.preparation to scoop out the carious or faulty material.
 This scooped appearance occurs on both the occlusalThis scooped appearance occurs on both the occlusal
and proximal portions.and proximal portions.
 The pulpal axial depths are dictated only by the depth ofThe pulpal axial depths are dictated only by the depth of
the lesion and are not necessarily uniformthe lesion and are not necessarily uniform

 The proximal extensions likewise are dictatedThe proximal extensions likewise are dictated
only by the extent of the lesion.only by the extent of the lesion.
 Another modified design is the box-only toothAnother modified design is the box-only tooth
preparation. This design is indicated only thepreparation. This design is indicated only the
proximal surface is faulty, with no lesions on theproximal surface is faulty, with no lesions on the
occlusal surface.occlusal surface.
 A proximal box is prepared either an invertedA proximal box is prepared either an inverted
cone or round diamond held parallel to the longcone or round diamond held parallel to the long
axis of the tooth crown.axis of the tooth crown.

 The diamond is extended through the marginal ridge in aThe diamond is extended through the marginal ridge in a
gingival direction.gingival direction.
 The axial depth is prepared 0.2mm inside the DEJThe axial depth is prepared 0.2mm inside the DEJ
 The facial ,lingual, and gingival extensions are dictated byThe facial ,lingual, and gingival extensions are dictated by
the fault or caries.the fault or caries.
 No beveling and secondary retention is indicated.No beveling and secondary retention is indicated.

CONCLUSIONCONCLUSION
 An interpretation of esthetics primarily is determined byAn interpretation of esthetics primarily is determined by
an individual’s perception and is subject to widean individual’s perception and is subject to wide
variations.variations.
 What is pleasing for one patient may be completelyWhat is pleasing for one patient may be completely
unacceptable to another.unacceptable to another.
 It is the dentist’s responsibility to present all logicalIt is the dentist’s responsibility to present all logical
restorative alternatives to a patient, but the patientrestorative alternatives to a patient, but the patient
should be given an opportunity to help make the finalshould be given an opportunity to help make the final
decision regarding which alternative will be slected.decision regarding which alternative will be slected.

REFERENCESREFERENCES
 STURDEVANT’S ART&SCIENCE OF OPERATIVESTURDEVANT’S ART&SCIENCE OF OPERATIVE
DENTISTRY 4DENTISTRY 4THTH
EDITIONEDITION
 ESTHETIC DENTISTRY ASCHEIM AND DALEESTHETIC DENTISTRY ASCHEIM AND DALE
 FUNDAMENTALS OF OPERATIVE DENTISTRY 2 NDFUNDAMENTALS OF OPERATIVE DENTISTRY 2 ND
EDITON RICHARD S SCHWARTZEDITON RICHARD S SCHWARTZ
 INTERNET SOURCESINTERNET SOURCES

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