2. [Type text]
2
Dentalcompositeresins
are types of synthetic resins which are used in dentistry as
restorative material or adhesives.
Synthetic resins evolved as restorative materials since they
were insoluble, aesthetic, and insensitive to dehydration and
were inexpensive.
It is easy to manipulate them as well.
Composite resins are most commonly composed of Bis-GMA
monomers or some Bis-GMA analog, a filler material such as
silica and in most current applications, a photoinitiator.
Dimethacrylates are also commonly added to achieve certain
physical properties such as flowability.
Further tailoring of physical properties is achieved by
formulating unique concentrations of each constituent.
3. [Type text]
3
Historyof use
Initially, composite restorations in dentistry were very prone
to leakage and breakage due to weak compressive strength
In the 1990s and 2000s, composites were greatly improved
and are said to have a compression strength sufficient for
use in posterior teeth.
Today's composite resins have low polymerization shrinkage
and low coefficients of thermal shrinkage, which allows
them to be placed in bulk while maintaining good
adaptation to cavity walls.
The placement of composite requires meticulous attention to
procedure or it may fail prematurely
ADA STATEMENT ON
POSTERIOR RESIN-BASED
COMPOSITES
1.composites used successfully till date in
o CLASS V RESTORATIONS.
4. [Type text]
4
o RESTORINGESTHETICALLYIMPORTANT
AREAS.
o IN PATIENTSALLERGICOR SENSITIVE
TO METALS.
2.other places where composites can be
used are
o PIT AND FISSURESEALING.
o PREVENTIVERESIN RESTORATIONS.
o INITIALCLASS I AND II LESIONS.
MODERATE-SIZED CLASS I AND II
RESTORATIONS
3.LITERATURE DOES NOT
SUPPORT THE SUCCESFULL
USE IN
o TEETHWITHHEAVYOCCLUSALSTRESS.
o IN SITESTHAT CAN’T BE ISOLATED.
IN PATIENTSALLERGICTO RESIN-BASED
COMPOSITES.
5. [Type text]
5
4.FUTURE RESEARCH IN
COMPOSITESSHOULD
ADDRESS
o REDUCTIONIN POLYMERIZATION
SHRINKAGE.
o IMPROVED DENTIN/ENAMELBONDING
TECHNIQUES.
o IMPROVED PLACEMENT AND
INSTRUMENTATION TECHNIQUES.
o IMPROVED CURING METHODS.
o CONTACT WEAR BEHAVIOR.
o POLYMERIZATIONINITIATORS.
o ALTERNATIVEMATRIX SYSTEMS.
o MORE EXTENSIVERESTORATIONS??
CASE SELECTION
Cavity preparationdesign
Locationof margin
6. [Type text]
6
Locationof restoration
Sizeof restoration
OCCLUSIONCONCERNS/ANTAGONISTICCUSP:
o GREATLYAFFECTS DEGRADATION OF
COMPOSITE.
o INCREASEDLOCALIZEDWEAR ON THE
COMPOSITE SURFACE WITHINCREASED
CONTACT AREA.
o INCREASEDGENERALIZED WEARON
THE CONTACT FREEAREA.
o BULK FRACTURE AND MARGINAL
DETERIORATION.
ANTAGONISTICCUSP:
o PRE-OP: USE OF ARTICULATINGPAPER.
o DESIGNOUTLINE FORM TO AVOID
CONTACT AREA.
7. [Type text]
7
o MODIFYTHE OPPOSINGCUSP TO
REDIRECT THE CONTACT AREAAWAY
FROM RESTORATION.
o ENAMELOPLASTYOF OPPOSINGCUSP TO
FLATTENTHE OCCLUSALLOAD OVER A
WIDERAREA.
MATERIAL OPTIONS
HYBRIDRESIN
MICROFILL ED RESIN
HYBRIDRESIN INTERNAL& MICROFILL
RESIN ON OUTER 1 MM.
PACKABLERESIN
PACKABLERESINWITHMICROFILLON
OUTER 1 MM.
CLINICAL TECHNIQUE
ISOLATION
RECOMMENDATIONS
8. [Type text]
8
RubberDam Isolationis Mandatory:
o Failureto maintaina dryfieldwillresultin
clinicalfailure.
o Preventionof moisturecontaminationand
protectionof gingivaltissues is of paramount
importance.
o Selectshadebeforerubberdam application.
Dentinshadeup to the DEJ level.
Incisal or enamelshadefor finalincrement.
PRE-WEDGING
Gains interproximalseparationto facilitatetight
contactarea.
INITIAL: 90 um movement.
AFTER 30 SECONDS:
o 30 um is lost.
90% RECOVERY: within30 seconds
removalof wedge.
CAVITYPREPARATION
9. [Type text]
9
ADHESIVE PREPARATION FOR POSTERIOR
COMPOSITES
DIFFERSFROM TRADITIONAL AMALGAM
PREPARATIONSIN MANY WAYS.
PREPARATION IS SHALLOWER.
RETENTIONIS PROVIDEDTHROUGH
BONDING
PREPARATION IS NARROWER:
o 1. LESS OCCLUSALCONTACT AREA.
o 2. REDUCESWEAR.
o 3. DECREASES AFFECT OF
POLYMERIZATION SHRINKAGE.
o 4. IMPROVED MARGINALINTEGRITY.
o 5. LESS CUSPALDEFLECTION.
PREPARATION HAS ROUNDEDINTERNALLINEANGLES:
o 1. CONSERVES TOOTHSTRUCTURE.
10. [Type text]
10
o 2. DECREASES STRESSCONCENTRATION.
o 3. ENHANCES RESINADAPTATION
DURING PLACEMENT.
NO EXTENSIONFORPREVENTION:
o 1. OCCLUSALSURFACEIS INVADED
ONLY IF CARIES DICTATES IT.
o 2. TREAT ADJACENT PITSAND FISSURES
WITHSEALANTS.
PROXIMAL BOX
PREPARATIONCONCERNS
SLOT PREPARATIONS:
o MECHANICALRETENTIONISN’T
IMPORTANT.
o DON’T EXTEND THEPREPARATION
BEYOND THEMARGINAL RIDGEBY
MORE THAN 2 MM.
11. [Type text]
11
GINGIVAL MARGIN
CONCERNS
SLOT PREPARATION OR CONVENTIONAL CLASSII PREP:
o GINGIVALFLOOR EXTENDED ONLY TO
DEPTHOF CARIOUSLESION.
o CONSERVEENAMELFOR BONDING AND
MICROLEAKAGEPREVENTION.
OCCLUSAL MARGIN OF
PREPARATION
o BEVELED OCCLUSALCAVOSURFACE
MARGIN:
o SIGNIFICANTLYINCREASES THEWEAR
RATE COMPAREDTO CONVENTIONAL
BUTT JOINT CAVOSURFACEMARGINS.
o WHY? THEBU-LIDIMENSION IS
INCREASEDAND INFLUENCES THE
AFFECT OF THE ANTAGONISTICCUSP
PULPAL PROTECTION
12. [Type text]
12
Postoperativesensitivity concerns:
o effects of polymerizationcontractionand/or
marginalleakagewithbacterialinvasion.
o Hermetically sealthe dentinwithyourchoiceof
dentinbonding agent material.
o Placea light curableresinmodifiedglass ionomer
cement that has the fluoridereleasingproperties
you may desire.
DENTIN/ENAMEL BONDING
AnotherClinicalDecisionto Make:
o yourchoiceof one of the currently availabledentin
bondingagents followingthe manufacturer’s
instructions.
CRITERIA FOR MATRICES
RE-ESTABLISHCONTOUR
FORM POSITIVECONTACT
SEAL GINGIVALMARGIN
ALLOW ADEQUATE BULK OF MATERIAL
13. [Type text]
13
LIMITEDTHICKNESS
PRODUCESMOOTHSURFACE
CRITERIA FOR MATRICES
PERMIT NON-DISRUPTIVEWITHDRAWAL
MUST AVOIDTOOTH DISTORTING
PRESSURES
MUST BE EASY TO PLACE
ALLOW FOR A VARIETY OF RESTORATIVE
MATERIALS
COMPOSITE PLACEMENT
TECHNIQUES
1.SEGMENTALPLACEMENT: < 5.0 MM.
14. [Type text]
14
o 1. FLOWABLERESIN(0.5-1.0MM LAYER)
o 2. DENTINSHADEOF PACKABLERESIN.
NO MORE THAN 3.0-3.5MM
INCREMENTS.
o 3. TINT PLACEMENT (OPTIONAL).
o 4. ENAMELSHADE(UNIVERSAL
HYBRID)
2.BULKFILLTECHNIQUE:
o A MAJOR CLAIMOF PACKABLE
COMPOSITE MANUFACTURERS.
o Incrementsshouldbe no greaterthan2mm to
obtaina uniformand maximumcure.
o Increasecavitydepthresultedin decreased
effectivenessof polymerizationforall exposure
times.
o Increasedexposuretimeresultedin an increased
hardnessratio and effectivepolymerizationat
depths of 3-4 mm.
15. [Type text]
15
THREE-SITED
LIGHT CURING
TECHNIQUE
FIRSTINCREMENT:
o CURED THROUGHTHELIGHT-
REFLECTINGWEDGE IN A GINGIVAL-
PROXIMALDIRECTION.
LARGER 2ND
and 3RD
INCREMENT:
o CURED FROM BUCCALAND LINGUAL.
o ENSURESSHRINKAGE VECTORS
TOWARD THECAVITY MARGINS.
FINALINCREMENT:
16. [Type text]
16
o ADDED TO THE OCCLUSALASPECT.
FINISHING PROCEDURES
12-B BLADETO REMOVEINTERPROXIMAL
GINGIVALEXCESS.
FINE-DIAMOND FINISHINGSTRIPS.
ALUMINUM OXIDEFINISHINGDISCS.
CARBIDE FINISHINGBURS.