Post on 14-Jun-2015
Introduction
I. Class 1 Direct Composite Restoration
Preparation design:Conventional (class I,II,V) in amalgam/90˚or buttjointModified (classV)Bevealed conventional (rarely used)
I. Class 1 Direct Composite Restoration
B. Inverted cone with rounded caries
Provide flat floorsProduces a more stronger margin on
the occlusal cavosurfaceCreates preparation walls that
converge occlusally Occlusally more conservative facial –
lingual preparation width
Class II Conventional direct composite
A. Occlusal preparation:330 or 245 diamond made parallel to
the long axis of the tooth.Pulpal depth is 1.5 mm from the
central groove (about 0.2mm in dentin); follows the rise and fall of DEJ mesiodistally but relatively flat faciolingually.
Class II Conventional direct composite
B. Proximal Box:Facial, lingual and gingival extensions
dictated by extend of caries or old restoration; may not be extended beyond the contact with the adjacent tooth.
Walls at 90˚, axial wall to 0.2mm in dentin
Gingival floor flat with minimal extension
Retained by micromechanical retention, no secondary retention necessary.
III. Class VI Composite Restoration
A. Preparation designThe typical class VI tooth preparation
should be as small in diameter and as shallow in depth as possible.
B. Flame - shape or round diamond
Either a flame-shaped or round diamond instrument to roughen the prepared surfaces.
Indirect tooth colored Restoration
Indications:EstheticLarge defects or previous
restorationsEconomic factors
Contraindications: Heavy occlusal forcesInability to maintain a dry fieldDeep subgingival preparation
Definition of terms
Indirect:Inlay
- restoration of metal, porcelain/ceramic or composite made to fit a tapered cavity preparation and luted into it by a cementing medium.
Onlay (overlay) - an inlay that includes the restoration of
all of the cusp of a tooth.
Definition of terms
Taper -permits an unobstructed removal of the
wax pattern and subsequent seating of the material. The wax pattern should be removed from the tooth without distortion.
TaperIntracoronal
-divergence from the floor of the preparation outwards.
Definition of terms
Extracoronal - converge from the cervical to the
occlusal or incisal surface.●shallow cavities (vertical walls unusually short)
Requires minimal taper of 2˚ occlusal divergence to enhance resistance and retention.
●deep cavities (increased gingivo-occlusal height of vertical walls)
As much as 5˚ taper to facilitate:Pattern withdrawal, trail seating and
cementing of restoration
Types of restorative materials
Laboratory-processed inlays and onlaysCeramic inlays and onlaysMachinable ceramics or
CAD/CAMFeldspathic porcelainHot-pressed ceramic
Laboratory-processed inlays and onlays
Polymerized under pressure, vacuum, inert gas, intense light, heat, or a combination of these devices to optimize physical properties of composite resins.More resistant to occlusal wear vs direct
composites but less wear resistance than ceramics.Easily adjusted, low wear of opposing
teeth good esthetics and has potential for repair.
Laboratory-processed inlays and onlays
Indications:If maximum resistance is desired
from composite restoration.Achievement of proper contour and
contacts would be difficult with direct composite.If ceramic restoration is
contraindicated because of wear of opposing dentition.
Advantages of heat cured composite inlay/onlay
restorationImproved physical properties/durability and
wear resistance compared to direct composite systems.Depth of cure not a problem unlike with direct
composite where there is limited depth of cure.Excellent marginal adaptation since the luting
composite fills any marginal contraction gap present.Non-extent polymerization shrinkage except in
luting resin cement.Post-operative sensitivity seldom encounetered
Ceramic inlays and onlays
Esthetics, durable, improved materials, fabrication techniques, adhesives and non based luting agents.
Fabrication steps for ceramic inlays and
onlaysAfter tooth preparation, an impression
is made and a “master” working cast is poured of die stone.The die is duplicated and poured with
a refractory investment capable of withstanding porcelain firing temperatures. The duplication method must result in the master die and the refractory die being accurately interchangable.
Fabrication steps for ceramic inlays and
onlaysPorcelain is added into the preparation
area of the refractory die and fired in an oven. Multiple increments and firings are necessary to compensate for sintering shrinkage.The ceramic restoration is recovered
from the refractory die, cleaned of all investment, and seated on the master die and working cast for final adjustments and finishing.
Feldspathic porcelain
Partially crystalline minerals (feldspar, silica, alumina) dispersed in a glass matrix.Porcelain restorations are made from
finely ground ceramic powders that are mixed with distilled water or a special liquid, shaped into the desired form, then fired and fused together to form a translucent material that looks like tooth structure.
Feldspathic porcelain
Some ceramic inlays and onlays are fabricated in the dental laboratory by firing dental porcelains on refractory dies.
Advantage: Low start-up cost
Disadvantage: its technique sensitivity
Hot Pressed Glass ceramics
Glass could be modified with nucleating agents and on heat treatment, be changed into ceramics with organized crystalline forms.Such “glass ceramics” were
stronger, had a higher melting point than non crystalline glass, and had variable coefficients of thermal expansion.
Hot Pressed Glass ceramics
Advantages:Similarity to traditional “wax-up” processesExcellent marginal fitRelatively high strengthThe surface hardness and occlusal wear of
these ceramics are similar to those of enamel.Stronger than porcelain inlays made on
refractory dies, they are still quite fragile until cemented.
Hot Pressed Glass ceramics
Disadvantges:its translucency, which
necessitated external application of all shading.Not significantly stronger than
fired feldspathic porcelains they do seem to provide better clinical service.
Chronological Events of Restorative
MaterialsHistory
First recommended over 25 years ago for posterior use.
1907 – cast gold1908 – silicate cement
First direct tooth colored restorative material.Disadventage:
Insoluble to oral fluid
Chronological Events of Restorative
Materials1950 – bonding agents1955 – acid etching by
Micheal J. Buonocore
1960 – sealants1962 – composite resin
-direct filled restorative material
Chronological Events of Restorative
Materials1962 – composite resin
According to the size of the filler:
Macrofill – for class V (problem: abfraction)
Microfill – anterior restorationHybrid
Microhybrid compositeNanofilled composite
Chronological Events of Restorative
Materials1962 – composite resin
Two types of composite:1. Packable composite
alternative to amalgam Supplied: unit dose, compules or in syringeHigher filler loading
FibersPorous filler particles Irregular filler particlesViscosity modifiers
Chronological Events of Restorative
Materials1962 – composite resin
Advantages:Produce acceptable class II restorationHigh depth of cure possibleBulk fill techniqueFiller loading: 80%Medium to high strengthHigh stiffnessLow wear rate: 3.5um/yearMolecules of elasticity :similar to amalgam
Chronological Events of Restorative
Materials1962 – composite resin
Disadvantages:New techniqueLess polishableLimited shadesIncreased post-operative sensitivityIncreased sensitivity to ambient light
Chronological Events of Restorative
Materials1962 – composite resin
Recommended uses:Class I restorationClass II restoration
Chronological Events of Restorative
Materials1962 – composite resin
2. Flowable compositesLow viscosity compositesLow filler contentIdeal for cervical lesionIdeal for non stress bearing areaIdeal for first increment in Class I
composite
Chronological Events of Restorative
Materials1962 – composite resin
Advantages:Syringeable Dispensed directly into cavityAdequate strength
Disadvantages:Higher polymerization shrinkageGreater potential for microleakageLow wear resistance
Chronological Events of Restorative
Materials1968 – Glass ionomer cement
Different types:Luting or cementing
mediumLiner or baseRestorative material
Chronological Events of Restorative
Materials1970 – microfill “polishable”
composite1973 – ultraviolet light1977 – microfill composite
Advantages: polishability, wear and resistance and color stabilityDisadvantages: low flexural/tensil
strength, localized wear and thus limited uses posteriorly.
Chronological Events of Restorative
Materials1978 – visible light curing
composite
Mid 1980’s hybrid:Hybrid – 0.04-3um particle size
rangeExamples: brands of hybrid
HerculitePrisma APHP-30
Chronological Events of Restorative
MaterialsMid 1980’s hybrid
Intended for universal use
Disadvantage of hybrid:Generalized wear
Chronological Events of Restorative
MaterialsMid 1980’s microhybrid:
Microhybrid – 0.6-0.7um particle size range
Examples: brands of microhybridPrisma TPHHerculite XRVCharisma Tetric ceram
Chronological Events of Restorative
MaterialsMid 1980’s microhybrid:
Advantages:Excellent physical propertiesGood finishing and polishing
characteristicsRelatively non sticky materials
Disadvantage:Do not hold a high polish over time
Chronological Events of Restorative
Materials1985 – CEREC ceramic system
1991 – CEREC 1 as modified by siemens 1994 – CEREC 2 with an upgrade
dimensional camera2000 – CEREC 3 with split
acquisition/design
CEREC
Chairside Economical Restoration of Esthetic Ceramiics
Chronological Events of Restorative
Materials1986 – Heliomolar
The sole exception to the microfill group of resins that were introduced for posterior use.70% filled anterior/posterior
microfill resin. very good wear characteristicLess than perfect esthetics
Thank you!