RECENT ADVANCES IN COMPOSITES

DR PRASHANT

CLASSIFICATONMonomers for reduced shrinkage/stress Monomers for enhanced cure& properties Hydrophobic monomers Anticariogenic monomers Bioactive materials Surface coatings Direct posterior composites Indirect posterior composites Fiber reinforced composites Nano fillers

MONOMERS FOR REDUCED SHRINKAGE

Spiro-ortho-carbonates.(1970) Polyol with oxirane. Vinylcyclopropanes(VCP)(1997) Polybutadiene rubber polymer(1999) Methacrylated styrene allyl alchol(mssa)1997

MONOMERS FOR ENCHANCED CURE & PROPERTIES 30wt%PEG600 DMA. BPA-mixed with TEGDMA-1999 Benzyl methacrylate and laurayl methacrylate added to BisGma/TEGDMA. Chain transfer agent propanol and diacetyl added to Bis-GMA/UDMA. ormocers

HYDROPHOBIC MONOMERSAddition of fluorine and phenyl to central carbon 10 methacryl oxidecyl trimethoxysilane Phenoxymethyl groups in UDMA

ANTIBACTERIAL MATERIALSMDPB

1wt%halo(active against S.mutans and action viscous for 10 wks).

BIOACTIVE FORMULATIONSACP -(amorphous calcium phosaphate)2000 SURFACE COATING Copolymer of acrylic acid, alcylmethacrylate and polysiloxane resist demineralization ,decreases plaque retention, resist tooth brush abrasion

SPIROSPIRO- ORTHOCABONATES(SOC}expanding monomers Early soc not compatible with BisGma incomplete polymerization Soc with lower melting point & structural variation- compatible with BisGma/TEGMA- less shrinkage Expansion---3.6% Soc + epoxy resins react at room temp by uv light

Prolong curing--- addition of polyol to epoxy resin , ratio 50: 50/or40:60 (Eick et al 1990) ADVANTAGES Dec polymerization shrinkage Inc toughness, Dec water penetration Bulk placement Dec post operative sensitivity

( b)

POLYOL WITH OXIRANE

Cyracure(2002) Prototype composite of (polyol)& oxirane monomers (epoxy) with zr silicate fillers Light cured& cationic initiated Shrinkage-1% at 60 min -1.6% at 24 hrs Contraction stress-1.0mpa,conventional composite 10mpa Low shrinkage-expansion of oxirane ring, opens during polymerization Higher strength.

Low stress- slower curing rates which allows stress relaxation. (c) VINYL CYLOPROPANES(VCP CYLOPROPANES(VCP) 1997 VCP monomers have been formulated Replaces Bis-gma /UDMA resin Shrinkage is 2/3 of Bis-gma /UDMA resin.

(D) POLYBUTADIENE RUBBER POLYMER 1999 20um polymer is absorbed into fumed silica and added Bis-gma / TEGDMA Reduces shrinkage by 25%

(f) Methacrylated Styrene Allyl Alcohol (MSSA) 1997 It replaced 20% Bis-gma/ TEGDMA with 62 vol% filler. Reduces shrinkage by 20%

MONOMERS FOR ENHANCED CURE AND PROPERTIES(a) 30wt% PEG 600 DMA- copolymer of DMApoly (ethylene glycol 600) dimethacrylate with diethyelene glycol dimethacrylate. Dc-95-100% (better strength& wear resistance) (b) BPA-mixed with TEGDMA BPATEGDMA 1999 Poly (isopropyl diphenol) E.g.-- solitaire

ADVATAGES Shrinkage reduction 10-15% Increase compressive strength Low water sorption Decrease wear rate.

(c) Benzyl methacrylate& lauryl methacrylate added to Bis-gma/ BisTEGDMA high degree of cure due to decreased viscosity (D) CHAIN TRANSFER AGENTS PROPANALOL AND DIACETYL ADDED TO BIS-GMA/ TEGDMA BIS(E) ORMOCERSEX DEFINITE ) ORMOCERS

HYDROPHOBIC MONOMERSADDITION OF FLUORINE AND PHENYL TO CENTRAL CARBON Adv decreases water sorption due to 10% Bis-gma (B) PHENOXYMETHYL GR IN UDMA ) 10- 30% reduction in water sorption

FLOWABLE COMPOSITESModification of hybrid & SPF Reduce filler content ADVANTAGES Consistency, good flow Spread uniformly Intimately adapted to cavity

DISADVANTAGESLow elastic modulii ,more polymerization shrinkage-inc filler content More susceptible to wear Difficult to manipulate- stickiness. INDICATION a To repair old composites, amalgam, crown margins b) Class 2 ,access difficult c) Cl-1 gingival areas d) Fissure sealants e) Class v lesions F) Porcelain repairs G) Resurfacing worn composites

DIRECT POSTERIOR COMPOSITESPACK ABLE COMPOSITES(1990) Elongated fibers, fibrous filler particles Size-100um in length, textured surface interlock and resist flow. Uncured resin is stiff and resistant to slumping ,yet moldable under forces of amalgam condensing instruments Similar to amalgam ,placement tech.

PRIMMDr .lars Ehrnford ,sweeden Polymer Rigid Inorganic Matrix Material Consist of resin& ceramic Filler-continuous network of ceramic Fibers-Al2o3,sio2 Diameter->2.0 um Crossection15.0- 20.0 um Silanization BisGma/ UDMA Colloidal silica ultrafine particles were in corporated to control handling chracterstics Viscosity, resistance to flow, condensibility, reduce stickness.

PROPERTIESincreased flexure strength. greater incorporation of ceramic fibers Increased resistance to wear high conc of ceramic fibers, wear more than enamel(5um) Higher depth of cure- 6mm, QTH Reduced polymerization shrinkage greater ceramic fibers, Silanization of ceramic surfaces so the resin does not pull away from surface of fibers Non-sticky

ADVANTAGESBetter marginal adaptation Lower potential for incorporation of micro porosities Lesser polymerization shrinkage (localized within ceramic chamber) Optimum mechanical characteristics, flexure strength, modulus of elasticity,coffthermal expansion Greater wear resistance.

Eg Solitare (kulzer) Alert (jeneric/ pentron) Surefil (dentsply) Filtek P60(3m)

ANTIBACTERIAL COMPOSITE Chlorhexidene was tried no uniform release unsuccessful.DISADVANTAGES Toxic effect on released material. Population shift of microorganism. Short lived antibacterial activity Deterioration of physical & mechanial properties of material

IMTIAZO ET AL(1994)Synthesized monomers MDPB (Methacryloxydecyl pyridinium bromide) Quaternary ammonia compound Chemically bound to resin matrix. ADVANTAGES Antibacterial effect was seen after long term immersion in water No adverse effect mechanical properties of BisGma Effect on streptococci.

SILVER Ag ions organic oxide sio2 Hydro thermally supported into space b/w crystal lattice network of filler particles. Supported in silica gel and thin film were coated over surface composites Direct contact with bacteria. Oligodynamic action

ADVANTAGES No adverse effect on mechanical properties, strength. Color stability Good depth of cure Do not disturb polymer network DISADVANTAGES When silica gel,as carrieer of ag ions water sorption adverse effect on mechanical properties

INDIRECT POSTERIOR COMPOSITESIndirect composites inlays & onlays reduce wear & leakage Art glass Bell glass hp Clearfil CR inlay Coltene inlay system Cristobal Sculpture Targis True vitality Visio gem

ART GLASSPolyglass Improved resin & filler technology Higher levels of cross-linking COMPOSITION Multifunctional methacrylates Bifunctional monomers filler--20% silica, Ba glass (mean particle size-0.7mm) Microglass filler

Emisssion range-320-500nm, xeno stroboscopic light Silica-reduces slumping, improve sculpt ability indication Metal & non metal crowns FPD Inlays, onlays, veeners Repair introrally-artglass liquid& charisma light cured composite resin

ADVANTAGESMore wear resistance than conventional light cured composites (i.e/yr 3-4um/1 yr) Good marginal adaptation Esthetics Proximal contact and contour

BELL GLASS HPBelle de. St .clair 1996 Resin marix- bis gma& fillers Dual cure indirect polymer ceramic Low wear, high strength . Physical properties-strength of porcelain Avg wear rate-1.2-1.5 um/yr Cure rate 98.5%,fiber optic light, heat level 140c, 60lb pressure in nitrogen environment.

Elevated temp- inc polymerization rate Inc atmospheric pressure dec monomer vaporization Nitrogen gas oxygen free environmentinc polymerization- inc translucency Why oxygen is not used 1. Interferes with curing process 2. Reduce translucency 3. Entrapment in resin mass- inhibit polymerization inhibit max curing potential- dec wear resistance

INDICATIONS Inlays Onlays Anterior veneers Implants Full coverage crowns Metal free partial dentures Long term provisional restorations splints

CLEARFIL CR INLAYkurary Hybrid composite Processed in CRC-100 curing oven inlay bonded with CR inlay cement, dual cured luting composite resin inlay. Light irradiation 40s- sets cement, stabilize inlay, chemical cure-beneath restoration ensures save bond Repaired intra orally- clear field posterior light cured composite resin.

COLTENE INLAY SYSTEMDirect & indirect application. Fabricated directly in the tooth& placed in special oven ,heat -120c& light -7min and cooled- 1min Brilliant dentin( hybrid resin composite) Repaired intra orally- brilliant light cure composite resin.

CRISTOBALPatented bioglass polymer material COMPOSITION Metal primer Adhesive liquid Intense color liquid Opaquer liquid(12 shades) Opaquer powder(20 shades) Modeling liquid Oxygen barrier Dentin opaque core(19 shades) )

Dentin core(17 shades) Incisal core(16 shades) Transparent core(4 shades) Opalescent core(4 shades) Gingival core(1 shade) Barium glass-74.2% Particle size-0.7um,matrix is bis Gma, TEGDMA,UDMA Very low polymerization shrinkage(0.12 after 24 hr) Low wear rate(>5um/yr) High compressive strengths.

SCULPTUREPolymeric ceramic Very low water sorption High wear resistance High fracture toughness Low polymerization shrinkage Truly challenge esthetics of porcelain, user friendly handling, excellent marginal integrity, polishability

Polymerization-cure-lite plus /hands free spectralite Surface glazed-light curing in pressure vessel under nitrogen atmosphere Final curing heat curing under vacuumraise mechanical prop, virtually eliminate residual monomers.

TARGISIvoclar,AG Ceromer (ceramic optimized polymer) Provided base, dentin and incisal shades Processed-heat& light oven for ideal polymerization (targis powder)

INDICATION Inlays On lays Veneers Single & multiple units of metal free restorations

TRUE VITALITYDen Mat inc Hybrid composite resin Three curing modes- heat cure, self, light curing Wear rate less than that of amalgam High compressive strength, tensile, flexural strength 3mm depth of cure, low water sorption Radiopaque,vita lumin shades Simple direct restoration to inlays, onlays,FPD, laminate veneers

VISIOVISIO- GEMESPE Dental AG Light vacuum cured micro filled composite designed for laboratory fabrication over the metal substructures for crown & FPD Initial curing- direct visible light source (visio alpha units) Final cure-light & vacuum chamber (visio beta unit) Vacuum completes curing of oxygen inhibited layer & results in greater color stability, enhanced physical properties.

FIBER REINFORCED COMPOSITESResin based restorations containing fibers, enhancing their physical properties. Gr is hetrogeneous, depending on nature of fibers, geometrical arrangement of fibers and overlying resin used. Fibers are bonded to resin via adhesive interface Fibers improved structural properties, acting as crack stopper.

CLINICAL APPLICATIONSReinforced resin based composites. Individual restorations (inlay, onlay, full veneer crown). Periodontal splinting/ post trauma splint. Immediate replacement trasitional-long term provisional bridges. Fixed bridges-ant & posterior, 1. Simple cantilever 2. Implant supported Reinforcing or repairing dentures. Fixed orthodontic retainers.

ADVATAGESSingle visit immediate treatment Suitable for transitional& long term replacement. Suitable for young pt Metal free restoration Improved esthetics Easy to make Can be frequently used with minimal or no tooth preparation Less wear of opposing tooth as compared to traditional composites

Suitable for transitional and long term provisional restorations. Readily repaired. DISADVANTAGES Potential wear of overlying veneering compositept with parafunctional habits Excellent moisture control required for adhesive technique Space requirement greater in comparison to metal occlusal surfaces to allow sufficient room for fibers & adequate bulk for veenerin composite onlay

May lack sufficient rigidity for long span bridges.

Uncertain longevity in comparison to traditional technique.

NANOFILLERSSize-0.005-0.01um Below wavelength of visible light(0.020.2um) Do not produce scattering or significant absorption. Nanosilicate bonded composite can be used for 1. Effectively invisible. 2. Do not tend to agglomerate in chains like silica- based fillers.

Nanofillers fit between several polymer chains high filler loading. Eg- filtek supreme(3M ESPE) New RBC-nanomer, nanocluster filler particles, strength of hybrid and polish of micro fill. Nanomer discrete, non-agglomerated nanosized particles. Nanoclusters- loosely bound agglomerates of particle size 20-75 um.

ORMOCERSOrganically modified ceramic. Developed by fraunhofer institute for silicate research, wurzburg, in co-operation with partners from dental industry Introduced in 1998 Classification Inorganic polymer Organic polymer Three structural segments chracterze the monomeric molecular perstages

1. The inorganic condensing molecule segment is used to build inorganic network . An inorganic si-o-si network is derived through targeted hydrolysis and in organic polycondensation in a sol-gel process. 2. The organically polymerizing molecular segment has (meth) acryl ate gr, which form an additional cross linked network matrix after induction of a radical based polymerization.

3. The inorganic polycondensation with organic polymerization result in formation of as inorganic- organic co polymer. SMART COMPOSITES 1998 releases f, OH, Ca ions as ph drops in area immediately adjacent to the restorative material due to plaque increase in release functional ions. Smart compositesalkaline glass fibers decreases in secondary caries at margins of restoration

Paste consist of Ba, Al and silicate glass fillers(1um) with yttrium fluoride, calcium silicate glass(1.6 um) in dimetharylate monomers. 80% wt,60% vol. Use of adhesive is not recommended. Dentin should be sealed to decreases the sensitivity. fluoride release from this material is lower than conventional GIC, but more than composites.

GIOMERSHybrid of GIC& composites. Prop of GIC (fluoride release, flouride recharge) resin based materials (esthetics, strength and biocompatibility). Pre reacted glass ionomer particles, fluorosilicate glass react with polyacrylic acid prior incorporation in resin. Similar to compomer and resin based materials, visible light cured, require use of bonding agent eg- beautifil(shofu),

INDICATION Class v Cervical erosion Root caries

SILORANES(DMSILORANES(DM-2005)Combination of siloxane+ oxirane Hydrophobic in nature Network generated by cationic ring opening, polymerization of cyloaliphatic oxirane low shrinkage,dec polymerization stress. INITIATING SYSTEM-3 components SYSTEMCamphroquinoneCamphroquinone- match emission spectra. An iodonium saltsaltAn electron donordonor-

Filler-quartz0.5 um Silane layer prevent attack of acidic si-oH gr of quartz,- prevents undesired initiation of cationic polymerization. ADVANTAGES Optimal balance b/w high polymerization rn& best light intensity Volumetric shrinkage0.94% at 60 s Low stress buildup

High reactivity Higest ambient light stability

REFERENCESRecent advances in restorative dental materials Dr .NAGESWAR RAO(PROF& H.O.D), Dr CAROL SEQUEIRA Jada-1997& 98 J am dent asso 132(5); 639-645,2001 Text book of operative dentistry- Vimal .k .Sikri Dental materials(2005),21,68-74 Dental materials(2002).18,413-421 Journal of esthetic dentistry (2000)12,216-226 J Am dent asso(1990),20;177 J am dent asso 106;634, 1983 J am dent asso 20;177,1990 J am dent asso 134(12);1581-9 2003