Restorative dentistry – aesthetics I. Contemporary trends • Minimally invasive approachinvasive approach • Adhesive materials and techniques - direct composite restorations - indirect composite and ceramic restorations (luted adhesively ) Composites Composites in dentistry Chemically bonded mixture of organic matrix and inorganic filles lroubalikova@gmail.com 5 matrix – transfers mechanical loading on inorganic fillers, protects the filler against moisture filler - support of the material, carries the loading coupling agents- enable the homogenous distribution of the filler in matrix Composition - matrixvysoká estetika, mechanická a chemická odolnost Nevýhody: polymerační kontrakce a pnutí, jiný koeficient tepelné roztažnosti ve srovnání se zubními tkáněmi, není chemická vazba ani antikariogenní vlastnosti. Náročná práce, zhoršení mechanických vlastností v průběhu času. • Bis GMA – Bowen´s monomer • (2,2-bis[4-(2hydroxy-3-metakryloyloxypropoxy) • fenyl]propan) • Bis DMA • UDMA • TEGMA /triethylenglykoldimethacrylate • EGMA ethylenglykoldimethacrylate • eBis –GMA • HDMA hexandioldimethacrylate Composition - matrixNevýhody: polymerační kontrakce a pnutí, jiný koeficient tepelné roztažnosti ve srovnání se zubními tkáněmi, není chemická vazba ani antikariogenní vlastnosti. Náročná práce, zhoršení mechanických vlastností v průběhu času. • Acid modified resins (compomers) • Polysiloxa chains with polymerizable groups (ormocers) • Silorans (ring opening monomers) • Milled quartz • Aluminimum silicate glass • Silicium dioxide • Prepolymer • Complexes of microfiller (aglomerates) Filler Macrofiller lroubalikova@gmail.com 9 • Particles µm or tenths of µm Good mechanical resistance , abrasion resistance, bad polishability. Microfiller lroubalikova@gmail.com 10 • Silicium dioxide (pyrogenous) • Particles hundreths µm Less amount of filler. Lower mechanical resistence, good polishability. Microfiller in complex particles lroubalikova@gmail.com 11 • Prepolymer • Aglomerates • Higher amount of filler, good mechanical resistance, good polishability Nanoparticles lroubalikova@gmail.com 12 • Particles 10 nm and less • Special technology, size, shape and binding to monomer Hybrid filler lroubalikova@gmail.com 13 • Macro particles + microparticles • Macro particles + microparticles+ prepolymer • macroparticles + microparticles + prepolymer + nanoparticles Coupling agent G -methacryloxypropyltrimetoxysilan (A 174) lroubalikova@gmail.com 14 lroubalikova@gmail.com 15 CH2=C(CH3)-R OCH3 OCH3 OCH3 H O-Si H O-Si H O-Si Glass particles Double bond - polymerizable Binding of the coupling agents to glass particles Activator and initiator Pigments Fluorescents Absorbers of light Inhibitors lroubalikova@gmail.com 16 Polymerization • Selfcuring composites Dibenzoylperoxide – terciary amin lroubalikova@gmail.com 17 Low colour stability • Initiator and sometimes also activator • Camphorchinon CQ • Phenylpropandion PPP • Trimetylbenzoylphosphino xid TPO Light curing composites lroubalikova@gmail.com 18 lroubalikova@gmail.com 19 Camphorchinon - CQ Yellow colour Activator: etyl-4-(N,N’-dimetylamino)benzoát (4EDMAB), N,N’-dimetylaminoetylmetakrylát (DMAEMA) Light shades of composites: combination of CQ and other initiators. Specrum of absorbtion Fotoiniciator Spectrum o absorption (nm) Maximum (nm) CQ 440 - 500 470 PPD 380 – 430 400 TPO 350 - 410 380 lroubalikova@gmail.com 20 Bonding lroubalikova@gmail.com 21 22 Adhesion Mechanic Specific lroubalikova@gmail.com lroubalikova@gmail.com 23 Adhesion Mechanic Irregulartiies of the surface lroubalikova@gmail.com 24 Adhesion Specific Physical Chemical lroubalikova@gmail.com 25 Adhesion Specific Physical – intermolecular forces - Van der Waals, hydrogenium bridges 26 Adhesion Specific Chemical lroubalikova@gmail.com 27 Adhesion Sandblasting Electrolytic Silanization Plazma coating Silanization lroubalikova@gmail.com 28 Adhesive preparation of surfaces  Creates irregularities Increases surface energy lroubalikova@gmail.com 29 Adhesion of dental materials Composites - micromechanical Adhesives – micromechanical, specific Glassionomers - specific lroubalikova@gmail.com Composits lroubalikova@gmail.com 30 lroubalikova@gmail.com 31 Mechanical Connection to enamel 32 Adhesion to dentin Dentin: o More water and organic substances in comp to enamel o Low surface energy o Tubular liquid o Connection with pulp chamber o Smear layer lroubalikova@gmail.com lroubalikova@gmail.com 33 Vazebný bond primer MechanicalConnection to dentin BONDING AGENTS Generations 1st Generation: (1956) – Glycerophosphoric acid – DMA Resin – Resin to tooth – No longer used (poor clinical results: 1-3 MPa) 2nd Generation: (1970’s) – Unfilled Resin – Bis-GMA or HEMA – Ionic bond to calcium – No longer used (weak bond strength, microleakage) Generations 3rd Generation: (1980’s) – Etch + Hydrophilic Primer + Unfilled Resin – Partial removal and/or Modification of smear layer – Resin did not penetrate through smear layer 4th Generation: (1982) – Total Etch (Phosphoric Acid) + Primer + Adhesive – Complete removal of smear layer – “Wet bonding” (risk of being too wet or dry) – Formation of hybrid layer and resin tags – Good clinical results Generations 5th Generation: (1990’s) – Total Etch + Adhesive – Hydrophilic monomers – Formation of hybrid layer and resin tags 6th Generation: (late 1990’s – 2000) – Self-etching primer + Hydrophobic adhesive – Partial removal of smear layer – Chemical instability of primer 7th Generation: (2000’s) – One bottle – Partial removal of smear layer – Chemical instability Adhesive materials Amalgam - Connection without gap - Less invasive preparation - Less risk of secondary caries - Hihger resistance - No problem with mercury lroubalikova@gmail.com 38 39 lroubalikova@gmail.com Adhesive systems contain resin monomers • 4-META • HEMA • TEGMA • PENTA P • 5-NMSA • Bis-GMA lroubalikova@gmail.com 40 Adhesive systems contain resin monomers • Hydrophobic monomers - bond Works in enamel Does not work in dentin without primer • Amphiphilic monomers – hydrophobic + hydrophilic part - primer Primer is necesssary for dentin If applied on enamel – residual of water can be removed lroubalikova@gmail.com 41 Dissolving agents • Aceton • Alcohol • Water • Watwer/alcohol lroubalikova@gmail.com 42 43 Acid etching Washing Priming Bonding Acid etching Washing Priming a bonding Selfetching priming Bonding Selfetching bonding Adhesives – classification acc to clinical steps lroubalikova@gmail.com 3- ERA 2- ERA 2- SEA 1- SEA Adhesives • Acid etching technique • Selfetching adhesive systems Adhesives • Acid etching technique Etching Washing Priming Bonding Adhesives • Selfetching adhesive systems Priming Bonding Less bonding strength in comparison to acid etching technique lenka.roubalikova@tiscali.cz 47 Dudek M. Adhezivní spoj a adhezivní systémy I. LKS 11/2013 Smaer layer infiltrated with adhesive systém Dentin tag Surface of dentin Smear layer Lateral tubul Dentin tubul Very mild acidic SEA Mild acidic sea Middle acidic SEA Strong acidic SEA Thickness of hybrid layer lenka.roubalikova@tiscali.cz 48 Collagen fibers with mineral salts (peri and intra) Collagen fibers with intrafibrillar crystals Collagen fibers without any crystals Dudek M. Adhezivní spoj a adhezivní systémy I. LKS 11/2013 (risk of hydrolysis and degradation with metaloproteinasis) Adhesives • Active and passive bonding Active – rubbing with microbrush (SEA, dentin) Passive – without any rubbing (ERA, enamel) Blow up Too thin layer does not allow complete conversion (polymerization) due to oxygen Too thick layer can contain still dissolving agent. 50 lroubalikova@gmail.com 51lroubalikova@gmail.com Polymerization 52 Pre –gel Gel Post -gel lroubalikova@gmail.com Polymer network Photocomposite 3,2mm 57 mm 3mm 8,5mm Byung, Suh Principles of adhesion dentistry 2013 53lroubalikova@gmail.com Photocomposite 102mm 48mm 54lroubalikova@gmail.com Polymerization strain and stress Selfcuring composite 434343 43mm 42mm 55lroubalikova@gmail.com Polymerization strain and stress Pregel phase • The material is still soft, forces of polymerization ahrinkage can release, deformation of the surface Gel point • Material became hard Postgel phase • Material is not soft, polymerization continues, due to polymerization shrinkage the polymerization stres occurs – forces on bonded surfaces can cause gaps or cracks. • Selfcuring composites – longer pregel phase • Photocomposites – Gel point comes earlier 59 lroubalikova@gmail.com Forces of polymerization shrinkage depend on - Composite material (content of filler) - Geometry of the cavity (C-factor) - Placement of the composite - Mode of polymerization Light curing 61 Too short illumination, low output energy causes lower conversion of material, the risk of fracture is higher, material changes the colour. lroubalikova@gmail.com Surface of adhesion/free surface of the filling 1/1 and less is optimal C – factor (Configuration factor) 5 2 1 Big free surface – lower polymerization stress, The forces can easier release through free surface – its deformation Forces of polymerization shrinkage depend on - Composite material (content of filler) Higher content of filler - lower shrinkage, higher polymerization stress. Mode of polymerization • Longer pre gel phase – realeasing of polymerization forces Continual polymerization Min. 500 mW/cm2 40 s 2 step polymerization 10 s cca 140 mW/cm2 750 mW/cm2 30 s Soft start Continuos increasing to 750 mW/cm2 during 10 s and polymerization 30s 2 step polymerization with interruption 100 – 300 mW/cm2 3-5 s, přerušoi na 3 min, pakpolymerovat 750 mW/cm2 po 30 s Period of pre gel phase Dentists polymerize mostly from the distance 4 mm – 10 mm.Diffusion of lihgt. Soft start programm is not necessary. 70 lroubalikova@gmail.com Quartz tungsten halogen (QTH) • Light emitting diode (LED) • Plasma – arc (PAC) • Energy and spectrum Polymerization units lroubalikova@gmail.com 71 Quartz tungsten halogen (QTH) • Light emitting diode (LED) • Plasma – arc (PAC) Polymerization units lroubalikova@gmail.com 72 600 -800 mW/cm2 1000 -1800 mW/cm2 modré 50 – 100 mW/cm2 fialové 1500 - 2000mW/cm2 • Recommended output power 12000 – 16000 mJ/cm2 12 000 mWs/cm2 Intensity mW/cm2 Time of polymerization Time of polymerization in s Distance 4 – 10 mm – ½ energy lroubalikova@gmail.com 73 • Recommended output power 12000 – 16000 mJ/cm2 12 000 mWs/cm2 Intensity mW/cm2 Time of polymerization Time of polymerization in s Distance 4 – 10 mm – ½ energy lroubalikova@gmail.com 74 Photoiniciators – spectrum of absorption Photoiniciator Spectrum of absorption (nm) Maximum (nm) CQ 440 - 500 470 PPD 380 – 430 400 TPO 350 - 410 380 lroubalikova@gmail.com 75 lroubalikova@gmail.com 76 lroubalikova@gmail.com 77 High C- faktor 78lroubalikova@gmail.com GAP in dentin, cracks in enamel Working with layers • Incremental technique lroubalikova@gmail.com 80 Flowable +thin layers 1 2 3 lroubalikova@gmail.com 81 Free surface – as big as possible in each layer lroubalikova@gmail.com 82 Selfcuring composite Light curing composite COMBINATION OF MATERIALS Glassionomer and composite lroubalikova@gmail.com 83 Sandwich technique GIC replaces lost dentin Composite replaces lost enamel Sealing of the filling lroubalikova@gmail.com 84 FLOWABLES Flowables indications • Filling of minicavities, pit and fissure sealing, tunnel • Reparations • Splinting • Marginal adaptation • Tratament of infractions • Block out of undercuts Flowables • Less amount of filler • Higher polymarization shrinkage • Lower modulus of elasticity • Lower polymerization stress 1. generation nízký obsah plniva, malá mechanická odolnost 2. generation: nanoparticles –hihger amount of filler Flowables indications • Filling of minicavities, pit and fissure sealing, tunnel • Reparations • Splinting • Marginal adaptation • Tratament of infractions • Block out of undercuts Bulk fill Application in bulks, deep polymerization (4 – 5mm) Heterogenous group 1. Flowables – SDR Flow (Dentsply), Venus Bulk Fill (Hereaus Kulzer), X-tra fill (VOCO), Filtek Bulk Fill (3M ESPE). 2. Packable composites (Tetric EvoCeram Bulk Fill (Ivoclar –Vivadent) a QuiXfill (Dentsply). 3. Sonic Fill (KaVo) – sonic activated composite Sonic Fill Sonic activation – materials become Flowable. Bulk fill • More translucent • More fotoiniciators • Combination of materials (flowable bulk fill + hybrid vomposite • Packable composite + flowable on the borrom • Sonic fill – combination with other materials is not necessary but useful. Bulk fill • The problem of polymerization stress is not solved completely. • Thinner layers than 4 mm recommended.