Restorative dentistry - aesthetics Contemporary trends • Minimally invasive approach • Adhesive materials and techniques Composites 5 Natural composites lenka.roubalikova@tiscali.cz Combination of materials – final product has much better properties in comparison to summation of the components Composites in dentistry Chemically bondedn mixture of organic matrix and inoprganic polymer Adhesion Bonding lroubalikova@gmail.com 9 10 Adhesion Adhesive Adherend lroubalikova@gmail.com 11 Adhesion Mechanic Specific lroubalikova@gmail.com lroubalikova@gmail.com 12 Adhesion Mechanic Irregulartiies of the surface lroubalikova@gmail.com 13 Adhesion Specific Physical Chemical lroubalikova@gmail.com 14 Adhesion Specific Physical – intermolecular forces - Van der Waals, hydrogenium bridges 15 Adhesion Specific Chemical lroubalikova@gmail.com 16 Adhesion Sandblasting Electrolytic Silanization Plazma coating Silanization lroubalikova@gmail.com 17 Adhesive preparation of surfaces  Creates irregularities Increases surface energy lroubalikova@gmail.com 18 Adhesion of dental materials Composites - micromechanical Adhesives – micromechanical, specific Glassionomers - specific lroubalikova@gmail.com lroubalikova@gmail.com 19 Enamel 20lroubalikova@gmail.com Aprismatic enamel 21lroubalikova@gmail.com Aprismatic etching, aprismatic retentive pattern 22lroubalikova@gmail.com Intraprismatic retentive pattern 23lroubalikova@gmail.com Interprismatic retentive pattern lroubalikova@gmail.com 24 Dentin 25 Dentin o More water and organic substances o Low surface energy o Tubular liquid o Connection with pulp chamber o Smear layer o Variable composition of dentin (young, old person, cavity, root canal). lroubalikova@gmail.com 26lroubalikova@gmail.com Smear layer lroubalikova@gmail.com 27 Etched dentin lroubalikova@gmail.com 28 Dentin tubules with collagen fibres 29lroubalikova@gmail.com Dentin tags Tooth Structure: ENAMEL Mineral Bonding do Enamel Tooth Structure: DENTIN OrganicMineral Tooth Structure: DENTIN 1.9µm 35% Phosphoric Acid Self Limiting Etch Bonding to Porcelain Etching – hydrofluoric acid Before After 1 minute 1 minute 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 7th Generation Bonding (all in one) + + or… Shampoo Rinse Conditioner 7th Generation Bonding (all in one) Perdigão J, Dutra-Corrêa M, Castilhos N, Carmo ARP, Anauate-Netto C, Cordeiro HJD, et al. One-year clinical performance of self-etch adhesives in posterior restorations. Am J Dent. 2007 Apr; 20(2):125-33 Variables Which Affect Quality Of Bonding 1) Etching Etching too long can etch too deep, making it difficult for the resins to reach sound tooth structure. 1.9µm Variables Which Affect Quality Of Bonding 2) Drying dentin Over drying the dentin after etching can be very destructive to bond values with some adhesives. Variables Which Affect Quality Of Bonding 3) Application time Too short of application time may not allow for proper volatilization of the solvents or complete resin hybridization. This is critical with self etching systems. Variables Which Affect Quality Of Bonding 4) Thinning / drying Too thin of adhesive layer doesn’t allow for proper curing due to oxygen inhibition. Too thick and the adhesive may still contain solvents. O2 O2 O2 O2O2 O2 Air thin / Dry TO TRANSLUCENCY Variables Which Affect Quality Of Bonding 5) Light curing Too short or insufficient light cure equals partially polymerized resins. Variables Which Affect Quality Of Bonding 6) Composite Placement Improper adaptation of the composite to the adhesive can create voids at the bonding interface. Condenser Variables Which Affect Quality Of Bonding 7) Contamination • Blood • Sulcular fluid • etc… Variables Which Affect Quality Of Bonding 8) Deteriorated product • Expired • Volatilized Too moist Just right 20 sec. lroubalikova@gmail.com 73 lroubalikova@gmail.com 74 lroubalikova@gmail.com 75 lroubalikova@gmail.com 76 Kdy máme správně nabondováno? Polymerization shrinkage Towards light source ? Ligth curing composits Ligth curing composits Selfcuring composits Polymerization stress depends on Material C - factor Mode of application Mode of polymerization Polymerization 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 Polymerization units Quartz Tungsten Halogen (QTH) • Plasma – Arc (PAC) • Light Emitting Diode (LED) 89 Light • Electromagnetic radiation -Wavelength -Amplitude Photons Beam - Reflection - deflection 90 Value Chroma Hue 3variables Chroma – wavelength Hue – amplitude Value - cleanliness 91 Transparencey Translucency Opacity 92 Dentin is more opaque than enamel Enamel is more translucent than dentin 93 11 Translucency 1 2 3 Old Middle age Young 94 Absorption of light and irradiation back – different wavelength Absorption ultraviolet – irradiation blue In dark room – teeth are bright and white after comming from sunny light 95 96 97 Opalescency – blue or grey colour up to incisal edge 98 Mamelons Opalescency Halo effect 99 Optical size 100 101 Surface texture Vanini Dentin shades Desaturation Enamel on the surface Opalescence White spots Characterization inside enamel Imitation of tooth structure Univerzální dentin Surface texture