Composites Chemically bonded combination of organic matrix and inorganic filler Composition  Organic matrix is a resin Bowen monomer Bis GMA (result of reaction of Bisphenol A and glycidyl methacrylate) UDMA Oligomer - dïmethacrylate TEGMA Composition Filler Milled quartz Aluminium silicate glass Silica Prepolymer Coupling Agents Silane Composition Iniciators and accelerators (activators) Other components Pigments UV absorbers Antioxidants Polymerization Accelerator Iniciator Double bonds - split Polymer network 5 Light Curing  Light cured composites - Light activated. Light activation is accomplished with blue light (470 nm) Initiator is camphorquinon, Phenylpropandion, Lucirin Chemically cured composites Iniciator is organic peroxide, accelerator amine Composite according to mode of curing Chemically curing (2 components) Light curing (1 component) Dual curing (2 components) Composites acc to size of filler Macrofiller (macrofilled) composites 1 – 10 mm Microfiller (microfilled) composites 0,01 – 0,04 mm Hybrid composites (contain macro and microfiller) Retention Principle of retention of composite filling materials is micromechanical retention Microscopic spaces in enamel and dentin are filled with the material. Adhesives  Adhesive systems using acid etching technique  Selfetching adhesive systems Adhesives  Acid etching technique Etching Washing Priming Bonding Adhesives  Selfetching adhesive systems Priming Bonding Adhesives  Active and passive bonding Active – rubbing with microbrush Passive – without any rubbing Cavity for amalgam Cavity for composite Retention Principle of retention of composite filling materials is micromechanical retention Microscopic spaces are filled with the material. Acid etching procedure creates microscopic spaces in enamel and dentin. 28% - 37% phosphoric acid is used 30 s in enamel 10s in dentin Acid etching gel is washed off Enamel  Enamel is etched after removing of aprismatic enamel which is on the surface  The spaces between enamel rods (an inside also) are obtained after the etching procedure. Dentin On the surface of dentin the smear layer occures (always after preparation, consists of smashed crystalls, collageb fibers, microbs). Acid etching removes this smear layer, dentin tubules are open and collagen betwork lost minerals - is denudated Adhesive system Primer Resin that goes easily to dentin, keep collagen network open (necessary for bonding) Bond Unfilled (or low filled) resin of the same composition as matrix of composite Flows into the spaces and enables the micromechanical connection Making filling  Preparation  Enamel is beveled in most cases – retentive border  Acid etching  Washing, slightl drying  Bonding, (appl. Of primer and bond), curing  Placement of filling material – in portions  Curing with light  Finishing and poloshing Glassionomers Composition Powder: Aluminiumsilicate glass(SiO2, Al2O5, CaO, N2O,P2O5, F) Liquid: Polyacid (polyacrylic, polymaleic) Tartaric acid, Water Glassionomers –principles of setting  Aluminium – calcium polymer network Glassionomers  Chemical bonding to hard dental tissues  Thermal expansion similar to dentin  Realeasing of fluoride ions Mechanical not strong enough Aesthetics acceptable Acido – basic reaction is a principle of hardening  Calcium and aluminium ions release from the glass. These ions react with carboxygroups of polyacid – the network is created OOC OOC Ca Al Glassionomers acc to setting reaction  Acid – base reaction  Dual cured glassionomers (resin admixed) dentin Glassionomers - indications Fillings Class V., III., I., II Sealants Protection of tooth surface Mixing Hand Power driven - capsulated Making filling  Preparation  Smoth bordes  Cavosurface margin limited on caries lesion only  Conditioning (conditioner is 20% polyacrylic acid) 20s.  Washing  Filling in one bulk