CompositesComposites Chemically bonded combination of organic matrix and inorganic filler CompositionComposition Organic matrix is a resin Bowen monomer Bis GMA (result of reaction of Bisphenol A and glycidyl methacrylate) UDMA Oligomer - dïmethacrylate TEGMA CompositionComposition Filler Milled quartz Aluminium silicate glass Silica Prepolymer Coupling Agents Silane CompositionComposition Iniciators and accelerators (activators) Other components Pigments UV absorbers Antioxidants PolymerizationPolymerization reactionreaction Accelerator Iniciator Double bonds - splitting Polymer network 5 Light CuringCuring 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 CompositeComposite accordingaccording to modeto mode ofof curingcuring Chemically curing (2 components) Light curing (1 component) Dual curing (2 components) CompositesComposites accacc toto sizesize ofof fillerfiller Macrofiller (macrofilled) composites 1 – 10 μm Microfiller (microfilled) composites 0,01 – 0,04 μm Hybrid composites (contain macro and microfiller) RetentionRetention Principle of retention of composite filling materials is micromechanical retention Microscopic spaces are filled with the material. RetentionRetention Principle of retention of composite filling materials is micromechanical retention Microscopic spaces are filled with the material. AcidAcid etchingetching procedureprocedure createscreates microscopicmicroscopic spacesspaces inin enamelenamel andand dentin.dentin. 28% - 37% phosphoric acid is used 30 s in enamel 10s in dentin Acid etching gel is washed off EnamelEnamel 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. DentinDentin 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 AdhesiveAdhesive systemsystem 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 MakingMaking fillingfilling 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 GlassionomersGlassionomers Composition Powder: Aluminiumsilicate glass(SiO2, Al2O5, CaO, N2O,P2O5, F) Liquid: Polyacid (polyacrylic, polymaleic) Tartaric acid, Water GlassionomersGlassionomers ––principlesprinciples ofof hardeninghardening Aluminium – calcium polymer network GlassionomersGlassionomers Chemical bonding to hard dental tissues Thermal expansion similar to dentin Realeasing of fluoride ions Mechanical not strong enough Aesthetics acceptable AcidoAcido –– basicbasic reactionreaction isis aa principleprinciple ofof hardeninghardening Calcium and aluminium ions release from the glass. These ions react with carboxygroups of polyacid – the network is created OOC OOC Ca GlassionomersGlassionomers accacc toto curingcuring Acid – base reaction Dual cured glassionomers (resin admixed) dentin GlassionomersGlassionomers -- indicationsindications Fillings Class V., III., I., II Sealants Protection of tooth surface MixingMixing Hand Power driven - capsulated MakingMaking fillingfilling Preparation Smoth bordes Limited on caries lesion only Conditioning (conditioner is 20% polyacrylic acid) 20s. Washing Filling in one block