Composites Chemically bonded mixture of organic matrix and inorganic filler Composition  Organic matrix Bowen monomer Bis GMA UDMA Oligomer – more flowable (thinning) TEGMA Composition Filler Milled quartz Aluminium silicate glass Silica Prepolymer Nanoparticles 3 Composition  Coupling agent Silan Binding between organic and inorganic part Homogenous distribution of filler in composite Composition Iniciators and accelerators Other components  Pigments  UV absorbers 5 Classification acc.to size of filler particles Macrofiller composites (size micrometers) Microfiller composites (size 0,02 -0,04 micrometers) Homogenous Non homogenous Hybride composites (combination of filler) Macrofiller Microfiller (pyrogenic SiO2) homogenious Microfiller Composite Macrofiller Composite Microfiller- complexes inhomogenious Microfiller- Composite Hybrid Composite Classification acc. type of filler Classification according to filler particles  Macrofiller (macrofilled composites)  Microfiller (microfiled composites) -homogenous -inhomogenous  Nanofiller (nanocomposites)  Hybride (hybrid composits) Filler particles Filler size (medium particle size) Composite category < 10 µm hybrid composite < 5 µm fine particle hybrid < 3 µm ultrafine particle hybrid < 1 µm submicron hybrid , nano composites More filler  Less amount of resin  Lower polymerization shrinkage Filler - example matrix Skleněné plnivo 0.4 ~ 1 µm Polymerization reaction Accelerator Iniciator Double bonds – split Polymer network 11 Curing  Light curing composites - (Light activated). Light activation is accomplished with blue light (470 nm) Initiator is camphorquinon Chemically cured composites Iniciator is organic peroxide, accelerator tertiary amine Classification acc to mode of curing  Light curing  Self curing (chemically curing)  Dual curing (cementzs)  Heat curing (for dental lab) Polymerization units  Quartz halogen units  LED units Blue light, 400 – 500 nm. Camphorchinon 470 nm (maximum absorption) Light Pre –gel phase Gel-point Post –gel phasePolymerization shrinkage Indications  Frontal area: Class III., IV, V. Posterior area Small – moderate cavities I. and II. class Contraindications  Bad level of oral hygiene  Dry operation field is impossible  Large cavities I. and II. class Principle of retention - micromechanical Acid etching of enamel Irregular surface – retentive pattern Speces between enamel rods or in enamel rods are created The material flows into these spaces Retention in enamel Aprismatic enamel  On the surface of enamel there is aprismatic enamel. It is difficult to be etched in order to achieve the retentive pattern. It must be removed with diamond (red coded, fine) Retention in dentin o More water and organic components o Tubular liquor o Smear layer (layer after preparation composed of collagen fibers, crystals of hydroxyapatite that have been destroyed during preparation and microbs) Smear layer With acid etching smear layer is removed, dentin tubuls are opened and the surface of collagen network decalcified The material can flow into dentin tubules and penetrates into spaces in collagen network. This is also micromechanical retention 35% - 37% phosphoric acid silica particles blue dye Adhesive system  We need adhesive systém for penetration into microscopic spaces after acid etching. It consist of primer and bond Bond  Flows into spaces in enamel after etching, into dentin tubules and to spaces in collagen network. Dentin must be pretreated with primer. Primer Open the collagen network in dentin and keep it open: Withiout it the bond wolud not be able to penetrate inside. Making filling  Preparation  Enamel is beveled in most cases – retentive border  Acid etching  Washing  Bonding  Placement of filling material – in portions  Curing with light  Finishing and polishing (extra and ultrafine dimonds and rubber instruments) Glassionomers Composition Powder: Aluminiumsilicate glass(SiO2, Al2O5, CaO, N2O,P2O5, F) Liquid: Polyacid (polyacrylic, polymaleic) Tartaric acid, Water Glassionomers  Principle of setting – acid base reaction Glassionomers  Chemical bonding to hard dental tissues  Thermal expansion similar to dentin  Realease fluoride ions Mechanical not strong enough Aesthetics acceptable Glassionomers acc to curing  Acid – base reaction  Dual cured glassionomers (resin modified) dentin Glassionomers - indications  Fillings Class V., III., I., II Sealants Protection of tooth surface Mixing Hand Power driven - capsulated Making filling  Preparation  Smoth bordes  Limited on caries lesion only  Conditioning  Washing  Filling in one block  Varnish after setting  Polishing in next appointment