Faculty of medicine, Dpt of restorative dentistry, ass.prof. L. Roubalikova1 Restorative dentistry IV1. Repetition Composite materials Chemically bonded mixture of organic matrix and inorganic fillers Coupling agent – binds organic matrix and the filler together Homogenous distribution of the filler particles in the material Excellent mechanical properties 3 Binding of the coupling agents to glass particles CH2=C(CH3)-R CH2=C(CH3)-R CH2=C(CH3)-R 4 H O-Si H O-Si H O-Si Double bond -polymerizable Glass particle Importance of the components ̶ matrix – a transfer mechanical loading on inorganic fillers, protects the filler against moisture ̶ filler - a support of the material, carries the loading ̶ coupling agents - a homogenous distribution of the filler in matrix 5 Kompozitní materiály podle plniva ̶ Makroplnivo - makrofilní ̶ Mikroplnivo – mikrofilní ̶ Kombinace – hybridní ➢konvenční hybridní ➢mikrohybridní Kompozity s nanoplnivem Composition - matrix 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 Dimethacrylates 7 Composition – matrix - Acid modified resins (compomers) - Polysiloxan chains with polymerizable groups (ormocers) - Silorans (ring opening monomers) 8 Filler ̶ Milled quartz ̶ Aluminimum silicate glass ̶ Silicium dioxide ̶ Prepolymer ̶ Complexes of microfiller (aglomerates) 9 Macrofiller ̶ Particles µm or tenths of µm ̶ Good mechanical resistance , abrasion resistance, bad polishability. 10 Microfiller • Silicium dioxide (pyrogenous) • Particles hundreths µm Less amount of filler due to big surface Lower mechanical resistence, good polishability. 11 Microfiller in complex particles ̶ Prepolymer ̶ Aglomerates - Higher amount of filler, good mechanical resistance, good polishability 12 Nanoparticles ̶ Particles 10 nm and less Special technology, size, shape and binding to monomer 13 Coupling agent ̶ G -methacryloxypropyltrimetoxysilan (A 174) 14 Other components ̶ Activator and initiator ̶ Pigments ̶ Fluorescents ̶ Absorbers of light ̶ Inhibitors 15 Selfcuring composites ̶ Dibenzolyperoxide Tertiary amine ̶ Initiator Activator 16 Light curing composites Initiator and sometimes also activator Camphorchinon CQ Phenylpropandion PPP Trimetylbenzoylphosphino xid TPO 17 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. 18 Composite materials – basic characteristics ̶ Matrix Filler Compressive strength Elasticity Polymerization shrinkage Polymerization stress Water sorption Classification of composite filling materials ➢ Size of the filler particles Macrofilled, microfilled (homogenous, non homogenous, hybrid) ➢ Matrix (monomers) Dimethacrylate, acid modifies, ormocers, silorans ➢ Viskosity (flowable, thick) History lroubalikova@gmail.com 21 Dimetacrylates Bowen 1960 – Bowen´s monomer Buoconore 1955 – acid etching History lroubalikova@gmail.com 22 Fusayama 1979 Adhesion to dentin Yoshida. Nakabaiashi Van Meerbeck 23lroubalikova@gmail.com Adhesion ̶ Mechanical adhesion ̶ Specific adhesion - Intermolecular forces - Chemical binding 24 25 lroubalikova@gmail.com Acid on aprismatic enamel Acid on prismatic enamel lroubalikova@gmail.com Dentin – special composition ̶ More water – always wett ̶ Less minerals ̶ Low surface energy ̶ Smear layer Composite is hydrophobic, we need hydrofilic substance 27 28 lroubalikova@gmail.com Bonding agent 29lroubalikova@gmail.com Adhesive systems contain resin monomers 4-META • HEMA • TEGMA • PENTA P • 5-NMSA • Bis-GMA 30 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 31 Dissolving agents ̶ Aceton ̶ Alcohol ̶ Water ̶ Water/alcohol 32 33 Acid etching Rinsing Priming Bonding Acod etchin Rinsing Priming a bonding Selfetching priming Bonding Selfetching bonding) Clinically oriented classification of the adhesive systems acc to number of steps lroubalikova@gmail.com lroubalikova@gmail.com34 Selfetching bonding agents lroubalikova@gmail.com35 36 TE – Total etch, ERA SE – Self etching SEA Two steps selfetching agents Acidic hydrophilic primer – evaporation of the solvant, penetration, dissolving of the smear layer Hydrofobic bond – sealing of the surface 37lroubalikova@gmail.com One step selfetching agents More vulnerable bonding, risk of hydrolysis 38lroubalikova@gmail.com FAKT !!! 39 Source: Dudek M. Adhezivní spoj a adhezivní systémy I. LKS 11/2013lroubalikova@gmail.com Smear layer layer Dentin tubules pH of the adhesive system thickness of the hybrid layer surface of dentin smear layer impregnated resin tag with the adhesive system very mild acidic sea mild acidic sea acidic sea strong acidic sea 40 Colagen fibers with interfibrilar and Instrafibrilar crystals od hydroxyapatite Colagen fibers with intrafibrilas crystals of hydrpoxyapatite only Colagen fibers without crystals of hydroxyapatites Zdroj obrázku: Dudek M. Adhezivní spoj a adhezivní systémy I. LKS 11/2013 lroubalikova@gmail.com ̶ Protection of collagen against hydrolysis as well as enzymatic degradation of collagen (due to activation of matrix metaloproteinasis) - Strong mineral acid id dangereous for good long term bonding - Clorhexidin for one minute can stabilize collagen Importance of hydroxyapatite 41 Definujte zápatí – název prezentace nebo pracoviště42 Enzymatic degradation of collagen lroubalikova@gmail.com43 Factor that influence the quality of bonding Structure and composition of hard dental tissues Quality of their surface – esp. presence of smear layer, contamination with moisture, saliva and blood Configuration factor – C- factor Mechanical loading of the adhesive connection Oral environment and external chemical materials (tooth pastes, asntiseptics, bleaching agent rtc.) 44lroubalikova@gmail.com ̶ Quality of the material ̶ C- factor ̶ Mode of application ̶ Mode of polymerization Polymerization stress depends on Definujte zápatí – název prezentace nebo pracoviště45 ̶ Quality of the material ̶ C- factor ̶ Mode of application ̶ Mode of polymerization Polymerization stress depends on Definujte zápatí – název prezentace nebo pracoviště46 ̶ Quality of the material ̶ C- factor ̶ Mode of application ̶ Mode of polymerization Polymerization stress depends on Definujte zápatí – název prezentace nebo pracoviště47 lroubalikova@gmail 48 0 10 20 40 80 plnivo% pnutí el.modul polym.kontrakce High content of filler increases the modulus of elasticity High modulus of elasticity increases the polymerization stress High content of filler decreases the polymerization shrinkage Polym. Stress Modulus of elasticity Polymerization shrinkage ̶ Quality of the material ̶ C- factor ̶ Mode of application ̶ Mode of polymerization Polymerization stress depends on Definujte zápatí – název prezentace nebo pracoviště49 50 5 2 1 Bonded area : Free area 1:1 and less - optimal ̶ Quality of the material ̶ C- factor ̶ Mode of application ̶ Mode of polymerization Polymerization stress depends on Definujte zápatí – název prezentace nebo pracoviště51 Mode of application ̶ Incremental technique Layer by layer with big free surface ̶ Importance of flowables Thin layer of flowable first –big free surface Good marginal adaptation Compensation of the stress of the other layers Bulk fill materials do not solve the problem with polymerization stress Definujte zápatí – název prezentace nebo pracoviště52 1 2 3 Placement of the material ̶ Quality of the material ̶ C- factor ̶ Mode of application ̶ Mode of polymerization Polymerization stress depends on Definujte zápatí – název prezentace nebo pracoviště54 Monomer Light Polymerization Polymer Pre –gel Gel Post -gel Pre gel phase should be long – soft start !!!! Three phases Phases - Pre-gel – material is soft - Gel-point – material became hard - Post –gel – material is not soft, postgel shrinkage Fotokompozit 102mm 48mm Photocpomosite 3,2mm 57 mm 3mm 8,5mm Selfcuring material 434343 43mm 42mm ̶ Longer pre-gel phase is better for releasing of polymerization stress - Soft start - Combination of materials (selfcuring composite materials have longer pre gel phase) Duration of pre-gel phase Definujte zápatí – název prezentace nebo pracoviště61