Plastic fillings (malleable)  The material is soft, it is cured (set) in the cavity amalgam, composite, glassionomer, temporaries. Rigid fillings - inlays • The material is rigid (already cured) Metal alloy, composite, ceramics. Inlays made of the metal alloy (usually precious alloys)  Rigid fillings  Manufactured in a dental lab  Direct or indirect method - Direct method rarely (class I. only) - Indirect method (most cases) Inlay  Crown inlay - a part of a clinical crown is replaced  Root canal inlay - The inlay is cemented into the root canal and replaces a crown (abutment tooth – stump, snag) Crown inlay Material  Metal Alloys  Composit  Ceramics Crown inlays Indications  A big loss of dental tissues (cusps replacemen  Next to the crowns and bridges made of metal alloy Inlays made of the metal alloy Indications  Large defects (i.e. – cusps replacement)  Large interdental spaces  Next to crowns and bridges made of metal alloys (risk of oral galvanism – electric current between two metals) Inlays made of the metal alloy Contraindications o High risk of dental caries o Small and shalow cavities o No in frontal area Inlay Advantages  Better anatomic form  Better polished Inlay Disadvantages  The technology is not easy  More time consuming  Expensive  Two appointments Basic rules of preparation  Box  No undercuts  Light divergence of the walls (facilitating shape). Angle of divergency 6 – 15° Box No undercuts Simple box Facilitating shape Inlay of metal alloy  Direct method (class I. or V.) - rarely  Indirect method (in most cases) Inlay of metal alloy  Direct method Direct modellation in the mouth Special wax – casting wax, (special polymers) Sprue pin Investment Method of the lost wax Class I. All fissures are involved No undercuts – facilitating form Asymetric outlines Depth 1,5 mm Sequence of operations Dental office - Preparation - Isolation of the cavity - Modellation of heated casting wax - Sprue pin – the thickest part,reservoir Dental lab - Investment - Casting (method of lost wax) -Finishing Dental office - Cementation Inlay of metal alloy Indirect method Taking of the impression Model Modellation of the casting wax, (special polymers) Sprue pin Investment Lost wax method Inlay Onlay Overlay Retention of rigid fillings Against axial forces, depends on 1. Geometry of the preparation 2. Qwuality of the luting material (cement) Taper Retentiong/mm2 Angle of convergency Rau G. 1994 Non metallic inlays  Composite  Ceramics Indirect method CAD CAM lenka.roubalikova@tiscali.cz 35 Preparation  Box  No undercuts  Facilitating shape – divergence of the walls appr. 6°  No bevel  Thickness of the material 1,5 – 2 mm Cementation  Adhesive materials – composite cements  Special materials requiring acid etxhing, priming and bonding  Chemically or dual curing low viscosity materials lenka.roubalikova@tiscali.cz 47 lenka.roubalikova@tiscali.cz