RESTORATIVE MATERIALS

Restorative Materials



Restorative Materials

Background3

Overview3

Direct Restorative Materials3

Dental Amalgam3

Safety of Dental Amalgam4

Efficacy of Dental Amalgam5

Resin-Based Composites6

Safety of Resin-Based Composites6

Effectiveness of Resin-Based Composites8

Direct versus Indirect Composites8

Glass Ionomers9

Safety of Glass Ionomers10

Effectiveness of Glass Ionomers10

Resin-Modified Glass Ionomers11

Safety of Resin-Modified Glass Ionomers11

Effectiveness of Resin-Modified Glass Ionomers11

Indirect Restorative Materials12

All-Ceramic12

Safety of Ceramic Materials13

Effectiveness of Ceramic Restoration13

Metal-Ceramic14

Safety of Metal-Ceramic Restorations14

Effectiveness of Metal-Ceramic Restorations15

Cast-gold (high noble metal) alloys15

Safety of Cast-Gold Alloys16

Effectiveness of Cast-Gold Alloys16

Base Metal Casting Alloys17

Safety of base metal casting alloys.17

Effectiveness of Base Metal Casting Alloys17

Conclusion18

Practice Implications18

References20

Restorative Materials

Background

In recent years, dentistry has benefited from a marked increase in the development of esthetic materials, including ceramic and plastic compounds. But the advent of these new materials has not eliminated the usefulness of more traditional restorative materials such as gold, base metal alloys and dental amalgam.

Overview

This report outlines important features of direct and indirect restoratives, with an emphasis on the safety and efficacy of each material.

Direct Restorative Materials

Dental Amalgam

A modern amalgam restoration is an alloy composed of mercury, silver, tin and copper along with other metallic elements added to improve physical and mechanical properties. A unique aspect of the amalgam restoration is that it starts out as a pastelike mixture of metals and, within a few minutes after placement, hardens in the mouth by a series of chemical reactions to form a stable metallic alloy. The mercury is transformed from the metallic liquid state into a solid and stable intermetallic compound.

Amalgam is especially suitable for Class I and II restorations in teeth that encounter heavy chewing forces. Class II restorations tend to be large with extensive tooth-material interface areas. These present a potential for leakage of oral fluids around the margins of the tooth-filling interface, increasing the risk for recurrent caries. However, amalgam has been reported to be capable of sealing the tooth-restoration margins with corrosion products that accumulate with time. Since it is metallic in composition, amalgam is unable to mimic the color or translucency of natural teeth, and its silver-gray color limits its use on anterior teeth.

Advantages of amalgam restorations over other direct-placement materials include resistance to wear; tolerance to a wide range of clinical placement conditions, especially wet fields; and excellent load-bearing properties. (Manhart, Garcia-Godoy & Hickel, 2002, pp 303-39) Amalgam's resistance to wear is superior to that of resin-based composites, especially for areas in direct and heavy contact with opposing teeth. This is due largely to amalgam's ability to adapt through deformation under load.

Ideally, amalgam should be placed in a clean, dry field. Often, cavity location or patient management considerations make this impossible, and amalgam is the only direct material currently available that can be used to provide a serviceable restoration under these conditions. The inability to keep a clean, dry cavity preparation occurs most frequently in very young patients, in deep cavities under the gingival margin or very far back in the mouth. In these very challenging situations, amalgam can provide a satisfactory and very serviceable restoration.

Safety of Dental Amalgam

Amalgam has been used successfully as a restorative material since the middle of ...