2. What are the alternatives for amalgam fillings?

Today, the use of alternative materials such as adhesive composite resins, glass ionomer cements (a combination of silicate and polyacrylate), ceramics and gold alloys is increasing, either because of their aesthetic properties or in response to perceived health concerns related to the use of dental amalgam.

Some alternative materials have been in clinical use for well over thirty years, but many materials were introduced recently. Initially, these alternative composites were used in anterior teeth, but they are now also used for restorations in posterior teeth. There is indeed a trend in dentistry towards techniques that use minimal intervention and materials which adhere to the tooth structure. These materials adhere to tooth structure by chemical interaction and/or micromechanical retention. Resins and glass ionomers are usually used for direct restorations where the material is shaped directly in the tooth, whereas ceramics and gold alloys are used for indirect restoration, where an imprint of the tooth is taken and the material is shaped outside the mouth and then bonded to the tooth.

Studies comparing amalgam with resin-based materials showed generally better longevity for amalgam. Alternative restorations fail primarily through secondary caries and fractures of the restoration and tooth. However, some recent studies showed very good long-term clinical effectiveness for resin composite restorations in molars with equal and better longevity than for amalgam. But even under optimal conditions, large composite restorations failed more often than amalgam fillings.

Amalgam alternatives used in indirect restorations have a good survival rate and, in general, they require less removal of healthy tooth substance than does amalgam, which requires that a larger space is made for the retention of the filling. On the downside, the costs of indirect restorations are considerably higher than direct restorations.