Biocompatibility and functionality of dental restorative materials

Dental restorative materials are required to fulfill basic prerequisites including similarity to tooth structures in their mechanical, physical, and esthetic properties. Although dental restorative materials differ significantly in their characteristics, they are all, once placed as restorations, subjected to the harsh conditions of the oral cavity. After placement, dental restorative materials are in constant interaction with the surrounding tissues. Although dental restorative materials are fabricated to be as durable and inert as possible, restorations may deteriorate, degrade or fail, and during these processes, constituents of these materials may be released into the oral cavity. Not only are these materials expected to maintain their integrity in such harsh conditions, but also to preserve these features during function for prolonged periods. As most restorative materials have a long lifespan, their functionality may alter their basic properties, including those related to biocompatibility. Restorative materials in function need to endure chewing forces, aqueous conditions, numerous microorganisms, fluctuations in pH, food products, temperature swings, and active enzymes. This chapter discusses the general functionality principles of the different material groups in relation to their biocompatibility.