Clinical testing of dental materials--histological considerations

In order to assess the biocompatibility of dental materials, clinical studies, as well as in vitro studies, are needed. Although no bacteria were detected inside tubules, pulp reactions were observed when either adhesives of the last generation aiming to create an hybrid layer were used or restorative materials controlling the interface between the biomaterial and dental tissues. However, the reactions were feeble to moderate. Reparative dentine seldom appeared after such treatments. Differences between odontoblast and pulp cells, the nature of the lesion (necrosis or apoptosis), and differences between sound experimental and carious teeth seen in the real clinical situation are discussed in the context of in vivo human studies.