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 eithe
r adhesives of the last generation aiming to create an hybrid layer we
re 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. D
ifferences between odontoblast and pulp cells, the nature of the lesio
n (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.