[Enamel pearls: the ultrastructural aspects and morphogenesis hypotheses].

Five enamel pearls were examined by scanning electron microscope. Some external pearls presented a bare enamel surface, others were covered by a thin layer of cementum. The enamel pearls showed irregular dystrophic enamel surface or a thin layer without structure, rows of irregular Tome's processes pits, enamel caps and focal holes.

[In vitro and in vivo biocompatibility tests of some endodontic cements].

The major goal of endodontic therapy has been achieved by condensing filling materials into the root canal. It is not uncommon to find excess material in the periapical tissue. It therefore becomes obligatory to use filling materials that have acceptable biocompatibility.