Mineralization of Streptococcus mutans in vitro. An ultrastructural study

Streptococcus mutans mineralization was studied in vitro, with the use of various metastable calcium phosphate solutions, fluoride-containing or otherwise. Degeneration of bacteria always occurred before their mineralization. After complete mineralization of the cytoplasmic area, growth of crystals was observed both in length and in thickness within the extracellular environment. Composition of the calcifying medium was an essential factor in the S. mutans mineralization process. The present study shows that, contrary to carbonate and magnesium ions that prevent intra- and extracellular deposits, fluoride ions promote crystal growth in the above mentioned mediums. Clinical implications of the role of fluoride, at the plaque level, are foreseen.