Organisms involved in pit and fissure caries:
Pit & fissure caries in initiated by a wide variety of organisms like S. mutans, Lactobacillus and Actinomyces species as they colonize in these retentive areas. However, only S.mutans (very significantly) & S. salivarius (by chance) have been proved to colonise smooth surfaces.
Streptococcus mutans.
Lactobacillus.
Actinomyces.
All of the above.