Changing concepts in caries microbiology

Concepts and beliefs about the cause of dental caries have evolved over many centuries, with the involvement of microorganisms being recognized since the late 1800s. A main thrust of enquiry since then has been to tackle the question of the relative importance of different bacteria in the disease and this article will consider how technical advances in our ability to identify, cultivate and count different species has influenced our understanding. Over the last decade, molecular biological approaches have had a major impact on views of the relative contribution of particular species of plaque bacteria to the caries process. At a more detailed level, molecular genetic studies of species such as Streptococcus mutans have given new insights into the way in which particular genes and the functions that they encode may affect virulence.