pH and Eh in Single and Mixed Culture Bacterial Plaque in an Artificial Mouth

The pH and E h of bacterial plaques produced on a tooth surface in an artificial mouth following inoculation with saliva, single cultures and mixed cultures were measured. The importance of these properties and the role of sucrose in controlling colonization by specific organisms, particularly anaerobes, was investigated. The degree of colonization was estimated from the viable counts in the effluent from the tooth. Interactions between the bacterial species in the multi‐culture plaques are discussed. The results are presented in support of the hypothesis that colonization of the teeth by anaerobes depends upon prior growth of aerobes during early plaque formation.