ABSTRACT
To gain greater understanding of the role of Streptococcus mutans and Veillonella in the caries process, studies of both aerobically and anaerobically grown plaques of S. mutans C67-1 and V. alcalescens V-1 on human enamel slabs were carried out in an artificial mouth. Plaque development, acid production, and demineralization were measured. Early plaque development of monobacterial and mixed bacterial plaques started from randomly adhering cells on day 1 to confluent multilayered microcolonies on day 4. Differences were observed in viable cell counts, total cell mass, and in acid production. In most cases CFU, DNA and acid production were higher in the mixed bacterial plaque, especially in the anaerobic mixed plaque. Lactic acid was the predominant acid in all cases following the supply of sucrose to the plaque. No decisive role could be found for acetic, formic, and propionic acid. No inhibition of demineralization was observed in the enamel slabs inoculated with both aerobic and anaerobic mixed plaques. Demineralization ranged from the more classical picture of lesion development in the aerobic monobacterial plaque-treated samples to an aggressive etching of the enamel surface in the anaerobically mixed treated slabs.
Subject(s)
Dental Enamel/microbiology , Models, Biological , Mouth , Streptococcus mutans/physiology , Veillonella/physiology , Aerobiosis , Anaerobiosis , Carboxylic Acids/metabolism , Dental Caries/microbiology , Dental Plaque/microbiology , Humans , Microradiography , Streptococcus mutans/growth & development , Streptococcus mutans/metabolism , Veillonella/growth & development , Veillonella/metabolismSubject(s)
Dental Enamel/microbiology , Dental Plaque/microbiology , Streptococcus mutans/metabolism , Dental Caries/metabolism , Dental Caries/microbiology , Dental Enamel/metabolism , Dental Enamel/ultrastructure , Dental Plaque/metabolism , Hardness , Humans , Models, Biological , Mouth , Time FactorsABSTRACT
A new apparatus for the continuous cultivation of mono and mixed bacterial plaque on solid surfaces is described. The features are: easy preparation and handling; freedom from technical problems and microbial contamination; self-sufficient for periods of up to 56 d; 12 samples are taken simultaneously; programmable supply inlet. Experiments were performed with Streptococcus mutans C 67-1 for mono bacterial inoculation and in combination with Veillonella alcalescens V-1 for mixed bacterial inoculations. The results showed that the controlled conditions and versatility of the apparatus make possible the study of plaque-development and lesion production on a time-dependent basis. It is concluded that the apparatus is suitable for a wide range of dental and non-dental applications.
