Objectives: The objective of this study is to confirm the validity of this population as a high risk group for having caries, by observing the microbiological parameters commonly associated with the disease. These are the presence of predominant aciduric bacteria, mutans streptococci and lactobacilli.
Methods: Plaque samples were obtained from the interproximal site of the 25 and 26 using sterile dental floss and were processed to obtain lactobacilli and mutans streptococci counts. Diluted samples were inoculated onto three microtitre trays containing brain heart infusion broth at pH 4.8, 5.2 and 7. These were incubated anaerobically for 5 days at 37ºC. Wells exhibiting growth were recorded and the mean probable numbers were calculated.
Results: The results show that there is a significant positive correlation between the numbers of predominant aciduric microbes and d1mft (Spearman's =0.20, p=0.01). There was also a significant association between the lactobacilli counts and the level of aciduric microbes (=0.21, p=0.02). No relationship was found between the presence of mutans streptococci and high levels of predominant aciduric bacteria.
Conclusions: As expected individuals with a high dmft harboured high levels of aciduric microbes and lactobacilli, which are commonly associated with caries. This verifies the identification of individuals selected to be at a high risk of having the disease and also confirms that they have good bacteriological foundation for measuring the effects of a potentially beneficial intervention. This clinical trial is funded by Gaba AG, Switzerland grant number RGDCGT.