Less dental caries among secretors than among non-secretors of blood group substance.

Salivary mucins can aggregate oral bacteria and also constituents of pellicle and plaque. A,B, and H blood group antigens are present on the mucins of secretors only. These mucins have also been shown to contain more carbohydrate than non-secretor mucins. The aim of the present study was to relate these genetically determined differences in mucin composition to caries prevalence. Data on blood group, secretor status, and caries prevalence were collected from 69 dental students. In all blood groups, the average caries prevalence was lower for secretors than for non-secretors. The difference was more pronounced for smooth surface than for total surface prevalence. The secretors of blood group mucin A had the lowest caries prevalence. The results would be consistent with an impact of the mucin composition upon the caries prevalence, and possible mechanisms are discussed.