SALIVARY MUTANS STREPTOCOCCI AND INCIDENCE OF CARIES IN PRESCHOOL-CHILDREN

The aim of this study was to assess the relationship between salivary mutans streptococcus (SMS) levels and the prevalence and incidence of dental caries in 148 children (mean baseline age 3.8 years) of low soc ioeconomic status. Caries data (dmfs) and semiquantitative SMS counts were obtained at baseline and annually for 2 years. The children were classified during each of the 3 years as low (0 colony-forming units; CFU), moderate (1-50 CFU), or high (> 50 CFU) caries risk based on tot al SMS counts. The results indicated that the prevalence of dental car ies increased with SMS levels at baseline and generally in both assess ment years. At baseline the mean dmfs of the children classified as lo w, moderate, or high caries risk was 0.15, 1.44, and 3.36, respectivel y, while the mean dmfs of the same children at year 2 was 1.18, 3.10, and 7.87, respectively. The mean dmfs of the high-caries-risk group in creased by 79% between baseline and year 1 and by 30% between year 1 a nd year 2. At year 2, 50% of the children in the low- and 47% in the m oderate-caries-risk groups. Thirty-three percent of the children exami ned remained in the same caries risk category from baseline to year 2; the incidence (Delta dmfs) of dental caries in those children designa ted as low, moderate, and high caries risk during this period was 1.44 , 3.36, and 10.07, respectively. The results indicate that there is an association between SMS levels and prevalence and incidence of dental caries in the primary teeth of these children and suggest that SMS le vels may be useful in predicting the caries risk in the deciduous dent ition of some populations.