RESTORATION RELATED SALIVARY STREPTOCOCCUS-MUTANS LEVEL - A DENTAL-CARIES RISK FACTOR

Objectives. The salivary level of Streptococcus mutans related to fill ed teeth was compared with the levels related to decayed and sound tee th, in order to establish whether the presence of restorations may inc rease the risk of infection of other teeth by Streptococcus mutans. Me thods: The sound, decayed and filled teeth were recorded in 809, 6-7-y ear-old school-children. Salivary Streptococcus mutans detection (i.e. more than 1 x 10(4) CFU/ml) and counts were evaluated. Streptococcus mutans log count means and prevalence values of subjects with only sou nd teeth (group 1), with filled? without decayed teeth (group 2), with decayed, without filled teeth (group 3), were calculated and compared using the Student's t-test and the chi-square test. The effect of fil led, decayed and sound teeth on Streptococcus mutans level was also ev aluated using logistic regression. Results. Log count means and preval ence values of group 2 subjects were significantly lower than values o f group 3 subjects (means, 0.92 vs 1.66; prevalence, 73.17% vs 94.63%) and statistically not-different from values of group 1 subjects (mean , 0.75; prevalence, 70.06%). The logistic regression analysis showed t hat the factors significantly increasing the risk of Streptococcus mut ans being detected in saliva were only primary and/or permanent decaye d teeth. The risk of Streptococcus mutans being detected in saliva was not affected by filled teeth more than sound teeth. Conclusions: In t he present study population, the salivary Streptococcus mutans level a ttributable to filled teeth was low; this suggests that treatment of a carious lesion would cause a lowering of Streptococcus mutans concent ration to the same levels as those shown by healthy subjects, thus red ucing the risk of infection to other teeth. (C) 1997 Elsevier Science Ltd.