RESUMO
AIM: Oral streptococci were found to be associated with Early Childhood Caries. The aim of this study was to evaluate the 6 different bacteria in the streptococcus group in the saliva of children with severe early childhood caries (S-ECC) by polymerase chain reaction (PCR). MATERIALS AND METHODS: A total of 60 children between 3 and 6 years of age were divided into two groups: children with S-ECC (Group S-ECC; n=30) and children who were caries-free (Group CF; n=30), according to the dmft and dmfs indices. Unstimulated saliva was collected from all participants for the detection of streptococcal group bacteria, including: Streptococcus mutans, Streptococcus oralis, Streptococcus sanguinis, Streptococcus gordonii, Streptococcus salivarius, and Streptococcus sobrinus, using PCR-restriction fragment length polymorphism (RFLP) of amplified 16S rRNA gene. The data were analysed using SPSS software. RESULTS: The prevalence of S. oralis was significantly higher in the S-ECC group compared to the CF group (p<0.05). However, the frequencies of S. mutans, S. sanguinis, S. gordonii, S. salivarius, and S. sobrinus were similar between the two groups (p>0.05). The amount of streptococci colonies was higher in the S-ECC group compared to the CF group (p<0.05). CONCLUSION: S. mutans or S. sobrinus alone may not be the only indicators for high risk of caries, but the prevalence of S. oralis in saliva may be a risk factor for increased caries activity in S-ECC.
