Methods: Supra gingival plaque samples were obtained from 64 children (CF=30, S-ECC=34). After DNA extraction and PCR confirmation by two sets of universal primers, S. sanguinis was identified using specific primers. In addition, children’s information was obtained by the questionnaire consisting of three categorizes which were general information, diet data and oral health care behavior. Pearson chi-square test was used for the statistical analysis of the difference in the prevalence and the association factor contributing to dental caries between two groups (p ≤ 0.05).
Results: The prevalence of S. sanguinis obtained from S-ECC and CF groups was not different. S. sanguinis DNA was detected in 13 samples from CF group (43%) and 22 samples from S-ECC group (65%). Mean age for S-ECC and CF were 2.49 ± 0.41 and 2.29 ± 0.42 respectively. The factor that showed a statistically significant association with caries was the parent educational levels and the regularity of taking water after bottle or breast feeding
Conclusions: The prevalence of S. sanguinis was not different between two groups in the initial plaque formation.