Association between S. mutans and S. sanguinis in Severe Early childhood Caries and Caries-Free Children A Quantitative Real-Time PCR Analysis

OBJECTIVES: To identify S. mutans and S. sanguinis in initial and overnight plaque between 2 groups and to analyze the association between them and caries-related factors. STUDY DESIGN: Collected supra gingival plaque from 140 Thai children aged 2-6 years old (S-ECC = 68, caries-free=72). Recorded plaque and gingival indices, dmft score, salivary mutans streptococci level, pH and buffer capacity. Firstly, the overnight plaque was collected, then, 4 hrs. after a thorough prophylaxis, the initial plaque was collected. Accessed parent's attitude and behavior in children's oral hygiene care and diet practice using a questionnaire. A quantitative real-time PCR was performed. RESULTS: For initial plaque, S. sanguinis was higher in caries-free. S. mutans (0.011) and S. mutans/S. sanguinis ratio (0.005) were higher in S-ECC. S. sanguinis amount was inverse correlated with dmft (0.00), gingival index (0.044), and plaque index (0.011). For overnight plaque, S. mutans (0.00) and S. mutans/S. sanguinis ratio (0.005) were also higher in S-ECC. S. mutans, S. mutans/S. sanguinis ratio were positive correlated to dmft (0.00). Parent education levels (0.004) and bottle feeding (0.011) between 2 groups were different. CONCLUSION: S. sanguinis, S. mutans and their ratio in initial and overnight plaque, low family income and bottle feeding are strongly associated with S-ECC.