Aim: To assess the relationship between clinical outcomes for children treated for Early Childhood Caries (ECC) and salivary mutans streptococci (MS) levels.
Study design and methods: The study cohort consisted of 79 children (42 males, 37 females) treated for ECC, aged from 2.3 to 7.3 years at time of entry. Whole non-stimulated saliva samples were obtained from each subject prior to dental surgery and at 6 mths post dental surgery, by saturating a cotton swab in the saliva pooled in the floor of the mouth. Samples were placed into PBS on ice and processed within 2 hours. Samples were sonicated, serially diluted and plated onto MSB and SBA agar plates, then incubated 48 hours anaerobically; SBA plates were incubated an additional 24 hours aerobically. The MS level in each sample was expressed as a percentage of the total cultivable flora. The cohort was evaluated for new caries lesions at 6 months post dental surgery. Relapse was defined as the presence of new smooth surface caries lesions.
Statistics: Comparisons between Relapse (R) and Non-Relapse (NR) groups with respect to mutans streptococci levels were performed using Wilcoxon tests. Within group comparisons were performed using Wilcoxon signed-rank tests.
Results: 57 children (72%) returned for the 6 months examination and 21 of these subjects (37%) relapsed. No statistically significant difference in median salivary MS levels existed between the R (0.20%) and NR (0.033%) groups at baseline (p=0.647) or at 6 months post dental surgery (R=0.03%; NR=0.01%; p=0.273). A statistically significant difference between baseline and 6 months post dental surgery was noted in the median salivary MS level within the R group (p=0.0007) and within the NR group (P<0.0001).
Conclusions: The relapse rate (37%) was high and rapid for children treated for ECC. Dental surgery resulted in a statistically significant reduction in salivary MS reservoirs for children treated for ECC. However, this did not translate into acceptable clinical outcomes.