Comparation betweens Mutans Streptococcus and Mutans Sobrinus in rampant caries

Objective: Investigate the number and distribution of Mutans streptococcus and Mutans sobrinus in the dental plaque of children with rampant caries , and offer the foundation to prevent rampant caries . Methods: A total of 92 plaques of pre-school children with rampant caries were detected by real time PCR with MGB probes designed according to the gtf gene of Mutans streptococcus and Mutans sobrinus. The results were then compared with the children without rampant caries.Results: Among those 92 children with rampant caries, Mutans streptococcus were found in 89 samples with 96.7% positive rate while Mutans sobrinus were found in 30 samples with 32.6% positive rate. Among other 92 children without rampant caries Mutans streptococcus were found in 88 samples with 95.6% positive rate, Mutans sobrinus were also detected in 4 samples with 4.3% positive rate. There is difference in the positive rate of Mutans sobrinus between them in evidence. The average of the ratio between the templates of the Mutans streptococcus and Mutans sobrinus in rampant caries is 5.61 ,while the ratio in the comparation is 17.61. Conclusion: The templates of Mutans sobrinus are less than Mutans streptococcus in rampant caries. The average of the ratio between the templates of the Mutans streptococcus and Mutans sobrinus in rampant caries is lower than the comparation.