Objective: In order to prevent rampant caries in children, the predominant pathogenic bacteria of rampant caries in children were defined.
Methods: The pathogenic bacteria of rampant caries were isolated and identified in 30 children with rampant caries, aged from 2 to 5 years old. Samples were collected from the caries of labial surfaces of maxillary anterior deciduous teeth, including caries lesions and caries-free smooth enamel surfaces. Plaque were obtained from the cervical third areas of the maxillary labial anterior deciduous tooth surfaces in children without rampant caries and caries-free children and served as controls respectively. The isolates were identified by colony morphology, biochemical tests and DNA base contents (mol percent G + C).
Results: The prevalence of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) in the plaque of caries lesions and the proportions of S. mutans and S. sobrinus in the plaque of 2 sampling sites of children with rampant caries were all significantly higher than those of children without rampant caries and caries-free children (P < 0.05).
Conclusion: S. mutans and S. sobrinus are predominant pathogenic bacteria in rampant caries in children.