Study of the adherence of St. mutans on bleached and fluoridated tooth surfaces : an in vitro study

الملخص EN

Aims: To evaluate Streptococcus mutans adherence on bleached enamel surface with (7.5% hydrogen peroxide , 16% carbamide peroxide) with or without topical fluoride theraby.

Materials and Meth-ods: Sixty specimens obtained from thirty maxillary premolars extracted for orthodontic reasons, cleaned, polished, and examined for any surface structural damage.

The roots were discarded and crowns sectioned in two pieces (mesiodistaly) using diamond separating disc in low speed hand piece.

The specimens randomly divided into six groups and exposed to one of the bleaching agents (7.5% hydrogen peroxide , 16% carbamide peroxide) with or without topical fluoride application.

The nega-tive control group specimens stored in deionized water.

The positive control group specimens stored in artificial saliva.

Adherence of Streptococcus mutans count to enamel surfaces was determined bacte-riologically.

The data analyzed statistically using one way ANOVA and Tukey test (p≤0.05).

Results: there is significant increasing in Streptococcus mutans adherence on enamel surface after bleaching procedure, which was decreased significantly when used fluoride application technique after bleach-ing.

Conclusions: Topical fluoride therapy has beneficial effect on reducing the Streptococcus mutans adherence on enamel surface after bleaching regimens which attributed in reducing the possibility of dental caries.