The effect of monitored chlorhexidine gel treatment on mutans streptococci in margins of restorations

Objectives: The objective of this study was to compare the effect of a monitored chlorhexidine (CHX) gel treatment with a conventional two-day CHX treatment in subjects with well-restored dentitions and high numbers of salivary mutans streptococci (MS). Methods: In the test group (n = 8), the effect of the CHX gel applications was monitored in margins of restorations and in saliva during a period of 12 weeks. Strip Mutans was used for monitoring and whenever a sample revealed growth of MS, the subject received a 3 × 5 min 1% CHX gel treatment at the clinic. Nine subjects (control group) were only given the baseline (conventional) treatment with CHX gel 3 × 5 min on two consecutive days. Results: The monitored treatment in the test group resulted in a more pronounced reduction of MS both in margins of restorations and in saliva than the conventional treatment. The difference between the level of MS in the margins in the two groups was, however, only significant at the 20-week examination. There was a large individual variation in the effect of the CHX treatment, and three to nine extra CHX gel applications were needed in the test group to keep MS below a detectable level during the 12 weeks. Conclusions: Our findings illustrate the difficulties to obtain a long-lasting reduction of MS in subjects with a large number of restorations and a high number of MS by antimicrobial treatment only. The results indicate the necessity to combine antimicrobial treatment with, for example, sucrose restriction, in order to keep MS at a low level for a longer period of time.