The effect of dental sealants on bacteria levels in caries lesions: A review of the evidence

Background. Concern about inadvertently sealing over caries often prevents dentists from providing dental sealants. The objective of the authors' review was to examine the effects of sealants on bacteria levels within caries lesions under dental sealants, Methods. The authors searched electronic databases for comparative studies examining bacteria levels in sealed permanent teeth. To measure the effect of sealants on bacteria levels, they used the log ₁₀ reduction in mean total viable bacteria counts (VBC.) between sealed and not-sealed caries and the percentage reduction in the proportion of samples with viable bacteria. Results. Six studies - three randomized controlled trials, two controlled trials and one before-and-after study - were included in the analysis. Although studies varied considerably, there were no findings of significant increases in bacteria under sealants. Sealing caries was associated with a 100-fold reduction in mean total VBC (four studies, 138 samples). Sealants reduced the probability of viable bacteria by about 50.0 percent (four studies, 117 samples). Conclusions. The authors found that sealants reduced bacteria in carious lesions, but that in some studies, low levels of bacteria persisted. Those findings do not support reported concerns about poorer outcomes associated with inadvertently sealing caries. Clinical Implications. Practitioners should not be reluctant to provide sealants - an intervention proven to be highly effective in preventing caries - because of concerns about inadvertently sealing over caries.