The Effect of Dental Sealants on Bacteria Levels in Caries Lesions: A Review of the Evidence

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ABSTRACT
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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 log10 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. These 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.

Section snippets

Inclusion criteria

This analysis was part of a broader systematic review of sealant effectiveness in known carious lesions in the pits and fissures of permanent teeth. Initially, we included all in vivo studies published in English that compared outcomes, such as caries progression or bacteria levels, in permanent teeth treated with sealants with outcomes in permanent teeth not treated with sealants. Comparisons could involve concurrent randomized controlled trials (RCTs), controlled trials or cohort studies

Description of studies

Of the six studies14, 15, 16, 17, 18, 19 used to calculate outcome measures in this analysis (representing 303 bacteria samples), two studies were RCTs,17, 18 one was a subgroup analysis of an RCT of split-mouth design,14 two were controlled trials that did not mention randomization15, 16 and one was of a before-and-after design (in which the same tooth was sampled before and after sealant placement)19 (Table 1).

About 94 percent of sampled lesions were cavitated at baseline (that is, allowed

DISCUSSION

Sealants were effective in reducing total bacteria counts in caries lesions. The reduction increased with time since sealant placement. At the last follow-up, there was a 100-fold decrease in mean bacteria counts in two studies14, 19 and a 1,000-fold decrease in the remaining two studies.15, 16 Sealants also reduced bacterial cultivability. On average, 47 percent of sealed lesions had viable bacteria (median = 50 percent) compared with 89 percent of unsealed lesions (median = 100 percent). When

CONCLUSION

We found that sealants significantly reduced bacteria levels in cavitated lesions, but that in some studies, low levels of bacteria persisted. These findings support those of a recent meta-analysis that sealants prevented caries progression.12 In combination, these two sets of findings suggest that when sealants are retained, and thus access to fermentable substrates is blocked, bacteria do not appear capable of exerting their cariogenic potential.

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  • Cited by (0)

    Disclosure: None of the authors reported any disclosures.

    The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the U.S. Centers for Disease Control and Prevention, Atlanta.

    The authors gratefully acknowledge the generous contribution of time and expertise by the U.S. Centers for Disease Control and Prevention's Dental Sealant Systematic Review Work Group: James D. Bader, DDS, MPH; Jan Clarkson, BSc, BDS, PhD, FDSRCS(Paed); Margherita Fontana, DDS, PhD; Daniel M. Meyer, DDS; R. Gary Rozier, DDS, MPH; Jane A. Weintraub, DDS, MPH; and Domenick T. Zero, DDS, MS.

    1

    Dr. Oong is a dental public health resident, Centers for Disease Control and Prevention/Division of Oral Health/Surveillance, Investigations, and Research Branch, Chamblee, Ga.

    2

    Dr. Griffin is a health economist, Centers for Disease Control and Prevention/Division of Oral Health/Surveillance, Investigations, and Research Branch, 4770 Buford Highway, MSF10, Chamblee, Ga. 30341

    3

    Dr. Kohn is the associate director of science, Centers for Disease Control and Prevention/Division of Oral Health/Surveillance, Investigations, and Research Branch, Chamblee, Ga.

    4

    Dr. Gooch is a dental officer, Centers for Disease Control and Prevention/Division of Oral Health/ Surveillance, Investigations, and Research Branch, Atlanta.

    5

    Dr. Caufield is a professor, Cariology and Comprehensive Care, New York University College of Dentistry, New York City.

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