- Purpose: To determine whether smear layer removal reduces leakage of obturated human teeth in vitro
- PubMed was searched for articles published between 1975 and 2005
- Results were categorized based on the method of leakage test.
- 26 eligible papers.
- The records then were divided into five groups based on the type of leakage test and further analysis was performed within each group. These groups were:
- (a) dye leakage test (44 comparisons); (b) fluid filtration test (7 comparisons); (c) electrochemical test (7 comparisons); (d) bacterial leakage test (6 comparisons); and (e) volumetric dye leakage test (1 comparison).
Most highlighted Results:
- Among 26 eligible papers with 65 comparisons:
- 53.8% of the comparisons reported no significant difference.
- 41.5% reported a difference in favor of removing the smear layer.
- 4.7% reported a difference in favor of keeping it.
- Of the 65 comparisons, 44 used the dye leakage test for evaluation. The combined effect in this group showed
smear layer removal decreases dye leakage.
- According to meta-regression, obturation type, test site and duration, sealer and dye, and publication year had no effect on the results.
Smear layer removal improves the fluid-tight seal of the root canal system whereas other factors such as the obturation technique or the sealer, did not produce significant effects.