2013 Volume 56 Issue 1 Pages 1-8
Purpose: The concept of minimal intervention has become popular and the importance of pulp conservation is now recognized. However, a standard for the removal of dental caries has not yet been determined. In the present study, we qualitatively and quantitatively investigated the effect of Er: YAG laser irradiation on residual bacteria after removal of softened dentin. Methods: Fifty-seven teeth which needed caries treatment were studied. After removing the caries with Caries Detector until the dentin was stained light pink, Er: YAG laser was irradiated to the cavity and the dentin sample was collected. In the control specimens, the dentin specimen was collected without Er: YAG laser irradiation. Then, the number and species of bacteria collected from the sample were evaluated. Some samples were subjected to confocal laser microscopic observation. Results: No patients complained of any clinical symptoms in either the experimental group or control group. In the control group, residual bacteria were detected in 69% of samples, whereas in the Er: YAG laser irradiated group the detection rate was only 43 % (p<0.05). The number of bacteria detected in the experimental samples was significantly less than that in the control samples (p<0.05). Confocal microscopic observation showed a similar tendency to these results. We could not find clear differences between the control and experimental groups concerning the species of detected bacteria. Conclusion: Er: YAG laser irradiation after removal of caries effectively reduced residual bacteria in the cavity.
