Combined Effects of Er:YAG Laser and Nano-Carbonate Apatite Dentifrice on Dentinal Tubule Occlusion: In Vitro Study

Objective: The aim of this study was to evaluate the occluding effects of Er:YAG laser and dentifrice containing nano-carbonate apatite (n-CAP) on the dentinal tubules. Background data: Although there are various treatment methods for dentin hypersensitivity (DH), more effective methods are still being sought. Methods: Sound human root dentin specimens were etched with 6% citric acid to open the dentinal tubules. The specimens were divided randomly into four groups: no treatment (control group), toothbrushing using 20% n-CAP dentifrice (n-CAP group), Er:YAG laser irradiation (LI group), and LI after n-CAP (combined group). The degree of occlusion of the dentinal tubules and the thickness of the deposition layer were evaluated by scanning electron microscopy and an image analyzer. Results: It was shown that the occlusion effect of the n-CAP group was 87%, that of the combined group was 54%, and that of the LI group was 52%, compared with that of the control group. And the n-CAP particles were observed not only under the irradiated surface and but also above the surface in the combined group. Conclusions: This combination method has the potential for enhancement of the dentinal tubule occlusion. However, further study is needed to present the combination effects with additional analysis, and the long-term effects.ope