Comparative assessment of morphological alterations in the dentin surface by sodium fluoride, 980 nm diode laser, and their combined application for use in the treatment of dentin hypersensitivity: An in vitro scanning electron microscopy study

Context: Lasers have been used as one of the most promising new modalities for dentin hypersensitivity. A synergistic action of lasers in association with desensitizing agents can favor the permanence of the desensitizer for a longer time than when they are used alone. Aims: The present study was aimed to evaluate the morphological characteristics of dentin surface by scanning electron microscopy after fluoride application and irradiation with 980 nm diode laser and their combined application. Materials and Methods: Sixty extracted human premolars were collected, prepared, and randomized into three groups. Group A involved tooth treated with sodium fluoride (NaF); Group B involved tooth irradiated by 980 nm GaAlAs (diode) laser; and Group C consisted of tooth sections irradiated by a diode laser with prior application of NaF. The morphological alterations were evaluated and compared using a scanning electron microscope. Statistical Analysis: The Kruskal–Wallis test was used for multiple group comparisons, and the post hoc Dunn's multiple comparison test was used for intergroup comparisons. Results: Group C, the fluoride-laser treated group, showed the lowest diameter of dentinal tubules (0.077 ± 0.021 μm) and had significantly the lowest number of open dentine tubules. Dunn's multiple comparison tests revealed that Group C had statistically significant tubule diameter reduction and had the lowest number of open tubules compared to both Group A and Group B (P < 0.0001 and P = 0.0007, respectively). In addition, Group C had significantly greater intertubular distance when compared to both Group A and Group B (P < 0.001). Conclusion: The 980 nm diode laser presents a promising new potential for treating dentin hypersensitivity, both alone and in conjunction with desensitizing agents. However, clinical trials are required to use it in regular clinical practice