Comparative Evaluation of Dentinal Tubule Occlusion Using Diode Laser and Potassium Oxalate Gel: An in vitro Scanning Electron Microscopic Study

Abstract

Background: Laser therapy has gained increasing attention in recent years as a treatment modality for dentinal hypersensitivity due to its ability to induce morphological alterations in dentin without the need for restorative intervention. Scanning electron microscopy (SEM) is a highly sensitive and reliable technique for evaluating dentinal surface morphology and the degree of dentinal tubule occlusion following various desensitizing treatment. Aim: The present in vitro study aimed to compare the effectiveness of diode laser and potassium oxalate gel in achieving dentinal tubule occlusion using scanning electron microscopy (SEM). Materials and Methods: Extracted human permanent teeth were used to prepare standardized coronal dentin discs following smear layer removal. The specimens were randomly allocated into three groups: Group I—diode laser treatment, Group II—potassium oxalate gel application, and Group III—control. Diode laser irradiation and potassium oxalate gel application were performed using standardized protocols, while control specimens received no treatment. All samples were evaluated under SEM at 5000× magnification. Dentinal tubule occlusion was assessed using a five-point scoring system. Statistical analysis was performed using SPSS software version 27. Intergroup comparisons were carried out using the Kruskal–Wallis test followed by Mann–Whitney U test. A p-value ≤0.05 was considered statistically significant. Results: SEM analysis revealed completely open dentinal tubules in the control group. Potassium oxalate-treated specimens demonstrated partial and superficial tubule occlusion with predominantly patent tubules. In contrast, diode laser-treated specimens showed marked narrowing and partial to near-complete occlusion of dentinal tubules due to surface melting and resolidification of dentin. The diode laser group exhibited significantly higher dentinal tubule occlusion scores compared to the potassium oxalate and control groups (p ≤0.05). Conclusion: Within the limitations of this in vitro study, diode laser treatment demonstrated superior dentinal tubule occlusion compared to potassium oxalate gel. The findings suggest that diode laser therapy may provide more uniform and stable dentinal tubule sealing and may be a more effective modality for the management of dentinal hypersensitivity.