Effectiveness of Desensitizing Dentifrices and 980 nm Diode Laser in Occluding Dentinal Tubules: An In Vitro Scanning Electron Microscopy Study

Introduction: This in vitro study aimed to compare the efficacy of three desensitizing dentifrices, alongside a 980 nm diode laser, in occluding dentinal tubules to reduce dentine permeability and alleviate hypersensitivity. The primary objective was to assess tubule occlusion using scanning electron microscopy (SEM). The secondary objectives were to evaluate the relative effectiveness of each treatment in reducing dentine permeability and to compare their potential to mitigate hypersensitivity symptoms by occluding the dentinal tubules. Materials and methods: This in vitro study was conducted on 50 extracted human first premolar teeth that were sectioned into 2 mm dentinal discs. The discs were ultrasonicated to remove the smear layer and randomly allocated into five groups (n = 10): Group 1 (control, brushed with distilled water; Merck Life Science Pvt. Ltd., Mumbai, India), Group 2 (brushed with Emoform, Dr. Wild & Co. AG, Muttenz, Switzerland), Group 3 (brushed with Propolis, Apis India Ltd., New Delhi, India), Group 4 (brushed with Sensodyne Repair and Protect, GlaxoSmithKline Consumer Healthcare, Brentford, UK), and Group 5 (treated with a 980 nm diode laser, Biolase Epic X, Biolase Inc., Irvine, USA). Groups 1-4 were brushed twice daily for seven days with a soft-bristled toothbrush (Colgate SlimSoft, Colgate-Palmolive India Ltd., Mumbai, India) using the respective slurries. Group 5 was lased at 0.8 W in continuous wave mode for 10 s. Specimens were gold-palladium-coated and analyzed by SEM (ZEISS EVO 18, Carl Zeiss AG, Oberkochen, Germany) at 5000x magnification to calculate the percentage of occluded tubules. Results: The Kruskal-Wallis test showed significant differences in tubule occlusion (p = 0.001). The laser group demonstrated the highest occlusion rate, followed by the Sensodyne Repair and Protect, propolis-based dentifrice, and Emoform groups, all of which significantly outperformed the control group (Dunn's test, p < 0.05). The laser group exhibited superior consistency, while Sensodyne Repair and Protect showed robust occlusion compared with the other dentifrices. Conclusion: The 980 nm diode laser was the most effective in occluding dentinal tubules, followed by Sensodyne Repair and Protect, propolis-based dentifrice, and Emoform. These treatments offer potential for managing dentine hypersensitivity, with the laser providing rapid occlusion and Sensodyne Repair and Protect as a practical alternative. Further in vivo studies are required to validate its clinical efficacy.