Effect of Post Preparation Dentinal Hypersensitivity Treatment by Fractional CO2 (10600 nm) Laser on Shear Bond Strength of Resin Cement to Dentin: In Vitro Study
Background: After crown preparation of vital tooth, the tooth would be sensitive due to increased number of open dentinal tubules. Dentinal hypersensitivity described as severe and sharp pain evoked by thermal, tactile, osmotic and chemical stimuli. Laser was considered as an effective treatment of dentinal hypersensitivity of exposed root dentin.
Aim of this study: To evaluate the desensitization effect of fractional CO2 laser (1 W, 2.5 ms, 2.5 mJ) and (1 W, 2.5 ms, 2.5 mJ) on shear bond strength of dentin to resin cement.
Materials and methods: Sixty three sound maxillary premolars (n=21) were collected and prepared occlusally to expose dentin, these teeth were divided into three groups. Group A: Dentin surface was irradiated with fractional CO2 (1 W, 2.5 mJ, 2.5 ms), group B: Dentin surface was irradiated with fractional CO2 (1 W, 3 mJ, 3 ms), group C: Control group. SEM investigation was done to evaluate laser effect on dentinal tubules after irradiation with fractional CO2. For each group temperature in the pulp during lasing was measured, furthermore roughness was measured before and after laser treatment. Shear Bond Strength (SBS) between dentin and cement was measured for all groups by universal testing machine.
Result: SEM evaluation showed complete occluding of dentinal tubules in group B, with partial occluding of tubules in group A. Laser treatment caused a significant increase in roughness in group A, with no significant increase in roughness in group B. Shear bond strength significantly increased with group A.
Conclusion: From obtained results, we can conclude that fractional CO2 laser can be considered as an effective treatment option for dentinal hypersensitivity. Shear bond strength can be improved with group A (1 W, 2.5 mJ, 2.5 ms).