Effect of a modified methyl methacrylate-p-styrene sulfonic acid copolymer-based gel desensitizer on dentin permeability and tubule occlusion in human dentin in vitro

Abstract

Background/purposeTubular occlusion is an effective method to treat dentin hypersensitivity. This study aimed to determine the effect of a modified methyl methacrylate-p-styrene sulfonic acid copolymer-based gel desensitizer on dentin permeability and tubule occlusion in extracted human premolars. Materials and methodsHydraulic conductance (HC) measurement (n = 50) and scanning electron microscopy (SEM; n = 64) were performed. Tooth specimens were divided into 6 groups and treated with: G1, distilled water for 30 s; G2, distilled water for 5 min; G3, gel desensitizer for 30 s; G4, gel desensitizer for 5 min; G5, 3% potassium oxalate for 30 s; G6, 3% potassium oxalate for 5 min. HC of dentin were measured before and after 30 s-etching with 35% phosphoric acid, at 0, 30, 60 min after group treatment and after 5-min acid challenge with 6% citric acid. The degree of tubule occlusion and the penetration depth of each agent were also determined. ANOVA and multiple comparison tests were used for data analysis. ResultsG3, G4, G5 and G6 significantly decreased in HC after group treatment every observation period, compared to after acid-etching (P < 0.001), and had 100% degree of tubule occlusion with penetration depth about 7.62, 7.94, 8.59 and 8.66 μm, respectively. However, G6 showed the greatest reduction in HC (P < 0.05). ConclusionGel desensitizer treatment, for only 30 s, could reduce dentin permeability and completely occlude the dentinal tubules, even though after acid challenge. However, 5-min treatment with potassium oxalate showed the greatest decrease in dentin permeability.