Objectives: The objectives of this in-vitro study were to evaluate dentin tubule occlusion caused by Predicta Bioactive Desensitizer, a methacrylate-free, nanohydroxyapatite-based desensitizer, and the effects of phytic acid pretreatment.
Materials and Methods: Occlusal surfaces were prepared from 55 caries-free human premolars extracted as part of orthodontic treatment with informed consent. The teeth were stored in 0.5% thymol solution at 4°C and then randomly allocated to 6 groups, each consisting of 10 samples except the control group. Using a low speed diamond saw, 2mm thick dentin discs were cut. The central area (5mm) was defined as the experimental area and polished with 600 and 1000 grit silicon carbide. These polished samples were immersed in 17% EDTA for 40 minutes to open up the dentin tubules. Groups A, B, C, D, and E (n=10 each) were treated with PredictaBioactive Desensitizer. Samples of Group D and E were pretreated with 1% phytic acid with and without wash, respectively; Group F (n=5) was left immersed in artificial saliva as a control. Micromorphological analysis using a scanning electron microscope was performed to assess tubular occlusion. A blinded reviewer independently scored the level of tubule occlusion. Means were compared using one-way analysis of variance (ANOVA).
Results: The mean occlusion scores computed from micromorphological analysis using scanning electron microscope showed that: Group E > Group D > Group C = Group B > Group A > Group F.
Conclusion: The tubule occlusion efficacy of Predicta Bioactive Desensitizer seems to be more effective with 1% phytic acid pretreatment than without.
Keywords: dentin, phytic acid, dentin sensitivity, smear layer, desensitizers, SEM, bioactive
