Efficacy of resin-based materials against erosive-abrasive wear in vitro

Abstract

Background: Increasing prevalence of dental erosion has been observed in many countries, in both children and adults. This condition is often associated with softening of the dental surface by acid exposure, which may lead to severe and irreversible damage. The use of fluoride, pit and fissure sealants, dental adhesives and more recently a resin infiltrant has been suggested to manage dental erosion. Objective: To compare the protective effect of a resin infiltrant and other resin-based materials against dental erosion/toothbrushing abrasion in vitro. Materials and methods: Bovine enamel and dentin slabs were prepared, embedded, flattened and polished. Dental erosion lesions were created using 0.01 M of hydrochloric acid (pH 2.3 for 30 sec) and treated with resin-based materials (HS: Helioseal pit and fissure sealant; SP: Seal and Protect dentin 78 sealant, and IC: Icon resin infiltrant) or fluoride varnish (FV: Duraphat). A no-treatment group represented the negative control (C). The specimens were subjected to an erosion-abrasion cycling model for a total of 10 days. Each cycling day consisted of 2 min immersion in 0.01M HCl, at room temperature, for 4 times; and toothbrushing with either of the abrasive suspensions (low and high, as previously determined by the radioactive dentin abrasivity method). Enamel and dentin surfaces were scanned at baseline, after treatment, at 5 days and at 10 days using an optical profilometer. Surface change (loss/gain) was determined by subtracting the treated area from the reference (protected) areas. Significance level of 5% was adopted for the statistical analysis. Results: No differences were found among groups at baseline, regardless of substrate. After treatment, surface deposition was found for all test groups except for IC, which did not differ from C. For enamel, at day 5, FV, HS and SP had less surface loss than C and IC (p<0.0008), which did not differ from each other (p=1.00). At day 10, similar trend was observed except for FV, which showed surface loss similar to C, when brushed with high abrasive suspension. High abrasive caused more surface loss than low abrasive only for C at day 5 (p=0.0117) and 10 (p=0.0162). For dentin, at day 5, FV, HS and SP had less surface loss than C and IC (p≤0.0001), which did not differ from each other (p=1.00). At day 10, HS and SP had less surface loss than C, IC, and FV (p<0.0001), and FV had less surface loss than C for low abrasive (p=0.0009). Overall, high abrasive had significantly more surface loss than low abrasive at 10 days (p=0.0280). Conclusion: HS was the most effective material protecting enamel and dentin from erosion-abrasion, followed by SP. FV offered limited protection, while no benefit was observed for resin infitrant IC.