Effect of erosive challenge before and after the restoration of primary teeth

The aim of this in vitro study was to investigate the erosive effect of a soft drink on primary teeth before and after restoration. Enamel blocks were obtained from 64 primary canines (N = 144) and divided into 3 groups (n = 48): 1, erosive challenge before and after restoration; 2, erosive challenge after restoration; and 3, no erosive challenge (control). The blocks received standardized preparations and were restored with 1 of 4 materials (n = 12): composite resin, bulk-fill composite resin, conventional glass ionomer cement, or resin-modified glass ionomer cement. The erosive challenge consisted of immersing the blocks in a cola soft drink for 1 minute at 25°C, 4 times a day for 5 days. The microhardness, roughness, marginal infiltration, and marginal adaptation of the specimens in all 3 groups were evaluated. Data were analyzed with the Kruskal-Wallis and Bonferroni tests. The results showed that the erosive challenge significantly altered all of the evaluated properties of all of the restorative materials (P < 0.05). The erosive challenge decreased the microhardness and marginal adaptation and increased the roughness and marginal infiltration of the tested materials. Composite resin had the highest values for microhardness and marginal adaptation as well as the lowest roughness value and dye infiltration score both with and without the erosive challenge. Subjecting teeth to erosive challenge before and after restoration altered the enamel microhardness and roughness significantly more than did erosive challenge only after restoration. Composite resin was the material least affected by the erosive challenge.