The Influence of a Flexible Model on the Marginal Adaptation of Inlay Composite Restorations: A MicroCT Analysis

The aim of this study was to evaluate the influence of flexible models on the marginal adaptation of indirect resin composite restorations. Thirty-six cavity preparations were made for class II restorations in permanent molar teeth. Three groups (n=12) were defined following three impressions/model material combinations: G(STONE), polyvinylsiloxane, and type IV stone model, as a control group; G(IMPRESSIONPVS), alginate and flexible polyvinylsiloxane; G(MODELPVS), alginate and flexible polyvinylsiloxane for models. All restorations were positioned on their respective teeth and evaluated by micro-computed tomography. Absolute marginal discrepancies were measured digitally (ImageJ). The results were compared using one-way ANOVA (p< 0.05). The mean ± SD absolute marginal discrepancy of indirect resin composite restorations made from flexible and rigid stone models was as follows: G(STONE), 206 (±79.95) µm; G(IMPRESSIONPVS), 221.50 (±61.73) µm; G(MODELPVS), 203.25 (±65.93) µm. Absolute marginal discrepancies were not significantly influenced by the flexible and rigid stone models (p=0.78). The flexible or rigid stone model did not influence the marginal adaptation of the indirect resin composite restorations.