Marginal and Internal Fit of Semi-Direct and Indirect Inlays Restorations

Objectives: The aim of this study was to investigate in vitro the marginal and internal fit the MOD inlays restorations performed with semi-direct and indirect restorative techniques.
Methods: A metal master model was made with MOD Class II cavity preparation, inlays restorations were obtained by different restorative techniques. The groups were formed according to the material and the restorative technique (n = 10): Group G1 (CAD / CAM): milling of prefabricated blocks for CAD / CAM (IPS e.max CAD); Group G2 (Pressed): hot pressing of a glass ceramic based on lithium disilicate (IPS e.max Press); and Group G3 (SD Polyether): semi-direct composite resin using a polyether model. The cementation was simulated using the cement-analog technique. The marginal fit was evaluated after the simulation of the cementation in stereomicroscopy (100x). Marginal fit was evaluated for each inlay as the conjunction of mean gap widths values of mesial and distal faces. The internal fit was evaluated by measuring the thickness of the silicone film in the stereomicroscopy (80x). Data were analyzed with the application of one-way ANOVA, Tukey and Games-Howell test.
Results: It was observed that the lowest values of marginal fit were obtained in groups G1 (CAD / CAM = 87.33 μm) and G3 (SD Polyether = 89.23 μm), which were statistically similar to each other. Group G2 (Pressed = 105,63 µm) was statistically different from G1, but is statistically similar to the G3 group. The groups G3 (75.61 μm) presented the lowest values of internal fit in comparison to the G1 (153.09 µm) and G2 (124.32 µm) groups.
Conclusions: The marginal fit was more accurate in the restorations obtained by the semi-direct technique, but only in relation to the pressed ceramic. The internal adaptation was more accurate in the restorations obtained by semi-direct technique.