Triple scan evaluation of internal and marginal adaptation of overlays using different restorative materials

Objective Problems in the confection of indirect restorations may increase the marginal and internal gap. This study aimed to quantify the marginal and the internal fit of overlays fabricated with three different materials. Materials and methods Standardized cavities were prepared on endodontically treated human third molars and digital impressions were done using an intraoral camera (Trios 3). Restorations were designed (n = 15) and fabricated with three materials: Hybrid ceramic (Cerasmart; GC Corp, EUROPE), high-strength lithium disilicate (GC Initial (R) LiSi Press; GC Corp, Tokyo, Japan), and zirconia reinforced Lithium Silicate Glass Ceramic (Vita Suprinity; Vita, Germany). Axial, marginal, pulpal, and gingival gaps were calculated by measuring the distance between the restoration and the tooth at several reference points. Two-Way analysis of variance was used for statistical analysis. The significance level was set at alpha = 0.05. Results Mean gap was significantly influenced by the material (p < 0.001), gap localization (p < 0.001), and interaction between the factors (p = 0.002). For all materials, the highest gap was observed at gingival and pulpal surfaces (p <= 0.015). LiSi Press achieved the overall lowest values at axial values measurements (p <= 0.003). Conclusions The performance of a CAD/CAM system relative to marginal adaptation is influenced by the restorative material used. High-strength lithium disilicate seems to be showed the best marginal adaptation. Clinical significance Marginal and internal adaptation of CAD/CAM restorations could be influenced by the type of material chosen.