Cement Thickness of Inlay Restorations Made of Lithium Disilicate, Polymer-Infiltrated Ceramic and Nano-Ceramic CAD/CAM Materials Evaluated Using 3D X-Ray Micro-Computed Tomography

PurposeTo evaluate the marginal and internal cement thicknesses of inlay restorations made of various CAD/CAM materials using 3D X-ray micro-computed tomography (micro-CT) technique. Materials and MethodsCaries-free extracted mandibular molars (N = 30) with similar size were randomly assigned to three groups (N = 10 per group). Mesio-occlusal-distal (MOD) cavities were prepared, and inlay restorations were obtained by milling out CAD/CAM materials namely, (a) IPS: monolithic lithium disilicate (control), (b) VE: polymer-infiltrated ceramic, and (c) CS: nano-ceramic using a CAM unit. Marginal and internal cement thicknesses were measured using 3D micro-CT. Data were analyzed using 1-way ANOVA and Tukey's tests (alpha = 0.05). ResultsThe mean marginal and internal cement thickness were not significant in all inlay materials (p > 0.05). Mean marginal cement thickness (m) was the lowest for the IPS group (67.54 10.16) followed by VE (84.09 3.94) and CS (95.18 +/- 10.58) (p > 0.05). The internal cement thickness (m) was the lowest in the CS group (54.85 +/- 6.94) followed by IPS (60.58 +/- 9.22) and VE (77.53 +/- 12.13) (p > 0.05). ConclusionMarginal and internal cement thicknesses of MOD inlays made of monolithic lithium disilicate, polymer-infiltrated ceramic, and nano-ceramic CAD/CAM materials were similar and all less than 100 m, which could be considered clinically acceptable. Clinical significanceMOD inlays made of different CAD/CAM materials presented similar cement thickness, less than 100 m.