Comparative analysis of marginal fit and internal adaptation in subtractive and additive 3D- printed indirect restoration before and after artificial aging

Aim: Marginal fit and internal adaptation of diverse all ceramic systems before and after artificial aging. Methods: A total of 48 teeth prepared following the manufacturer’s recommendation of at least a 1.0 mm shoulder margin with internal rounded angles, 1.5 mm occlusal reduction, and 1.5 axial reductions, were fabricated from four different materials: IPS E.max Press, IPS E.max CAD/CAM, ZLS, and 3D printing nanoceramic (n=12 for each material). 24 samples (6 from each material) underwent thermocycling, then all samples were cemented with resin cement, and marginal fit and internal adaptation testing were performed. Results: Marginal fit show that the thermocycling had a lower impact value on the material (E.max press) and the technique (additive technique) than on other materials and techniques. Regarding the impact of materials on marginal fit, E.max press show high marginal fit before thermocycling and 3D printing nanoceramic show high marginal fit after thermocycling. In terms of technique, no significant differences were observed between the techniques before and after thermocycling. Internal adaptation shows that the thermocycling had a lower impact value on the material (3D printing nanoceramic) and the technique (additive technique) than on other materials and techniques. Regarding the impact of materials on internal adaptation, 3D printing nanoceramic show high internal adaptation before and after thermocycling. In terms of technique, Additive technique show high internal adaptation before and after thermocycling. Conclusion: Marginal fit and internal adaptation had negative impacts based on the techniques and materials used after thermocycling.a