Evaluation of Internal Fit of CAD/CAM Implant Abutments with Hybrid and Internal Hex Connections Using Different Materials

Objective: The aim of this study was to evaluate the internal fit of hybrid and internal hex connections using different materials. Materials&Methods: Forty abutments were divided into 2 groups according to connection type. Each group was subdivided into 4 subgroups according to material (Zr, Ti, Co-Cr and soft-milled Co-Cr-Mo). Internal fit was measured using replica technique. Results: All the samples had clinically acceptable gap values ≤150 µm where internal hex connection had narrower gap than conical connection. Zirconia was the material with lowest gap values, followed by titanium and soft-milled Co-Cr-Mo. Co-Cr had the largest gap distance. Conclusions: 1: Internal hex connection has better internal fit than hybrid connection with more consistent results among different materials. 2: Zirconia showed the best overall internal adaptation with consistent performance among the two connections used. 3: Low marginal gap distance of CAD/CAM conical abutments may not necessarily indicate proper seating of the abutments.