Purpose: This study aimed to assess the accuracy of implant custom abutments according to the different radii of the curvature value.
Methods: Two custom abutments with different radii of the curvature value were designed based on dental computer-aided design. Then, a total of 20 customized abutments, 10 of each design, were milled according to the designs. The fabricated custom abutments were scanned using a model scanner. Using Geomagic Control X (3D Systems) scanned files were superimposed on the designed files to evaluate trueness, and scanned files for each group were superimposed on each other to evaluate precision.
Results: The trueness values of radius of curvature value (CV)-0.75 and CV-1.50 were 56.26±5.66 μm and 47.10±2.64 μm, respectively. A significant difference (p<0.001) was found between the groups. The precision values of CV-0.75 and CV-1.50 were 26.87±1.24 μm and 26.08±1.03 μm, respectively. No significant difference was found between the groups.
Conclusion: The radius of the curvature value in the custom abutment design affected the machining accuracy.

Keywords: Dental abutment, Dental computer-aided design/computer-aided manufacturing, Precision, Radius of curvature value, Trueness