An evaluation of virtually planned and 3D-printed stereolithographic surgical guides from CBCT and digital scans: An in vitro study

The process of manufacturing stereolithographic surgical guides for static computer-guided implant placement involves a series of steps. Errors can be incorporated in various forms and at various stages of manufacturing these guides. Errors introduced during this process have not been fully investigated. The purpose of this in vitro study was to assess the errors introduced during the manufacture of stereolithographic surgical guides generated from cone beam computed tomography (CBCT) and digital scans by using a virtual implant planning software. Ten stereolithographic surgical guides with the associated standard tessellation language (STL) files of their virtual design were used in this study. The STL files of the virtual design and the scans of the stereolithographic surgical guides were superimposed. Linear deviation at the center of the sleeve top and sleeve base and the angular deviation at the center of the sleeve were measured. The minimum and maximum linear deviation at the center of the sleeve top and the sleeve base was found to be 0 and 40 μm, with less linear deviation observed at the center of the sleeve top (mean ±standard deviation 18 ±7 μm) than at the center of the sleeve base (20 ±7 μm). The minimum and maximum angular deviation at the center of the sleeve was found to be 0 degrees and 5.9 degrees respectively, with a mean ± standard deviation of 1.36 ±0.74 degrees. Errors were found in the sleeve position between the virtual design and the stereolithographically manufactured surgical guide. This error may introduce errors in the final implant position.