# Digital Evaluation of the Accuracy of Computer-Guided Dental Implant Placement: An In Vitro Study
## 3 Results  
For the 20 study models in which implant fixtures were placed, the depth and angle of the planned implant fixture and the placed implant fixture were compared and, as a result, the mean apical deviation of Deltanine and R2 gate software was 0.603 \(\pm\) 0.19 mm and 0.609 \(\pm\) 0.18 mm, while the mean angular deviation of Deltanine and R2 gate software was 1.97 \(\pm\) 0.84\({}^{\circ}\) and 1.92 \(\  
non-radiographic method that overlapped the scan image of the study model with the scan body and the scan body-implant fixture complex, respectively. In 2019, [PERSON] et al. compared the traditional radiographic method of evaluating the implant position using CBCT, with the non-radiographic method of overlapping the scan data and inferring the implant position, and reported that there were no statistically significant differences between these methods [20]. Therefore, the evaluation of the implant position in this study is acceptable. The positioning accuracy of the implant surgical guides can be determined by evaluating the deviation between the planned implant position and placed implant position [28]. These deviations represent different values in various papers [14]. However, a 1\({}^{\circ}\) deviation of the insertion angle makes an apical deviation of 0.34 mm based on a 10 mm implant fixture. In other words, a 5\({}^{\circ}\) deviation of the insertion angle represents an apical deviation of 1.7 mm. If the space between the implant and the adjacent tooth root is 1.5 mm, an angular deviation of 5\({}^{\circ}\) implies that it can invade the adjacent tooth root [29]. When considering important anatomical structures such as the inferior alveolar nerve, implant surgical guides have an allowable vertical and angle deviation of up to 1.5 mm and 3\({}^{\circ}\), respectively [30]. Therefore, the vertical deviation and angle deviation in this study are within clinical tolerance. As a result of placing implant fixtures in each of the 20 study models, there was no surgical guide fabricated with the two software programs outside the vertical deviation of 1.5 mm, and there was no statistically significant difference between the two software programs (\(p\) = 0.948). One surgical guide fabricated with the Deltanine software was out of tolerance of the 3\({}^{\circ}\) angle deviation, but there was no statistically significant difference between the two software programs (\(p\) = 0.884). In light of these results, it can be concluded that the surgical guide fabricated according to the software showed no difference in the positioning accuracy of the implants. The Deltanine software used in this study was compared to the R2 gate software, which has been verified in the accuracy of implant placement in a previous study [17]. Although not compared to traditional implant surgical guides, the Deltanine software has been verified in comparison to the R2 gate software and verified in a previous study. The 20 resin study models used in this study had a rigid cortical bone. The inside surface was removed and filled with a mixture of orthodontic resin and sawdust, which had a lower physical property, thereby forming the cancellous bone. Since the thickness of the cortical bone varies in the clinical setting, this study also arbitrarily set the thickness of the cortical bone. In the case of a rigid personal 3D printer resin, the drill and fixture got stuck in the hard resin during the drilling process resulting in an error. In addition, fabrication of the implant surgical guides with personal 3D printers was thought to cause internal errors due to the removal of undercuts and nodules and the proficiency of the surgeon who placed the implants. Given that this was an in-vitro study measuring the accuracy of implant surgical guides made with personal 3D printers, errors above the mean can be fatal in the clinical setting. However, since the cortical bone has lower strength and higher elasticity compared to hard resin, errors due to the drill would be smaller when the implant is placed.