A Retrospective Study of the Accuracy of Implant Placement comparing Partial and Fully Guided Surgery in an Academic Setting

Background Ideal three-dimensional (3D) implant positioning increases the likelihood of achieving optimal prosthetic contours and maintaining peri-implant tissues health, thereby reducing the risk of biological and technical complications. Fully guided implant surgery (FGS) has been shown to be more accurate than partially guided implant surgery (PGS);however, clinical outcome data comparing PGS and FGS in an academic setting remains limited. Aim To investigate the accuracy of implant placement when static computer aided implant surgery (sCAIS) PGS and FGS are utilized in an academic setting and analyze the factors that may influence implant deviations. Furthermore, as part of a pilot study, we investigated residents and predoctoral dental students about their perception of the implant digital workflow at VCU. Materials & Methods This study is a retrospective observational study in which data from patients treated with dental implants at VCU, School of Dentistry (SOD) Graduate Periodontics Clinic was collected. All patients were treated with sCAIS and implant deviations were measured through the superimposition of digital models in a dedicated planning software. The mean global, horizontal, depth and angular deviations between the virtually planned and actual implant position were analyzed by a blinded calibrated examiner. Secondary factors that can influence implant deviation from planned positions were also evaluated: operator experience, history of grafting, alveolar ridge characteristics, cortical plate engagement, existing adjacent restorations and guide support (bilaterally or free end). A digital survey was distributed to predoctoral students and periodontics residents using Research Electronic Data Capture (REDCap) tools. The null hypothesis of the study is that there are no differences between PGS and FGS sCAIS for implant final position compared to planned position. Results Data from 31 patients was available for evaluation. 14 implants were placed via PGS and 17 implants through FGS. Global apical deviation and horizontal apical deviations demonstrated a statistically significant association with the guide technique used (p-value=0.0284, 0.00725, respectively). The PGS method was associated with a significantly larger global apical deviation, by an average of 0.61mm (1.86 vs 1.25 mm; 95% CI: 0.07, 1.15). PGS was also associated with a significantly larger horizontal apical deviation, by an average of 0.77mm (1.49 vs 0.73 mm; 95% CI: 0.22, 1.31). Although the remaining metrics did not demonstrate a significant difference between the two guide techniques, the average of each was larger for the PGS method than the FGS. Implants placed at molar vs premolar sites (p = 0.0079) and implants with a 5mm width vs 4mm width (p = 0.0384) were associated with a significantly larger horizontal apical deviation. Horizontal coronal deviation was significantly associated with the number of adjacent teeth with a crown (p-value=0.0127) and the bone type at the crest (p-value=0.0450). Thirty-five predoctoral students and 16 surgical residents responded as having participated in VCU’s implant digital workflow. On average, predoctoral students found navigating the software (7.0/10) to be the most difficult part of the process, while residents reported difficulty with communication between providers (6.7/10). Most residents believed that FGS will give them greater accuracy in implant placement than free-handed surgery (81.3% of responses) and most (81.3%) believe they will use FGS protocols 1-75% of the time. Write-in suggestions (6) included wanting more support and training with the implant planning software. Conclusions Fully guided sCAIS can improve implant placement accuracy as compared to partially guided sCAIS especially at the apical positioning. Other factors like molar sites, wider implants, adjacent crowns and crestal bone type can also significantly affect implant placement accuracy. Predoctoral students at VCU struggle with the implant planning software and want additional training. Residents struggle with communication between providers but most believe sCAIS will improve their implant placement accuracy and plan on using guided protocols at least some of the time in their clinical practice.