Accuracy of Guided Implant Surgery in 25 Edentulous Arches: A Laboratory Observational Study.

PURPOSE: To assess the accuracy of template-guided implant surgery for edentulous arches. MATERIALS AND METHODS: The stone master casts of 25 edentulous arches treated with either 4 or 6 implants with CBCT generated template-guided surgery were included in this observational cohort study. The stone casts generated from the surgical templates (group one) prior to implant placement were digitized into Standard Tesselation (STL) files with a reference scanner. For comparison, the stone master casts derived from intraoral complete-arch impressions after implant placement (group two) were also digitized. The resultant STL files were superimposed and best-fit-alignment algorithm was used to quantify the 3D deviations present between the two groups. Descriptive statistics were computed for all categorical variables. Due to the presence of nonindependent samples between maxillary and mandibular casts, a mixed-effects model was used. RESULTS: Deviations between the implant analogs of the stone casts representing digitally planned versus actually placed implants were found. The mean root-mean-square error (RMSE) between all 25 arches was found to be 0.2 mm (SD ± 0.15). The mean RMSE between presurgical and postsurgical maxillary stone casts were 0.19 ± 0.15 mm, while between mandibular stone casts were 0.21 ± 0.16 mm and were not significant (p = 0.67). The mean RMSE between presurgical and postsurgical stone casts arches with 4 versus 6 implants were found to be significant (p = 0.01). CONCLUSIONS: According to the results of the study and based on the amount of 3D deviations between the digitally planned implant positions and the actually placed implants, template-guided surgery is a safe treatment modality for implant placement in edentulous arches.

Digital Workflow: From Guided Surgery to Final Full-Arch Implant Prosthesis in Three Visits.

The purpose of this article is to report a digital workflow protocol for full-arch implant rehabilitation from guided surgery to final prosthesis in only three visits. This expedited protocol allows for implant placement with a surgical template generated from preoperative virtual planning and production of the CAD/CAM prosthodontic rehabilitation using a digital workflow. At the first visit, a guided implant placement protocol with the All-on-4 concept and immediate loading with the conversion prosthesis technique was done. At the same visit, final impression and interocclusal records, cast verification and mounting, as well as digital scanning of the conversion prosthesis were carried out. During the second visit, the framework try-in was performed. Lastly, the third visit included delivery of the final full-arch prosthesis opposed by a maxillary complete denture.