Guided-welded approach planning using a computer-aided designed prosthetic shell for immediately loaded complete-arch rehabilitations supported by conometric abutments.
In guided surgery, implants can be planned from radiographic guide information according to a restoratively driven treatment plan. Unfortunately, the palatal or lingual surface of teeth cannot be easily identified. The present article describes the use of a digitally designed prosthetic shell to improve the accuracy of guided-welded approach planning for immediate restorations supported by conometric abutments. Importing the virtual shell into the planning software provides an effective protocol for using the definitive prosthetic space information to plan the framework shape and position predictably. This method increases the accuracy of virtual planning and reduces the time needed to reline the prosthetic shell.
Computer-supported implant planning and guided surgery: a narrative review.
AIM
To give an overview of the workflow from examination to planning and execution, including possible errors and pitfalls, in order to justify the indications for guided surgery.


MATERIAL AND METHODS
An electronic literature search of the PubMed database was performed with the intention of collecting relevant information on computer-supported implant planning and guided surgery.


RESULTS
Currently, different computer-supported systems are available to optimize and facilitate implant surgery. The transfer of the implant planning (in a software program) to the operative field remains however the most difficult part. Guided implant surgery clearly reduces the inaccuracy, defined as the deviation between the planned and the final position of the implant in the mouth. It might be recommended for the following clinical indications: need for minimal invasive surgery, optimization of implant planning and positioning (i.e. aesthetic cases), and immediate restoration.


CONCLUSIONS
The digital technology rapidly evolves and new developments have resulted in further improvement of the accuracy. Future developments include the reduction of the number of steps needed from the preoperative examination of the patient to the actual execution of the guided surgery. The latter will become easier with the implementation of optical scans and 3D-printing.
Conventional multi-slice computed tomography (CT) and cone-beam CT (CBCT) for computer-aided implant placement. Part II: reliability of mucosa-supported stereolithographic guides.
PURPOSE
Deviations of implants that were placed by conventional computed tomography (CT)- or cone beam CT (CBCT)-derived mucosa-supported stereolithographic (SLA) surgical guides were analyzed in this study.


MATERIALS AND METHODS
Eleven patients were randomly scanned by a multi-slice CT (CT group) or a CBCT scanner (CBCT group). A total of 108 implants were planned on the software and placed using SLA guides. A new CT or CBCT scan was obtained and merged with the planning data to identify the deviations between the planned and placed implants. Results were analyzed by Mann-Whitney U test and multiple regressions (p < .05).


RESULTS
Mean angular and linear deviations in the CT group were 3.30° (SD 0.36), and 0.75 (SD 0.32) and 0.80 mm (SD 0.35) at the implant shoulder and tip, respectively. In the CBCT group, mean angular and linear deviations were 3.47° (SD 0.37), and 0.81 (SD 0.32) and 0.87 mm (SD 0.32) at the implant shoulder and tip, respectively. No statistically significant differences were detected between the CT and CBCT groups (p = .169 and p = .551, p = .113 for angular and linear deviations, respectively).


CONCLUSIONS
Implant placement via CT- or CBCT-derived mucosa-supported SLA guides yielded similar deviation values. Results should be confirmed on alternative CBCT scanners.