Accuracy of a New Method To Combine Digital Impressions With CBCT Scans Of The Edentulous Mandible

Background and Aims: The treatment of edentulous arches with dental implants offers significant benefits over traditional removable prosthetics. However, current implant placement methods, whether freehand or guided, present challenges in terms of accuracy, invasiveness, and postoperative discomfort. The primary aim of this thesis was to address the concern of placement inaccuracy in fully edentulous patients and introduce a more precise method. Materials and Methods: A novel approach, the "Fixed Edentulous Implant Guide" (FEIG), is introduced. Unlike conventional tooth-based guides, the FEIG employs three two-part screws to aid matching of reference points to precisely align digital impressions with CBCT scans during virtual planning. This research explored the method's efficacy through in vitro studies and comprehensive literature reviews along with a novel approach to the calculation of the implant position used in the final study. Results: The findings of both the preliminary and final studies show that the novel method presented in this thesis is more accurate than both existing methods of edentulous guided surgery (mucosal borne and bone guides) and dentate guided implant surgery. Through statistical analysis with an independent samples t-test, the final study revealed that the significance is less than than 0.05 for each comparison between the novel FEIG method and the conventional mucosal borne edentulous guided surgery (p<0.001), and a statistically significant difference between the two methods is concluded. The evidence suggests that this approach is both safe and precise, especially when referencing the model to the CBCT scan. Conclusions: The final objective of the thesis was to examine whether it is both safe and accurate to place implants with flapless surgery with this new method that references the model to the CBCT scan. The study findings suggest that this statement can be upheld, and given the accuracy in terms of trueness and precision, it is concluded that the novel method provides an accurate method to place implants in an edentulous arch. Furthermore, as guided implant surgery can often mean that bone can be utilised in an angular or unconventional approach to avoid grafting, using this method may mean that patients with a medical contraindication to conventional flapped surgery may also benefit from full arch rehabilitation.