SupplementDOI: 10.11607/prd.2138, PubMed ID (PMID): 24956092Pages 58-69, Language: EnglishTestori, Tiziano / Robiony, Massimo / Parenti, Andrea / Luongo, Giuseppe / Rosenfeld, Alan L. / Ganz, Scott D. / Mandelaris, George A. / Del Fabbro, MassimoComputer-aided design/computer-assisted manufacture (CAD/CAM) guides for surgery are becoming a widespread tool in implant dentistry. This study sought to evaluate the accuracy and precision of a new guided surgery system. Twenty-five patients were treated in eight centers, and a total of 117 implants were placed using CAD/CAM surgical guides supported by bone, mucosa, and/or teeth. A postoperative computed tomographic (CT) scan of each patient was taken and superimposed on a preoperative CT scan to evaluate any discrepancies between the planned and actual implant positions (apex and platform positions), as well as the implant tilt. Implant placement using bone- and mucosa-supported guides was found to be more precise compared to using guides supported by teeth or a combination of teeth and mucosa. However, the differences were not statistically significant. The accuracy of the guided surgery system is in line with the data found in the literature. Considering the mean positioning discrepancies between the planned and actual implant outcomes, clinicians are advised to maintain a safe distance between implants and anatomical structures of at least 2 mm. In immediate loading cases, relining a provisional prosthesis to compensate for any discrepancies between the virtual and clinical implant positions is recommended.