Does flap opening or not influence the accuracy of semi-guided implant placement in partially edentulous sites?

Abstract

To investigate the effect of open-flap or flapless approaches on the accuracy of implant placement partially guided by tooth-supported surgical templates. A total of 36 edentulous sites were selected from seven human cadaver heads. Following the preoperative implant planning using Blue Sky Plan, surgical guides were fabricated by an in-office desktop 3D printer. All the sites were randomly divided into two groups: flapless approach (n = 18), and open-flap approach (n = 18). After guided osteotomy preparation with subsequent freehand implant placement, digital intraoral scanning was performed to obtain post-operative implant positions. Based on the image registration, the deviations between the planned and actual implant position were measured and compared. Statistically significant variance differences between the two approaches were found in the global coronal (open-flap: 0.86 ± 0.23 mm; flapless: 1.3 ± 0.62 mm; P < .001), global apical (open-flap: 1.38 ± 0.37 mm; flapless: 1.9 ± 0.78 mm; P = .002), and depth (open-flap: 0.59 ± 0.34 mm; flapless 0.89 ± 0.78 mm; P < .001) deviations. The differences were not significant regarding lateral (coronal and apical) and angular deviations. In semi-guided implant surgery, the open-flap and flapless approaches demonstrate similar lateral and angular deviations. The open-flap group shows better depth control when manually inserting the implant.