Comparison of flapless and conventional flap and the effect on crestal bone resorption during a 12-week healing period.

Unlabelled: There is evidence suggesting that flapless, or minimally invasive, procedures can preserve bone vascularization because they will not disturb the periosteum of the alveolar bone. The aim of this randomized, controlled clinical trial study is to compare the effect of flapless (FL) and full-thickness flap (FT) techniques on crestal bone resorption during healing periods.

Methods: Twenty-two implants were placed by FL and FT flap in nine patients in split mouth design; each patient received two implants, except for two patients who received four implants. A periapical radiograph was taken at implant placement, as well as 6- and 12-week intervals. Crestal bone level was compared between FL and FT during these intervals and compared between intervals for each group.

Results: Median (IQR) crestal bone level at implant placement for the FL was 2.70 (0.60) and for the FT was 2.60 (1.20). At six weeks, median (IQR) for the FL was 3.55 (0.70) and for the FT was 3.40 (0.75). At 12 weeks, median (IQR) for the FL was 3.60 (0.30) and for the FT was 3.75 (0.85). Statistically insignificant differences were obtained between the two techniques at implant placement, as well as 6- and 12-week intervals, and were p = 0.894, p = 0.477, p = 0.755, respectively. There was a significant difference between the bone level at implant placement and at the 6-week interval for both the FL (p = 0.006) and FT (p = 0.045), whereas there was no significant difference between the bone level at 6- and 12-week intervals for the FL (p = 0.722) and for the FT (p = 0.229). Conclusions Based upon this study of nine patients with 22 implants, there was no significant difference in crestal bone resorption between FT and FL techniques during a three-month healing period. The preservation of periosteum in the FL group resulted in early progressive bone resorption.