Dimensional changes after horizontal and vertical guided bone regeneration without membrane fixation using the retentive flap technique: A 1-year retrospective study

Abstract

AbstractAim:To evaluate the dimensional changes after horizontal and vertical guided boneregeneration (GBR) without membrane fixation using the retentive flap technique.Methods:This study retrospectively examined two cohorts that received vertical orhorizontal ridge augmentations (VA or HA groups). GBR was performed using partic-ulate bone substitutes and resorbable collagen membranes. The augmented siteswere stabilized using the retentive flap technique without any additional membranefixation. The augmented tissue dimensions were assessed using cone-beam com-puted tomography at preoperative, immediately postoperative (IP), 4 months (4M),and 1 year (1Y).Results:Postoperative vertical bone gain in 11 participants of VA group amounted to5.96 ± 1.88 mm at IP, which decreased to 5.53 ± 1.62 at 4M and to 5.26 ± 1.52 mm at1Y (intragroupp< 0.05). The horizontal bone gain at IP in 12 participants amountedto 3.98 ± 2.06 mm, which decreased to 3.02 ± 2.06 at 4M and to 2.48 ± 2.09 mm at1Y (intragroupp< 0.05). The mean implant dehiscence defect height after 1Y was0.19 ± 0.50 mm in the VA group, and 0.57 ± 0.93 mm in the HA group.Conclusion:GBR without membrane fixation using the retentive flap techniqueseems to preserve the radiographic bone dimensions of vertically augmented sites.This technique may be less effective at preserving the width of the augmentedtissue.KEYWORDSguided bone regeneration, horizontal ridge augmentation, radiographic analysis, retrospectivestudy, vertical ridge augmentationSummary BoxWhat is knownThe evidence of dimensional changes after horizontal and vertical guided bone regeneration(GBR) without membrane fixation is limited. The graft material stability without membrane fixa-tion could be achieved by optimal flap management namely the“retentive flap technique.”However, this technique has not yet been clinically assessed.