Healing complications and their detrimental effects on bone gain in vertical-guided bone regeneration: A systematic review and meta-analysis.

PURPOSE: Guided bone regeneration (GBR) utilizes a barrier membrane to allow osteogenic cells to populate a space by excluding epithelial and connective tissue cells. The purpose of this systematic review was to investigate the ratio of means (RoM) of vertical bone gained (Outcome) in vertical GBR procedures with healing complications (Intervention) and in vertical GBR procedures without healing complications (Comparison) in patients with vertically resorbed edentulous ridges that require dental implant placement (Population). A further aim was to investigate the incidence of complications after vertical GBR, and the influence of the timing of implant placement and regenerative devices on complications. MATERIALS AND METHODS: MEDLINE (through PubMed), EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched in duplicate up to, and including, November 2020 for randomized and controlled clinical trials and prospective and retrospective case series. Outcomes included patient-level and site-level RoM of vertical bone gain between healing complications and uneventful healing, and incidences of complications that occurred after vertical GBR. Random-effects and fixed-effects meta-analyses were performed where appropriate. This study was registered on PROSPERO (CRD42021226432). RESULTS: A total of 31 publications were selected for the qualitative and quantitative analyses. The RoM of vertical bone gained was 0.65 [95% CI = 0.47, 0.91] and 0.62 [95% CI = 0.45, 0.85] when membrane exposure without suppuration and abscess formation without membrane exposure occurred respectively, in comparison to uneventful healing. The overall incidence proportion of healing complications occurring at the augmented site at a site- and patient-level was 11.0% [95% CI = 7.0, 15.6] and 10.8% [95% CI = 6.6, 15.7]. At a patient-level, there were no significant differences between a simultaneous or staged approach, or with the regenerative device used. The site-level incidence proportion of membrane exposure without suppuration, membrane exposure with suppuration, and with abscess formation without membrane exposure was 8.7% [95% CI = 4.2, 14.2], 0.7% [95% CI = 0.0, 2.9], and 0.5% [95% CI = 0.0, 1.7], respectively. The site-level weighted mean incidence proportion of neurologic complications occurring at the donor site was 0.8% [95% CI = 0.0, 5.3]. CONCLUSIONS: There is a significant reduction in bone gain when healing complications occur. However, healing complications are relatively uncommon surgical complications after vertical GBR.

Clinical and histological sequelae of surgical complications in horizontal guided bone regeneration: a systematic review and proposal for management.

It is not uncommon to encounter post-surgical complications after horizontal guided bone regeneration (GBR). The primary aim of this review was to evaluate the incidence and types of complications that occur after horizontal GBR and propose management strategies to deal with these clinical situations. A secondary aim was to conduct a histomorphometric review of the wound healing process at sites that experienced post-surgical complications after GBR. A keyword search of MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials for studies published in English from January 2015 to January 2020 was conducted for the primary aim and 23 studies were selected. A second search addressing the secondary aim was conducted, and five studies were included. Site-level analysis showed that the weighted mean incidence proportion of minor wound dehiscence and minor infections occurring at the augmented site was 9.9% [95% CI 6.4, 13.9, P < 0.01] and 1.5% [95% CI 0.4, 3.1, P = 0.21) respectively. Patient-level analysis showed minor and major complications occurring at a weighted mean incidence proportion of 16.1% [95% CI 11.9, 20.8, P = 0.01] and 1.6% [95% CI 0.0, 4.7, P < 0.01] respectively, while neurosensory alterations at the donor site was 7.0% [95% CI 1.3, 15.5, P < 0.01]. Subgroup analysis also revealed that the use of block grafts increased the incidence proportion of minor post-surgical complications, whereas a staged GBR procedure increased the incidence proportion of both minor and major post-surgical complications. Although exposure of the barrier membrane is often associated with less bone regeneration and graft resorption, the type of membrane used (resorbable or non-resorbable) had no statistically significant influence on any post-surgical complication. Histologically, a layer of fibrous connective tissue instead of bone is commonly observed at the interface between the native bone at the recipient site and the regenerated bone in cases with membrane exposure after GBR procedure. Minor wound dehiscence was the highest incidence proportion of post-surgical complications. Methods ranging from daily application of antiseptics, use of systemic antimicrobials, regular reviews, and total removal of the non-integrated biomaterials are commonly prescribed to manage these post-surgical complications in attempt to minimise the loss of tissue at the surgical site.