A randomized controlled study comparing guided bone regeneration with connective tissue graft to reestablish buccal convexity at implant sites

OBJECTIVES: To volumetrically compare guided bone regeneration (GBR) with connective tissue graft (CTG) to reestablish convexity at the buccal aspect of single implants.

MATERIALS AND METHODS: Patients with a single tooth gap in the anterior maxilla and horizontal alveolar defect were enrolled in a single-blind randomized clinical trial (RCT). All sites had a buccopalatal bone dimension of at least 6 mm, received a single implant, and were randomly allocated to the control (GBR) or test group (CTG) to reestablish buccal soft tissue convexity. Patients received a provisional crown at 3 months and a permanent crown at 6 months. Primary outcomes were volumetric increase (mm3 ) and linear increase (mm) in buccal soft tissue profile (BSP) within a well-defined area of interest at fixed time points. Alveolar process deficiency was a secondary outcome.

RESULTS: Twenty-one patients were included per group (control: 11 females, mean age 51; test: 9 females, mean age 48). After 1 year, GBR resulted in a significant volumetric increase of 20.74 mm3 (P < .001) corresponding to linear increase in BSP of 1.30 mm (P < .001). For CTG, this was 15.86 (P < .001) and 1.19 mm (P < .001), respectively. The changes over time in volume (P = .173) and BSP (P = .241) were not significantly different between the groups. Twenty-nine percentage and 26% of the final volumetric increase was the result of installing and altering prosthetic components in the control and test groups, respectively. Alveolar process deficiency significantly reduced from pre-op to 1 year following GBR (P < .001) and CTG (P < .001). The difference between the groups was not significant (P = .342). However, 58% of the patients treated with GBR and 38% treated with CTG failed to show perfect soft tissue convexity at the buccal aspect.

CONCLUSION: GBR as well as CTG are effective in reducing horizontal alveolar defects for aesthetic purposes. However, in about half of the cases, either strategy failed to optimally reestablish buccal convexity.