Safety and performance of a novel collagenated xenogeneic bone block for lateral alveolar crest augmentation for staged implant placement

Objectives: To evaluate the performance and safety of placing a collagenated xenogeneic bone block (CXBB) graft for the lateral bone augmentation of the alveolar crest prior to implant placement. Material & Methods: In patients with single or multiple tooth gaps and a severe horizontal collapse of the alveolar ridge, a ridge augmentation procedure was performed using CXBB fixated with osteosynthesis screws to the atrophic bone crest and complemented with deproteinized bovine bone mineral particles (DBBM) and a native bilayer collagen membrane (NBCM). Patients were examined with CBCT prior to and 24 weeks after the augmentation. Twenty-six weeks postoperatively, are-entry procedure was performed to evaluate the bone width and availability for adequate implant placement. Results: Fifteen patients received 28 CXBB, and in 13 patients, a re-entry procedure was performed. Eleven patients (84.6%) gained enough bone volume for implant insertion without additional contouring or secondary bone augmentation. The mean crest width at baseline was 2.83 mm (SD 0.57), and the mean crest width at re-entry was 6.90 mm (SD 1.22), with a mean ridge width increase of 4.12 mm (SD 1.32). Soft tissue dehiscence occurred during the follow-up in 5 of 14 patients (35.7%) at various time points. In addition, there was a high incidence of early implant loss (30.8% [patient-based]). Conclusions: CXBB achieved significant horizontal crestal width gains allowing a secondary implant placement in the majority of the patients. However, the occurrence of soft tissue dehiscence may notably affect the outcome of the subsequent implant therapy.