This study aimed to compare two different methods used to augment bone in the posterior lower jaw prior to implant placement in patients with insufficient bone width. Eligible patients were included in the study and received a horizontal bone augmentation with one of two methods, which differed in the materials used for the bone augmentation. The group allocation was randomised. After 6 months of healing following parameters were assessed: histological evaluation, survival of the bone graft, the need for further bone augmentation at the time of implant placement, changes in soft tissue characteristics, radiologically and clinically assessed changes in bone width.

Objective: The objective of this study is to compare the histological, clinical, and radiographic outcomes of particulate bone substitutes versus allogenic bone block grafts for primary bone augmentation in the posterior mandible.

Materials and Methods: This randomised controlled clinical trial included adult patients in need for a staged bone augmentation prior to implant placement in the posterior mandible. Patients were randomly assigned to one of two treatments groups. Patients allocated in the BBL group received allogenic bone blocks, whereas patients in the GBR group received allogenic bone granules for the primary bone augmentation. In both groups grafting materials were covered with a resorbable collagen membrane, which was fixated with non-resorbable fixation pins. The primary outcome of this study was defined as the composition of the histological samples at least 6 months after the primary bone augmentation. Secondary outcomes included graft survival rates, the need for further augementation procedures at time of implant placement, soft tissue measurements and radiographically and clinically analyzed changes in bone width and radiographically analyzed changes in bone volume. These outcomes were measured at baseline (prior to bone augmentation surgery) and at the follow-up (at least 6 months after bone augmentation).

Inclusion Criteria:

• Aged ≥18 years
• Insufficient bone width in posterior mandible requiring staged bone augmentation prior to implant placement
• Minimum of 1 mm bone width available
• Willing to provide signed informed consent

Exclusion Criteria:

• Pregnant or lactating
• Known or suspected incompliance
• Patients smoking more than 10 cigarettes per day
• Systemic diseases or medications affecting bone metabolism (such as osteoporosis, intake of bisphosphonates)
• Active periodontal disease