A main drawback of bone block graft surgery is the resorption occurring in early stages of healing. The aim of this work was investigate different factors associated with graft resorption in allogeneic bone block graft surgery.

Introduction: A main drawback of bone block graft surgery is the resorption occurring in early stages of healing. The aim of this work was investigate different factors associated with graft resorption in allogeneic bone block graft surgery.

Materials and methods: Twenty-eight patients referred for implant placement and with insufficient bucco-lingual (BL) alveolar bone width (<4 mm) were included in the study. Patients received freeze dried bone allograft (FDBA) blocks of either allogeneic cancellous or cortico-cancellous bone obtained from the iliac crest. The aforementioned groups were compared in regards to bone resorption using General Estimating Equations (GEE) and logistic regression. Demographic data, trabecular bone density, graft site were also analyzed.

Inclusion Criteria:

• Twenty eight totally and partially edentulous patients referred for dental implant therapy from January 2011 to September 2015 were enrolled in the study. All patients had insufficient bucco-lingual (BL) alveolar bone width (<4 mm) that prevented placement of regular size implants

Exclusion Criteria:

• Patients with severe systemic disease (American Society of Anesthesiology III or IV) were excluded from the study. In addition, patients who were pregnant, or patients with diseases affecting bone, such as Paget's disease, osteomalacia, diabetes, vitamin D deficiency, alcoholism, hyperthyroidism cancer or osteoporosis as well as those on medications that might affect bone metabolism, such as bisphosphonates, corticosteroids or antiepileptic medicaments were also excluded from the study.

Patients included in the clinical trial were randomly allocated by a blinded assistant in two groups: in the cortico-cancellous group (CC), and cancellous group (C). Allocation of participants to intervention groups in a truly unpredictable, randomized sequence was performed using a computerized random number generated by the GraphPadQuickCalc software (GraphPad Software Inc., La Jolla, CA). Blocked randomization was performed to maintain equal group size. As a result 14 patients were randomly assigned to de CC group and other 14 to the C group. All bone augmentation surgeries were performed by the same oral surgeon, with expertise on block surgeries (JT).