HORIZONTAL AND VERTICAL COMPUTER GUIDED BONE REGENERATION WITH SLOW-RESORBING BOVINE PERICARDIUM MEMBRANE: CASE SERIES RESULTS ONE YEAR AFTER LOADING

PURPOSE. To assess, 1 year after placement of definitive prostheses, the performance of implants inserted via a computer guided bone regeneration approach on ridges horizontally and vertically reconstructed with 50% bovine bone and 50% autologous bone, covered with 0.8-mm-thick slow-resorption bovine pericardium membrane. MATERIALS AND METHODS. In this case series, severe horizontal bone defects in the posterior mandible (Cawood and Howell class IV) or maxilla were treated using a 1:1 mixture of autogenous bone and bovine bone, covered by slow-resorbing bovine pericardium membrane. Six months after augmentation, implant placement via a computer guided pilot drill approach was planned, based on a 3D reconstruction of the cone-beam computer tomography (CBCT) scan to assess the amount of regenerated bone. Patients were monitored for one year after the fitting of definitive prostheses. Primary outcome measures were implant and prosthesis survival rates and complications. Secondary outcome measures were horizontal and vertical dimensional changes and peri-implant marginal bone loss. RESULTS. Twelve consecutive patients were enrolled, and 31 implants were inserted. One year after loading, no patients had dropped out. No implants or prostheses had failed during the entire follow-up, with only one early exposure of the membrane occurring. Six months after the regenerative procedure, the mean horizontal augmentation, measured at the middle of the augmented area, was 5.28 ± 1.81 mm (95% CI 4.26-6.30 mm), while the mean maximum horizontal augmentation was 5.39 ± 1.85 mm (95% CI 4.34-6.44 mm). The mean vertical augmentation, measured at the centre of the augmented volume, was 2.01± 1.06 mm (95% CI 1.41-2.61 mm), and the mean maximum vertical augmentation was 2.05 ± 1.04 mm (95% CI 1.46-2.64 mm). One year after loading, the mean marginal bone loss from implant placement was 0.36. ± 0.11 mm (95% CI 0.30-0.42 mm). CONCLUSIONS. Within the limitations of the present case series, the use of slow-resorbing pericardium membrane combined with autologous bone and particulate bovine bone in a 1:1 ratio seems to permit the alveolar reconstruction of medium to severely horizontally resorbed ridges and provide minor vertical bone augmentation.