Clinical Success of Dental Implants Placed in Posterior Mandible Augmented With Interpositional Block Graft: 3-Year Results From a Prospective Cohort Clinical Study

Purpose: The purpose of the present cohort study was to investigate the 3-year efficacy and clinical performance of implant-supported rehabilitations in posterior mandibles augmented with the sandwich osteotomy technique. Materials and Methods: Twenty-three partially edentulous patients who developed atrophy of the posterior mandible (residual ridge height, 3 to 7 mm) were treated (32 surgical sites) with vertical bone augmentation using interpositional equine cancellous bone blocks and porcine corticocancellous bone particulate. All implants were placed 4 months after augmentation and were loaded with fixed dental prostheses. One side per patient was selected and followed for 3 years, and the patient was the unit of analysis. Linear radiographic vertical bone gain and peri-implant marginal bone loss were assessed; secondary outcomes—complication rates after surgery, prosthesis and implant failure rates, width of keratinized mucosa, and patient satisfaction—were evaluated. Results: All patients reported postoperative paresthesia that resolved over a period of 2 months after the augmentation procedure. The mean vertical bone gain was 5.6 mm after 4 months. Ninety-one dental implants were positioned into the augmented areas. The global 3-year survival rate was 95.5%. The mean peri-implant marginal bone loss around implants was 1.06 ± 0.37 mm 3 years after loading, whereas the width of keratinized mucosa had an overall increase of 0.39 ± 0.36 mm. Conclusion: The results of the present 3-year study suggested high success rates for implants placed in areas augmented with the osteotomy sandwich technique. This surgical approach could be helpful in the presence of a low residual vertical height in the posterior mandible before implant placement.