Bilayer Technique for Alveolar Ridge Augmentation in Pre-Prosthetic Implant Surgery: Indications and Problems

Abstract Background: Prosthetic rehabilitation of missing teeth with dental implant-supported restorations has recently become a predictable treatment option in contemporary dentistry with a highly successful rate. Due to different factors, vertical and horizontal bone loss could present, and the available alveolar bone may not be sufficient for optimum implant position. Ridge augmentation procedures could be applied to increase the volume of the deficient sites for accurate prosthetic implant placement, which assures functional and esthetic stability of tissues around the implants, essential for long-term success. Our study aims to evaluate the efficiency of the bilayer technique of guided bone regeneration for alveolar ridge augmentation procedure in cases of bone deficiency for optimum implant placement and long-term success. Materials and methods: We present several cases of alveolar bone deficiency treated with the bilayer technique – the combination of allo- and xenograft, covered by collagen membrane, with long-term follow-up. The defects were filled with allograft, and a layer of xenograft and barrier membrane was placed above it. This technique combines the benefits of all xenografts and barrier membranes. Results: The bilayer technique with allo- and xenograft and collagen membranes is predictable, with a high success rate and lower morbidity. We have a 100% survival rate of the implants placed in a grafted area with long-term follow-up with excellent aesthetic and functional results. Conclusions: The bilayer technique uses the benefits of two bone graft materials, is associated with less morbidity for the patients, and has excellent long-term results if performed accurately according to indications and technique.