Maxillary sinus augmentation using sinus membrane elevation without grafts - A Systematic Review

Implants have a predictable outcome and are the foremost treatment modality for prosthetic rehabilitation of edentulous patients. Due to loss of bone after extraction and pneumatization of maxillary sinus, there is insufficient bone volume for implant placement. The direct maxillary sinus lift procedure has been performed with different grafting materials (autogenous bone grafts, alloplasts, allografts, and xenografts) and without grafting material, having new bone formation around the implant. There is no evidence to prove the need for grafting material in all direct sinus lift procedures, hence the need for this review. Previous meta-analysis showed that survival rates of implants placed in grafted maxillary sinuses had similar survival rates whether autogenous, allogenous, or alloplastic grafts were used. This paper aims to review scientific data on the direct sinus elevation technique without use of any grafting material, volume of new bone formed, and also mechanism behind this technique. Articles were searched from 1997 to October 2014 in PubMed, Google Scholar, and Cochrane CENTRAL. The study eligibility criteria were (1) direct sinus lift procedure without any graft material during implant placement and (2) human or animal studies with a minimum follow-up of 6 months or more. Two authors independently scrutinized the literature and if any controversy was raised, third author's opinion was sought to arrive at a mutual consensus for including the study in the review. Due to the heterogeneity across all studies in all study designs, the data were not pooled and a meta-analysis was not performed. Taking into consideration all factors reviewed in this regard along with the outcomes, the direct sinus lift technique without grafting can be suggested as a viable treatment option keeping in mind the limitations involved. The average bone gain was seen across all studies ranging from 2.37 to 10 mm and with an implant survival rate ranging from 79.9% to 100% across studies.