<img src="http://blog.drnemeth.com/Portals/35943/images/dental_implants.jpeg” border=”0″ alt=”<a href="http://thedentalimplantcenterlv.com”>dental implants” class=”alignRight” style=”float: right;” />Implants are now a well-established standard of care for treatment of partial and total tooth loss. One review of 17 studies using almost 7500 implants from six manufacturers found a polled five-year survival rate of 96%. However, the placement of <a href="http://thedentalimplantcenterlv.com”>dental implants in the posterior maxilla continues to be a challenging process, mainly because of two factors: bone quality and bone quantity.
The reduced bone height and proximity of the maxillary sinus limit the placment of implants in the posterior maxilla. The bone quality available for implant placement is influenced by the extent of the maxillary sinus and the amount of bone resorption after tooth loss. In addition, after tooth loss the periosteum of the Schneiderian (sinus) membrane exhibits increased osteoclastic activity that can cause bone resorption which further limit the quantity of bone available for implant placement. Furthermore, studies have shown that a deficiancy in bone quality is often encountered in the posterior maxilla.
Inadequate alveolar bone (less than 10 mm of vertical bone height) can preclude success for implants in the posterior maxilla. Therefore, maxillary sinus elevation to increase alveolar bone height has become a common procedure with several different approaches and materials employed.
Cho-Lee et al. described the results of 177 maxillary sinus elevation procedures over a 12-year period. The procedures were performed in 119 patients with a mean age of 50 plus or minus 11.5 years. The patients received several different materials for their maxilary sinus augmentation; autogenous intraoral bone, autogenous extraoral bone, and mixed autogenous bone (50%) and bovine inorganic bone (50%). Some patients also received platelet-rich plasma. Nearly two-thirds of all implants were placed at the same time as the sinus augmentation procedure. Implants were loaded either three or six months after implant placment, depending upon the type of grafting material used.
The patients received 272 implants, one to four per patient. Follow-up occurred at five years or less for 162 implants and more than five years for 110 implants; mean follow-up occurred at 60.7 plus or minus 36.5 months. Nineteen implants were lost during follow-up for a 93 percent survival rate. The procedure used, grafting material used, placement timing, smoking status, and associated comorbidities were not associated with any significant differences. The only variables that predicted implant survival were the presence of peri-implantitis and the presence of complications related to the augmentation procedure.
The study’s authors concluded that maxillary sinus augmentation for implants in the posterior maxilla appears to be a predictable and versatile procedure that allows patients with atrophic posterior maxilla to receive implant-supported restorations.
