[Subantral graft: clinical application of the biological principles osseoinduction in the treatment of posterior maxillary atrophy].

Severe resorption in the posterior maxilla following the loss of natural teeth is frequently associated with severe pneumatization of the maxillary sinus. This condition reduces the possibility of using implants in the subantral maxilla to surgical and prosthetic limits that cannot be resolved by simple techniques. For these cases, maxillary sinus elevation surgery and subantral grafting are required in order to increase this segment of the maxilla. The availability of new biomaterials has increased the possibilities of performing these techniques by reducing the amount of autogenous bone that must be harvested. Osteogenesis, osteoinduction, osteoconduction, osteotrophism, and osteophilia are the biologic mechanisms involved in the formation of new bone. Presence of these mechanisms permit augmentation of the subantral osseous band and bone to dimensions needed for implant placement. Conductive biomaterials permit bone neoformation to begin at the margins of the defect and advance towards the center. In a clinical study of 42 months, 228 implants (Steri-Oss, Yorba Linda, CA were placed; 180 of them are loaded and functional. The threaded design, HA-coating, hex lock head, and a resorbable membrane promote osseointegration and longevity. A subantral graft was placed in the space created after release and elevation of the sinus mucosa. The histologic evidence and the supportive clinical and radiologic findings clearly demonstrate consolidation and integration of the graft and the implant.