An experimental and clinical study of osseointegrated implants penetrating the nasal cavity and maxillary sinus.

Implants were inserted in the upper jaw of three dogs in such a way that they penetrated the bone wall of the nasal cavity. The dogs were killed one year later, and the hard and soft tissues around the penetrating implants were analyzed. Radiographic and histologic examinations did not show any signs of adverse tissue reaction. The implants were all integrated in bone without fibrous tissue formation in the interface. A total of 139 implants, which pierced the bone of the sinus or nasal cavity, were inserted in the upper jaws of 101 patients. Forty-four sinus- and 47 nasal-penetrating implants were observed for five to ten years. The success rates were 70% and 72%, respectively. For 25 sinus- and 23 nasal-penetrating implants that were observed for two to five years, the success rates were 88% and 96%, respectively. The implant losses in nearly all clinical cases occurred during the first two years of function.