Abstract
The purpose of this study was to investigate whether the implants penetrating the bone and mucosa of the maxillary sinus increased the risk of infection or impeded the normal bone formation.
In 16 adult monkeys, the premolars of the upper jaw were extracted. After 3 months, cylindrical apatite implants were implanted in each side so as to penetrate into the maxillary sinus. The monkeys were killed at 1 and 2 weeks and 1, 3, 6 and 9 months after implantation. The specimens of the maxillae with the implants were histologically examined by light microscopy. The implants were penetrating into the sinus in various conditions according to the site of implantation, the form of the sinus and so on.
Some of the implants introduced into the sinus were coverd with normal mucosa, the others perforating the mucosa.
In all cases, the bone formation around the apatite implants was normal and the bone was formed on almost the entire surface of the implants inside in the jaw bone.
In the case of the implants perforating the mucosa, the mucosa around the implants was more or less injured. But at 3, 6 and 9 months after implantation, no problematical situation was particularly recognized in the mucosa around the implants.
