Methodology and criteria in the evaluation of dental implants.

This study was designed to develop an inexpensive, reproducible method for studying the reaction of the tissues of the oral cavity to the endosseous implant. Thirty-six guinea pigs, three materials (Teflon, Vitallium, and Titanium 6Al-4V), two observation periods (two and 12 weeks), and two implant designs (one with exposure to the oral cavity and one without exposure to the oral cavity) were used. The inflammatory response was significantly greater in the exposed implants than in the unexposed implants. In the implants that were exposed 12 weeks, there was a strong interrelationship between severe inflammation, bacteria, and epithelial invagination. These factors are significant causes for failures of implants.