Experimental Study of Occlusal Trauma to Osseointegrated Implant: Part 2

Abstract

We have been investigating the effect of occlusal trauma on osseointegrated implants to determine the pathogenesis of peri-implantitis that develops around the peri-implant tissue. In the first study, we placed experimental IMZ implants in crab-eat-ing monkeys (Macaca fascicularis) that had good oral health and mounted a 100-μm super-high superstructure in each animal to produce experi-mental occlusal trauma to the implant for one to four weeks. The results of histopathological examination showed that the implant integrated firmly with the bone, without bone resorption by trauma, in all animals. In particular, the monkeys that received an excessive traumatic occlusal force for three to four weeks showed obvious new bone formation on the outer side of the overload area. In this present study, a continuation of the first study, the same monkey model received an exces-sive traumatic occlusal force according to the same procedure. However, in addition, experimental inflammation was induced around the implant. The results showed that as the period of overload-ing of traumatic occlusal force progressed, the peri -imprant tissues clearly deteriorated, as evidenced by vertical bone resorption. These results suggest that peri-implant tissue destruction is encouraged by the combination of peri-implant inflammation and traumatic occlusal force, and that the excessive force clearly affects the process of peri-implantitis