2002 年 15 巻 4 号 p. 446-450
Osseointegrated implants have been used for general dental treatments with high predictability. On the other hand, a possible complication of this method is implant fractures happening at a part of implant body to abutment joint and a superstructure. However, a solid-type fracture is rare.
The purpose of this study is to find the cause of fractures of two connected freestanding implant abutment of solid implants, which occurred 18 months after they were sat on a one-piece superstructure. This clinical case was examined from first visit to recovery, and analyzed by electric microscopy(SEM)on the fracture surface.
Consequently, it is important for an implant to be created according to a well-considered design that has taken into account not only strength of materials but also the composition, possible locations where stress risers may be created, and flaws that can initiate cracks, in order to avoid fatigue fractures.
Also, it is important that a superstructure be constructed in consideration of strength of materials, as well as a reduction in lateral stress during lateral excursion, by proper occlusion of the prosthesis, and by the use of a night guard for bruxism.