Abstract
In recent years, dental implant treatment has been credited with being highly predictable. However, since its prognosis depends on local or systemic factors and surgical techniques, there are some implants that need to be removed due to unknown causes.
Therefore we classified those cases with an unfavorable prognosis over the last five years, into early-type abnormalities, delayed-type abnormalities and abnormalities after fitting the implant prosthesis. Out of these three categories, we paid particular attention to the early-type abnormalities and, as a result of investigating this category, we found 17 implants. Furthermore, from these abnormal cases, we selected and examined 5 cases where oval characteristic radiopaque image, gingival fistula and infection were identified at the upper or central part of the implant body during observation.
The standard procedure for the placement of multiple implants was performed on each of these cases. However, 5 implants eventually had to be removed. One of the possible causes was considered to be overheating from the drilling procedure to create the implant holes, but the definite cause is still under study. As for surgical methods, in all the cases the standard implant procedure (without GBR) was performed.
