Diagnostic parameters and peri-implantitis

Peri-implantitis affects the predictability of long-term implant survival and success rates. Appropriate treatment guidelines are lacking and the precise prevalence of the disease is unknown. How are peri-implantitis cases currently defined in prevalence studies?
Case definitions of peri-implantitis usually consist of composite evaluations of peri-implant tissue inflammation, such as bleeding on probing, bleeding scores, or assessments of marginal bone loss with different thresholds (ranging from <1 to >3 mm). However, among the 41 studies evaluating peri-implant tissue inflammation which were included in the present review, there were many discrepancies between the case definitions reported. 15 lacked a case definition and the remaining 26 studies applied 15 different criteria.

Are diagnostic parameters still valid for gauging the real prevalence of peri-implantitis?
When assessing the mean values of the three diagnostic parameters (MBL, BoP and PD), the values did not correlate with the reported prevalence of peri-implantitis. The mean values are therefore not adequate parameters for assessing the prevalence of the disease. Rather than mean values, frequency distribution of diseased sites should be considered the most appropriate outcome measure.

How should peri-implantitis be diagnosed in clinical practice?
The diagnosis should not be based on a single parameter, but on multiple clinical and radiographic parameters. It should be necessary for these parameters to be obtained at baseline for reference, preferably after the bone adaptation stage and once the peri-implant tissues have fully healed. The baseline parameters should be used to detect significant changes in peri-implant tissues, and should be used as a basis for diagnosis of peri-implantitis. In the absence of baseline values, certain thresholds which are generally accepted may be used (for example, if the radiographic bone level is 3mm from the coronal portion of the intraosseous component of the implant).

New diagnostic tools are needed with improved sensitivity and specificity which would allow clinicians to assess changes in marginal bone levels and distinguish between healthy and diseased peri-implant soft tissues.