Interventions for replacing missing teeth: treatment of perimplantitis.

BACKGROUND: One of the key factors for the long-term success of oral implants is the maintenance of healthy tissues around them. Bacterial plaque accumulation induces inflammatory changes in the soft tissues surrounding oral implants and it may lead to their progressive destruction (perimplantitis) and ultimately to implant failure. Different treatment strategies for perimplantitis have been suggested, however it is unclear which are the most effective.

OBJECTIVES: To identify the most effective interventions for treating perimplantitis around osseointegrated dental implants.

SEARCH STRATEGY: We searched the Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE. Handsearching included several dental journals. We checked the bibliographies of the identified randomised controlled trials (RCTs) and relevant review articles for studies outside the handsearched journals. We wrote to authors of all identified RCTs, to more than 55 oral implant manufacturers and an Internet discussion group to find unpublished or ongoing RCTs. No language restrictions were applied. The last electronic search was conducted on 15 March 2006.

SELECTION CRITERIA: All RCTs of oral implants comparing agents or interventions for treating perimplantitis around dental implants.

DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted in duplicate and independently by two review authors. We contacted the authors for missing information. Results were expressed as random-effects models using weighted mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals (CI). Heterogeneity was to be investigated including both clinical and methodological factors.

MAIN RESULTS: Seven eligible trials were identified, but two were excluded. The following procedures were tested: 1) use of local antibiotics versus ultrasonic debridement; 2) benefits of adjunctive local antibiotics to debridement; 3) different techniques of subgingival debridement; 4) laser versus manual debridement and chlorhexidine irrigation/gel; 5) systemic antibiotics plus resective surgery plus two different local antibiotics with and without implant surface smoothening. Follow up ranged from 3 months to 2 years. No meta-analysis was conducted due to different interventions tested and outcomes used. No side effects occurred in any of the trials. The only significant statistically differences were observed in a 4-month follow-up RCT evaluating the use of adjunctive local antibiotics to manual debridement in patients having lost at least 50% of the supporting bone around the implants. There were improved probing attachment levels (PAL) mean differences of 0.61 mm (95% CI 0.40 to 0.82), and reduced probing pockets depths (PPD) mean differences of 0.59 mm (95% CI 0.39 to 0.79) in those patients receiving adjunctive local antibiotics. This trial was judged to be at high risk of bias.

AUTHORS' CONCLUSIONS: There is no reliable evidence suggesting which could be the most effective interventions for treating perimplantitis. This is not to say that currently used interventions are not effective. However, the use of local antibiotics in addition to manual subgingival debridement was associated with a 0.6 mm additional improvement for PAL and PPD over a 4-month period in patients associated with severe forms of perimplantitis. In three trials, the control therapy which basically consisted of a simple subgingival mechanical debridement seemed to be sufficient to achieve results similar to the more complex and expensive therapies. Smoothening of rough implant surfaces was not associated with statistically significant improvements of the clinical outcomes. However, sample sizes were small, therefore these conclusions have to be considered with great caution. More well-designed RCTs are needed.