No reliable evidence suggesting what is the most effective interventions for treating peri-implantitis.
METHODS
The Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase databases were searched. Authors of trials were contacted as were more than 55 dental implant manufacturers and an Internet discussion group to find unpublished or ongoing randomised controlled trials (RCTs).


METHODS
All randomised controlled trials (RCTs) evaluating interventions to treat peri-implantitis, including studies with parallel group and split-mouth designs.


METHODS
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. Results were expressed as random-effects models using 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.


RESULTS
Nine studies were included with follow-up ranging from three months to four years. They compared different non-surgical interventions (five trials); adjunctive treatments to non-surgical interventions (one trial); different surgical interventions (two trials); adjunctive treatments to surgical interventions (one trial). No study was judged to be at low risk of bias. Statistically significant differences were observed in two small single trials judged to be at unclear or high risk of bias. After four months, adjunctive local antibiotics to manual debridement in patients who lost at least 50% of the bone around implants showed improved mean probing attachment levels (PAL) of 0.61 mm (95% confidence interval (CI) 0.40 to 0.82) and reduced probing pockets depths (PPD) of 0.59 mm (95% CI 0.39 to 0.79). After four years, patients with peri-implant infrabony defects > 3 mm treated with Bio-Oss and resorbable barriers gained 1.4 mm more PAL (95%CI 0.24 to 2.56) and 1.4 mm PPD (95%CI 0.81 to 1.99) than patients treated with a nanocrystalline hydroxyapatite.


CONCLUSIONS
There is no reliable evidence suggesting which could be the most effective interventions for treating peri-implantitis. This is not to say that currently used interventions are not effective. A single small trial at unclear risk of bias showed 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 four-month period in patients affected by severe forms of peri-implantitis. Another small single trial at high risk of bias showed that after four years, improved PAL and PPD of about 1.4 mm were obtained when using Bio-Oss with resorbable barriers compared to a nanocrystalline hydroxyapatite in peri-implant infrabony defects. There is no evidence from four trials that the more complex and expensive therapies were more beneficial than the control therapies which basically consisted of simple subgingival mechanical debridement. Follow-up longer than one year suggested recurrence of periimplantitis in up to 100% of the treated cases for some of the tested interventions. As this can be a chronic disease, re-treatment may be necessary. Larger well-designed RCTs with follow-up longer than one year are needed.
Department of Reconstructive Sciences, University of Connecticut Health Center, Farmington, CT, USA.
Avinash S
AS
Bidra