The effect of the hyaluronic acid treatment on peri-implantitis has not been tested. The aim was to analyze the effect of a hyaluronic acid-containing gel on the clinical variables and the expression of biochemical inflammatory markers in the crevicular fluid of implants receiving perimplantitis treatment.

The aim was to analyze the effect of a hyaluronic acid-containing gel on the clinical variables and the expression of biochemical inflammatory markers in the crevicular fluid of implants receiving perimplantitis treatment.

A randomized, controlled, double-blind clinical trial was designed on 100 perimplantitis affected implants placed in 61 subjects. Inclusion criteria were implants with at least 1 year of functional loading and with diagnosis of perimplantitis following the criteria from the Association of Dental Implantology. All implant received perimplantitis treatment. Each patient was randomly assigned to receive a gel containing 0.8% HA (Test group), a gel without HA (Placebo group) or no gel treatment (Control group). After a first gel application at baseline, test and placebo patients performed gel applications at home 3 times/day for 45 days. Clinical variables of each implant were recorded at baseline, 45 and 90 days (probing depth, attachment loss, bleeding). Intraoral radiographs of each implants were performed to measure marginal bone level. Peri-implant crevicular fluid was collected from each implant at baseline and after 45 days of treatment, to assess IL-1β and TNFα levels by ELISA technique. Clustering analysis, considering multiple implants within each patient, was performed.

Inclusion Criteria:

• Implants with at least one year of functional load.
• Implants diagnosed with peri-implantitis according to the criteria of the Association of Dental Implantology.

Exclusion Criteria:

• Previous peri-implantitis treatment.
• Pregnancy or breast-feeding.
• Neoplastic disease.
• Antibiotic treatment during the previous month.