Clinical, radiographic and immunological effects of surgical treatment associated with photodynamic therapy with 0.2% toluidine blue in peri-implantitis: randomized 1-year longitudinal clinical study

The aim of the present study was to evaluate the clinical, radiographic and immunological effects of surgical treatment for peri-implantitis after 1 year. Twenty-one patients with peri-implantitis participated in this study (mean age 56.0 ± SD 9.6 years). Patients were divided into a test and control group at random. The following clinical parameters were used: probing depth (PS); plaque index (PI)and probing bleeding index (BOP). Periapical radiography was used as a baseline and 1-year radiographic parameter. Peri-implant fluid samples were collected with periopaper and frozen at -70° C for further analysis. Bone metabolism biomarkers included TNF-α, SOST, PTH, OPG, OPN, OC, Leptin, IL-6, IL-1ß FGF-23. Patients in both groups received peri-implant surgical treatment for scaling. The test group underwent a photodynamic therapy with 0.2% toluidide blue, in which pulsed infrared radiation is emitted at a wave length of 2.94 mm. The laser parameters were set at 100 mJ/pulse (12.7 J/cm2) and 10 pps (pulse energy at the tip: about 85 mJ/pulse). Clinical data were collected in four visits in both groups (baseline, 3 months, 6 months and 1 year). Radiographic and immunological data were collected (baseline and 1 year). Biomarkers were measured using a multiplex immunoassay. The results showed a significant reduction in clinical parameters 3 months after treatment, in both groups. In the baseline, the control group presented the values of PBS 8.5 mm ± 0.9, ISS 100%, ISG 100% VPI 100%, while the test group presented PBS 8.6 mm ± 0.700%, ISS 100% and ISG 100% After 3 months, the average values of PBS, ISS, ISG and VPI were 5.7 mm ± 0.5, 11%, 100% and 0% in the control group and 5.7 mm, 8%, 100% and 0% in the test group ( p <0.05). These values remained constant until the 12-month follow-up, at which point a statistically significant bone gain was observed in the control group (baseline 6.2 ± 1 mm x 12 months 5.7 ± 0.6 mm) (p = 0.008). In the test group there was a bone gain (baseline 6 ± 0.8 mm x 12 months 5.9 ± 0.6 mm) (p> 0.5). The immunological analysis showed a significant reduction in the levels of IL6 and OC in both groups, after 1 year of treatment. However, in the test group there was a significant reduction in Leptin (p = 0.05) and a tendency towards a reduction in OPN levels (p = 0.08). In conclusion, peri-implant surgical therapy led to a significant improvement in peri-implant clinical parameters after 1 year, a bone gain in the control group, and a reduction in biomarkers in both groups. The additional use of photodynamic therapy for surgical treatment in the test group did not present superior results to those observed in the control group