Effect of multiple sessions of photodynamic therapy on bone regeneration around dental implants among patients with peri‑implantitis

The aim of the present study was to assess the effect of multiple sessions of antimicrobial photodynamic therapy (aPDT) on bone regeneration around dental implants among patients with peri‑implantitis.Patients with peri‑implantitis were included. Therapeutically, patients were randomly divided into 4 groups: (a) Group-I: Mechanical debridement (MD) alone; (b) Group-II: MD at baseline followed by a single session of adjunct a PDT; (c) Group-III: MD at baseline followed by aPDT at baseline and at 3-months of follow-up; and Group-IV: MD at baseline followed by aPDT at baseline and at 3- and 6-months of follow-up. Demographic data was collected and peri‑implant clinical (plaque index [PI], gingival index [GI], and probing depth [PD]) and radiographic (crestal bone loss [CBL]) parameters were assessed at baseline and after 9 months. Sample-size estimation was done on data from a pilot investigation and group comparisons were done using one-way analysis of variance and Bonferroni post-hoc adjustment tests. Level of significance was set at P<0.01.Twenty-two, 22, 22 and 22 patients with peri‑implantitis were enrolled in groups -I, -II, -III and -IV. The mean age of individuals in groups -I, -II, -III and -IV were 59.2 ± 5.3, 60.5 ± 2.8, 59.6 ± 3.1 and 58.7 ± 0.8 years, respectively. Compared with Group-I, there was a statistically significant reduction in PI (P<0.01), GI (P<0.01) and PD (P<0.01) in all groups at 9-months follow-up. There was no significant difference in PI, GI and PD in groups -II, -III and -IV at 9-months follow-up. There was no statistically significant difference in CBL in all groups at baseline and at 9-months-follow-up.The use of aPDT as an adjunct to MD reduces the severity of peri‑implant mucositis but does not contribute towards bone regeneration in peri‑implant osseous defects.