Role of antimicrobial photodynamic therapy in reducing subgingival oral yeasts colonization in patients with peri-implant mucositis

Objective: The aim was to assess the role of antimicrobial photodynamic therapy (aPDT) in reducing subgingival oral yeasts colonization (OYC) in patients with peri-implant mucositis (PIM). Methods: Patients diagnosed with PIM were included. Patient demographics were recorded and implant placement and prosthetic rehabilitation protocols were retrieved from patients' records. Peri-implant clinical parameters (modified plaque index [mPI], modified bleeding index [mBI] probing depth [PD]) and subgingival OYC and were assessed using standard techniques. All patients were randomly divided into test-and control groups. In the test-group, patients underwent mechanical debridement (MD) of implant surfaces and supra and sub-gingival peri-implant sulci peri-implant immediately followed by a single session of aPDT. In the control group, patients underwent MD alone. Peri-implant clinical parameters and OYC were re-assessed at 3-months' follow-up. Sample-size estimation was done on data from a pilot investigation and group-comparisons were done using the paired t-and Mann Whitney U-tests. Correlation between age, mPI, mBI, PD and OYC at baseline and 3 months' follow-up was assessed using regression analysis models. A statistically significant difference between the groups was recorded when P-values were less than 0.01. Results: Thirty-four individuals (17 and 17 in the test-and control groups, respectively) were included. There was no significant difference in the mean age, scores of mPI, mBI, PD and OYC among patients in the test-and control-groups at baseline. At 3-months of follow-up, there was a statistically significant reduction in scores of mPI (P<0.001), mBI (P<0.001), PD (P<0.001) and OYC (P<0.001) among patients in the test-compared with the control-groups. There was no significant correlation between age, mPI, mBI, PD and OYC in both groups. Conclusion: In the short term, a single session of aPDT as an adjunct to MD is effective in reducing peri-implant soft tissue inflammation and OYC in patients with PIM.