Efficacy of antimicrobial photodynamic and photobiomodulation therapy against Treponema denticola, fusobacterium nucleatum and human beta defensin-2 levels in patients with gingivitis undergoing fixed orthodontic treatment: A clinic-laboratory study

Background: Evidence suggests that molecular pathways are involved in human beta-defensin (hBD)-2 mRNA regulation in human gingival epithelial cells stimulated with periodontal bacteria. This clinical and laboratory study evaluated the efficacy of two laser therapies including antimicrobial photodynamic therapy (aPDT) and photobiomodulation (PBM) therapy as an adjunct to ultrasonic scaling (US) on the gingival crevicular fluid (GCF) levels of hBD-2 and subgingival Treponema denticola (T. denticola) and Fusobacterium nucleatum (F. nucleatum) spp., in patients undergoing fixed orthodontic therapy and gingivitis. Materials and methods: Forty-five patients undergoing fixed orthodontic treatment were randomly divided into three groups based on the type of treatment rendered: Group-I: aPDT as an adjunct to US, Group-II: PBM as an adjunct to US and, Group-III: US alone. Full-mouth plaque scores (FMPS), bleeding on probing (FMBOP) and probing depth (PD) were assessed. GCF was collected for estimation of hBD-1 using enzyme-linked immunosorbent assay. Plaque samples were used to quantify T. denticola and F. nucleatum spp by quantitative polymerase chain reaction. All clinical and laboratory investigations were carried out at baseline (T-0), day 30 (T-30) and day 60 (T-60). Results: FMPS and FMBOP showed statistically significant reduction in all groups at T-30 and T-60 from T-0. No inter-group differences were observed between any groups at follow-up. Mean PD remained stable for Group-II and Group-III, while Group-I showed progressive reduction at T-60. The GCF levels of hBD-2 progressively decreased in Group-I (aPDT) while the levels increased slightly at T60 in Group-III. The levels in Group-II (PBM) remained stable from T-30 to T-60. Statistically significant reduction was seen for Group-I when compared with Group-II and Group-III at T60 (p = 0.045). A significant reduction was observed for T. denticola in only Group-I patients at T-30 (p = 0.031) and T-60 (p = 0.047). A significant reduction was seen in both Group-I and Group-II patients at T-30 and T-60. The number of sites with BOP was correlated with both bacterial species (Table 4). Only T. denticola showed positive correlation to mean BOP after correcting for multiple testing. Conclusion: aPDT and PBM showed similar improvement in gingival inflammatory and microbiological parameters compared to US. aPDT assisted in modest reduction of hBD-2 in patients undergoing fixed orthodontic treatment.