Application of photodynamic therapy against periodontal bacteria in established gingivitis lesions in adolescent patients undergoing fixed orthodontic treatment

Abstract

Background: The aim of this 4 week follow up randomized controlled clinical trial is to evaluate the effectiveness of photodynamic therapy (PDT) as an adjunct to ultrasonic scaling (US) in the reduction of gingival inflammatory parameters and periodontal pathogens in established gingival inflammation in adolescent patients undergoing fixed orthodontic treatment.

Materials and methods: A total of 22 adolescent patients (mean age: 17.5 years) undergoing fixed orthodontic treatment and presenting with persistent local gingival inflammation were randomized into two groups: Group-US: patients receiving ultrasonic scaling (US) with usual oral hygiene instructions and Group-PDT: in which patients received adjunctive PDT with US. Dichotomous recording for plaque scores (PS) and bleeding on probing (BOP) was used to assess the clinical inflammatory status. The total bacterial counts of P. gingivalis and T. forsythia were estimated and were expressed as log CFU/mL. All assessments were performed at baseline, 1 week and 4 weeks. For intergroup comparisons, student's t-test was computed along with Bonferroni correction for post hoc multiple comparisons. To identify differences between repeated follow-ups, ANOVA multiple rank test was used.

Results: Both treatment modalities reported statistically significant reduction in PS and BOP in patients undergoing fixed orthodontic treatment (p < 0.05). However, there was no significant difference in PS and BOP when US was compared with PDT (p > 0.05). Group-US showed statistically significant reduction in T. forsythia at 1 week only (p < 0.05). Group-PDT showed statistically significant reduction in P. gingivalis and T. forsythia from baseline to 1 week and 4 weeks (p < 0.05). This was also significant when compared with US on both the time points (p < 0.05).

Conclusion: PDT was effective in significantly reducing periodontal pathogens in established gingivitis lesions in adolescent patients undergoing fixed orthodontic treatment in short term.

Keywords: Bleeding; Fixed orthodontic treatment; Gingivitis; Photodynamic therapy; Porphyromonas gingivalis.