Effectiveness of single versus multiple sessions of photodynamic therapy as adjunct to scaling and root planing on periodontopathogenic bacteria in patients with periodontitis.

ABSTRACT

OBJECTIVE: The aim of the present 6-months' follow-up study was to assess the influence of single versus multiple sessions of photodynamic therapy (PDT) as adjunct to scaling and root planning (SRP) on periodontopathogenic bacteria in patients with periodontitis. METHODS: Forty-five patients with periodontitis were included. The patients were randomly divided into 3 groups. In groups 1 (n = 15), 2 (n = 15) and 3 (n = 15), the patients under went SRP with PDT at (a) baseline; (b) baseline and after 1-month; and (c) baseline and after 1- and 3-months. Peri-implant plaque index (PI), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL) and marginal bone loss (MBL) were measured at baseline and 6-months follow-up. Counts of Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum and Aggregatibacter Actinomycetemcomitans were determined before SRP and at 4- and 6-months follow-up. RESULTS: All patients had grade-B periodontitis. There was no statistically significant difference in age and gender in all groups. At- 6-months' follow-up, patients that underwent SRP once showed significantly higher counts of periodontopathogenic bacteria in the oral biofilm compared with patients that received photobiomodulation twice or three times (P < 0.05). There was no significant difference in the periodontal parameters and counts of gram-negative bacteria in patients that received photobiomodulation 2 or 3 times. CONCLUSION: At least 2 sessions of PDT following baseline SRP is essential to achieve a significant reduction in the counts of subgingival bacteria in periodontitis patients over a 6-month follow-up period.