comparison of the efficacy of subgingival irrigation with 2% povidone‑iodine and tetracycline hcl in subjects with chronic moderate periodontitis: a clinico microbiological study

background: this study was performed to evaluate and compare the clinical and antimicrobial efficacy of subgingival irrigation with tetracycline and povidone‑iodine as an adjunct to nonsurgical periodontal therapy. materials and methods: twenty subjects with chronic moderate periodontitis were recruited in this split‑mouth study with probing pocket depth of >3 and ≤5 mm and clinical attachment loss of 3–4 mm in relation to 16, 36, and 46. in each subject, three selected periodontal pockets were assigned to receive one out of three irrigants (1) sterile water (control) in 16; (2) tetracycline at 10 mg/ml in 36; (3) 2% povidone‑iodine in 46, and these sites were designated as group a, group b, and group c, respectively. plaque score, gingival score, pocket probing depth, and clinical attachment level were evaluated before treatment and at 1 and 3 months posttreatment. multiplex polymerase chain reaction was used to detect porphyromonas gingivalis and tannerella forsythensis which have been implicated as the major risk factors for periodontal disease. subgingival plaque collected before treatment and at 1 and 3 months posttreatment. data were analysed using anova and repeated measure anova. results were considered significant if p < 0.05. results: clinical and microbiological parameters were reduced posttreatment, the reduction being significantly higher in group b compared to group c. conclusion: it can be concluded that chemical and mechanical therapies were of slight benefit in the treatment of chronic moderate periodontitis, and there was an adjunctive effect of significance when scaling and root planing was combined with a single subgingival irrigation with tetracycline or povidone‑iodine in lower concentration. key words: polymerase chain reaction, povidone‑iodine, subgingival irrigation, tetracycline