Local disinfection with sodium hypochlorite as adjunct to basic periodontal therapy: a randomized controlled trial

Aim: To investigate the clinical and microbiological effects of local disinfection with 0.5% sodium hypochlorite (NaOCl) with or without systemic antimicrobials (amoxicillin and metronidazole, AM) during basic periodontal therapy (BPT).
Material and Methods: In a randomized clinical trial (four groups), 110 chronic periodontitis patients received BPT plus local irrigation with saline (BPT + S), local disinfection with NaOCl (BPT + DIS), BPT + DIS + AM or BPT + S + AM. The outcome was analysed at baseline, 3, 6 and 12 months.
Results: There was no difference in clinical attachment level gain at 12 months between the four groups. BPT + DIS showed no additional improvement compared to BPT + S; BPT + DIS + AM showed fewer sites with probing pocket depth (PPD) ≥7 mm versus BPT + S only up to 6 months (p = 0.037). In factorial analyses, additional clinical reduction for PPD (p = 0.023) and number of sites with PPD ≥5 (p = 0.007), ≥6 (p = 0.002) and ≥7 mm (p < 0.001) were found when AM was added to BPT, but not when DIS was applied. In all groups, a comparable decrease in targeted bacteria was found. AM caused adverse events in 22% of the patients.
Conclusion: Local disinfection with NaOCl, also in combination with AM, showed, after 1-year follow-up, no additional clinical and microbiological effects compared to BPT alone.