Changes in clinical parameters following adjunctive local sodium hypochlorite gel in minimally invasive nonsurgical therapy (MINST) of periodontal pockets: a 6-month randomized controlled clinical trial

BACKGROUND: The mechanical disruption and removal of the subgingival biofilm represent the most important step in the treatment of periodontitis. However, in deep periodontal pockets, mechanical removal of the subgingival biofilm is difficult and frequently incomplete. Preliminary findings indicate that the use of amino acid buffered sodium hypochlorite (NaOCl) gel may chemically destroy the bacterial biofilm and facilitate its mechanical removal. OBJECTIVES: To clinically evaluate the efficacy of minimally invasive nonsurgical therapy (MINST) of periodontal pockets with or without local application of an amino acid buffered sodium hypochlorite (NaOCl) gel. MATERIALS AND METHODS: Forty untreated patients diagnosed with severe/advanced periodontitis (i.e. stage III/IV) with a slow/moderate rate of progression (i.e. grade A/B) were randomly allocated in two treatment groups. In the test group, the periodontal pockets were treated by means of MINST and NaOCl gel application, while in the control group, treatment consisted of MINST alone. Full-mouth plaque scores (FMPS), full-mouth bleeding scores (FMBS), probing depths (PD), clinical attachment levels (CAL) and gingival recessions (GR) were assessed at baseline and at 6 months following therapy. The primary outcome variable was PD reduction at sites with PD ≥ 5 mm at baseline. RESULTS: At 6 months, statistically significant differences between the two groups were found (p = 0.001) in terms of PD and CAL change. No statistically significant differences were found in terms of GR (p = 0.81). The number of sites with PD ≥ 5 mm and BOP (+) decreased statistically significantly (p = 0.001), i.e. from 85.3 to 2.2% in the test group and from 81.6 to 7.3% in the control group, respectively. Statistically significant differences between test and control groups were recorded at 6 months (p = 0.001). MINST + NaOCl compared to MINST alone decreased statistically significantly (p = 0.001) the probability of residual PDs ≥ 5 mm with BOP− (14.5% vs 18.3%) and BOP+ (2.2% vs. 7.2%). CONCLUSIONS: Within their limits, the present results indicate that (a) the use of MINST may represent a clinically valuable approach for nonsurgical therapy and (b) the application of NaOCl gel in conjunction with MINST may additionally improve the clinical outcomes compared to the use of MINST alone. CLINICAL RELEVANCE: In patients with untreated periodontitis, treatment of deep pockets by means of MINST in conjunction with a NaOCl gel may represent a valuable approach to additionally improve the clinical outcomes obtained with MINST alone SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00784-021-03841-8.