Concentration of sodium hypochlorite disinfection in regenerative endodontic procedure: A systematic review

Objectives: To evaluate whether low concentration sodium hypochlorite (NaOCl) disinfectant protocol can achieve a sufficient amount of disinfection to provide a conducive environment for clinical and radiographic success of regenerative endodontic procedure. Materials and methods: This systematic review includes necrotic immature permanent anterior teeth below 20 years of age using triple antibiotic paste as an intra-canal medicament and autologous platelet concentrates as scaffold. The interventional group was low concentration (≤2%) NaOCl and comparator group included high concentration (>2%) NaOCl as disinfectant. Cochrane risk of bias assessment 2 (RoB 2) tool was used for assessment of risk of bias. Included studies were evaluated for the absence of clinical signs and symptoms, increase in root length and apical closure on radiograph, and positive response to vitality testing. Results: After evaluation, seven studies were included. Clinical success rate was seen in 98.33% cases in low concentration (≤2%) and 95% cases in high concentration (>2%) NaOCl. The radiographic success rate was 86.66% in low concentration (≤2%) and 80% in high concentration (>2%) NaOCl disinfection. Positive response for vitality testing was seen in 46.66% cases in low concentration (≤2%) and 38.70% in high concentration NaOCl (>2%). Conclusion: Low concentration (≤2%) NaOCl is as effective as high concentration (>2%) to achieve disinfection of the root canal. However, an increased success rate is associated with the use of low concentration (≤2%) NaOCl. Response to pulp vitality is observed to be superior with low concentration (≤ 2%) NaOCl although it might be attributed to a longer follow-up period.