Effect of lowering the pH of sodium hypochlorite on dissolving tissue in vitro.

Sodium hypochlorite (NaOCl), a common antimicrobial and tissue-dissolving irrigant, comes from the manufacturer at pH 12. When the pH is lowered, NaOCl becomes more antimicrobial. The aim of this study was to examine what effect lowering the pH has on the property of tissue dissolution. Seven groups were tested for dissolving porcine muscle tissue at varying pH, concentrations, and times. When groups were examined solely by pH, there was no significant difference between the pH 12 and 9 groups, but a statistically significant level was found between pH 12 and 9 versus the pH 6 groups (P < .05). Higher concentrations and greater time periods all led to greater amounts of tissue dissolution.