Objective: To compare the antimicrobial activity and tissue dissolution capacity of calcium hypochlorite (Ca(OCl)2) solution with sodium hypochlorite (NaOCl) solution at 0.5%, 1.0%, 2.5%, 5.25% concentrations.
Methods: To determine the inhibition halos produced by the tested substances against Enterococcus faecalis, the agar diffusion method was employed. Additionally, the broth contact method was used to determine the time required for the inhibition of E. faecalis. Bovine pulp fragments were used to test the dissolution, and half of the pulps were freely deposited samples in cell culture wells and the remaining samples were fixed on bovine dentin bases.
Results: For both Ca(OCl)2 and NaOCl solutions, the greatest inhibition zones were observed at 5.25% concentration. However, the most significant inhibition zone was measured with 5.25% Ca(OCl)2 solution (17.38 mm). Hypochlorite solutions at 2.5% and 5.25% concentrations required less time to inhibit E. faecalis than those with 0.5% and 1.0% concentrations (P<.05). There was no difference in inhibition times between 2.5% and 5.25% hypochlorite solutions (P>.05). For dissolving pulp fragments, the most effective hypochlorite solution concentrations were 5.25% and 2.5% (P<.05). Additionally, suspended pulp fragments were more susceptible to dissolution than fragments attached to dentin blocks (P<.05), with the only exception being 0.5% Ca(OCl)2.
Conclusion: Ca(OCl)2 solutions showed antimicrobial activity against E. faecalis and could dissolve pulp tissues. Further studies should be conducted to determine whether Ca(OCl)2 solutions can be employed as alternative irrigants in the chemicalmechanical preparation of the root canal system.