OR18 - Reported versus Actual Concentration of Commercial Sodium Hypochlorite

Abstract: Objective: To evaluate the actual concentrations of commercial sodium hypochlorite, including those marketed to the dental professional, at the time of use in clinic. Methods: Four brands of sodium hypochlorite (CanalPro, Henry Schein, Sultan healthcare, Clorox) were used in this study. Samples were prepared per brand and concentration evaluated at time of preparation and after 1 week of preparation. Concentration was measured by adding potassium iodide to consume the hypochlorite followed by titration with sodium thiosulfate. Volume of sodium thiosulfate was then used to calculate the actual concentration of the sodium hypochlorite. A minimum of three samples from each brand were evaluated. Student’s T test was used for statistical analysis with p< 0.05 as statistical significance. Results: Clorox’s reported concentration was 8.25% and actual concentration was 7.74+0.045% (p < 0.05), Canal Pro 3%’s reported concentration was 3% and actual concentration was 3.076%+0.086 (p>0.05), Canal Pro 6%’s reported concentration was 6% and actual concentration was 5.337%+0.029 (p < 0.05), Henry Schein’s reported concentration was 6% and actual concentration was 5.607%­+0.017(p< 0.05), and Sultan Healthcare’s reported concentration was 5.25% and actual concentration was 5.046%+0.11(p < 0.05). Conclusion: All brands, except Canal Pro 3%, showed a significant decrease in actual concentration compared to labeled concentration.