Evaluation of cytotoxicity of calcium hydroxide, sodium fluoride and their mixture in order to introduce the best combination for use in root canal treatment

In dentistry, antimicrobial materials are selected due to their antimicrobial effects and tissue-compatibility. In the present study, cell-toxicity of calcium hydroxide and sodium fluoride powders were evaluated in L929 fibroblast cell line. Also in this study, possible effect of calcium hydroxide was evaluated in decreasing cell-toxicity effect of sodium fluoride.

Experimental materials were evaluated in time points of 6, 12, 24, 48 and 72 hrs with concentrations of 0.05, 0.1, 0.25, 0.5, 0.75, 1, 5, 25, 100, 500 and 1000 ppm by MTT test on L929 fibroblast cells and as negative control untreated cells were evaluated.  

Calcium hydroxide alone, showed low cell-toxicity (p<0.05). Sodium fluoride in concentrations of 500 and 1000 ppm showed a meaningful difference versus negative control sample (p<0.05). Combination of calcium hydroxide and sodium fluoride reduced sodium fluoride cell-toxicity meaningfully in concentration of 500 ppm (p<0.05).

Using of new compounds is so useful in dentistry for disinfection. One solution is reducing current compounds cell-toxicity. In the other hand, calcium hydroxide did not show noticeable cell-toxicity but it reduced sodium fluoride cell-toxicity in a combination form.