Low surface tension calcium hydroxide solution is an effective antiseptic.

The antimicrobial effects of a saturated calcium hydroxide solution, and in combination with 10% and 20% detergent, were evaluated on Streptococcus faecalis, Streptococcus sanguis, Streptococcus mutans, Streptococcus salivarius, Neisseria sp., diphtheroid, Staphylococcus aureus, Lactobacillus sp., Staphylococcus epidermidis, Bacillus subtilis and Candida albicans. The saturated calcium hydroxide solution was effective against only four of the 11 microorganisms studied over a 60-min exposure time. The calcium hydroxide solutions containing detergent killed all 11 test organisms over a 30-min exposure time. This difference was statistically significant (P < 0.01). No statistically significant difference in antimicrobial action was found between the 10% and 20% detergent calcium hydroxide solutions (P > 0.01). However, the low surface tension (46.5 x 10(-3) Nm-1) and high pH (10.8) of the calcium hydroxide solution with 20% detergent establish it as the more effective solution.