In vitro antimicrobial activity of calcium hydroxide cements on Streptococcus sanguis NCTC 7864

Several studies have questioned the antimicrobial role of calcium hydroxide cements. This study assessed the antimicrobial activity of four commercially available calcium hydroxide cements on Streptococcus sanguis NCTC 7864 using inoculated Mueller-Hinton growth medium. Growth curves from optical density analysis, pH measurements, and viability counts were compared over a 24 h period. Significant differences occurred (P < 0.05) between pH measurements but not the growth curves or the viability counts. All cements exerted a cidal effect although this cannot be attributed to an increase in alkalinity alone.