Comparison of Antibacterial Properties of Three Different Dental Cements by Direct Contact Test

Antibacterial activity of cement materials can play an important role in caries prevention. The aim of this study is comparison of anti-bacterial properties of three different dental cement. Subjects and

The experimental study was undertaken to compare antibacterial properties of three dental cements: zinc phosphate (Harvard)، zinc polycarboxylate (Harvard) and glass ionomer (GC) with 2 different powder/liquid ratios، while Streptococcus mutans suspension was placed directly on the cement. For the direct-contact test، micro titer plates were divided into 7 groups that contain 12 wells. 6 groups of them were for two concentration of the three cements and 1 group was for positive control. After coating the wells with tested cement، adding bacteria to the groups and 1 hour،1day،1 week and1month after ancubation، optical density in each well were monitored by using spectrophotomete.. The data were subjected to repeated measure،1-way ANOVA and Tukey test.

One hour، 1 day and 1 week after cementation، zinc phosphate and glass ionomer demonstrated antibacterial activity but zinc polycarboxylate did not show any antibacterial properties. In 1 month aged microtiter plate zinc phosphate and glass ionomer exhibited weaker antibacterial properties than before while zinc polycarboxylate cement did not show any antibacterial properties. The different concentration of cements، in 1 hour،1 day and 1 week after cementations، had no effect on the antibacterial properties of tested cements. One month after aging the cements، outgrowth of bacteria in standard glass ionomer was more than diluted glass ionomer. The same result was shown for zinc phosphate.

Zinc phosphate and glass inomer demonstrated antibacterial properties even after 1 month، while zinc polycarboxylate exhibited no antibacterial activity.