Comparative Study of Antibacterial Activity of Five Luting Cements on Strains of Streptococcus mutans: An In Vitro Study

Abstract

The purpose of the study was to evaluate and compare the antibacterial activity of five luting cements on Streptococcus mutans. Agar diffusion test (ADT) and direct contact test (DCT) were carried out to measure the antibacterial activity. In the DCT, the bacterial growth was highest in polycarboxylate cement, but zinc phosphate cement produced the maximum zone of inhibition in the ADT while no zone of inhibition was found in polycarboxylate cement.Purpose: To evaluate and compare the antibacterial activity of five luting cements (zinc phosphate, zinc polycarboxylate, glass ionomer, resin-modified glass ionomer and resin cements) on the strains of Streptococcus mutans using the direct contact test and agar diffusion test.Material and methods: For the agar diffusion test, three readings of the inhibition halo were recorded at 24 hours, 48 hours and 72 hours, respectively, and were repeated seven times for each material. In the direct contact test, the kinetics of the bacterial outgrowth were recorded at 650 nm in a temperature-controlled spectrophotometer for 24 hours, 48 hours, 72 hours and one week, respectively. The antibacterial activity of the tested specimens was analyzed using mixed ANOVA and Bonferroni post hoc tests (P < 0.05).Results: In the DCT, the bacterial growth was highest in polycarboxylate cement with mean (95% CI) growth of 0.58 mm and least in resin modified glass ionomer cement with mean (95% CI) growth of 0.26 mm. Although zinc phosphate cement showed the maximum zone of inhibition with mean value of 23.69 mm, zinc polycarboxylate cement did not produce any inhibition halo in the ADT.Conclusion: Resin-modified glass ionomer cement possessed the best antibacterial efficacy when the DCT was employed while zinc phosphate cement produced the best antibacterial property in the ADT. No zone of inhibition was found in polycarboxylate cement.