Determining the best anti-microbial properties of dental cements used for pulp capping procedures using deep dentinal carious material

INTRODUCTION: The exposure of the healthy pulp in cases of deep dentinal caries (DDC) that contain carious microorganisms can be prevented by placing a layer of pulp capping agent on the affected dentin. The cements used for pulp-capping should also ensure good anti-microbial properties. The present study was carried out to detect the antimicrobial efficacy of the commonly used cements by culturing the samples directly from DDC. AIMS: To determine the efficacy of dental cements in the growth inhibition of microorganisms involved in DDC using direct contact anaerobic culture test. METHOD: 100 samples of DDC were collected in RTF. Ten microliters of the specimen containing RTF was incubated in thioglycolate broth consisting of 1 mm(3) cement blocks of GIC, CaOH(2), ZnOE and MTA anaerobically for 24 hours. This was further sub-cultured using selective media for streptococcus mutans, lactobacillus and bifidobacterium. Growth inhibition was measured by calculating the number of CFUs and statistically analysed using ANOVA and Tukey's post-hoc tests. RESULTS: Tests showed variation in the anti-microbial effects of the cements and was highly significant at P < 0.001. Bifidobacterium showed most number of CFUs. MTA was the most effective pulp capping agent exhibiting 87.13% reduction in microbial growth, followed closely by ZnOE (84.6%). CONCLUSION: A conservative approach to treat DDC is the need of the hour which calls for the use of pulp capping cements of good antimicrobial efficacy. The current study revealed bifidobacterium to be the most prevalent in DDC and the cement that would best inhibit the mixed culture growth was MTA followed closely by ZnOE.