Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 14 2 2017 08 06 76 83 EN Zahra Khamverdi Professor, Dental Research Center, Department of Restorative Dentistry, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran Matin Kordestani Post Graduate Student, Department of Restorative Dentistry, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran Alireza Soltanian Professor, Department of Biostatiatics, School of Public Health and Modeling of Noncomunicable Diseases Research Center, Hamadan University of Medical Sciences, Hamadan, Iran 2017 01 11 2017 04 15 Objectives: The aim of this study was to evaluate the effect of dentin remineralization using proanthocyanidin (PA), fluoride varnish and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) paste and their various combinations on microhardness of demineralized root dentin. Materials and Methods: One-hundred and twenty freshly extracted sound human premolars were selected and randomly divided into eight groups for dentin treatment as follows. C: Deionized water (control); PA: 6.5% PA solution; F: fluoride varnish (5% NaF, 22600 ppm fluoride); CP: CCP-ACP; PAF: 6.5% PA + fluoride varnish; PACP: 6.5% PA + CCP-ACP; FCP: fluoride varnish + CCP-ACP and PAFCP: 6.5% PA + fluoride varnish + CCP-ACP. All specimens were subjected to Vickers microhardness test (500 g, 10 seconds, 3 points). Data were analyzed using one-way ANOVA and Tukey’s post hoc test. The significance level was set at 0.05. Results: The mean and standard deviation (SD) values of Vickers hardness number (VHN) in groups C, PA, F, CP, PAF, PACP, FCP and PAFCP were 37.39±4.97, 38.68±4.62, 48.28±2.68 ,41.91±3.32, 48.59±2.55, 53.34±2.57, 48.413±4.00 and 55.20±1.82, respectively. Pairwise comparisons of the groups revealed that there was no significant difference between groups C and PA, PA and CP, F and PAF, F and FCP, PAF and FCP, and PACP and FPACP (P>0.05); but significant differences were observed between other groups (P<0.05). Conclusions: The results of this study showed that the tested dentin treatments increased the microhardness of demineralized root dentin except for PA application.       https://fid.tums.ac.ir/index.php/fid/article/view/1697 https://fid.tums.ac.ir/index.php/fid/article/download/1697/947