Evaluating the antibacterial effect of synthesized herbal toothpastes and their efficacy for dentine tubule occlusion: Scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis.

The tubule occlusion of two newly developed herbal toothpastes was examined. They were prepared based on the mixture of pomegranate peel and Equisetum arvense extracts with strontium acetate. The antimicrobial activity of pomegranate peel and E. arvense were determined using minimum inhibitory concentration (MIC). Then, 30 mid-coronal dentin discs from the human third molars were etched for 30 s with the lemon juice (pH = 2.4). The specimens divided into the three groups. While the control group had 6 specimens, Groups 1 and 2 were including 12 specimens. Group 1 brushed with toothpaste containing 10% strontium acetate and 5% hydroalcoholic extracts of pomegranate peel, and Group 2 brushed with 5% strontium acetate, 5% hydroalcoholic extracts of E. arvense, and 5% hydroalcoholic extracts of pomegranate peel. Brushing was simulated for 6 months with 2 N loading. Then, 50% of discs in each group were immersed in lemon juice for 1 min. Moreover, specimens in control group were brushed with distilled water. Finally, all 30 discs were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDXS). The occluded dentin tubules were counted and statistically evaluated. It was found that the number of open dentin tubules decreases significantly after brushing with both tested toothpastes compared with control group (p < .001). Moreover, a significant difference was observed between two toothpastes before and after acid immersion process (p < .001). The SEM micrographs confirmed the dentin tubule occlusion of both herbal dentifrices. Besides, EDXS analysis approved the strontium and silica presence on the dentin tubules for the toothpaste which was based on E. arvense.