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.

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The effects of a nonthermal atmospheric plasma jet with argon and argon/oxygen (Ar/O₂) gases on live human dental pulp stem cells (hDPSCs) were studied to verify tooth vitality in the pulp-capping process. Using MTT assay, the surviving hDPSCs after plasma jet exposure for 1, 2, and 3 min were counted. First, for the pulsed plasma jet the frequency varied from 10 to 50 kHz for 5 groups with Ar and 5 groups with Ar/O₂ plasma jet. Later, with the alternating current (AC) plasma jet, the voltage was changed between 5.5 and 16.05 kV for 13 groups. The cells in the control group were only exposed to Ar and Ar/O₂ gases. To control thermal damage to hDPSCs, optical emission spectroscopy was used. For data analysis, the ANOVA repeated measure was used. There were significant differences between the various frequencies and exposure durations (<i>p</i> &#60; 0.05) for the Ar plasma. For the Ar/O₂ gas, there were significant differences between frequencies (<i>p</i> &#60; 0.001). For the AC plasma jet with Ar gas, there were significant differences between voltages (<i>p</i> &#60; 0.001). At the higher pulsed jet frequencies, temperatures increased. Eventually, the suitable durations for root canal disinfection and hDPSC survival with the Ar pulsed jet were 2 and 3 min at 10 and 30 kHz, respectively. Since cold plasma disinfection keeps hDPSCs alive, it can be helpful in promoting tooth survival and durability for pulp capping in clinical treatments.