Introduction: The objective of this in vitro study was to compare the effectiveness of a propolis-based herbal toothpaste with 5% sodium fluoride varnishin obstructing human dentinal tubules; Scanning electron microscopy was utilised to obtain quantitative and qulitative data on tubular obstruction.

Methods: Thirty-nine extracted human premolar teeth were collected. The cementum layer was removed using a water-cooled diamond bur and the smear layer using ethylenediaminetetraacetic acid (EDTA) 17%. Then, the samples were randomly divided into 3 groups (n = 13 each), as follows: group 1: dentin discs exposed to the propolis-based herbal toothpaste (Herbex); group 2: dentin discs exposed to 5% sodium fluoride varnish; and group 3: control. Then, all discs were observed and imaged in 4 non-overlapping fields by an electron microscope at 2000× magnification. The topography and number of open, closed, and semi-closed tubules were counted in all images. The data were analysed using Kruskal-Wallis test, Mann-Whitney U test, and Friedman test. The statistical analysis was performed with SPSS statistic 22.0 software, with a significance level of α = 0.05.

Results: In pairwise comparisons of the groups considering the percentage of open, closed, and semi-closed tubules, the difference was not statistically significant between the 5% sodium fluoride varnish and propolis groups in the closed and semi-closed tubules, but it was statistically significant with the control group. Additionally, the percentage of open tubules in the propolis-based herbal toothpaste group was significantly lower than in the 5% sodium fluoride varnish and control group.

Conclusions: Both propolis-based herbal toothpaste and 5% sodium fluoride varnish is effective in blocking human dentin tubules to various extents.