In vitro evaluation and comparison of the abrasive capacity of zirconia whitening toothpaste at different concentrations on the radicular dentin surface of human teeth.

BACKGROUND

Marketed toothpastes vary in the extent to how much abrasive wear they cause to dentin. New abrasive particles in a dentifrice should be evaluated since there they can be at risk of abrasion to dentin and root surfaces.

AIM

The aim of this in vitro study was to evaluate abrasive dentin wear and surface roughness after brushing with whitening toothpaste containing zirconia at four different concentrations.

MATERIAL AND METHOD

This study tested 40 extracted human teeth. After crown removal, root dentin samples were randomly divided into four experimental groups based on zirconia toothpaste concentration: Group A (10 samples) brushed for 5 min with 0.5 % zirconia toothpaste, Group B (10 samples) with 1 %, Group C (10 samples) with 2 %, and the last 10 samples with 5 %.Before brushing, specimens were weighed three times using a precision analytical scale and measured with a Profile Projector. After completing the brushing cycles, surface roughness was measured to evaluate the differences after brushing.

RESULTS

The Kruskal-Wallis test showed no significant difference in the weight of samples at 0.5 %, 1 %, and 2 % toothpaste concentrations. However, at the 5 % toothpaste concentration, there was a significant difference in sample weight measurements (P < 0.05). The mean roughness difference in the three lower concentrations indicated no significant statistical difference, but with the 5 % toothpaste, there was an increase in average dentin roughness (P < 0.05).

CONCLUSION

Results showed that percentage ≤2.0 % of zirconium powder added in a toothpaste, can lead to dentin minimal wear and better roughness by polishing effect. Toothpaste containing 5 % zirconia showed an abrasive effect on dentin and increased surface roughness.