Relationship between toothpaste brushing, surface roughness, and bacterial adherence using contemporary tooth-colored restorative materials: a laboratory study

Introduction:
As rough surfaces have more surface area and surface energy, there is an increased likelihood of plaque accumulation. Studies focusing on correlations between the effect of toothbrushing with paste on surface roughness and microbial adhesion of these restorative materials are limited.

Objectives:
To evaluate and compare the effect of toothpaste brushing on surface roughness (SR) and bacterial adherence of zirconia, zirconomer, and cention N.

Material and methods:
Eighty standardized rectangular-shaped samples were prepared using cention N, zirconia, zirconomer, and enamel. SR and bacterial adherence of each sample were measured using profilometer and colony forming unit/ml, respectively. Samples were then subjected to toothpaste brushing for 10 min, using powered toothbrush and herbal toothpaste. Post-brushing SR and bacterial adherence of samples were re-assessed. Independent t-test was applied in analysis with SPSS 25.0 software. Level of statistical significance was set at p < 0.01.

Results:
The roughest surface before and after brushing was found on enamel (0.98-1.67 μm), and the least SR was observed on zirconia (0.51-0.62 μm). The maximum bacterial adherence pre- and post-brushing was observed in the cention N group (164-88), and the minimum in the zirconia group (85-46). After toothpaste brushing, SR of all materials increased, and bacterial adherence decreased. This difference was statistically significant.

Conclusions:
Within the limitations of the present laboratory study, it can be concluded that surface roughness increases and bacterial adherence decreases post-brushing. In addition, there is a relationship between surface roughness and bacterial adherence after toothbrushing.