355 - Toothbrushing and Dentifrices on Roughness of Pediatric Zirconia Crowns

Purpose: To evaluate the effect of toothbrushing and dentifrices on the surface roughness of 3 different brands of prefabricated pediatric zirconia crowns (ZRCs).

Methods: Thirty-two maxillary right central incisor prefabricated pediatric ZRCs were obtained from each of the following manufacturers: Kinder Krowns, NuSmile, and Sprig. ZRCs from each brand were equally assigned to 4 dentifrices with different abrasivities based on their Relative Dentin Abrasion (RDA) values: Tom’s of Maine Children’s toothpaste (Low), Crest Kid’s (Medium), Prevident 5000 Original (High), and Crest Pro Health (Harmful). ZRCs were brushed 10,000 strokes with a V-8 Cross Brushing Machine using the assigned dentifrices. Pre- and post-intervention data for the surface roughness of ZRCs, represented in R_a (average roughness) and R_z (mean roughness depth), were obtained using Bruker DektakXT Stylus Profilometer in μm. Data were analyzed independently using two-way ANOVA with the Holm-Sidak method (α=0.05).

Results: The ΔR_a of Kinder Krowns and Sprig EZCrowns indicated statistically significant differences (P < .05). ΔR_a of Sprig EZCrowns and NuSmile using Crest Kid's also had statistically significant differences (P < .05). There was no statistical significance in ΔR_z.

Conclusions: Despite its statistical significance, with changes in the surface roughness (ΔR_a and ΔR_z) at a μm scale, it was difficult to indicate any signs of clinically significant differences. Although this study does not address how toothbrushing and different dentifrices may affect the mechanical properties, durability, and/or retention properties of ZRCs, the study's results provide confidence to clinicians when using prefabricated pediatric ZRCs as a sustainable treatment option.