Surface Roughness of Prefabricated Pediatric Zirconia Crowns Following Simulated Toothbrushing

Area of Science:

• Materials Science
• Pediatric Dentistry
• Biomaterials

Background:

• Prefabricated pediatric zirconia crowns (ZRCs) are an increasingly common restorative option for children.
• Understanding the long-term durability and surface integrity of ZRCs under daily use conditions, such as toothbrushing with different dentifrices, is crucial for clinical application.
• Surface roughness can impact plaque accumulation, aesthetics, and the longevity of dental restorations.

Purpose of the Study:

• To assess the impact of simulated toothbrushing with various dentifrices on the surface roughness of three distinct brands of prefabricated pediatric zirconia crowns (ZRCs).
• To compare the surface roughness changes (Ra and Rz) across different ZRC brands and dentifrice formulations.

Main Methods:

• Ninety-six pediatric ZRCs from Kinder Krowns®, NuSmile®, and Sprig® were subjected to 10,000 simulated toothbrushing strokes.
• ZRCs were paired with four different dentifrices exhibiting varying Relative Dentin Abrasion (RDA) values: Tom's of Maine Children's, Crest Kid's, Prevident 5000, and Crest® Pro-Health.
• Surface roughness was measured using a stylus profilometer before and after brushing; data were analyzed using two-way repeated measures ANOVA.

Main Results:

• Statistically significant differences in surface roughness were observed between baseline and post-brushing measurements for specific ZRC brands and dentifrice combinations (e.g., Kinder Krowns® with Prevident, Sprig® with Crest Kid's).
• Differences in roughness changes were noted when comparing Sprig® and NuSmile® ZRCs with Crest Kid's dentifrice.
• NuSmile® ZRCs showed distinct baseline and post-brushing roughness values compared to both Sprig® and Kinder® ZRCs across all tested dentifrices.

Conclusions:

• While statistically significant differences in surface roughness were detected, the actual changes were minimal in scale.
• The study provides preliminary confidence for clinicians regarding the use of prefabricated pediatric ZRCs as a sustainable restorative option.
• Further research is recommended to investigate the effects of toothbrushing and various dentifrices on the mechanical properties, durability, and retention of ZRCs.