Wear resistance and color stability of innovate esthetical Bioflx crowns compared to zirconia pediatric crowns

Abstract

Background: Zirconia crowns are the most common aesthetic option for full coverage in pediatric dentistry. Bioflx crowns have been recently introduced, offering a unique combination of aesthetics, flexibility, and durability. Aim: The objective of this study was to evaluate and compare the wear of the crowns and opposing enamel. Additionally, to assess the color stability of Bioflx pediatric crowns following thermodynamic aging compared to zirconia crowns. Methods: Forty acrylic resin dies were fabricated based on specific criteria and equally divided into two groups: zirconia crowns and Bioflx crowns. Thermodynamic cycling was conducted to simulate oral conditions over six months. Wear resistance was quantitatively assessed utilizing a Universal Serial Bus (USB) digital microscope with an integrated camera. Color stability was measured using a spectrophotometer before and after thermal aging and following immersion in various solutions (water, milk chocolate, orange juice, and cola). Data were collected, tabulated, and statistically analyzed using the Shapiro–Wilk test and paired sample t-tests. The level of statistical significance was set at a p-value of 0.05. Results: A statistically significant difference was observed between zirconia and Bioflx crowns regarding volume loss and average roughness height [µm] of the opposing enamel (P = 0.021 and 0.001, respectively). Furthermore, there were significant differences in volume loss (µm3) and average roughness height (µm) between the zirconia and Bioflx crowns (P < 0.001). In contrast, the results of color change revealed non-significant differences between zirconia and Bioflx crowns (P = 0.470) before and after thermocycling aging, as well as following immersion in different solutions. Conclusions: Zirconia crowns cause more wear on opposing natural teeth than Bioflx crowns. Bioflx crowns show a higher average wear rate than zirconia. There are no significant differences between the two crown’s materials in terms of color change after aging and immersion in various solutions.