Evaluating the effect of repeated autoclave cycles on the glossiness of pediatric zirconia crowns

Background and objectives. Dental caries, the most prevalent infectious disease in children, can lead to significant tooth destruction that needs to be repaired. Zirconia crowns, in particular, are excellent for restoring both function and appearance in children when compared to stainless steel. The durability and attractive appearance of zirconia crowns have made them more popular, despite the fact that they are more expensive and require more preparation. The aim of the current study was to evaluate the effect of repeated autoclave cycles on the glossiness of pediatric zirconia crowns. Materials and methods. Glossiness of the labial and palatal surfaces of pediatric zirconia crowns from two manufacturers was measured on 24 specimens using a small-area gloss meter. Samples were equally divided as Group 1 = 12 crowns (Nu-Smile), Group 2 = 12 crowns (Kids E Dental Crowns). Glossiness was measured using a small surface-area glossometer. The crowns were placed on the aperture of the glossometer and the same location on the occlusal or palatal surfaces was measured. Initial gloss readings were taken for all 24 samples. After each cycle of sterilization, glossiness was measured and the values were tabulated. Results. The gloss meter evaluation revealed divergent trends between the two crown systems upon sequential autoclave sterilization. Nu-Smile crowns demonstrated a progressive decline in glossiness across cycles, with mean values of 10.16 ± 2.71 (baseline), 8.08 ± 2.44 (after first cycle), and 7.10 ± 2.51 (after second cycle). In contrast, Kids E crowns exhibited an incremental rise in gloss values—10.62 ± 3.88, 14.94 ± 4.54, and 15.89 ± 6.15, respectively. While intergroup comparisons via independent t-tests revealed no statistically significant differences at any time point, intra-group analysis using paired t-tests indicated a significant increase in gloss values within the Kids E group across sterilization cycles (p < 0.05). Conclusions. Kids E crowns exhibited higher mean glossiness than Nu-Smile, though differences were not statistically significant. The post-sterilization gloss increase in Kids E crowns may reflect material-specific surface changes requiring further investigation.