Marginal Gap Distance and Dynamic Fatigue Performance of Esthetic Crowns for Primary Teeth.

BACKGROUND

The growing demand for esthetic restorative materials highlights the need to evaluate their marginal accuracy and fracture resistance to ensure optimal clinical outcomes for primary molars.

AIM: The aim was to assess the vertical marginal gap distance and fracture resistance of esthetic restorative materials after cyclic loading.

DESIGN

Forty extracted primary molars were randomly divided into four groups: Group I, stainless steel veneered crowns with tooth-colored material; Group II, prefabricated monolithic zirconia crowns; Group III, yttria-partially stabilized zirconia computer-aided design/computer-aided manufacturing (CAD/CAM) crowns; and Group IV, hybrid ceramic CAD/CAM crowns. A stereomicroscope was used to measure the vertical marginal gap distance. The fracture resistance was then evaluated by applying cyclic loading.

RESULTS

Group I (1710 μm) exhibited the highest total median vertical marginal gap distance, followed by Groups II, III, and IV (418.3, 341.7, and 86.7 μm, respectively; with an overall statistically significant difference, p < 0.001). Regarding fracture resistance, Group III exhibited the best performance (2018.5 ± 236.0 N), followed by Groups II, IV, and I (1185.4 ± 326.1, 782.8 ± 278.5, and 728.3 ± 247.4 N, respectively). The CAD/CAM crowns exhibited better marginal gap distances than the prefabricated crowns. The CAD/CAM hybrid ceramic crowns exhibited better marginal accuracy than the CAD/CAM zirconia crowns.

CONCLUSIONS

Zirconia crowns showed promising results regarding marginal adaptation, whereas hybrid ceramics showed promising results regarding fracture resistance.