The Effect of Nanosilica-Lithium Spray Coating on the Adaptation of Zirconia Crowns

Objectives: To evaluate the effect of a nanosilica–lithium spray coating on the internal and marginal fit of high translucent zirconia crowns using a digital quantitative evaluation method.
Methods: A three-dimensional analysis model of a zirconia abutment was digitally scanned using a dental scanner, and 30 monolithic high translucent zirconia crowns were designed and fabricated. They were divided into groups (n=10) according to the surface treatment method: no treatment: as-sintered zirconia; airborne-particle abrasion with 50 μm Al₂O₃ particles; and nanosilica–lithium spray coating. Three-dimensional data for the abutment, crown, and crown seated on the abutment were obtained using a dental scanner. The three-dimensional seated fit between the crown and abutment was reconstructed using registration technology, and a three-dimensional deviation analysis was used to evaluate the effect of different modification methods on the internal and marginal fit of the crowns using root mean square (RMS) values. The results of one-way ANOVA showed that different surface treatments had no effect on the RMS values of the occlusal surface area, axial surface area and marginal area of the high translucent zirconia crown (P >0.05).
Results: The three-dimensional deviation analysis of all groups conformed to a normal distribution (P >0.05), and the variance was homogeneous (P >0.05). The different surface treatments had no significant effect on the RMS values in the occlusal, axial, and marginal regions of the high translucent zirconia crowns (P >0.05).
Conclusions: Nanosilica-lithium spray coating for the modification of as-sintered zirconia is clinically feasible and does not affect the internal or marginal fit of high translucent zirconia crowns.