Preliminary study on the clinical suitability of stereolithography-fabricated monolithic zirconia crowns

Abstract Statement of problem. Stereolithography (SLA), an additive manufacturing (AM) technique, appears to be a promising alternative for fabricating zirconia restorations. However, few studies have focused its clinical suitability. Purpose. This study evaluated and compared the clinical suitability of monolithic zirconia crowns (MZCs) fabricated by stereolithography (SLA) technology with MZCs by CAD/CAM milling technology. Material and Methods. We selected 40 cases of patients suffering from tooth defects that would be repaired with zirconia crowns. According to a routine clinical operation procedure, digital final crowns were obtained with STL document format and corresponding crowns were fabricated with SLA and CAM/CAM milling technology. The experimental group used SLA (the SLA group) and its added binder was photosensitive. The control group adopted zirconia pieces with CAD/CAM milling technology (the milling group). The two crowns of the same prepared tooth were try-in, and the clinical suitability was evaluated—namely, the adjacent tightness, stability, positioning suitability, occlusal contact stability, and so on. Statistical analysis was conducted to identify differences between the crowns made from the two technologies. Results. The results indicated that there were no statistical differences in adjacent tightness, stability, positioning suitability, occlusal contact stability, adjacency adjustment time, and occlusal adjustment time between the two groups (P > 0.05). Furthermore, the occlusal contact distribution in the SLA group was better than that in the milling group (P < 0.05). Conclusion. Monolithic zirconia crowns fabricated with SLA are clinically suitable and have good application prospects.