Evaluation of full-veneer crowns fabricated with 3D printing resin material for definitive prostheses: A 1-year randomized controlled prospective study.

OBJECTIVES

To compare the 1-year clinical performance of definitive 3D-printed resin crowns (RCs) and monolithic zirconia crowns (ZCs) used as tooth-supported posterior single crowns.

METHODS

Fifty-six adults requiring tooth-supported posterior single crowns were randomized 1:1 to receive an RC or ZC. Marginal and internal gaps were measured before cementation using the replica technique. Occlusal wear was assessed from intraoral scans obtained at 1 week and 1 year. Crown fractures, periodontal outcomes, and patient satisfaction were also evaluated. Survival distributions were compared with the two-sided log-rank test, and other outcomes were analyzed using Fisher exact or Mann-Whitney U tests.

RESULTS

Six RCs and 2 ZCs fractured. One-year fracture-free survival was 78.6% (95% confidence interval [CI], 58.4% to 89.8%) for RCs and 92.9% (95% CI, 74.3% to 98.2%) for ZCs, with no significant difference (P=0.12). Seven of the 8 fractures occurred in the most-posterior restored teeth, and this status was associated with fracture incidence (P=0.002). Marginal and axial gaps did not differ significantly, whereas axio-occlusal and occlusal gaps were smaller for RCs (P<0.05). RCs showed greater wear depth (92.33 ± 69.81 versus 14.48 ± 7.95 μm) and wear volume (4.31 ± 3.68 versus 0.47 ± 0.31 mm³) than ZCs (P<0.05). Periodontal outcomes and patient satisfaction did not differ significantly.

CONCLUSIONS

Definitive 3D-printed resin crowns showed acceptable marginal adaptation, with no significant differences from zirconia crowns in short-term periodontal outcomes or patient satisfaction. However, their greater occlusal wear and numerically higher fracture incidence may raise concerns regarding mechanical durability as definitive posterior restorations. Longer-term studies are required before broader clinical application.

CLINICAL SIGNIFICANCE: The definitive 3D-printed resin crowns showed acceptable marginal adaptation but greater measured occlusal wear and a numerically higher fracture incidence than monolithic zirconia crowns over 1 year. These findings warrant caution when using these restorations as definitive posterior single crowns, with continued monitoring of wear and restoration integrity.