One simple printing change could improve fit of 3D-printed dental crowns

Dentists use crowns to restore damaged teeth and help patients chew comfortably again. For a crown to succeed, it must fit closely to the prepared tooth. However, if the fit is poor, bacteria can enter the gap between the crown and the tooth, increasing the risk of microleakage, secondary caries, periodontal problems, and premature failure.

As 3D printing becomes more widely used in digital dentistry, researchers are working to understand how simple printing choices can affect the quality of the final restoration. In a study published in the KeAi journal Dental Research, a team of researchers in China investigated how print angle and layer thickness influence the accuracy and fit of permanent resin-based ceramic crowns made with digital light processing, a light-based 3D-printing technology.

"We designed a mandibular first molar crown and printed it at nine different angles, from 90° to 270°, and at two layer thicknesses, 50 and 100 μm," shares  corresponding author Shizhu Bai, a researcher at the School of Stomatology, The Fourth Military Medical University. "We then measured how closely each printed crown matched its digital design and how well it fit a prepared tooth model."

The team found that both print angle and layer thickness had significant effects on crown accuracy and fit. "Overall, crowns printed at moderate angles of 150° to 180° performed best, while crowns printed with 50-μm layers showed better trueness and internal fit, and crowns printed with 100-μm layers showed more concentrated deviation distributions and more repeatable results across repeated prints. All crowns in the study remained within the clinically acceptable fit range," says Bai.

Further, the researchers found that printing deviations were not evenly distributed across the crown's inner surface. "Marginal areas tended to shrink inward, whereas occlusal regions were more likely to bulge outwards — this helps explain why a crown may appear acceptable overall but still require adjustment before delivery," adds Bai.

The believe their findings can provide practical guidance for dental 3D printing. "For routine production, a print angle of 150° to 180° combined with a 50-μm layer thickness may offer the best balance between manufacturing accuracy and clinical fit, while a 100-μm layer thickness may be useful when reproducibility is the main priority," Bai emphasizes.

Contact author:

Shizhu Bai

State Key Laboratory of Oral Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Stomatology, Digital Dentistry Center, School of Stomatology, The Fourth Military Medical University, Xi'an 710004, PR China. baishizhu@foxmail.com

Funder: 

This research was supported by the Shaanxi Laboratory of Advanced Materials Project (grant number 2024ZY-JCYJ-04-12), the National Clinical Research Center for Oral Diseases (grant number LCA202201), the Regional Cooperation Project of Shanxi Province (grant number 202304041101037), and the New Technology and New Business Projects of the Third Affiliated Hospital of Air Force Medical University (grant number LX2023-407).

Conflict of interest: 

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

See the article:

Zhang, J., Song, S., Xu, K., Liu, M., Liu, N., Li, F., Bai, S., and Zhao, Y., Effect of print parameters on the accuracy and fit of 3D-printed resin-based ceramic crowns, Dental Research, Volume 1, 2026, Article 100004, https://doi.org/10.1016/j.dtrs.2025.100004