Comparing the accuracy of crown fitting between milling and 3D printing techniques using CAD/CAM technologies

Abstract

BACKGROUND:

The accuracy of dental crowns is crucial for their longevity and effectiveness.

OBJECTIVE:

This study aims to investigate how the precision of crowns is affected by two different fabrication methods, either subtractive (milling) or additive (3D printing), within computer-aided design/computer-aided manufacture (CAD/CAM) technology.

METHODS:

A standardised digital scan of a maxillary first molar with a shoulder margin (.stl file) was used to design and fabricate crowns through both subtractive (milling) and additive (3D printing) processes. The crowns’ marginal and internal fits were assessed comprehensively. Statistical analysis, including two-way ANOVA and independent t-tests, revealed significant differences in fitting accuracy between the two methods.

RESULTS:

Crowns produced via 3D printing demonstrated superior fitting with minimal marginal (14 $\pm$ 5 $\mu$ m) and internal discrepancies (22 $\pm$ 5 $\mu$ m) compared to milling (marginal: 22 $\pm$ 4 $\mu$ m, internal: 23 $\pm$ 3 $\mu$ m), indicating a statistically significant advantage in precision ( $ps⩽$ 0.022 for marginal fit).

CONCLUSION:

The findings suggest that 3D printing may offer a more accurate alternative to milling in the fabrication of digital dental prostheses, potentially revolutionising the field with its enhanced precision capabilities.