Three-dimensional non-destructive visualization of teeth enamel microcracks using X-ray micro-computed tomography

Abstract

Although the topic of tooth fractures has been extensively analyzed in the dental literature, there is still insufficient information about the potential effect of enamel microcracks (EMCs) on the underlying tooth structures. For a precise examination of the extent of the damage to the tooth structure in the area of EMCs, it is necessary to carry out their volumetric [(three-dimensional (3D)] evaluation. The aim of this study was to validate an X-ray micro-computed tomography ($$\mu $$ μ CT) as a technique suitable for 3D non-destructive visualization and qualitative analysis of teeth EMCs of different severity. Extracted human maxillary premolars were examined using a $$\mu $$ μ CT instrument ZEISS Xradia 520 Versa. In order to separate crack, dentin, and enamel volumes a Deep Learning (DL) algorithm, part of the Dragonfly’s segmentation toolkit, was utilized. For segmentation needs we implemented Dragonfly’s pre-built UNet neural network. The scanning technique which was used made it possible to recognize and detect not only EMCs that are visible on the outer surface but also those that are buried deep inside the tooth. The 3D visualization, combined with DL assisted segmentation, enabled the evaluation of the dynamics of an EMC and precise examination of its position with respect to the dentin-enamel junction.

Multi‐Level Approach for Comprehensive Enamel Phenotyping

“…Computed X‐ray microtomography (MicroCT) is a non‐destructive method to study morphological changes in mouse such as mineralized tissue phenotypes (Dumbryte, Vailionis, Skliutas, Juodkazis, & Malinauskas, 2021). 3D volumes are used for structural analysis, but 2D sections can also be obtained to study a specific section microstructurally (Schmitz et al., 2014).…”

Microcracks as tooth structural element: revealed by X-ray tomography and machine learning

“…The introduction of an X-ray micro-computed tomography (µCT) in dental studies has opened up new possibilities for enamel thickness and tooth measurements, caries research, characterization of enamel white spot lesions and cortical bone microdamage, analysis of root canal morphology and preparation, detection of various types of teeth fractures, and dental tissue engineering [25][26][27][28][29][30][31][32][33][34] . This is an accurate 3D imaging technique that utilizes X-rays to see inside an object, not limited to slice-by-slice views 34 .…”

“…The introduction of an X-ray micro-computed tomography (µCT) in dental studies has opened up new possibilities for enamel thickness and tooth measurements, caries research, characterization of enamel white spot lesions and cortical bone microdamage, analysis of root canal morphology and preparation, detection of various types of teeth fractures, and dental tissue engineering [25][26][27][28][29][30][31][32][33][34] . This is an accurate 3D imaging technique that utilizes X-rays to see inside an object, not limited to slice-by-slice views 34 . One of the most important advantages of the method is the ability to provide volumetric information about the microstructure in a non-destructive way (today's most advanced laboratory-based µCTs can achieve resolutions up to 0.7 −1 µm (4 −10 µm resolution usually selected for biological samples) using geometrical magnification), and generally eliminating an extensive sample preparation step 34,35 .…”

“…This is an accurate 3D imaging technique that utilizes X-rays to see inside an object, not limited to slice-by-slice views 34 . One of the most important advantages of the method is the ability to provide volumetric information about the microstructure in a non-destructive way (today's most advanced laboratory-based µCTs can achieve resolutions up to 0.7 −1 µm (4 −10 µm resolution usually selected for biological samples) using geometrical magnification), and generally eliminating an extensive sample preparation step 34,35 .…”

“…In our recently published study X-ray µCT has been validated as a method suitable for the 3D non-destructive visualization of enamel MCs with distinct precision and versatility 34 . However, it is assumed that the potential of this method is much broader and that the proposed approach is fully expandable towards the more detailed teeth microstructure analysis 34 .…”