J Korean Acad Prosthodont.  2010 Oct;48(4):301-307. 10.4047/jkap.2010.48.4.301.

A study on enamel thickness of maxillary incisors using X-ray micro computed tomography

• Cho YW
• Cho JH
• Lee KB

• KMID: 2195550
• DOI: http://doi.org/10.4047/jkap.2010.48.4.301

Abstract

PURPOSE
The objectives of the current study are to assess the accuracy of X-Ray Micro Computed Tomography (microCT) in measuring enamel thickness and to evaluate enamel thickness in maxillary incisors of Koreans. MATERIAL AND METHODS: Five maxillary incisors were embedded in resin block. These teeth were longitudinally sectioned labiolingually through the medial axis. After polishing, the teeth were scanned using a microCT (X-EYE SYSTEM; DRGEM, Seoul, Korea). On a scanning electron microscope (S-4300; Hitachi, Tokyo, Japan) (x20) and a microCT, nearly identical planes were reconstructed. In each tooth, the thickness of labial enamel was measured 1, 3 and 5 mm above the cementoenamel junction (CEJ). Thus, the accuracy of the microCT was evaluated. In addition, using 26 maxillary central incisors and 11 maxillary lateral incisors, in the medial axis and 2 mm remote areas mesially and distally from the medial axis, the thickness of labial enamel was measured 1, 3 and 5 mm above the CEJ along the long axis of the teeth
RESULTS
Measurements from nearly identical planes in physical and microCT sections differed by 3.81%. An independent t-test was performed and this showed that there were no significant differences in the measurements between the two methods. Mean values of labial enamel thickness in maxillary central incisors 1, 3 and 5 mm above the CEJ were 0.32 +/- 0.01, 0.50 +/- 0.02 and 0.70 +/- 0.02 mm, respectively. Mean values of labial enamel thickness in maxillary lateral incisors 1, 3 and 5 mm above the CEJ were 0.30 +/- 0.01, 0.55 +/- 0.03 and 0.80 +/- 0.02 mm, respectively.
CONCLUSION
In measuring enamel thickness, microCT is one of useful way of measurement. So according to the results of this research, when restoring a porcelain laminate veneer on maxillary incisors in Koreans, careful consideration is needed in the amount of enamel reduction.

Keyword

Enamel thickness; MicroCT (X-Ray Micro Computed Tomography); Scanning Electron Microscopy; Cementoenamel junction; Porcelain laminate veneer

MeSH Terms

Axis, Cervical Vertebra
Dental Enamel
Dental Porcelain
Electrons
Incisor
Microscopy, Electron, Scanning
Tokyo
Tooth
Tooth Cervix
X-Ray Microtomography
Dental Porcelain

Figure

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  Fig. 1. The microCT used in this study.

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  Fig. 2. The FE-SEM used in this study.

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  Fig. 3. MicroCT image (left) and scanning electron micrograph (right) of the same cross-section Scale bar = 1 mm.

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  Fig. 4. Tooth landmarks used for measurements A, Labial surface of maxillary incisor. Points are 1, 3 and 5 mm above the CEJ. B, Sagittal plane in the median axis.

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  Fig. 5. Method of measurements in 2 mm remote axis mesially and distally from the medial axis A, Horizontal plane 1 mm above the CEJ. B, Horizontal plane 3 mm above the CEJ. C, Horizontal plane 5 mm above the CEJ.

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  Fig. 6. Comparison of enamel thickness measured with microCT and SEM.

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  Fig. 7. Comparison of enamel thickness on the each measurement site.

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