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Comparison of mechanical property and role between enamel and dentin in the human teeth.

Chun K, Choi H, Lee J - J Dent Biomech (2014)

Bottom Line: However, judging from the measured hardness values, enamel was considered harder than dentin.Therefore, enamel has higher wear resistance, making it suitable for grinding and crushing foods, and dentin has higher force resistance, making it suitable for absorbing bite forces.The different mechanical roles of enamel and dentin may arise from their different compositions and internal structures, as revealed through scanning electron micrographs of enamel and dentin.

View Article: PubMed Central - PubMed

Affiliation: Department of Advanced BioMedical Enginnering, Korea Institute of Industrial Technology, Cheonan-si, Republic of Korea.

ABSTRACT
The mechanical properties of enamel and dentin were studied using test specimens having the same shape and dimensions because these properties might vary with the experimental conditions and specimen shapes and dimensions. Healthy human teeth were used as specimens for mechanical tests. The stress (MPa), strain (%), and elastic modulus (E, MPa) of the specimens were obtained from compression tests. The maximum stresses of the enamel, dentin, and enamel-dentin specimens were 62.2 ± 23.8, 193.7 ± 30.6, and 126.1 ± 54.6 MPa, respectively. The maximum strains of the enamel, dentin, and enamel-dentin specimens were 4.5 ± 0.8%, 11.9 ± 0.1%, and 8.7 ± 2.7%, respectively. The elastic moduli of the enamel, dentin, and enamel-dentin specimens were 1338.2 ± 307.9, 1653.7 ± 277.9, and 1628.6 ± 482.7 MPa, respectively. The measured hardness value of enamel specimens (HV = 274.8 ± 18.1) was around 4.2 times higher than that of dentin specimens (HV = 65.6 ± 3.9). Judging from the measured values of the stress and strain of enamel specimens, enamel tended to fracture earlier than dentin; therefore, it was considered more brittle than dentin. However, judging from the measured hardness values, enamel was considered harder than dentin. Therefore, enamel has higher wear resistance, making it suitable for grinding and crushing foods, and dentin has higher force resistance, making it suitable for absorbing bite forces. The different mechanical roles of enamel and dentin may arise from their different compositions and internal structures, as revealed through scanning electron micrographs of enamel and dentin.

No MeSH data available.


Related in: MedlinePlus

Specimen preparation: (a) cross-sectioned after fixing a tooth within epoxy resin, (b) dimensions of enamel and dentin specimens, and (c) dimensions of ED specimens.ED: enamel–dentin.Here, P is load or force. Specimens were machine-cut and extracted along the direction of the force applied.
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fig1-1758736014520809: Specimen preparation: (a) cross-sectioned after fixing a tooth within epoxy resin, (b) dimensions of enamel and dentin specimens, and (c) dimensions of ED specimens.ED: enamel–dentin.Here, P is load or force. Specimens were machine-cut and extracted along the direction of the force applied.

Mentions: Five healthy human canines and 10 first premolars (age = 19.3 ± 4.1 years) were extracted and used as dental hard tissue specimens for the mechanical tests. Protocols were approved by the Institutional Review Board of the Samsung Medical Center for human research, and all individuals gave informed consent (IRB No. KBC12150). The extracted teeth were fixed in epoxy resin (ELR-3200; SPC Inc., Korea) moldings (epoxy resin:epoxy hardener = 40:10) and then cross-sectioned, as shown in Figure 1(a). The cross-sectioned teeth were machine-cut to obtain 10 dentin specimens, 10 enamel specimens, and 10 ED specimens having width, height, and length of 1.2, 1.2, and 3.0 mm, respectively, for the compression tests, as shown in Figure 1(b) and (c). Here, the geometric error was ±0.02 mm for the machine-cut process described below. Furthermore, the specimens were machine-cut along the direction of the force applied.


Comparison of mechanical property and role between enamel and dentin in the human teeth.

Chun K, Choi H, Lee J - J Dent Biomech (2014)

Specimen preparation: (a) cross-sectioned after fixing a tooth within epoxy resin, (b) dimensions of enamel and dentin specimens, and (c) dimensions of ED specimens.ED: enamel–dentin.Here, P is load or force. Specimens were machine-cut and extracted along the direction of the force applied.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC3924884&req=5

fig1-1758736014520809: Specimen preparation: (a) cross-sectioned after fixing a tooth within epoxy resin, (b) dimensions of enamel and dentin specimens, and (c) dimensions of ED specimens.ED: enamel–dentin.Here, P is load or force. Specimens were machine-cut and extracted along the direction of the force applied.
Mentions: Five healthy human canines and 10 first premolars (age = 19.3 ± 4.1 years) were extracted and used as dental hard tissue specimens for the mechanical tests. Protocols were approved by the Institutional Review Board of the Samsung Medical Center for human research, and all individuals gave informed consent (IRB No. KBC12150). The extracted teeth were fixed in epoxy resin (ELR-3200; SPC Inc., Korea) moldings (epoxy resin:epoxy hardener = 40:10) and then cross-sectioned, as shown in Figure 1(a). The cross-sectioned teeth were machine-cut to obtain 10 dentin specimens, 10 enamel specimens, and 10 ED specimens having width, height, and length of 1.2, 1.2, and 3.0 mm, respectively, for the compression tests, as shown in Figure 1(b) and (c). Here, the geometric error was ±0.02 mm for the machine-cut process described below. Furthermore, the specimens were machine-cut along the direction of the force applied.

Bottom Line: However, judging from the measured hardness values, enamel was considered harder than dentin.Therefore, enamel has higher wear resistance, making it suitable for grinding and crushing foods, and dentin has higher force resistance, making it suitable for absorbing bite forces.The different mechanical roles of enamel and dentin may arise from their different compositions and internal structures, as revealed through scanning electron micrographs of enamel and dentin.

View Article: PubMed Central - PubMed

Affiliation: Department of Advanced BioMedical Enginnering, Korea Institute of Industrial Technology, Cheonan-si, Republic of Korea.

ABSTRACT
The mechanical properties of enamel and dentin were studied using test specimens having the same shape and dimensions because these properties might vary with the experimental conditions and specimen shapes and dimensions. Healthy human teeth were used as specimens for mechanical tests. The stress (MPa), strain (%), and elastic modulus (E, MPa) of the specimens were obtained from compression tests. The maximum stresses of the enamel, dentin, and enamel-dentin specimens were 62.2 ± 23.8, 193.7 ± 30.6, and 126.1 ± 54.6 MPa, respectively. The maximum strains of the enamel, dentin, and enamel-dentin specimens were 4.5 ± 0.8%, 11.9 ± 0.1%, and 8.7 ± 2.7%, respectively. The elastic moduli of the enamel, dentin, and enamel-dentin specimens were 1338.2 ± 307.9, 1653.7 ± 277.9, and 1628.6 ± 482.7 MPa, respectively. The measured hardness value of enamel specimens (HV = 274.8 ± 18.1) was around 4.2 times higher than that of dentin specimens (HV = 65.6 ± 3.9). Judging from the measured values of the stress and strain of enamel specimens, enamel tended to fracture earlier than dentin; therefore, it was considered more brittle than dentin. However, judging from the measured hardness values, enamel was considered harder than dentin. Therefore, enamel has higher wear resistance, making it suitable for grinding and crushing foods, and dentin has higher force resistance, making it suitable for absorbing bite forces. The different mechanical roles of enamel and dentin may arise from their different compositions and internal structures, as revealed through scanning electron micrographs of enamel and dentin.

No MeSH data available.


Related in: MedlinePlus