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Updated: Apr 3, 2026

Micro-dissection of Enamel Organ from Mandibular Incisor of Rats Exposed to Environmental Toxicants
Published on: March 29, 2018
Enamel surface alterations after repeated conditioning with HCl
W H Arnold1, B Haddad2, K Schaper3
1Department of Biological and Material Sciences in Dentistry, Faculty of Health, School of Dentistry, Witten/Herdecke University, Witten, Germany. Wolfgang.Arnold@uni-wh.de.
Background:
The aim of this study was to investigate the influence of etching time with 15% hydrochloric acid (HCl) on the enamel surface destruction by studying the resulting roughness and erosion depth.
Methods:
The vestibular surfaces of 12 extracted, caries free human incisors were divided into four quadrants, and each quadrant was etched with 15% HCl for different numbers of etching cycles (1×2, 2×2, 3×2 and 4×2 min). Surface roughness and erosion depth were measured quantitatively with optical profilometry, and the surface morphology was imaged with scanning electron microscopy (SEM).
Results:
After two minutes of 15% HCl application a median enamel substance loss of 34.02 μm was observed. Lengthening of etching time (2×2, 3×2 and 4×2 min) resulted in significantly increase in erosion depth to each additionally, between 13.28 -15.16 μm (p < 0.05) ending up in a total median enamel surface loss of 77 μm. Regarding surface roughness no significant (p > 0.05) difference was found between unetched enamel and the etched enamel surfaces.
Conclusion:
Repeated 15% HCl conditioning of the enamel surface increases the depth of the etched surface erosion. However, the total erosion depth is rather shallow and therefore negligible.
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