Effect of sterilization by gamma radiation on nano-mechanical properties of teeth

Abstract

NOTICE: this is the author’s version of a work that was accepted for publication in Dental Materials. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Dental Materials, [VOL 24, ISSUE 8, (2008)] DOI: 10.1016/j.dental.2008.02.016.Objectives: Extracted teeth used in dental research need to be considered infective and hence be sterilized without the materials' properties being altered. This study examined the effect of gamma radiation on the nano-mechanical properties of dentin and enamel of extracted human third molars. Methods: Whole teeth were sterilized using gamma radiation doses of 7kGy and 35kGy, respectively; teeth of the control group were not treated with gamma radiation. Crowns were sectioned occlusally and polished. Elastic modulus and hardness were tested using atomic force microscopy with nano-indentations under wet conditions. Results: The authors found no significant dose-response relationship in elastic modulus or hardness in either dentin or enamel. Significance: Nano-indentation is a common technique for the determination of local mechanical properties in biological hard tissues. Gamma radiation is an efficient way to sterilize extracted teeth while alteration of dentin and enamel mechanical properties are minimized