受漂白剂处理的人类前磨牙的纳米压痕研究。

Nanoindentation study of human premolars subjected to bleaching agent.

作者信息

Hairul Nizam B R, Lim C T, Chng H K, Yap A U J

机构信息

Nano Biomechanics Laboratory, Division of Bioengineering & Department of Mechanical Engineering, National University of Singapore, 117576 Singapore.

出版信息

J Biomech. 2005 Nov;38(11):2204-11. doi: 10.1016/j.jbiomech.2004.09.023.

DOI:10.1016/j.jbiomech.2004.09.023

PMID:16154407

Abstract

Bleaching of teeth is gaining popularity due to cosmetic reasons. However, the effect it has on teeth is still largely unknown. This paper seeks to evaluate the effect of a bleaching agent, 30% hydrogen peroxide, on the nanomechanical properties of dentin and enamel using the nanoindentation technique. The Young's modulus and hardness obtained from nanoindentation before and after bleaching were compared. Five newly extracted human premolars were used. Nanoindentation was first done on the sliced enamel and dentin regions to determine their mechanical properties. One batch of samples was kept in Hank's balanced salt solution as control while the other was bleached in 30% hydrogen peroxide for 24h. The same number of nanoindentations was then done near the previously indented regions for both the control and bleached samples and the results compared. Using paired sample t-tests with alpha=0.05, it was found that there were no significant differences in both the Young's modulus and hardness of dentin and enamel kept in control. However, the mechanical properties of the bleached dentin were significantly decreased. For intertubular dentin, the mean hardness decreased by 29-55% and the mean Young's modulus decreased by 19-43%. For enamel, the mean hardness decreased by 13-32% while the mean Young's modulus decreased by 18-32%. The exact mechanism by which hydrogen peroxide affects the dentin and enamel has yet to be fully elucidated. However, it is observed to have an undermining effect on the nanomechanical properties of teeth.

摘要

由于美容原因，牙齿美白越来越受欢迎。然而，其对牙齿的影响在很大程度上仍不为人知。本文旨在使用纳米压痕技术评估一种漂白剂——30%过氧化氢对牙本质和牙釉质纳米力学性能的影响。比较了漂白前后通过纳米压痕获得的杨氏模量和硬度。使用了五颗新拔除的人类前磨牙。首先在切片的牙釉质和牙本质区域进行纳米压痕以确定它们的力学性能。一批样品保存在汉克平衡盐溶液中作为对照，而另一批在30%过氧化氢中漂白24小时。然后在对照样品和漂白样品之前压痕区域附近进行相同数量的纳米压痕，并比较结果。使用α = 0.05的配对样本t检验，发现保存在对照中的牙本质和牙釉质的杨氏模量和硬度均无显著差异。然而，漂白后的牙本质的力学性能显著下降。对于管间牙本质，平均硬度下降了29 - 55%，平均杨氏模量下降了19 - 43%。对于牙釉质，平均硬度下降了13 - 32%，而平均杨氏模量下降了18 - 32%。过氧化氢影响牙本质和牙釉质的确切机制尚未完全阐明。然而，观察到它对牙齿的纳米力学性能有破坏作用。