Nanotribological behaviour of tooth enamel rod affected by bleaching treatment

作者：Garrido M A; Giraldez I; Ceballos L; Gomez del Rio M T; Rodriguez J^*

来源：Wear, 2011, 271(9-10): 2334-2339.

DOI：10.1016/j.wear.2011.01.059

• Nanoscratch
• Enamel
• Wear rate
• Friction coefficient

Tooth enamel is a hybrid organic-inorganic bionanocomposite comprised predominantly of enamel rods. Understanding the effects of bleaching treatment on the biomechanical properties of this tissue is essential for clinical applications. Accordingly, this study is focused on the wear behaviour of the enamel using nanoscratch tests when a 38% hydrogen peroxide bleaching agent was applied.
A rounded conical diamond nanoindenter tip (1 mu m radius and 45 degrees semiangle) was used to abrade untreated and bleached bovine enamel. Abraded lines of 10 mu m length were generated with constant maximum loads ranging from 100 mu N to 500 mu N. In addition normal and lateral forces were simultaneously measured along the single scratched lines. After the wear tests, the worn areas were scanned by the conical tip to determine the residual profile. Different friction coefficients and wear resistances were obtained depending on the enamel zone and the treatment applied.
The work was completed with the determination of mechanical properties by nanoindentation. Elastic modulus, hardness and fracture toughness were obtained to complete the analysis of bleaching agent effect.
Variations in the values of elastic modulus and hardness depending on the bleaching treatment have been observed. Additionally, friction coefficients and wear rates were affected by the application of bleaching. After initial increase, the enamel exhibited a recovery of properties when it was stored in artificial saliva.

• 出版日期2011-7-29