Surface Analysis of Resin-Matrix Dental Composites

 

Manshui Zhou*, James L. Drummond°, and  Luke Hanley*

*Department of Chemistry

°Department of Restorative Dentistry

University of Illinois at Chicago

Chicago, IL 60607-7061

www.chem.uic.edu/hanley

 

Abstract

The objective of this study was to characterize the surface chemistry of resin-matrix dental composites (Choice and Micronew) using secondary ion mass  spectrometry (SIMS) and x-ray wavelength dispersive spectrometry (WDS).

Methods: The specimens, 3×3×25 mm bars, were aged for 4 months in artificial saliva, distilled water, and a 50/50 mixture of ethanol and distilled water, then examined for Sr content.  SIMS measurements allow a relative quantitative analysis for dental composites by using C⁺ or CH₃CO⁺ as a ubiquitous reference ion. These peaks are used to standardize the signal of SIMS data for the quantification of SrO on the surface of dental composites before and after the aging. In WDS experiments, a thin layer of carbon is evaporated onto the surface of dental  composites to avoid charging. The SIMS analysis involves a much larger surface area than the WDS analysis.