Journal of Dental Research, Vol 70, 221-225, Copyright © 1991 by International & American Associations for Dental Research Online Journals
Abrasion of human enamel by different dental ceramics in vitro
R. R. Seghi, S. F. Rosenstiel and P. Bauer
School of Dentistry, University of California, Los Angeles 90024.
Manufacturers generally quote indentation hardness values when predicting
the clinical wear potential of newly introduced ceramic restoratives. The
objective of this study was to determine whether in vitro two-body wear
correlated well with hardness. A modified polisher was used to abrade
enamel cylinders against polished disks of commercially available dental
porcelains and glass. Enamel loss after four h was measured with a
micrometer. Five ceramic materials were tested, and enamel abrasion rates
were correlated with Knoop hardness values. Dicor and Dicor coated with a
shading porcelain were found to cause the lowest wear of enamel. These
rates were statistically significantly lower than those obtained with
Optec, the most abrasive material. These findings may be due to
microstructural differences between the materials. Knoop hardness showed
poor correlation with the results of the abrasive testing.
