Click on images to view full size. Objective: This study compares in-vitro soft, third-body wear with physical
properties of composite resins. Method: The development of a soft,
three-body in-vitro wear method was previously described (IADR Abst. # 424, March
2007). In this study, physical properties of composite resins including compressive
strength (CS), diametral tensile strength (DTS), flexural strength (FS), and hardness
(H) were measured and compared to the wear data. Properties were measured according
to ISO 4049 (FS), ADA Specification No. 1 (CS), No. 27 (DTS) and Rockwell 15T
instructions. Five samples each were measured and the means and standard
deviations (S.D.) calculated. All samples were cured according to
manufacturers instructions and stored in 37ºC water for 1 week before testing.
Anova analysis (p<0.05) was conducted for each property to determine
significant differences between the means. The physical property data were
plotted against soft-third body wear and correlation coefficients were reported
for positive correlations. Results: The individual data for several
products are reported in the attached table. Superscript letters in each row
indicate significant differences between the means. Positive
correlations were found for plots of CS (0.73) and H (0.82) vs. wear; whereas poor
correlation was found for DTS and FS. Threshold limits for CS (379 MPa) and H
(84) were found, corresponding to the y-intercept of a linear trendline. Conclusion:
Positive correlations were found for CS and H vs. soft, three-body wear. The
plots indicate that threshold limits may exist for CS and H where wear
approaches zero (research funded by Kerr Corp.).
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