J Korean Acad Prosthodont.  2015 Oct;53(4):325-329. 10.4047/jkap.2015.53.4.325.

Effect of working time on the film thickness of dental resin cements

• Yi YS
• Kim SH
• Lee JB
• Han JS
• Yeo IS
• Ha SR
• Kim HK

• KMID: 2118804
• DOI: http://doi.org/10.4047/jkap.2015.53.4.325

Abstract

PURPOSE
The aim of this study was to compare the film thicknesses of several resin cements as a function of time after mixing and to examine the effect of working time on the film thicknesses.
MATERIALS AND METHODS
The film thickness (microm) of 4 resin cements (n=10), 1 composite resin (Panavia F 2.0), 3 self-adhesive resin (Clearfil SA luting, Zirconite, RelyX U200) cements was measured at 20-second intervals after mixing of the cements up to 200 seconds under a load of 50 N. Linear regression was fitted to verify the effect of working time on the film thickness of each cement. Data were compared to the working time recommended by manufacturers using Wilcoxon test (alpha=.05).
RESULTS
All of the materials showed a positive linear correlation between the film thickness and working time. There was no statistically significant difference between the working time based on our results and the values recommended by the manufacturers even though there was a discrepancy between those two values.
CONCLUSION
The film thickness of resin cements could increase with the increase of working time. Working time to meet the ISO standard of 50-microm maximum film thickness could be different from the manufacturer's recommended value.

Keyword

Resin cements; Film thickness; Working time

MeSH Terms

Linear Models
Resin Cements
Resins, Synthetic*
Resin Cements
Resins, Synthetic