The effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements : a comparative in vitro study

الملخص EN

Background : color changes that are detectable to human eye can affect the esthetic appearance of ceramic veneers.

The purpose of this study was to evaluate and compare the effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements.

Materials and Methods : sixty discs were prepared with 0.5 mm thickness, 30 discs made from IPS e.max press (Ivoclar Vivadent) and 30 discs were made from VITA Enamic (VITA Zahnfabrik).

The discs were cemented with three resin cements : variolink veneer mv 0 shade (ivoclar Vivadent), Rely X veneer Translucent shade (3M ESPE) and NX3 Nexus Clear shade (Kerr Corporation) with 0.1 mm thickness.

The spectrophotometer Easyshade Advance was used to measure the color parameters (Lightness, axis a* of chroma and axis b*of chroma) immediately after cementation, after 150 and 300 hours of aging.

The specimens were subjected to artificial accelerated aging in Accelerated Weathering Tester.

Color change greater than 3.3 was considered unacceptable.

One-way ANOVA, paired t-tests and Bonferroni adjusted t-test were used for statistical analysis (p <0.05).

Results : artificial aging caused high significant color change in both ceramic types, but there were non-significant difference in color change among the three resin cements used.

The color change was between1.997-14.8 after 150 hours and it was between 2.179-15.68 after 300 hours.

The color change of e.max discs after aging were within acceptable limit<3.3 whereas Vita Enamic specimens had shown unacceptable color change >3.3 after aging.

Conclusions : the majority of color change after aging related to veneering materials while resin cement have only slight effect on color change after aging.

IPS e.max had shown an acceptable color change after aging, so it is suitable for fabrication of restorations in esthetic zone while Vita Enamic should not be used in esthetic zone since it has poor color stability according to the results of this study.