|dc.description.abstract||Statement of problem. Zirconia complete-coverage crowns are being widely used as restorations because of their improved
esthetic characteristics. Data about the enamel wear potential of this ceramic after chair side adjustments are sparse.
Purpose. The purpose of this study was to investigate the 3-body wear of enamel opposing 3 types of ceramic (dense sintered
yttrium-stabilized zirconia; Crystal Zirconia; DLMS) (Z), a lithium disilicate (IPS e-max CAD; Ivoclar Vivadent) (E), and a
conventional low-fusing feldspathic porcelain (VitaVMK-Master; Vita Zahnfabrik) (P), treated to impart a rough, smooth, or
Material and methods. Twenty-four specimens of each of the zirconia and the lithium disilicate ceramic were sectioned from
computer-aided design and computer-aided manufacturing blocks into rectangular plates (15 12 2 mm). Twenty-four
specimens of the feldspathic porcelain were formed into disks (12 mm diameter) from powders compressed in a silicone
mold. All specimens (n¼72) were prepared according to the manufacturers’ recommendations. Specimens of each ceramic
group were placed into 1 of 3 groups: group R, rough surface finish; group S, smooth surface finish; and group G, glazed
surface finish. A total of 9 groups with 8 specimens each were placed in a 3-body wear simulator, with standardized enamel
specimens (n¼72) acting as the substrate. The wear of the enamel specimens was evaluated after 50 000 cycles. The data
were analyzed with 2-way ANOVA and the Tukey HSD multiple comparison test (a¼.05).
Results. The data showed that the smooth zirconia group (ZS) was associated with the least amount of enamel wear
(1.26 0.55 mm2). The most antagonistic enamel wear was associated with the glazed groups ZG (5.58 0.66 mm2),
EG (3.29 1.29 mm2), and PG (4.2 1.27 mm2).
Conclusions. The degree of enamel wear associated with monolithic zirconia was similar to conventional feldspathic
porcelain. Smoothly polished ceramic surfaces resulted in less wear of antagonistic enamel than glazing.||en_US