IADR Abstract Archives
Microhardness of Light- and Dual-Cured Resin Cements After Light Activation Through Various Translucencies of Monolithic Zirconia
Objectives: This study aimed to investigate the Vickers Hardness Number (VHN) of light- and dual-cured resin cements cured through monolithic zirconia of various translucencies: translucent (T); super translucent (ST); high translucent (HT); and extra translucent (XT), at 0, 24, and 48 h.
Methods: Four zirconia specimens from four translucencies were prepared. Two light-cured resin cements; Variolink N LC (VL-LC) and RelyX Veneer (RX-LC), and two dual-cured resin cements; Variolink N DC (VL-DC) and RelyX U200 (RX-DC) were used. The cement was mixed and loaded in a mold and cured for 20 s through the zirconia specimen. The upper surface of resin cements was tested for VHN using a microhardness tester. The VHN were analyzed using two-way repeated ANOVA, Brown-Forsythe ANOVA with Games Howell, and independent t-tests.
Results: At 48 h, VL-LC and RX-LC were significantly lower when cured under T groups than under XT groups. At each post curing time of each translucency, VL-DC showed higher VHN than VL-LC, and RX-DC also showed higher VHN than RX-LC (p<0.05). All groups showed significantly higher VHN from 0 to 24 h (p<0.05), but not significantly higher from 24 to 48 h, except in VL-LC and RX-DC under T groups.
Conclusions: The translucency of zirconia had an effect on the VHN for light-cured resin cements, but had no effect on dual-cured resin cements. Dual-cured resin cement exhibited higher VHN than light-cured resin cement from the same manufacturer.
Methods: Four zirconia specimens from four translucencies were prepared. Two light-cured resin cements; Variolink N LC (VL-LC) and RelyX Veneer (RX-LC), and two dual-cured resin cements; Variolink N DC (VL-DC) and RelyX U200 (RX-DC) were used. The cement was mixed and loaded in a mold and cured for 20 s through the zirconia specimen. The upper surface of resin cements was tested for VHN using a microhardness tester. The VHN were analyzed using two-way repeated ANOVA, Brown-Forsythe ANOVA with Games Howell, and independent t-tests.
Results: At 48 h, VL-LC and RX-LC were significantly lower when cured under T groups than under XT groups. At each post curing time of each translucency, VL-DC showed higher VHN than VL-LC, and RX-DC also showed higher VHN than RX-LC (p<0.05). All groups showed significantly higher VHN from 0 to 24 h (p<0.05), but not significantly higher from 24 to 48 h, except in VL-LC and RX-DC under T groups.
Conclusions: The translucency of zirconia had an effect on the VHN for light-cured resin cements, but had no effect on dual-cured resin cements. Dual-cured resin cement exhibited higher VHN than light-cured resin cement from the same manufacturer.