IADR Abstract Archives
Shear Bond Strength of Nexus Universal to Various CAD/CAM Substrates
Objectives: Nexus Universal (Kerr) is a new adhesive resin cement that can bond strongly to various restorative substrates without a primer/adhesive. The goal of this study was to evaluate the shear bond strength (SBS) of Nexus Universal to CAD/CAM restorative substrates without an adhesive and compare it to several commercial resin cements in combination with their recommended adhesives.
Methods: The restorative substrates were polished with 600 grit SiC paper. Nexus Universal was applied without a primer/adhesive, and other cements were applied to substrates per manufacturer’s instructions using the manufacturer’s recommended primer/adhesive in an Ultradent bonding jig with a cylindrical mold (D=2.38mm). Each cement was self-cured for one hour at 37°C (~90% relative humidity). The bonded specimens (n=6) were then stored in deionized water at 37°C for 24 hours before being subjected to shear force on an Instron mechanical tester following ISO29022. Statistical analysis was performed using one-way ANOVA and Tukey’s pairwise comparison method to determine significant differences among groups at p<0.05 level.
Results: Nexus Universal without an adhesive yielded the highest mean bond strength on all three CAD/CAM substrates among groups tested. ANOVA analysis revealed that Nexus Universal cement demonstrated significantly higher (p<0.05) SBS to zirconia than all other cement/adhesive combinations (p < 0.05). On lithium disilicate, Nexus Universal produced statistically higher (p<0.05) bond strength than RelyX Ultimate/Scotchbond Universal combination, but not statistically different from the other cement/adhesive combinations On Vitablocs, Nexus Universal yielded statistically higher (p<0.05) SBS than Panavia V5/Clearfil Ceramic Primer Plus and RelyX Ultimate/Scotchbond Universal combinations, but not statistically different from the other two cement/adhesive combinations.
Conclusions: On all three CAD/CAM substrates, Nexus Universal without a primer/adhesive produced higher or comparable bond strength to other commercial resin cement/adhesive combinations. The ability of Nexus Universal to achieve high bond strength to various restorative substrates without the need to use a primer/adhesive can significantly simplify the cementation procedure.
Methods: The restorative substrates were polished with 600 grit SiC paper. Nexus Universal was applied without a primer/adhesive, and other cements were applied to substrates per manufacturer’s instructions using the manufacturer’s recommended primer/adhesive in an Ultradent bonding jig with a cylindrical mold (D=2.38mm). Each cement was self-cured for one hour at 37°C (~90% relative humidity). The bonded specimens (n=6) were then stored in deionized water at 37°C for 24 hours before being subjected to shear force on an Instron mechanical tester following ISO29022. Statistical analysis was performed using one-way ANOVA and Tukey’s pairwise comparison method to determine significant differences among groups at p<0.05 level.
Results: Nexus Universal without an adhesive yielded the highest mean bond strength on all three CAD/CAM substrates among groups tested. ANOVA analysis revealed that Nexus Universal cement demonstrated significantly higher (p<0.05) SBS to zirconia than all other cement/adhesive combinations (p < 0.05). On lithium disilicate, Nexus Universal produced statistically higher (p<0.05) bond strength than RelyX Ultimate/Scotchbond Universal combination, but not statistically different from the other cement/adhesive combinations On Vitablocs, Nexus Universal yielded statistically higher (p<0.05) SBS than Panavia V5/Clearfil Ceramic Primer Plus and RelyX Ultimate/Scotchbond Universal combinations, but not statistically different from the other two cement/adhesive combinations.
Conclusions: On all three CAD/CAM substrates, Nexus Universal without a primer/adhesive produced higher or comparable bond strength to other commercial resin cement/adhesive combinations. The ability of Nexus Universal to achieve high bond strength to various restorative substrates without the need to use a primer/adhesive can significantly simplify the cementation procedure.