Effect of surface pretreatment and artificial aging on the retention of lithium disilicate crowns cemented to zirconia implant abutments

Statement of problem. Recent advancements in restorative dentistry have seen an increase in the use of ceramic restorations and zirconia implant abutments. However, how the pretreatment of a zirconia abutment and different artificial aging protocols affect the bond strength of a cemented, monolithic lithium disilicate crown is unclear. Purpose. The purpose of this in vitro study was to evaluate the effect of surface pretreatment on the retentive strength of milled lithium disilicate crowns bonded to custom zirconia implant abutments with different resin cements after thermocycling and long-term aging. Material and methods. A total of 144 crowns (n=8) were milled and bonded to 144 abutments. In the experimental groups, 72 abutments were airborne -particle abraded with 50 -mm aluminum oxide before bonding. All specimens were stored at 37 C-degrees in 100% humidity for 24 hours. Fortyeight specimens were subjected to thermocycling, and another 48 were subjected to aging for 6 months. Retentive strength was measured by using a pull -off test with a universal testing machine. Retentive strength values were calculated and compared with 3 -way analysis of variance and a Tukey-Kramer post hoc test (a=.05). Results. In the 24 -hour aging group, retention for all experimental groups was significantly higher (P<.05) than for the control group, except for Panavia 21 with Clearfil Ceramic Primer. In the thermocycling and long-term aging groups, all cements in the experimental group displayed significantly higher retention than the control. The airborne -particle abrasion of custom zirconia implant abutments with 50 -mm aluminum oxide before bonding to lithium disilicate crowns significantly increased the bond strength of the Multilink Hybrid Abutment with Monobond Plus and RelyX Ultimate with Scotchbond Universal cements after 24 -hour aging, but not of Panavia 21 with Clearfil Ceramic Primer. Conclusions. Airborne -particle abrasion significantly increased the bond strength of all 3 cements after thermocycling and long-term aging. (J Prosthet Dent 2024;131:459-67)