Er,Cr:YSGG laser irradiation influence on Y-TZP bond strength to resin cement

The aim of this study was to evaluate Y-TZP surface pretreatment with different protocols on microshear bond strength (μSBS) ceramic-cement interface. One hundred and sixty pre-sintered IPS e-max ZirCAD (Ivoclar-Vivadent) blocks were randomly divided into sixteen groups according to surface treatment (n=20): G1- no treatment (control); G2- ceramic primer; G3- tribochemical silica coating; G4- tribochemical silica coating+primer; G5- airborne particle abrasion (Al2O3); G6- airborne particle abrasion (Al2O3)+primer; G7- Er,Cr:YSGG laser; G8- Er,Cr:YSGG laser+primer. All specimens were sintered before surface treatment, except lasers groups, which were sintered after laser irradiation. Ceramic blocks were bonded with Panavia F resin cement (Kuraray, Okayama, Japan) (n=10) or RelyX ARC (3M ESPE, St. Paul, MN, USA) (n=10). The μSBS tests were carried out in a universal testing machine at a speed of 1mm/min after 24 h (n=5) or 6 months storage (n=5). Differences were found for both resin cements and storage conditions in relation to μSBS values (p<0.05). However, no significant difference for interaction between factors was observed in cemented blocks with RelyX ARC. Panavia F resin cement showed significant differences for interaction between factors (p<0.05). Laser treatment was not sufficient to increase μSBS values between Y-TZP and resin cements. Tribochemical silica coating followed by primer achieved the highest immediate μSBS values. The storage did not affect negatively μSBS values to both evaluated cements.