Title: Effect of the Er,Cr:YSGG Laser on Debonding a Y-TZP Ceramic
David Remley (Presenter)
University of Mississippi Medical Center
Steve Magee, University of Mississippi Medical Center
Laurel Stringer, University of Mississippi Medical Center
Darrell Hutto, University of Mississippi Medical Center
Jason Griggs, University of Mississippi
Susana Salazar Marocho, University of Mississippi Medical Center
Objectives: To determine the effect of different powers of the Er,Cr:YSGG laser on the debonding strength between a Y-TZP ceramic and a resin cement.
Methods: Slices (1 mm-thick) of a Y-TZP ceramic were submitted to tribochemical silica-coating and bonded to a resin composite cylinder (Ø=~3.8 mm) with a dual-cured resin cement (Variolink, Ivoclar). The sets were randomized and divided into three groups according to the power of the Er,Cr:YSGG laser (Waterlase MD, Biolase) application, as shown in the Table. The laser irradiation was performed with a sapphire tip (Ø=1 mm, MG6; Biolase) in contact mode. The tip was brushed across the simulated occlusal surface over the bonding area in one direction and was kept perpendicular to the Y-TZP surface. After the laser application, the sets were submitted to the shear bond strength test using a wire loop at a loading rate of 1 mm/min until failure.
Results: The data passed the normality test (S-W, p=0.199). The Tukey’s test (α=0.05) showed that the control group had a similar bond strength value to the 2.5 W and 4.5 W groups. However, the 2.5 W group was significantly different from the 4.5 W group that exhibited the lowest bond strength (p≤0.05).
Conclusions: The high power setting (4.5 W at 20 PPS) decreased the strength necessary to debond the Y-TZP ceramic from the resin cement by ~21% when applied for 30 s.