Influence of Er:YAG laser surface treatment on flexural and bond strengths to glass-infiltrated zirconia-reinforced ceramic

• Published in: Lasers in medical science Vol. 36; no. 7; pp. 1487 - 1495
• Main Authors: Moretto, Simone Gonçalves, de Freitas, Patricia Moreira, Inca, Héctor Eduardo Cepeda, Cesar, Paulo Francisco, Bello-Silva, Marina Stella, de Paula Eduardo, Carlos
• Format: Journal Article
• Language: English
• Published: London Springer London 01.09.2021; Springer Nature B.V
• Subjects: Aluminum; Aluminum oxide; Bonding strength; CAD/CAM; Cement; Ceramic bonding; Ceramics; Composite materials; Conditioning; Dentistry; Flexural strength; Lasers; Medicine; Medicine & Public Health; Optical Devices; Optics; Original Article; Photonics; Quantum Optics; Resins; Semiconductor lasers; Silica; Silicon dioxide; Substrates; Surface treatment; Variance analysis; YAG lasers; Zirconia; Zirconium dioxide; Er:YAG laser; Surface conditioning; Adhesion; Zirconia-based ceramics; Microtensile bond strength; Flexural strength
• ISSN: 0268-8921; 1435-604X
• DOI: 10.1007/s10103-020-03205-w

To evaluate the effect of Er:YAG laser conditioning of a glass-infiltrated alumina-based zirconia-reinforced ceramic on its flexural strength and on bonding to a resin cement. Sixteen blocks (5 × 5 × 4 mm) and 50 discs (Ø 12 mm, 1 mm thickness) of In-Ceram Zirconia (ICZ) obtained from CAD-CAM blocks were infiltrated with glass. For the microtensile bond strength (μTBS) test, all blocks were treated with aluminum oxide (AOX) and divided into 4 groups ( n  = 4): G1 (AOX), no combined surface treatment; G2 (ROC), tribochemical silica-coating; G3 (EY200), Er:YAG laser 200 mJ/15 Hz; and G4 (EY250), Er:YAG laser 250 mJ/10 Hz. The ceramic blocks were silanated and cemented with a resin cement (Panavia F2.0/Kuraray) to composite resin blocks and subjected to the μTBS test. For the flexural strength evaluation, the discs were divided into 5 groups ( n  = 10) as described above, in addition to a control group (G5 – CTRL, mirror-polished without further treatment). Each surface treatment was submitted to qualitative evaluation under SEM. One-way ANOVA ( α  = 5%) revealed the highest bond strength value for EY200 with no significant difference from ROC. The groups AOX and EY250 showed similar μTBS values that were statistically lower than those of EY200. For flexural strength, ROC was the only group with significantly lower values when compared with the CTRL. The use of Er:YAG laser at 200 mJ/15 Hz can be considered an innovative and effective alternative for surface conditioning of ICZ since it did not reduce the flexural strength of the ceramic and improved the resin cement bond to this substrate.