Effect of repeated laser surface treatments on shear bond strength between zirconia and veneering ceramic

Adil O Abdullah; Hui Yu; Sarah Pollington; Fenik K Muhammed; Sun Xudong; Yi Liu

doi:10.1016/j.prosdent.2019.10.007

Effect of repeated laser surface treatments on shear bond strength between zirconia and veneering ceramic

J Prosthet Dent. 2020 Feb;123(2):338.e1-338.e6. doi: 10.1016/j.prosdent.2019.10.007. Epub 2019 Dec 13.

Authors

Adil O Abdullah¹, Hui Yu², Sarah Pollington³, Fenik K Muhammed⁴, Sun Xudong⁵, Yi Liu⁶

Affiliations

¹ Graduate student, Dental Research Center, School and Hospital of Stomatology, China Medical University, Shenyang, PR China; Assistant Lecturer, Prosthodontics Department, Erbil Polytechnic University, Erbil, Kurdistan Region Government, Iraq.
² Lecturer, School of Environmental and Chemical Engineering, Dalian University, Dalian, PR China.
³ Clinical Lecturer, Restorative Department, School of Clinical Dentistry, The University of Sheffield, Sheffield, United Kingdom.
⁴ Graduate student, Dental Research Center, School of Stomatology, China Medical University, Shenyang, PR China.
⁵ Professor, School of Environmental and Chemical Engineering, Dalian University, Dalian, PR China.
⁶ Professor, School of Stomatology, China Medical University, Shenyang, PR China. Electronic address: liuyi@cmu.edu.cn.

PMID: 31839330
DOI: 10.1016/j.prosdent.2019.10.007

Abstract

Statement of problem: Delamination failure may occur between ceramic frameworks and veneering ceramics, shortening the lifetime of fixed dental prostheses in load-bearing areas.

Purpose: The purpose of this in vitro study was to compare the effect of different repeating CO₂ laser treatment methods and conventional approaches on the shear bond strength of zirconia frameworks and veneering ceramics.

Material and methods: Zirconia disks (N=110) were prepared and divided into 5 groups: milling without surface treatment (group M), airborne-particle abrasion (group APA), single laser treatment (group LX1), 2 laser treatments (group LX2), and 3 laser treatments (group LX3). The specimens in the first 2 groups were treated before the framework was coated using the spraying technique. Specimens in the remaining groups were coated with veneering ceramic using the spraying process, and then subjected to laser treatment. Surface roughness and topography, interface properties, phase transformation, shear bond strength, and fracture modes were investigated. Outcomes were analyzed using a profilometer, a scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD), a stereomicroscope, and a universal testing machine for mechanical testing.

Results: The XRD showed that phase transformation from tetragonal to monoclinic occurred after airborne-particle abrasion. This phenomenon was not observed in laser-treated specimens. Groups LX2 and LX3 had the highest surface roughness values, 1.18 ±0.23 μm and 1.21 ±0.22 μm, among all groups, and group LX3 had the highest shear bond strength values for unaged and aged conditions, 32.08 ±2.45 MPa and 31.43 ±2.07 MPa. The mixed-fracture mode was the most common type of fracture observed.

Conclusions: The results indicated that the shear bond strength between the zirconia framework and veneering ceramic was higher after laser surface treatments than after milling alone or after airborne-particle abrasion. Laser treatment methods, particularly LX2 and LX3, could be considered reliable approaches for zirconia surface treatment.

MeSH terms

Ceramics
Dental Bonding*
Dental Porcelain
Dental Stress Analysis
Dental Veneers*
Materials Testing
Shear Strength
Surface Properties
Zirconium

Substances

Dental Porcelain
Zirconium
zirconium oxide