The Influence of Alumina Airborne-Particle Abrasion with Various Sizes of Alumina Particles on the Phase Transformation and Fracture Resistance of Zirconia-Based Dental Ceramics

Abstract

The surface of zirconia-based dental ceramic restorations require preparation prior to adhesive cementation. The purpose of this study was to assess the influence of airborne-particle abrasion with different sizes of alumina particles (50 μm, 110 μm, or 250 μm) on the mechanical strength of zirconia-based ceramics’ frameworks and on the extent of phase transformations. A fracture resistance test was performed. The central surface of the frameworks was subjected to a load [N]. The identification and quantitative determination of the crystalline phase present in the zirconia specimens was assessed using X-ray diffraction. The Kruskal–Wallis one-way analysis of variance was used to establish significance (α = 0.05). The fracture resistance of zirconia-based frameworks significantly increases with an increase in the size of alumina particles used for air abrasion: 715.5 N for 250 μm alumina particles, 661.1 N for 110 μm, 608.7 N for 50 μm and the lowest for the untreated specimens (364.2 N). The X-ray diffraction analysis showed an increase in the monoclinic phase content after air abrasion: 50 μm alumina particles—26%, 110 μm—40%, 250 μm—56%, and no treatment—none. Air abrasion of the zirconia-based dental ceramics’ surface with alumina particles increases the fracture resistance of zirconia copings and the monoclinic phase volume. This increase is strongly related to the alumina particle size.

The Influence of Alumina Airborne-Particle Abrasion on the Properties of Zirconia-Based Dental Ceramics (3Y-TZP)

“…The apparent benefits of alumina air abrasion are a significant increase in the bond strength of zirconia to resin cements and the efficient cleaning of the zirconia surface by removing contaminants [8,[13][14][15][16]18]. Many researchers have found that such treatment results in an increase in the monoclinic phase content within the topmost layer of zirconia [23,25,33,34,41] while also increasing the biaxial flexural strength of zirconia [19][20][21]. Airborne-particle abrasion affects the microstructure of the superficial surface of zirconia by creating irregular grooves, which are considered a degradation zone [23,25,33,34].…”

“…Studies indicate that while alumina airborne-particle abrasion can improve the bonding strength of 3Y-TZP to resin cements, it also affects its mechanical properties and the structure of the topmost layer of zirconia [8][9][10][11][12][13][14][15][16][19][20][21]23,25,[32][33][34][35][36]41]. Although such changes following alumina air abrasion have already been reported, it is difficult to obtain a coherent understanding of the data, especially since many studies were not intended as specific assessments of the role of the size of the alumina particles used in air abrasion.…”