Effects of dimensions of laser-milled grid-like microslits on shear bond strength between porcelain or indirect composite resin and zirconia

Abstract

Purpose: Zirconia cores and frameworks are widely used in restorative dentistry. Although these structures are veneered with porcelain for esthetic reasons, the use of indirect composite resins (ICRs) is expected to increase in the future. The purpose of this study was to investigate the effects of microslits of different dimensions formed by Nd:YVO 4 laser machining on the bond strength between two types of zirconia (3 mol% yttria-partially stabilized zirconia (Y-TZP) and ceria-partially stabilized zirconia/alumina nanocomposite (Ce-TZP/A)) and porcelain or an ICR. Methods: The zirconia disks were assigned as follows: 1) blasted with alumina particles (AB) and 2-4) surface machined with gridded microslits with a width, pitch, and depth of 50, 75, or 100 µm (MS50, MS75, and MS100, respectively). After the bonding of the veneering materials to the disks, half of the specimens veneered with the ICR were subjected to thermocycling (4-60°C, 20000 cycles). All the specimens were subsequently shear tested (n = 10/group). Results: There was no significant difference between the groups of the disks bonded to porcelain. On the other hand, for the disks bonded to the ICR, the bond strengths of the MS groups after thermocycling were statistically higher than that of the AB group. However, there was no significant difference in the bond strengths of the disks with different microslits. Conclusions: Within the study limitations, it can be concluded that, for porcelain, the design of the mechanical retentive structure must be modified. However, for the investigated ICR, a simple gridded pattern can improve the bond strength with zirconia.

Innovation Glass-Ceramic Spray Deposition Technology Improving the Adhesive Performance for Zirconium-Based Dental Restorations

“…Additionally, a ceramic primer cannot be used to form a covalent bond with the zirconia crystalline structure. Thus, the primary goal of continuous improvement in the clinical practice of prosthodontics and operative dentistry is determining how to treat the zirconia surface to modify its physical or chemical properties to improve the bond between zirconia and dental cement [ 13 , 14 , 15 , 16 , 17 ].…”

“…This method is convenient and cost-effective and can effectively increase the wettability and roughness of the zirconia [ 24 , 25 ], thereby improving the bonding durability of zirconia restorations [ 22 , 23 , 26 ]. Some scientists have recently attempted using plasma [ 2 , 27 , 28 ], laser [ 3 , 15 , 17 ], and fusion sputtering [ 29 , 30 ] for surface treatment. These techniques improve the zirconia–resin bond strength, but require unique or expensive equipment, involve complicated operation processes, and are difficult to standardize and impractical for dental practices.…”

Surface modification of zirconia or lithium disilicate-reinforced glass ceramic by laser texturing to increase the adhesion of prosthetic surfaces to resin cements: an integrative review

“…Of the 13 selected studies, yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) were assessed by 9 studies [8,9,[26][27][28][29][30][31][32] although ceria-stabilized tetragonal zirconia polycrystals (Ce-TZP) were also assessed by one study [27]. The effects of laser irradiation on lithium disilicatereinforced glass ceramic were investigated by four studies [33][34][35][36].…”

“…The effects of laser irradiation on lithium disilicatereinforced glass ceramic were investigated by four studies [33][34][35][36]. The following types of laser were assessed by the selected studies: Er,Cr:YSGG [9,30], Er:YAG [33,34,36], Nd:YAG [34], CO 2 [8,32,35,], and Nd:YVO 4 [27]. The laser irradiation parameters varied among the studies as seen in Table 1.…”

Effect of laser engraving on shear bond strength of polyetheretherketone to indirect composite and denture-base resins

“… 26 Subsequently, multiple studies have confirmed that laser engraving can significantly increase the SBS of Zr to DBRs or ICRs by creating micro-slits prior to bonding, which increases the surface area. 27 , 28 , 29 , 30 , 31 Accordingly, it is believed that laser engraving could improve the surface characteristics of PEEK, enhance mechanical bonding, and ultimately increase the SBS. 26 , 27 , 28 , 29 , 30 , 31 This study aims to evaluate the impact of grid-like microslits created by laser engraving on PEEK's surface and compare it with other mechanical surface treatments for bonding PEEK to DBRs or ICRs.…”