The effect of subpressure on the bond strength of resin to zirconia ceramic

Abstract

ObjectiveThis study was conducted to investigate the effect of subpressure on the bond strength of resin to zirconia ceramic. The subpressure would create a pressure gradient which could clean out the bubbles in the adhesives or bonding interface.MethodsTwenty-eight pre-sintered zirconia discs were fabricated. Half of them were polished (group P, n = 14), and the rest were sandblasted (group S, n = 14). After sintered,the surface roughness of the zirconia discs was measured. Then, they were randomly divided into two subgroups (n = 7). The groups were named as follows: PC: P + no additional treatments; PP: P + 0.04 MPa after application of adhesives; SC: S + no additional treatments; and SP: S + 0.04 MPa after application of adhesives. Resin columns were bonded to the zirconia specimens to determine shear bond strength (SBS). The bonding interfaces were observed and the fracture modes were evaluated. Statistical analysis was performed on all data.ResultsThe surface roughness of group S was significantly higher than that of group P (P<0.05). The SBS values were PC = 13.48 ± 0.7 MPa, PP = 15.22 ± 0.8 MPa, SC = 17.23 ± 0.7 MPa and SP = 21.68 ± 1.4 MPa. There were significant differences among the groups (P<0.05). Scanning electron microscopy (SEM) results showed that the adhesives of group SP and PP were closer and denser to the zirconia ceramic than that of group PC and SC. The proportion of the mixed fracture mode significantly increased after adding subpressure (P< 0.05).ConclusionSubpressure can improve the shear bond strength of resin to zirconia ceramics and increase micro-infiltration between the adhesives and the zirconia ceramics, especially on the rough surfaces.

Cytotoxicity and Bonding Property of Bioinspired Nacre-like Ceramic-Polymer Composites

“…Poor bonding may lead to loosening or dislodging of the dental restorations. Therefore, the bonding ability is very important and is the main factor required for the restoration to perform its function in long-term durations, especially for the silica-free zirconia ceramic restorations ( Li et al, 2017 ). Although there is no consensus on a specific bonding procedure when treating zirconia restorations ( Cavalcanti et al, 2009 ; Tanış et al, 2018 ), the method of using resin cements combined with preliminary zirconia surface treatment is highly recognized ( Mizrahi, 2008 ; Yassaei et al, 2015 ).…”

“…A possible bonding mechanism of the bioinspired ceramic-polymer composites with Lamellar and Brick-and-mortar structures was shown in Figure 8 . According to the current mechanical theory, the adhesive must penetrate into the voids inside the bonding surface as much as possible to remove the air bubbles on the interface so as to promote bonding ( Li et al, 2017 ). Sandblasting could effectively amplify the penetration of the adhesives into the micro-pits and micro-hollows on the surface of zirconia, thereby increasing the bonding area and mechanical interlocking effect.…”

Introduction to subpressure-driven soft deformation method for removing inherent voids in green components manufactured by material extrusion

“…Subpressure refers to the application of pressures below the atmospheric pressure. Improvements in the bonding strength between adhesive or coating films and substrates by applying subpressure with heat treatment have been reported to improve bonding strength [ 16 ] or to remove the void between films [ 17 ]. In the MIM feedstock, this control exploits the shear thinning effect, which is a non-Newtonian phenomenon where the viscosity decreases as the shear rate increases [ 18 ].…”