Improvement of Total Etching Dentin Bonding with Subpressure

Abstract

This study aimed to investigate the effects of subpressure on the bond properties of total-etching adhesive to dentin. Thirty-six caries-free premolars were sectioned parallel to the occlusal plane and randomly divided into four groups (n = 9): a control group (C, no treatment) and three subpressure groups, which were treated under 0.8, 0.6 or 0.4 bar after applying adhesives, named S8, S6 and S4, respectively. Afterward, resin was bonded to the dentin surface, and 27 beams (1.0 mm × 1.0 mm) of each group were sectioned. One was selected to observe the bonding interface from each group by SEM. Each group was divided into two subgroups (n = 13): 24 hours of water storage (I) and 10,000 thermocycling (A). The microtensile bond strength (μTBS), failure modes and nanoleakage expression were evaluated. SEM results showed that the subpressure groups had longer and denser resin tags. The μTBS of the subpressure groups was higher than that of the control group (p < 0.05). The subpressure groups were dominated by mixed failure, whereas main interfacial failure appeared in group C. The subpressure groups showed less silver deposition than the control group (p < 0.05). The subpressure technique may remarkably improve bonding strength and decrease nanoleakage on total-etching bonding.

The Effect of Curing Pressure on Shear Bond Strength of Zirconia to Resin Cement

“…The sub pressure infiltration technique explains voids elimination by the gas that traps between the adhesive agent, and the substrate can be exhausted when sub pressure is applied due to the pressure gradient, when releasing the sub pressure, the atmosphere automatically instantly presses the adhesive agent replacing those voids. Interfacial voids are eliminated, and the adhesive agent can infiltrate into all the micro-pits that cause the adhesive agent to intimately contact the substrate as a consequence of the sub pressure infiltration technique [12]. On the contrary, our SEM images demonstrated voids within the resin cement layer, and some gaps between resin cement-zirconia and the bond strength were not different from other groups.…”

“…Studies reported that pressure regulating triple syringe could help adhesive agents to spread a thinner uniform film to entire substrate surface irregularities [11]. Another study showed that the sub pressure (negative pressure) or vacuum exhaust gas in the dentinal tubule facilitate adhesive agents to penetrate the entire dentinal tubule [12]. Li et al [13] suggested that the sub pressure infiltration technique (negative pressure) can result in improvement in the adhesion between zirconia and resin by eliminating voids and promoting intimate contact between resin cement and zirconia.…”

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 ].…”

The Effect of Different Adhesive System Application Modes on Nanolekage At Superfacial And Deep Dentin After Varying Storage Interval

“…In contrast to Zhuge RS. et al findings from 2017 43 , which examined the effects of subpressure on the bond properties of total-etching adhesive to dentin and came to the conclusion that subpressure provided a reliable interfacial morphology, enhanced the short-and long-term bonding strength, and decreased nanoleakage, which had a positive impact on the total-etching dentin bonding and increased bond durability.…”