Effect of an additional hydrophilic versus hydrophobic coat on the quality of dentinal sealing provided by two-step etchand-rinse adhesives

Abstract

Objective:To test the hypothesis that the quality of the dentinal sealing provided by two-step etch-and-rinse adhesives cannot be altered by the addition of an extra layer of the respective adhesive or the application of a more hydrophobic, non-solvated resin.Material and Methods:full-crown preparations were acid-etched with phosphoric acid for 15 s and bonded with Adper Single Bond (3M ESPE), Excite DSC (Ivoclar/Vivadent) or Prime & Bond NT (Dentsply). The adhesives were used according to the manufacturers' instructions (control groups) or after application to dentin they were a) covered with an extra coat of each respective system or b) coated with a non-solvated bonding agent (Adper Scotchbond Multi-Purpose Adhesive, 3M ESPE). Fluid flow rate was measured before and after dentin surfaces were acid-etched and bonded with adhesives.Results:None of the adhesives or experimental treatments was capable to block completely the fluid transudation across the treated dentin. Application of an extra coat of the adhesive did not reduce the fluid flow rate of adhesive-bonded dentin (p>0.05). Conversely, the application of a more hydrophobic non-solvated resin resulted in significant reductions in the fluid flow rate (p<0.05) for all tested adhesives.Conclusions:The quality of the dentinal sealing provided by etch-and-rinse adhesives can be significantly improved by the application of a more hydrophobic, non-solvated bonding agent.

Bonding efficiency and durability: current possibilities

“…147 To counteract this limitation of simplified adhesives, it has been proposed that the application of an additional layer of hydrophobic fluid resin should be incorporated to their bonding protocol. 24,148,149,150,151,152 This strategy proved to be effective in minimizing nanoleakage and improving the polymerization of simplified adhesives 150 as well as their immediate 40,146,150 and long-term 146 bond strength. It could also improve the sealing ability of two-step etch-and-rinse adhesives by reducing fluid conductance across the adhesive interface.…”

“…It could also improve the sealing ability of two-step etch-and-rinse adhesives by reducing fluid conductance across the adhesive interface. 151 All things considered, an extra coating of hydrophobic resin should be applied over dentin treated with both simplified adhesive systems, etch-and-rinse or self-etch. Advantages of this technique can be the improvement of marginal sealing, bond strength and degree of conversion, together with a reduced post-operative hypersensitivity.…”

Two methods to simulate intrapulpal pressure: effects upon bonding performance of self‐etch adhesives

“…, Silva et al . ). This explains the stability of silorane adhesive under pulpal pressure (Perdigao ).…”

“…,b, Silva et al . ). On the other hand, both methods to simulate pulpal pressure were less damaging to the silorane adhesive and the G‐Bond Plus.…”

Effect of an hydrophobic layer on a universal adhesive

“…The hybrid layer observed in self-etch adhesive systems is porous and allows the passage of fluids that are consequently capable of causing the accumulation of liquid on the surface of the adhesive layer, and leading to reduction in bond strength values [14,15]. This justifies the present research, since the bond strength test results after three and six months were lower than the immediate values in the SB group, and thus confirm impairment of the adhesive interface in the control group.…”