Effect of Prior Acid Etching on Bonding Durability of Single-Step Adhesives

Abstract

SUMMARYThis study investigated the effect of prior phosphoric acid etching on the enamel bond strength of five single-step self-etch adhesive systems: Absolute, Clearfil tri-S Bond, Fluoro Bond Shake One, G-Bond and One-Up Bond F Plus. Bovine mandibular incisors were mounted in self-curing resin, and the facial surfaces were wet ground with #600 silicon carbide paper. Adhesives were applied to the enamel surfaces with or without prior phosphoric-acid etching and light irradiated. The resin composites were condensed into a mold and light irradiated. In total, 40 specimens were tested per adhesive system with and without prior acid etching and were further divided into two groups: those stored in water at 37°C for 24 hours without cycling and those stored in water at 37°C for 24 hours followed by thermal cycling between 5°C and 55°C with 10,000 repeats. After storage under each set of conditions, the specimens were tested in shear mode at a crosshead speed of 1.0 mm/minute. Two-way analysis of variance, the Student's t-test and the Tukey HSD test were used to analyze the data at a significance level of 0.05. For the specimens without prior acid etching, the mean bond strengths to enamel ranged from 11.0 to 14.6 MPa after 24-hour storage in water, while the corresponding values for specimens with prior acid etching ranged from 15.2 to 19.3 MPa. When these specimens were subjected to thermal cycling, the

Bonding efficiency and durability: current possibilities

“…154,155,156 The pH of self-etch and self-adhesive materials directly relates to their reduced potential, as compared to that of phosphoric acid, 157,158 to etch the highly-mineralized enamel. 25,155,156,157,159,160,161,162,163,164 Hence, increasing its surface area and creating deep etch-pits remains important for the achievement of an effective and durable bond to enamel. 4,165,166,167,168 According to the buffering capacity that such substrate offers to the action of self-etch systems in general, it can be expected that they do have a lower demineralizing effect on the hydroxyapatite-rich enamel, which ultimately compromise their bonding effectiveness.…”

Influence of enamel acid-etching on mechanical properties and nanoleakage of resin composite after aging

“…Selective etching has been shown to increase the bond strength of enamel 18 , improve the marginal sealing, and reduce the incidence of cracks 19 . Acid-etching of the substrate increases the longevity of the restoration, by reducing degradation of the tooth/restoration interface, compensating for the characteristically poor penetration of the adhesive into the enamel 12,13 , and reducing the infiltration into and degradation of the internal walls. These previous findings are consistent with our observation that the bond strength of dentin after artificial aging was reduced in the absence of acid-etching of the cavosurface enamel.…”

“…However, self-etch adhesives can present deficient penetration of the enamel 8 , leading to faster degradation of the interface [9][10][11] and subsequent infiltration of the hybrid layer. Acid-etching of the cavosurface enamel has been suggested as a means to improve the bond strength of the enamel, as well as the longevity and quality of the interface 12,13 . However, the vector of polymerization shrinkage is directed towards the walls with the highest bond strength.…”

Enamel Wetness Effects on Bond Strength Using Different Adhesive Systems

“…Although bovine enamel presents structural differences from human enamel, its use in this research concurs with previous studies. 20,21 Bovine dentin has been proposed 22 as a suitable alternative for human dentin. Krifka and others, 23 for example, compared the shear bond strengths of enamel and dentin derived from both bovine and human primary teeth, showing that bovine primary teeth may be used as alternatives to human teeth.…”