Etch-and-rinse vs self-etch mode for dentin bonding effectiveness of universal adhesives

Abstract

In this study, dentin bond fatigue resistance and interfacial science characteristics of universal adhesives through etch-and-rinse and self-etch modes were investigated. Resin composite was bonded to human dentin with four universal adhesives, namely, Adhese Universal, All-Bond Universal, G-Premio Bond, and Scotchbond Universal Adhesive. The initial bond strengths, bond fatigue strengths, and interfacial science characteristics of the universal adhesives with dentin through etch-and-rinse and self-etch modes were determined. Bond fatigue resistance (initial bond strength and bond fatigue strength) of universal adhesives in etch-and-rinse mode showed no significant difference in contrast to that in self-etch mode and was material-dependent regardless of the etching mode. Although phosphoric acid conditioning of dentin did not have a strong impact on the bond fatigue resistance, surface free energy and parameters of dentin were significantly decreased by etching and by application of universal adhesives regardless of etching mode. Changes in γ S and γ S h for when universal adhesive was applied to etched and ground dentin were significantly different depending on the adhesive. The results suggest that bonding performance of universal adhesives was effective in both etching modes; however, bonding mechanisms may be different for each. Keywords; light-curing of dental adhesives, dental debonding, dental etching, dental restoration failure, dental stress analysis Materials and Methods Study materials Four universal adhesives were used in this study: (i) Adhese Universal (AU, Ivoclar Vivadent, Schaan, Liechtenstein), (ii) All-Bond Universal (AB, Bisco, Schaumburg, IL, USA), (iii) G-Premio Bond (GB, GC, Tokyo, Japan), and (iv) Scotchbond Universal Adhesive (SU, 3M Oral Care). Ultra-Etch (Ultradent, South Jordan, UT, USA) was used as a 35% phosphoric acid pre-etching agent and Z100 Restorative (3M Oral Care) as the resin composite employed to make specimens. Table 1 lists the tested materials and their lot numbers and components. Specimen preparation This study used de-identified extracted human molar teeth. To comply with research ethics, the protocol was reviewed and approved by the Ethics Committee for Human Studies of NU (#2015-06) and Biomedical Institutional Review Board at CU (#760765-1). Preparation of the teeth was done in the manner described in the study by Nagura et al. [18], except that a flat dentin surface, rather than enamel surface, was prepared. Specimens with and without etching were prepared for each adhesive, giving a total of eight experimental groups for each of the procedures performed (Table 2). Initial bond strength testing Initial bond strength testing was carried out as described by Nagura et al. [18]. Bond fatigue strength testing Bond fatigue strength testing was carried out as described by Nagura et al. [18].

Comparison of shear bond strength of etch and rinse, self-etch adhesive system followed by flowable composite resin, and self-adherent composite resin

“…Both pH level incorporated with adhesive only partially removes the smear layer so that some smear layers still cover the dentinal tubules and collagen fibres. 13,15 Unlike the results of this study, Sachdeva 10 showed that there was a statistical significance in shear bond strength between self-adherent composite resins and conventional composite resins with etch and rinse adhesive systems in primary teeth. However, the same result was observed between the self-etch compared to etch and rinse adhesive system, where the self-etch system had lower bond strength than the etch and rinse system because it formed thinner and shorter resin tags, this was also observed in this present study.…”

“…Therefore the etch and rinse adhesive system is still widely clinically used despite its longer step for application, however, postoperative sensitivities are more commonly reported using this system compared to the self-etch adhesive system, particularly in deep cavities. 13,14,15,16,17 Studies on the comparison of shear bond strength between etch and rinse adhesive system as the gold standard, self-etch adhesive system, and self-adherent composite resin are still limited. Therefore this study will compare the bonding strength of these three different bonding approaches to dentin structure.…”

Effect of 9.3 μm CO2 and 2.94 μm Er:YAG Laser vs. Bur Preparations on Marginal Adaptation in Enamel and Dentin of Mixed Class V Cavities Restored With Different Restorative Systems

“…Nevertheless, one possible explanation for the lower values after loading of SBU and especially GPB might be, next to the laser-specific dentin properties, the adhesive system's water content. Literature reports the double amount of water in GPB in comparison to SBU, which might be more difficult to evaporate in the microporosities of Er:YAG laser dentin (19). It may be even further speculated that the more acidic GPB compared to SBU and OBU demineralizes deeper on the already laser-etched surface with its microporosities where the adhesive system itself does not penetrate entirely, thus producing an incomplete hybrid layer, potentially explaining its lower resistance to loading (38).…”

“…The performances of adhesive systems are strongly dependent on differences in the composition of hydrophobic and hydrophilic monomers, photoinitiators and co-initiators, organic solvents as well as additives such as nanofillers and bioactive components, and also the manufacturers' instructions for application and not only by the bonding approach (additional step for etching or self-etching) (16)(17)(18)(19)(20).…”

A three-year randomized clinical trial evaluating direct posterior composite restorations placed with three self-etch adhesives

“…Thus, their etching abilities are affected, resulting in a defective adhesion to enamel, which partly explains the poor performance of the Scotchbond universal adhesive [ 35 ]. Previous studies have reported no significant difference in the clinical behaviour of resin composites bonded with universal adhesives in any mode [ 36 , 37 ]. So far, mild SE adhesives and universal adhesives have proven to be clinically effective [ 7 , 38 ].…”