Effect of different air-drying time on the microleakage of single-step self-etch adhesives

Abstract

Objectives: This study evaluated the effect of three different air-drying times on microleakage of three self-etch adhesive systems. Materials and Methods: Class I cavities were prepared for 108 extracted sound human premolars. The teeth were divided into three main groups based on three different adhesives: Opti Bond All in One (OBAO), Clearfil S 3 Bond (CSB), Bond Force (BF). Each main group divided into three subgroups regarding the air-drying time: without application of air stream, following the manufacturer's instruction, for 10 sec more than manufacturer's instruction. After completion of restorations, specimens were thermocycled and then connected to a fluid filtration system to evaluate microleakage. The data were statistically analyzed using two-way ANOVA and Tukey-test (α = 0.05). Results: The microleakage of all adhesives decreased when the air-drying time increased from 0 sec to manufacturer's instruction (p < 0.001). The microleakage of BF reached its lowest values after increasing the drying time to 10 sec more than the manufacturer's instruction (p < 0.001). Microleakage of OBAO and CSB was significantly lower compared to BF in all three drying time (p < 0.001). Conclusions: Increasing in air-drying time of adhesive layer in one-step selfetch adhesives caused reduction of microleakage, but the amount of this reduction may be dependent on the adhesive components of self-etch adhesives. ( IntroductionRecently introduced dental adhesives offer simplified clinical application and eliminate technique sensitivity.1 The major benefit of the one-step self-etching systems is that they are less technique sensitive than multi-step systems. While the adhesive system becomes simpler, careful product management is still required in order to attain optimum bonding procedures. However, according to recent studies, the bond quality of these products were affected by several factors, such as enamel surface treatment, smear layer thickness, grit size of the bur, moisture condition of the adhesive surface, drying time after application of the adhesives, and number of multiple coating.2-5 The etching effect of the self-etch adhesives attributed to hydrogen ions derived from the acidic monomers. 6 Water is an essential component in the adhesives, which allows them to generate the hydrogen ions. 7 The moisture control of the adhesive surface can be considered in two parts: the surface moisture before the application of the adhesive agent and the removal of the solvent after application. 8Since self-etching adhesives contain acidic functional monomers and water, which

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

“…These facts may support the hypothesis that differences in recommendations for air-drying may be at least partly responsible for the distinct performance of OBU and GPB in dentin. Literature reports a significant improvement of self-etching universal adhesives by increasing the time for air-drying from 5 to 15 s but also by varying the air pressure (51,52). This may lead to the suspicion that OBU performs better with prolonged air-drying, as already recommended for GPB by its manufacturer.…”

The Effect of Air Drying Time on Bonding (Self Etch) With Ethanol as a Solvent to the Shear Bond Strength of Bioactive Composite Resin

“…Air drying on bonding can provide better solvent evaporation and only leaves the priming resin on the surface of the dentin, it produced a higher degree of conversion. 18 All solvents must be completely removed from the adhesive prior to the light activation. Therefore, prolonged time are needed for the solvent to carry out its function then evaporates and ensures the properties of the appropriate adhesive layer.…”

“…The solvent present in the adhesive acts like a transporter medium and lower viscosity of the resin in the adhesive solution, allowing the resin monomer to penetrate into the demineralized porous surface of the dentin. 18 The solvent can move the water in the dentin when the monomer enters the demineralized dentin. The physical properties of solvents such as solubility parameters, vapor pressure, and hydrogen bonding capacities affect bonding of dentin.…”

Microleakage Evaluation of Adhesive Systems Following Pulp Chamber Irrigation with Sodium Hypochlorite

“… 25 In addition, bonding substrate and the chemical composition of adhesive systems have an important role in microleakage. 26 NaOCl removes predentin; however, adhesive systems use acidic conditioners that etch the NaOCl-treated surface to expose fresh collagen fibrils for resin-dentin hybridization. It seems that the oxidizing effect of NaOCl could be stable even two weeks after irrigation with NaOCl.…”