Effect of Multiple Consecutive Applications of One-step Self-etch Adhesive on Microtensile Bond Strength

Abstract

Aim:The aim of this study was to evaluate the effects of multiple consecutive coatings of a one-step self-etch adhesive system (Clearfil Tri-S Bond) on the microtensile bond strength (MBS) to dentin. Methods and Materials:Nine caries-free human lower third molars were sectioned perpendicular to the long axis to expose the mid-coronal dentin. The teeth were separated into three experimental groups (n=3) according to the number of adhesive resin coats applied. In Group 1 one layer of Clearfil Tri-S Bond was applied according to the manufacturer's instructions. In Group 2 and Group 3 the adhesive was applied in two and three layers, respectively. In these two groups the first layer was applied according to the manufacturer's instructions but the second and third layers of adhesive were not light cured after application. After the placement of the composite, the teeth were sectioned to obtain approximately 1 mm 2 beams for testing. Eighteen beams were prepared for each group using the 'non-trimming' method. The MBS values of all specimens were tested, and fracture modes were then determined using a stereomicroscope. Results:The mean MBS values (in MPa) of Group 1 (one coat of the adhesive) was significantly lower (p=0.04) than those of Group 3 (three applied coats of the adhesive). There were no statistically significant differences between Groups 1 and 2 and Groups 2 and 3. Conclusion:Within the limitations of this in vitro study the application of multiple coats of a one-step self-etch o adhesive may provide an increase in bond strength compared to the application of only one coat of adhesive. Abstract © Seer PublishingClinical Significance: Three consecutive coats of one-step self-etching adhesive application can improve MBS.

Effect of Double Coating of One-step Self-etching Adhesive on Micromorphology and Microtensile Bond Strength to Sound vs Demineralized Dentin

“…Nevertheless, bond strength should not be associated only to the formation of resin tags, but also to the penetration of resin monomers into intertubular dentin. 6 Results of the present study are different from those of Arisu et al 16 which found that the application of three consecutive layers significantly increased bond strength of an one-step adhesive (Clearfil Tri S Bond, pH 2.7). 21 Clearfil Tri S Bond adhesive has a lower pH (more acidic) than Adper Easy One adhesive (which has a pH of about 3.5).…”

“…Accordingly, adhesive monomer penetration may be deeper with the application of a 2.7 pH adhesive (Clearfil Tri S Bond) as opposed to a 3.5 pH adhesive, such as that used in this study. This may explain the increase in bond strength to sound dentin reported by Arisu et al 16 Similarly, Bellis et al 17 found that the additional coats of ultramild pH adhesives (Clearfil Tri S Bond, pH 2.7 and Adper Easy Bond, pH 2.5) helped improve microtensile bond strength to sound dentin.…”

“…8,[13][14][15] In an attempt to increase clinical performance of one-step self-etching adhesives, the application of multiple consecutive layers of these adhesives has been recommended. 16,17 This is especially important when mild-pH and ultra-mild-pH adhesives are considered, because they demineralize dentin only to a superficial depth. 1 However, this application protocol has not been tested on demineralized dentin.…”

The Thickness of the Adhesive Layer Increases the Misdiagnosing of the Radiolucent Zones and Restoration Replacement Indication

“…These findings might raise concerns considering that applying two or more layers has previously been suggested for one‐step self‐etching systems to increase bond strength . However, Taschner et al (2014) showed that the effect of additional layers on bond strength is dependent on material and that this procedure did not improve the performance of SBU.…”

“…These findings might raise concerns considering that applying two or more layers has previously been suggested for one-step self-etching systems to increase bond strength. [20][21][22] However, Taschner et al (2014) 23 showed that the effect of additional layers on bond strength is dependent on material and that this procedure did not improve the performance of SBU. Therefore, it can be considered that thicker layers of this adhesive are not recommended because it increases the risk of misinterpretation in radiographic images, leading to incorrect indication of restoration replacement.…”