Effect of Replacing a Component of a Self-Etch Adhesive by Chlorhexidine on Bonding to Dentin

Abstract

The purpose of this study was to evaluate the effect of replacing a component of the self-etch adhesive Adper Scotchbond SE (liquid A + liquid B) by 2% chlorhexidine (CHX) on bond strength to dentin after 1 day, 3 months or 6 months of water storage. Eight human teeth were sectioned to expose a flat dentin surface and were then randomly assigned to 2 groups. In the control group, the dentin surfaces were treated with the adhesive according to the manufacturer's instructions. In the experimental group, liquid A was replaced by 2% CHX. Next, a 6-mm-high resin composite block was incrementally built on the bonded surfaces. The restored teeth were then sectioned to produce stick-shaped specimens (cross-sectional area - 0.8 mm2). The microtensile bond strength (µTBS) was recorded, and the failure modes were assessed. Data were analyzed by two-way repeated measures ANOVA (α=0.05). Four additional teeth were processed in order to conduct a micromorphological analysis of the resin-dentin interface. The µTBS values did not significantly decrease after water storage in either the control or the experimental group, whose values did not differ significantly irrespective of storage time. The morphological aspect of the bonding interface appears not to have been affected by CHX. A higher incidence of cohesive failures within the adhesive and mixed failures (cohesive within adhesive and resin composite) was observed for both groups. It may be concluded that dentin pre-treatment with 2% CHX did not influence significantly the bonding performance of the evaluated adhesive.

Long-term bond strength and endogenous enzymatic activity of a chlorhexidine-containing commercially available adhesive

“…Zhou et al found that the incorporation of 0.1%-1% CHX into a SE primer could preserve dentin bond strength after a 12-month aging [18]. On the other hand, a study incorporating 2% CHX into a SE adhesive found no influence of CHX on bonding performance after 6 months [24]. It is thought that acid etching during E&R procedures can denaturize enzymes within the etched dentin, due to the low pH values of the phosphoric acid.…”

“…It is assumed that the ability of CHX to inhibit MMPs derives from its binding properties [4,14]. CHX has been investigated in numerous in vitro and in vivo studies, used as either as a separate primer in water solution [16,17], or incorporated in one of the components of etch-and-rinse (E&R) or self-etch (SE) adhesive systems, within the primer [18][19][20] or the adhesive [21][22][23][24][25] agent.…”

“…So far, CHX showed mixed outcomes. Several authors found beneficial effect of the use of CHX strength of the adhesive layer [16][17][18][21][22][23][26][27][28], while others found no difference between the treated and untreated groups [24,25,[29][30][31]. These studies differ in methodology, materials used, as well as aging time, which could be the cause of the discrepancies among the available results.…”

Influence of Cariogenic Challenge on Bond Strength Stability of Dentin

“…In this study, even using an effective MMP inhibitor, the small quantity of pre-treated dentin was not able to preserve the resin-dentin interface stability. This was shown in the aging with artificial saliva or deionized water (19), even when the CHX is added to the adhesive composition (20). For the CHX dentin pretreatment, the percentage of reduction of the microtensile bond strength values was smaller for all aging conditions when compared to the control pre-treatment, though it was not statistically significant.…”

Effects of solvent volatilization time on the bond strength of etch-and-rinse adhesive to dentin using conventional or deproteinization bonding techniques

“…Even with the evolution of adhesive systems in recent decades, the establishment of a predictable bonding interface for dentin tissue has remained a challenge for clinicians. 1 , 2 , 3 Although the self-etching adhesive systems have gained popularity, etch-and-rinse adhesives remain as suitable option for adhesive procedures in clinical practice. For etch-and-rinse adhesives, phosphoric acid is applied before the adhesive system, partially removing the mineral content of the dentin tissue to expose the collagen mesh.…”