Chlorhexidine does not increase immediate bond strength of etch-and-rinse adhesive to caries-affected dentin of primary and permanent teeth

Abstract

The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate (CHX) on immediate bond strength of etch-andrinse adhesive to sound (SD) and caries-affected (CAD) primary dentin compared with permanent dentin. Flat dentin surfaces from 20 primary molars (Pri) and 20 permanent molars (Perm) were assigned to 8 experimental groups (n=5) according to tooth type (Pri or Perm), dentin condition (SD or CAD -pH-cycling for 14 days) and treatment (control -C or 60 s application of 2% CHX solution after acid etching -CHX). The bonding system (Adper Single Bond 2) was applied according to manufacturer's instructions followed by resin composite application (Filtek Z250). After 24 h water storage, specimens with cross-section area of 0.8 mm 2 were prepared for being tested under microtensile test (1 mm/min). Data were submitted to ANOVA and Tukey's post hoc test (α=0.05). Failure mode was evaluated using a stereomicroscope at ×400. Treatment with CHX did not result in higher bond strength values than no pretreatment (C groups), independently of tooth type. Primary teeth and caries-affected dentin showed significantly lower (p<0.05) bond strength means compared with permanent teeth and sound dentin, respectively. Predominance of adhesive/mixed failure was observed for all groups. CHX did not influence the immediate bond strength to sound or caries-affected dentin of primary and permanent teeth.

Effects of cavity disinfectants on bond strength of an etch-and-rinse adhesive to water- or ethanol-saturated sound and caries-affected dentin

“…[31,41] Moreover, the use of CHX on CAD might have inhibited the degradation of adhesivedentin bonds more greatly than in sound dentin. [35] In addition, the application of CHX on CAD surfaces in the present study might have allowed for deeper penetration of CHX into the intertubular dentin, which is vulnerable to the action of MMPs, [35] resulting in an increased bond strength.…”

“…[4] In addition, dentin adhesives cannot penetrate as deeply into demineralized intertubular structures as acids can, which results in a lower μTBS than that of sound dentin. [1,35] Arrais et al [1] reported that acid-etching, even for an extended period of time, did not increase the bond strength of CAD over that of sound dentin.…”

“…Contrary to our findings, other studies have demonstrated that the use of CHX did not negatively affect the bond strength to dentin. [9,35,39,40] Although CHX application decreased the μTBS values of sound dentin, it seems that its application increased the bond strength in the CAD groups and this value was not significantly different in the negative control group. This Journal of Adhesion Science and Technology 9 may be caused by increased MMP activity in CAD than in sound dentin.…”

Influence of Protease Inhibitors on Bond Degradation of Self-Etch Adhesive Systems to Caries-Affected Dentin: An &lt;i&gt;in Vitro&lt;/i&gt; Study

“…In addition, applying the primer and bonding agent in separate steps increases the hydrophobicity of the adhesive layer, thus reducing water flow in the dentin tubules [42]. In a study by Lenzi et al [43], chlorhexidine also failed to influence immediate bonding strength to caries-affected dentin in permanent teeth, using a conventional two-step adhesive system. On the other hand, Shafiei et al [38] tested the influence of pretreatment with 2% chlorhexidine on the bond strength of two self-etch, two-bottle adhesive systems to healthy dentin.…”

Aplicação dos sistemas adesivos nos últimos cinco anos

“…Lenzi et al 13 pesquisaram a influência da clorexidina no aumento da resistência adesiva na utilização de sistemas de três passos, em dentes permanentes com dentina afetada. Verificaram e confirmaram que a utilização da clorexidina não interfere na resistência adesiva quando aplicada em dentes com dentina afetada.…”