Effect of Chlorhexidine on Nanoleakage and Bond Durability of Two Adhesives to Dentin: An In Vitro Study

Aim: This study aimed to investigate the effect of chlorhexidine CHX on nanoleakage and dentin bond durability of two adhesives after water storage. Materials and Methods: Thirty-six extracted molars were divided into three groups and their buccal surfaces were reduced to expose flat dentin surfaces. In group 1 Single Bond Universal Adhesive SBU was used, in group 2 Peak universal Bond PUB was applied while in group 3 Chlorhexidine Gluconate Disinfecting Solution followed by Single Bond Universal Adhesive (CHX+SBU) was used. Application of resin composite restorations was performed in all three groups. For each bonding procedure, specimens were subdivided into three subgroups according to storage period (24 hours, three & six months). After storage, resin-dentin slabs were obtained, immersed in silver nitrate and then photo developed. NL was evaluated with scanning electron microscopy. Data were explored for normality using Kolmogorov-Smirnov and Shapiro-Wilk tests and showed parametric distribution. One-way ANOVA followed by Tukey post hoc test was used to compare between more than two groups in non-related samples. Repeated measure ANOVA test was used to compare between more than two groups in related samples. Paired sample t-test was used to compare between two groups in related samples. Two-way ANOVA was used to test the interaction between different variables. The significance level was set at P ≤ 0.05. Statistical analysis was performed with IBMSPSSStatistics Version 20 for Windows. Results: No statistically significant difference was detected between SBU, PUB and CHX SBU at 24 hours. For stored specimens, there was no statistically significant difference between (SBU) and PUB, but a statistically significant difference occurred between both of them and CHX SBU. Conclusions: Chlorhexidine containing universal adhesive suppressed the occurrence of nanoleakage at the interface, while chlorhexidine as a therapeutic primer had an adverse effect. Water storage negatively affected bond durability of chlorhexidine containing and free universal adhesives by showing more nanoleakage at the interface.