Bond strength of self-adhesive resin cements to dentin after antibacterial and chelating solution treatment

Abstract

Objective. The aim of this study was to evaluate the effect of tetracycline HCl, 1-hydroxyethylidene−1, 1-bisphosphonate (HEBP) and chlorhexidine digluconate (CHX) on micro push-out (µ-PO) bond strengths of two self-adhesive resin cements on dentin. Materials and methods. Sixty discs of 1.25 mm thickness (middle dentin) were prepared from human molars perpendicular to the tooth axis. Two standardized occlusal cavities of 2.20 mm occlusal diameter and 1.25 mm cervical diameter were prepared in each disc. The cavities were divided into three groups in accordance with the surface treatment (50 mg/ml tetracycline HCl, 18% HEBP and 2% CHX solutions). Following the treatment of the discs for 5 min, cavities were filled with two different self-adhesive resin cements (Clearfil^™ SA Cement and RelyX^™ Unicem). After light polymerization of cements, µ-PO bond strength tests were performed. Failure modes were examined and dentin morphologic assessments were done. Statistical significance was determined by a multivariate analysis of variance (MANOVA) followed by Tukey's post-hoc test (p < 0.05). Additionally, a paired-samples T-test was used to compare the µ-PO bond strengths of self-adhesive resin cements (p < 0.05). Results. Paired-samples T-test revealed that there was no significant difference between tested self-adhesive resin cements (p = 0.612). No significant two-factor interaction was observed between Clearfil^™ SA Cement and chemical agents (p = 0.457). Similarly, tetracycline HCl and CHX did not have a significant effect on the bond strength of RelyX^™ Unicem (p > 0.05). However, HEBP significantly decreased the bond strength of RelyX^™ Unicem when compared to the control (p < 0.05). Conclusion. The tetracycline HCl and CHX solutions do not have beneficial effects on µ-PO bond strengths of self-adhesive resin cements. Additionally, the results of this study do not justify the use of self-adhesive resin cements, following HEBP treatment of dentin. Clinical significance: The application of topical HEBP solution treatment to dentin could have adverse effects on the µ-PO bond strengths of RelyX^™ Unicem.