Purpose: To evaluate the effect of carbodiimide (EDC) and chitosan (CHI) on the enzymatic activity (EA) and bond strength (BS) of different composite cements to root dentin.
Materials and Methods: Ninety (90) maxillary canines were sectioned, standardizing the length of the roots. The roots were endodontically treated, prepared, divided into 3 groups according to dentin treatment (distilled water [DW], CHI 0.2 wt%, or EDC 0.5M), and further subdivided into 3 subgroups according to composite cement (RelyX ARC [3M Oral Care], Panavia F 2.0 [Kuraray Noritaki], or RelyX U200 [3M Oral Care]). Of the slices obtained by sectioning, the most cervical of each third were subjected to a push-out test and the most apical were subjected to in-situ zymography. Half of the slices were analyzed immediately, and the other half after 6 months. The results were analyzed with ANOVA or the chi-squared test.
Results: RelyX ARC showed higher BS associated with CHI, while RelyX U200 showed higher BS associated with EDC (p = 0.044). For Panavia F 2.0, the treatment did not influence BS (p > 0.05). For the cervical and middle thirds, no differences were observed between the cements, while the apical third revealed higher BS for RelyX U200 (p < 0.001). The highest percentage of adhesive-to-dentin failures was observed for Panavia F 2.0. EDC showed the lowest percentage of adhesive-to-dentin failures. According to zymographic analysis, DW and CHI showed greater fluorescence for RelyX ARC, while EDC exhibited the lowest fluorescence of all cements (p > 0.05).
Conclusion: The different mechanisms of action of solutions for pre-treatment of intraradicular dentin yielded different results depending on the adhesive used. EDC resulted in higher bond strength and higher enzyme inhibition for RelyX U200, while the treatment with chitosan resulted in higher bond strength and lower enzymatic activity for RelyX ARC. Although EDC and chitosan treatments did not influence the bond strength for Panavia F 2.0, both resulted in higher enzyme inhibition for this composite cement.