Push-Out Bond Strength of Different Luting Cements Following Post Space Irrigation with 2% Chitosan: An In Vitro Study

Background: The optimum bond strength of glass fiber posts can be compromised; it has not yet been established which final irrigant, when used in combination with luting cement, can improve this bond strength. Objectives: This study assessed the effectiveness of 2% chitosan as a final irrigant in combination with different types of luting cement used to improve the bond strength of glass fiber posts bonded to root canal-treated teeth. Methods: Thirty single-rooted anterior teeth were collected and sectioned 2 mm above the most incisal point of the cementoenamel junction. After root canal filling, post spaces were prepared and irrigated in Group I using 17% EDTA for 3 min and in Group II using 2% chitosan for 3 min. Each group was divided into three subgroups: Fiber posts were cemented in subgroup A with Fuji II Cement (resin-reinforced glass ionomer cement), in subgroup B with RelyX Unicem (self-adhesive resin cement), and in subgroup C with Metacem Refill (total-etch resin cement). Push-out bond strength (N) for each sample was measured using a universal testing machine, and the failure mode was assessed with a stereomicroscope at 30× magnification. The fiber post’s morphological structure was analyzed through scanning electron microscopy. Statistical analysis included one-way ANOVA followed by Tukey’s post hoc test in the case of significant differences between the groups. p-Values less than 0.05 were considered statistically significant. Results: This study found no statistically significant difference between using 17% EDTA and 2% chitosan as the final irrigant before post placement (p > 0.05). RelyX Unicem cement showed significant bonding strength when used with 2% chitosan in the coronal, middle, and apical thirds (p = 0.009, p = 0.02, p = 0.01, respectively). Conclusions: Chitosan at 2% can be considered a good alternative to 17% EDTA when used as a final irrigant for the post space.