Intracanal Medicaments Compromise Fiber Post Adhesion: Influence of Irrigation Techniques.

Aim: This study evaluated the effect of intracanal medicaments and final irrigation techniques on resin cement penetration and the push-out bond strength of fiber posts. Methodology: Ninety extracted mandibular premolars were allocated into three groups: no medicament (control), calcium hydroxide (CH), and triple antibiotic paste (TAP). CH and TAP groups were then subdivided based on final irrigation techniques: Conventional needle irrigation (CNI), sonic irrigation, passive ultrasonic irrigation, and XP-endo Finisher (XPF). Fiber posts were cemented with RelyX™ U200 resin cement. Confocal laser scanning microscopy was used to evaluate cement penetration, and push-out bond strength was measured. Data were analyzed using one-way and two-way ANOVA (P < 0.05). Results: Compared to the control, both CH and TAP significantly decreased cement penetration and bond strength. XPF significantly enhanced these outcomes in CH-medicated canals. In TAP groups, all activation protocols improved adhesion results over CNI; however, the values remained significantly lower than those of the control. A significant interaction between medicament and irrigation protocol was observed only for maximum penetration depth. Conclusion: Intracanal medicaments adversely affect fiber post bonding. Activated irrigation technique, notably with XPF, enhances bonding, especially following CH treatment. Bonding outcomes in TAP-treated canals remained inferior despite the use of activation procedures.