Intracanal Medicaments Compromise Fiber Post Adhesion: Influence of Irrigation Techniques

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.

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).

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.

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.