Effect of antibacterial/adhesive approaches on bonding durability of fiber posts cemented with self-etch resin cement

BACKGROUND: Longevity of post-retained restoration is highly depended on bonding stability of fiber post (FP) to root dentin. This study evaluated the effect of different antibacterial/adhesive approaches on bonding durability of FPs luted into root canal with a self-etch cement. MATERIAL AND METHODS: Seventy-two human maxillary central incisor roots were divided into six groups after endodontic treatment, based on the antibacterial/adhesive treatments as follows: 1)ED primer II (ED, control); 2) Clearfil Protect Bond (PB); 3) 2% chlorhexidine (CH) pretreatment + ED primer II (CH+ED); 4) CH-incorporated into ED primer II (CH in ED); 5) CH pretreatment + Clearfil SE Bond (CH+SE); and 6)CH-incorporated into SE primer (CH in SE). The FPs were then cemented using PanaviaF2.0. After micro-slicing the bonded root dentin, a push-out bond strength (PBS) test was performed immediately or after two years of water storage. Data were analyzed using ANOVA and post hoc Tukey tests (α=0.05). RESULTS: The effects of antibacterial/adhesive approach, time and interaction between the main factors were significant (p=0.01). There was no significant difference between the immediate groups, except between the CH+ED group (the lowest PBS) and PB and CH in SE groups (the highest PBS) (p≤0.03). After aging, the same difference was observed (p≤0.02); the control group exhibited a significantly lower PBS compared to the other groups (p≤0.01), except for CH+ED. Aging significantly decreased PBS of all the groups (p≤0.01); the control group exhibited the highest reduction. CONCLUSIONS: CH incorporated into self-etch primers or in pretreatment step prior to two-step self-etch adhesive and antibacterial adhesive could improve bond stability of self-etch cemented fiber post. However, none of these was capable of inhibiting bond degradation over time. Key words:Push-out bond strength, Fiber post, Chlorhexidine.