J Adhes Dent 16 (2014), No. 1 28. Feb. 2014
J Adhes Dent 16 (2014), No. 1 (28.02.2014)
Page 87-92, doi:10.3290/j.jad.a30556, PubMed:24027772
Effect of Chlorhexidine and Ethanol on Push-out Bond Strength of Fiber Posts under Cyclic Loading
Cecchin, Doglas / Giacomin, Mateus / Farina, Ana Paula / Bhering, Cláudia Lopes Brilhante / Mesquita, Marcelo Ferraz / Ferraz, Caio Cezar Randi
Purpose: To investigate the effects of pretreatment with 2% chlorhexidine in a gel base (CHX) and 100% ethanol (EtOH) on the bond strength between fiber posts relined with resin composite and root dentin under cyclic loading.
Materials and Methods: Forty bovine incisor roots were divided into four groups after phosphoric acid etching: group 1 (control), irrigation with physiological saline solution; group 2, 5 min pretreatment with CHX; group 3, 1 min pretreatment with EtOH; group 4, 5 min pretreatment with CHX followed by 1 min with EtOH. Fiber posts relined with resin composite were cemented with RelyX ARC and the etch-and-rinse adhesive system Scotchbond Multi-Purpose. Each group was randomly divided into two subgroups: 24 h of storage (immediate groups) and cyclic loading (loading groups) with 250,000 cycles in a controlled chewing simulator. All roots were sectioned transversely and push-out tests were performed. Failure modes were observed and the bond strength means were analyzed using ANOVA and Tukey's test (a = 0.05).
Results: The mean values for the bond strength test (MPa) in immediate groups were: group 1, 5.44 ± 1.48; group 2, 5.57 ± 1.41; group 3, 5.49 ± 1.48; group 4, 5.57 ± 1.42. Immediate groups showed similar bond strength values (p > 0.05). In the cyclic loading groups, the bond strength values were: group 1, 2.80 ± 0.79; group 2, 4.02 (1.30); group 3, 4.50 ± 1.67; group 4, 4.97 ± 2.00. After cyclic loading, a significant decrease in the control group was observed (p < 0.05), while CHX pretreatment resulted in intermediate values (p < 0.05) and EtOH alone or associated with CHX preserved the bond strength values (p > 0.05).
Conclusion: Chlorhexidine and/or ethanol pretreatment preserved the bond strength of the fiber post after cyclic loading.
Keywords: bond strength, chlorhexidine, cyclic loading, ethanol, fiber post, root canal