[Effect of different surface treatments on the bond strength of fiber posts to resin cement].

ABSTRACT

PURPOSE: To evaluate the effects of five different surface treatments on the bond strength between fiber posts and resin cement. METHODS: Fifty fiber posts were randomly divided into 5 groups for different surface treatments. Group A was treated with silane coupling agent (Clearfil Porcelain Bond Activator,Kuraray); Group B was treated with silane coupling agent and then coated with dentin bonding agent (Clearfil SE Bond,Kuraray); Group C was immersed in 30% H(2)O(2); Group D was immersed in 30 % H(2)O(2) and then treated with silane coupling agent; Group E received no surface treatment (control group). After bonding to resin cement, each group was then divided into 2 subgroups equally, while one group was stored in sodium chloride for 24 h at 37 degrees centigrade, and the other group was stored in sodium chloride for 24 h at 37 degrees centigrade and then subjected to thermal cycling for 10000 times. Microtensile bond strengths were tested and the data was statistically analyzed using SPSS17.0 software package. RESULTS: The microtensile bond strength before thermal cycling was (6.7±0.7) MPa for group A,(14.4±1.1) MPa for group B,(10.7±0.9) MPa for group C,(16.0±1.0) MPa for group D and (6.7±1.0) MPa for group E. After thermal cycling, the microtensile bond strength was (6.7±0.7) MPa for group A, (13.1±0.7) MPa for group B, (9.0±0.7) MPa for group C, (15.0±0.9) MPa for group D and (5.6±0.7) MPa for group E. The results showed that surface treatments had significant impact on the bond strength (P<0.05). There was no significant difference between group A and group E. Group D had the highest bond strength compared with the other groups. Microtensile bond strengths were significantly different before and after thermalcycling treatment in each group (P<0.05). CONCLUSIONS: Thermocycling treatment decreases the bond strength of fiber posts to resin cement with these 5 surface treatments. Coupled with 30 % H(2)O(2) solution and silanization, the bonding strength of fiber posts to resin cement can increase significantly.