Abstract:

BACKGROUND: Fiber post has a favorable aesthetics feature, the elasticity modulus of it is similar to dentin, which has a good dispersion stress; with its clinical application increase, losing bonding phenomenon of fiber post and root canal is gradually increase. Thus it is meaningful to improve the bonding of fiber post. Polyurethane binder is binding materials developed in recent years. Recent researches showed that polyurethane binder has great bonding strength to many materials, but there is little research in prosthodontics field.
OBJECTIVE: To compare bonding strength of the fiber post after 4 different surface treatments by using of polyurethane binder.
METHODS: Totally 25 single root canal of upper jaw to exsomatize the intercepting dental crown, then preparing root canal, root-canalfilling as well as post space preparation, which were randomly divided into 5 groups: sand blast treatment group, hydrogen peroxide treatment group, silicon alkylation treatment group, hydrofluoric (HF) acid treatment and control group. Before cementation of fiber post surface, it underwent sand blast treatment, hydrogen peroxide treatment, silicon alkylation treatment and HF treatment, and no treatment was given in the control group. The treated fiber post was cemented with polyurethane binder to make test specimen in the root canal. The tooth was cut into 2 mm piece to perform push-out experiment. The bonding strength was detected by universal testing machine, and glass fiber post was observed by scanning electron microscope (SEM) before and after surface treatment.
RESULTS AND CONCLUSION: Each group has difference in bonding strength, hydrogen peroxide treatment group > silicon alkylation treatment group > sand blast treatment group > HF acid treatment treatment > control group. There was no significant difference in bonding strength between silicon alkylation treatment group and sand blast treatment group (P > 0.05). There was significant difference in other groups (P < 0.05). SEM observation showed that the surface of the fiber post had varying degrees of resin matrix dissolution after surface treatment, some fiber post came out. Fiber post can improve the strength of materials combined with polyurethane binder after 4 different surface treatments; the bonding strength of it is the greatest after hydrogen peroxide treatment.