Effect Of Different Surface Treatments On Bond Strength And Mechanical Properties Of Fiber Posts

Objective: A good combination of fiber posts and resin cores is critical to the success of clinical repair.Surface treatment can effectively improve the bond strength of both.In this study,micro push out tests,bending strength tests and scanning electron microscope(SEM)observations were used to compare the effects of four different surface treatments on the bond strength and mechanical properties of fiber posts and provide reference for clinical applications.Methods: 60 POPO fiber posts were randomly divided into 5 groups,each with 12 for surface treatment.Group A: No treatment;Group B: Hydrogen peroxide + Ascorbic acid solution;Group C: Potassium permanganate;Group D: Ultraviolet light irradiation;Group E: Silane coupling agent + Binder.The treated fiber posts was tested as follows:1.Each group randomly selected 4 to form a cylindrical model with the bond of resin cement,and cut it into 1mm thin slices with 20 pieces in each group.After being stored in physiological saline at 37°C for 24 h,each group was randomly selected 10 for 10,000 thermocycling.All specimens were placed on a universal testing machine for micro push out test.2.The stereomicroscope was used to observe the fracture modes of post-core specimens.3.The remaining parts of each group were randomly selected 6 for three-point bending strength test.4.The last two in each group was placed under SEM to observe its surface morphology.Results: 1.After different surface treatments,the bond strength of each experimental group was significantly higher than that of control group(P<0.05),and the bond strength was D>B>C>E>A.The bond strength of each group decreased after thermocycling(P<0.05).2.The fracture mode of each experimental group was mainly bond failure.3.After surface treatm ent,the bending strength of fiber posts in each experimental group was slightly lower than that of the control group.Except for group C(P<0.05),there was no significant difference in group A,B,D and E(P> 0.05).4.SEM shows that the surface morphology of fiber posts is different after different surface treatments.Conclusions: 1.Surface treatment can improve the bond strength of glass fiber posts and resin cement.2.Compared with silane coupling agent,the hydrogen peroxide solution,potassium permanganate etching and ultraviolet light(UV)irradiation is more effective for the improvement of the bond strength between fiber post and resin cement,and does not affect its own mechanical properties.