Abstract:

BACKGROUND: Bond strength of fiber posts is closely related to different surface treatments.
OBJECTIVE: To compare the effect of four surface treatments on the surface morphology and bond strength of fiber posts.
METHODS: According to the four different surface treatments, 25 mandibular premolars were randomly divided into five groups: hydrogen peroxide group, sodium ethoxide group, phosphoric acid group, hydrofluoric acid group, and control group (distilled water). Twenty-five single-rooted mandibular premolars that had similar dimensions were used. After endodontic treatment, removal of the crown and canal preparation, cemented POPO glass fiber posts were inserted in to the root canal. Then each root was cut perpendicularly to the long-axis with the slow saw to obtain three 2.0-mm-thick slides as test samples. Specimens of each group (n=15) were loaded with a universal testing machine until failure occurred. The data obtained were submitted to the one-way analysis of variance and multiple comparisons, and the failure mode of each specimen was observed.
RESULTS AND CONCLUSION: Bond strength values from the highest to the lowest were as follows: sodium ethoxide group>hydrogen peroxide group > hydrofluoric acid group > phosphoric acid group > control group. Significant difference (P < 0.05) was showed between every two groups except for hydrofluoric acid and phosphoric acid groups (P > 0.05). Failure- modes of specimens were mainly mixed damage. These findings indicate that sodium ethoxide and hydrogen peroxide treatment combined with surface treatment can enhance the bond strength of fiber posts to the root dentin.