COMPARING RETENTION OF TWO TYPES OF DUAL CURE CEMENT SELF-CARE AND SEPARATE ACID-ETCH ADHESIVES ON A NON-METAL POST

Objectives: In the recent years, the use of fiber post has been increased significantly due to it's pleasant physical qualities. One of the most common problems with these posts is their detachment from dentin which is mainly because of the type of cement. Although, some researchers have claimed that self-adhesive cements are stronger, others were more interested in separate acid-etch adhesives. The aim of this study was comparing the differences of two types of dual cure resin cements, self-adhesive and separate acid-etch adhesive, on the amount of retention of a non-metal types of posts in different areas of the root.

Methods: 20 first and second endodontically root treaded premolars were prepared 1mm coronal to CEJ. Samples were divided into two groups (10 teeth in each group) and were prepared for insertion of 12mm posts. First group were cemented with Rely X Unicem and cured according to manufacture guide. In the second group, canals were etched, bonded with All-Bond 2, cemented with Dou Link and light cured. The posts were cut into three equal pieces by a Diabond blade; push-out energy was placed on the samples till they became dislodged.  Statistical programs used for analysis were t-test, one-sample kolmogorov-simirinov.

Results: There was significant difference in all areas of 2 groups. Separate Acid-etch adhesive group had more strength in coronal and middle areas. Strength decreased from coronal to apical. Self-adhesive group was stronger in apical areas (p<0.001) and the bond strength increased from coronal to apical (p<0.05).

Conclusions: Since there is an increase in bond strength in middle and coronal thirds of the root, while using separate Acid- Etch technique in comparison with self-adhesive system, it is more rational to use separate Acid- Etch technique in cementing FRC posts.

Keywords: Fiber reinforced composite post, Push-out test, Bond strength.