• Siriporn Arunpraditkul, D.D.S, M.S.
• Wacharasak Tumrasvin, D.D.S, Ph.D.
• Sariya Saoraya, D.D.S.
• Kamolporn Wattanasirmkit, D.D.S, M.S., Ph.D.

Background/Objectives To evaluate the microtensile bond strength (μTBS) between epoxy-based
or dimethacrylate-based fiber posts and resin cores after various post surface treatments.

Materials and methods Eighty DT light (DT) and forty FRC Postec Plus (FRC) posts were divided
into 8 groups; group 1: silanization (S), group 2: silanization and application of bonding agent (SB),
groups 3, 5, 7: etching with 37% phosphoric acid for 1 minute (P), 30% hydrogen peroxide for 10
minutes (H30), 35% hydrogen peroxide for 1 minute (H35), respectively, followed by S, groups 4, 6,
8: etched as in groups 3, 5, and 7, but followed by SB. The cores were built up with Multicore flow.
Twenty stick-shaped specimens per group were randomly selected for the μTBS test with a universal
testing machine. The failure modes were classified by stereomicroscope. The post surfaces after chemical
treatment and cross-sectioned specimens of the fiber posts were examined by scanning electron microscope.
The data were analyzed with two-way analysis of variances and Tukeyûs test.

Results Types of resin matrix and surface treatment and the interaction between them significantly
affected μTBS (p < 0.05). The DT groups showed significantly higher bond strength than those of the
FRC groups. Post surface treatment with SB, phosphoric acid or hydrogen peroxide followed by S or
SB significantly increased the μTBS compared to S without other surface treatments.

Conclusion Post surface treatments and types of resin matrix of the fiber posts affected on the μTBS
between fiber posts and resin composite cores.

(CU Dent J. 2016;39:81-94)