Microtensile bond strength of photoactivated and autopolymerized adhesive systems to root dentin using translucent and opaque fiber-reinforced composite posts.
BACKGROUND
The use of fiber-reinforced composite resin posts in endodontically treated teeth has increased. However, selecting an adhesive system that provides reliable and long-lasting bonding to root canal dentin remains difficult.


OBJECTIVE
This study evaluated the microtensile bond strength of 2 adhesive systems to root dentin and 2 different fiber-reinforced composite resin posts.


METHODS
Forty single-rooted teeth were instrumented, and root canals were prepared for translucent (Light Post [LP]) or opaque (Aestheti Post [AP]) quartz fiber-reinforced composite resin posts. Two adhesive systems were used: Scotchbond Multi-Purpose Plus (SBMP) (autopolymerized) as a control group, and Single Bond (SB) (photoactivated). Teeth were assigned to 4 groups (n=10): SBMP+LP, SBMP+AP, SB+LP, SB+AP. After post cementation, roots were perpendicularly sectioned into 1-mm-thick slices, which were trimmed to obtain dumbbell-shaped specimens. The specimens were divided into 3 regions: cervical (C), middle (M), and apical (A). To determine the bond strength, the bonding area of each specimen was calculated, and specimens were attached to a device to test microtensile strength at a crosshead speed of 1 mm/min. Data were analyzed using 3-way analysis of variance and the Tukey test (alpha=.05). Fractured specimens were examined under a x 25 stereomicroscope to determine the mode of fracture.


RESULTS
There were significant differences only among root dentin regions (P<.001). The cervical third (9.16 +/- 1.18 MPa) presented higher mean bond strength values, especially for SBMP. Middle and apical regions demonstrated lower values (7.08 +/- 0.92 and 7.31 +/- 0.60 MPa, respectively). Adhesive and post main factors did not demonstrate significance. Also, no interaction was significant. No cohesive fractures within resin cement, fiber-reinforced composite resin post, or root dentin were identified.


CONCLUSIONS
Both adhesive systems tested demonstrated reliable bonding when used with translucent and opaque fiber-reinforced composite posts.
Mallmann
Andre
A
School of Dentistry, Bahiana Foundation for Science Development, Salvador, Bahia, Brazil.
Jacques
Leticia Borges
LB
Valandro
Luis Felipe
LF
Muench
Antonio
A
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects; D002484:Cementation; D003188:Composite Resins / Q000737:chemistry; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents; D006801:Humans; D044367:Phase Transition; D011176:Post and Core Technique; D011791:Quartz; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects; D013718:Tensile Strength
D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C425844:Scotchbond Multi-Purpose Plus; C115612:single bond; D011791:Quartz; D017438:Bisphenol A-Glycidyl Methacrylate