Bonding of composite resin luting cement to fiber-reinforced composite root canal posts.
OBJECTIVE
The aim of this study was to compare bonding of composite resin luting cement to a fiber-reinforced composite (FRC) root canal post with either a cross-linked or a semi-interpenetrating polymer network (IPN) polymer matrix.


METHODS
Four different types of prefabricated FRC posts with a cross-linked polymer matrix and two types of FRC posts with a semi-IPN polymer matrix which were individually formed were tested. Serrated titanium posts served as the reference. An auto-polymerizing resin luting cement was used for cementing the posts into the holes of composite resin disks. The pull-out force was measured using a universal testing machine after the post/cement/disk system had been stored dry or thermocycled (5 degrees C/55 degrees C, 6000x) in water. The bonding sites of the posts were examined with SEM.


RESULTS
The FRC posts with a semi-IPN polymer matrix gave significantly higher pull-out force values than the prefabricated FRC posts with a smooth surface and a cross-linked polymer matrix (p < 0.004). The highest pull-out force was obtained with serrated titanium posts. Both the type of FRC post and thermocycling had a significant effect on the pull-out force (n = 8, ANOVA p < 0.001 and p < 0.007, respectively). SEM photomicrographs confirmed the results.


CONCLUSIONS
This study showed that FRC posts with a semi-IPN polymer matrix bonded better to composite resin luting cement than did prefabricated FRC posts with a cross-linked polymer matrix, although their pull-out force was not as high as that of the mechanically interlocked serrated titanium posts.
Le Bell
Anna-Maria
AM
Department of Prosthetic Dentistry and Biomaterials Research, Institute of Dentistry, University of Turku, Turku, Finland. ami.lebell@utu.fi
Tanner
Johanna
J
Lassila
Lippo V J
LV
Kangasniemi
Ikka
I
Vallittu
Pekka
P
D000180:Acrylic Resins / Q000737:chemistry*; D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D017220:Dentin-Bonding Agents; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry*; D011176:Post and Core Technique
D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D011108:Polymers; D011140:Polyurethanes