Influence of oval and circular post placement using different resin cements on push-out bond strength and void volume analysed by micro-CT.
OBJECTIVE
To evaluate the percentage volume of voids within cement layers, to determine the push-out bond strength of circular and oval fibre posts luted with different commercial resin cements in oval cross-sectional root canals, and to correlate push-out bond strength values and volume of voids of circular and oval fibre posts.


METHODS
Seventy-two mandibular premolars with oval-shaped root canals were selected. The specimens were divided into two main groups according to the post type (oval and circular). Groups were further divided into three subgroups (n = 24) according to resin cement type: Maxcem Elite, Rely-X Unicem and Duo-Link. The volumes of voids within the cements were analysed by micro-computed tomography (micro-CT). The bond strength was then measured using a push-out test with an Instron universal testing machine. The failure modes were evaluated. Statistical analyses were performed using a three-way anova, Tukey's post hoc, Pearson's correlation and chi-square test (P = 0.05).


RESULTS
The push-out bond strength values were significantly affected by root canal region, post type and cement type (P < 0.001). Root canal region, post type and cement type also significantly affected void volume (P < 0.001). There was a significant interaction between post type and cement type (P < 0.001). The most frequent failure type was adhesive failure in all the groups. There was no significant correlation between the push-out bond strength and void volume (P > 0.05).


CONCLUSIONS
Void volume did not affect push-out bond strength of oval and circular posts luted in oval canals.
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
I
I
Uzun
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
A
A
Keleş
Department of Endodontics, Faculty of Dentistry, Ataturk University, Erzurum, Turkey.
H
H
Arslan
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
B
B
Güler
Department of Endodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
C
C
Keskin
Department of Dentomaxillofacial Radiology, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
K
K
Gündüz
D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D008963:Molar / Q000601:surgery; D011176:Post and Core Technique / Q000295:instrumentation; D011861:Radiography, Dental; D019279:Resin Cements / Q000627:therapeutic use*; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods; D055114:X-Ray Microtomography
D019279:Resin Cements
fibre post; micro-computed tomography; oval-circular; oval-shaped canals; push-out; self-adhesive