Light transmission through fiber post: the effect on adhesion, elastic modulus and hardness of dual-cure resin cement.
OBJECTIVE
The aim of this study was to investigate the effect of fiber post light transmitting ability to the continuity of resin cement-root dentin (C-RD) and resin cement-fiber post (C-FP) interface, elastic modulus and hardness of a dual-cure resin cement.


METHODS
Spectrophotometric measurements were applied for the determination of light transmission at coronal, middle and apical level as well as at the apical tip through Tech 21 X-OP (TECH) and DT Light Post (DT). Posts were cemented using dual-cured resin cement (Calibra). Roots were sectioned longitudinally through the post. Epoxy resin replicas were made and used to evaluate C-RD and C-FP interface under SEM. Modulus of elasticity (E) and Vicker's hardness (VH) of the cement layer were assessed.


RESULTS
No light transmission was detected through TECH. Light transmission through DT decreased from coronal to apical and rose at the apical tip. TECH presented a significantly lower percentage of continuous C-RD and C-FP interface in comparison to DT. Coronal third of C-RD interface in TECH specimens had a significantly higher percentage of continuity than apical third. No regional differences in continuity of C-RD interface were found in DT specimens. E and VH were significantly lower when TECH was used, and decreased from coronal to apical for both posts.


CONCLUSIONS
Cementation of fiber post with no light transmitting ability using a dual-cured resin cement resulted in lower E and VH of the cement layer, and lower percentage of continuous C-RD and C-FP interface in comparison to cementation of light transmitting fiber post.
Radovic
Ivana
I
Clinic for Pediatric and Preventive Dentistry, Faculty of Dentistry, University of Belgrade, Dr. Subotica 11, Beograd 11000, Serbia. ivana.radovic@iritel.com
Corciolani
Gabriele
G
Magni
Elisa
E
Krstanovic
Goranka
G
Pavlovic
Vladimir
V
Vulicevic
Zoran R
ZR
Ferrari
Marco
M
D001713:Biphenyl Compounds / Q000737:chemistry; D002484:Cementation; D001840:Dental Bonding; D017267:Dental Prosthesis Design; D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003804:Dentin / Q000648:ultrastructure; D004548:Elasticity; D004852:Epoxy Compounds / Q000737:chemistry; D006244:Hardness; D006801:Humans; D008027:Light; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D055668:Photochemical Processes; D011176:Post and Core Technique / Q000295:instrumentation*; D011407:Propane / Q000737:chemistry; D016628:Replica Techniques; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D012822:Silicon Dioxide / Q000737:chemistry; D013053:Spectrophotometry; D013499:Surface Properties; D019227:Tooth Apex / Q000648:ultrastructure; D019228:Tooth Crown / Q000648:ultrastructure; D015040:Zirconium / Q000737:chemistry
D001713:Biphenyl Compounds; D004852:Epoxy Compounds; D011407:Propane; D019279:Resin Cements; D012822:Silicon Dioxide; D015040:Zirconium; C433205:Calibra; C010574:biphenyl; C028541:zirconium oxide; C009068:propylene oxide