Influence of endodontic sealer cement on fibreglass post bond strength to root dentine.
OBJECTIVE
To test the hypothesis that the composition of endodontic sealer cements and the time elapsed between root filling and fibreglass post fixation interferes with adhesion to root canal dentine.


METHODS
Sixty bovine incisor roots were divided into five groups (n = 12): CI, unfilled; SI, filled with a calcium hydroxide-based cement-Sealer 26, and immediate post fixation; S7, Sealer 26 and post fixation after 7 days; EI, filled with a zinc oxide and eugenol-based cement-Endofill and immediate fixation; and E7 Endofill and post fixation after 7 days. The posts were cemented with adhesive system and dual resin cement. Ten roots were cross-sectioned to obtain two 1-mm-thick discs for each cervical (TC), middle (TM) and apical (TA) third of the prepared root portion. The posts were submitted to a micropush-out test. The other two teeth were evaluated using scanning electron microscopy to analyse the bond interface. Data were analysed using anova, Tukey and Dunnett tests (P < 0.05).


RESULTS
Group EI was associated with a significant reduction in bond strength values irrespective of the root region; TC = 3.50 MPa (P = 0.0001); TM = 2.22 MPa (P = 0.0043) and TA = 1.45 MPa (P = 0.003). Region of canal had an influence on the values for the cement used in group E7, in which only the TA presented differences from the CI.


CONCLUSIONS
Endofill interfered negatively with the bond to root dentine along its full length and in the TA when post fixation was delayed for 7 days. Bond strength decreased from crown to apex in all groups.
Menezes
M S
MS
School of Dentistry of Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
Queiroz
E C
EC
Campos
R E
RE
Martins
L R M
LR
Soares
C J
CJ
D000818:Animals; D001729:Bismuth / Q000737:chemistry / Q000627:therapeutic use; D002126:Calcium Hydroxide / Q000737:chemistry / Q000627:therapeutic use; D002417:Cattle; D001840:Dental Bonding / Q000379:methods; D003738:Dental Cements / Q000737:chemistry*; D018772:Dental Marginal Adaptation; D017268:Dental Prosthesis Retention / Q000379:methods; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects*; D004347:Drug Interactions; D005898:Glass / Q000737:chemistry; D066298:In Vitro Techniques; D007180:Incisor; D011176:Post and Core Technique; D019279:Resin Cements / Q000737:chemistry / Q000627:therapeutic use; D012387:Root Canal Filling Materials / Q000737:chemistry* / Q000627:therapeutic use; D012389:Root Canal Obturation / Q000379:methods*; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014092:Tooth Root / Q000187:drug effects; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry / Q000627:therapeutic use
D003738:Dental Cements; D019279:Resin Cements; D012387:Root Canal Filling Materials; C080620:Sealer 26; D015035:Zinc Oxide-Eugenol Cement; C009753:fiberglass; D002126:Calcium Hydroxide; D001729:Bismuth