The effects of dentine pretreatment on the adhesion of root-canal sealers.
OBJECTIVE
The adhesion of five root-canal sealers to dentine and gutta-percha was studied. The effects of various dentine pretreatments on adhesion were also investigated.


METHODS
Root dentine cylinders, 4 mm in diameter, were prepared from human teeth. The dentine surfaces were conditioned with either 37% H(3)PO(4) for 30 s, 25% citric acid for 30 s, 17% EDTA for 5 min or a rinse with 10 mL distilled water (control). Gutta-percha cylinders, 4 mm in diameter, were prepared and their end surfaces polished flat. The dentine and gutta-percha surfaces were coated with freshly mixed sealer: Grossman's sealer (GS), Apexit (AP), Ketac-Endo (KE), AH Plus (AH), RoekoSeal Automix (RS) or RoekoSeal Automix with an experimental primer (RP). The surfaces were pressed together and the sealers allowed to set. The test specimens were subjected to a tensile force in a universal testing machine.


RESULTS
Mean tensile bond strengths (MPa +/- SD) ranged from 0.07 +/- 0.01 (AP) to 1.19 +/- 0.47 (AH). Pretreatment with EDTA showed no effect or produced weaker bonds than controls. Phosphoric and citric acid pretreatments increased adhesion of GS. A primer used with RoekoSeal significantly enhanced its adhesion to untreated dentine. Inspection of fractured surfaces indicated failure of adhesion to dentine for GS and RS and to gutta-percha for KE and RP. The failure appeared to be mainly cohesive within the sealer for AH and AP.


CONCLUSIONS
Removal of the smear layer may impair sealer adhesion to dentine. Different sealer types require different dentine pretreatments for optimal adhesion.
Saleh
I M
IM
NIOM, Scandinavian Institute of Dental Materials, Haslum, Norway. imans@odont.uio.no
Ruyter
I E
IE
Haapasalo
M
M
Ørstavik
D
D
D000134:Acid Etching, Dental; D000268:Adhesiveness; D002126:Calcium Hydroxide / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D004492:Edetic Acid / Q000737:chemistry; D004853:Epoxy Resins / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D016369:Smear Layer; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D015035:Zinc Oxide-Eugenol Cement / Q000737:chemistry
C074418:Apexit; D002614:Chelating Agents; D003738:Dental Cements; D004853:Epoxy Resins; D005899:Glass Ionomer Cements; C074934:Ketac Endo; D010756:Phosphoric Acids; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C534916:epoxy resin-based root canal sealer; C465381:roeko seal; C045432:Grossman's sealer; D019343:Citric Acid; D006171:Gutta-Percha; D004492:Edetic Acid; C030242:phosphoric acid; D002126:Calcium Hydroxide