[Effect of different irrigants on radicular dentin cleansing and resin tag formation after post space preparation].
OBJECTIVE
To evaluate the effect of different root canal irrigants on smear layer removal and dentinal tubule opening of root canal surfaces after post space preparation.


METHODS
Thirty maxillary anteriors were endodontically treated. After post space preparation, the teeth were assigned to three groups with ten teeth each: group A, B, C. 3% H2O2, 15% ethylenediamine tetraacetic acid(EDTA), 15% EDTA and 3% NaClO were used as irrigant of group A, B, C. After post space irrigation, eight teeth of each group were examined under scanning electron microscope (SEM) for smear layer removal and dentinal tubule opening. The left two specimens were restored with fiber posts and prepared for evaluation of resin tag formation.


RESULTS
The cleansing effectiveness of group A, B and C was respectively 3.89 +/- 0.36, 1.77 +/- 0.30, 1.25 +/- 0.21. The dentinal tubule opening of group A, B and C was respectively (2.53 +/- 0.19), (3 11 +/- 023) (3.83 +/- 0.52) microm. The cleansing effectiveness and dentinal tubule opening of root canal surfaces were significantly affected by different root canal irrigants (P < 0.05). Excessive erosion of the dentin was observed in group C. Resin tag formation differed between the three irrigant groups, and group B showed excellent resin tag formation.


CONCLUSIONS
Irrigation with 15% EDTA after post space preparation can excellently remove the smear layer and improve dentinal tubule opening, permitting well penetration of resin adhesive into the dentinal tubules and collagen fibrillar structure.
Mao
Cai-Yun
CY
Dept. of Stomatology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
Gu
Xin-Hua
XH
D003786:Dental Pulp Cavity; D003804:Dentin; D004492:Edetic Acid; D006801:Humans; D006861:Hydrogen Peroxide; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants; D018915:Root Canal Preparation; D012390:Root Canal Therapy; D016369:Smear Layer; D012973:Sodium Hypochlorite; D014092:Tooth Root
D012388:Root Canal Irrigants; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D012973:Sodium Hypochlorite