The Effect of Final Irrigation on the Penetrability of an Epoxy Resin-Based Sealer Into Dentinal Tubules: A Confocal Microscopy Study

Clin Oral Investig. 2016 Jan;20(1):117-23. doi: 10.1007/s00784-015-1474-8. Epub 2015 Apr 24.


Introduction: The aim of this study was to compare the effect of QMix, BioPure MTAD, 17 % EDTA, and saline on the penetrability of a resin-based sealer into dentinal tubules using a confocal laser scanning microscope (CLSM) and to describe the cleaning of root canal walls by SEM.

Methods: Eighty distobuccal roots from upper molars were selected and randomly divided into four groups (n = 20) before root canal preparation according to the solution used in the final rinse protocol (FRP): QG (QMix), MG (BioPure MTAD), EG (17 % EDTA), and CG (control group: saline). Ten roots of each group were prepared for SEM, and images (×2000) from the canal walls were acquired. The remaining canals were filled with a single gutta-percha cone and AH Plus with 0.1 % Rhodamine B. The specimens were horizontally sectioned at 4 mm from the apex, and the slices were analyzed in CLSM (×10). Sealer penetration was analyzed with Adobe Photoshop software.

Results: QG and EG presented similar amounts of sealer penetration (P > .05). MG and CG presented the lowest penetrability values (P < .05). The best results for smear layer removal of the apical third of the root canal were achieved by the QG and EG groups when compared with MG and CG (P < .05).

Conclusions: Seventeen percent EDTA and QMix promoted sealer penetration superior to that achieved by BioPure MTAD and saline.

Clinical relevance: Despite studies have not confirmed the relationship between sealing ability of endodontic sealers and their penetration in dentinal tubules, sealer penetration assumes importance, since endodontic sealers, unlike gutta-percha, are able to penetrate in dentinal tubules, isthmus, and accessory canals, filling the root canal system.

Keywords: Confocal laser scanning microscopy; Endodontics; Final irrigation solution; Root canal irrigant; Scanning electron microscopy; Smear layer.

Publication types

  • Comparative Study

MeSH terms

  • Biguanides / chemistry
  • Citric Acid / chemistry
  • Doxycycline / chemistry
  • Edetic Acid / chemistry
  • Epoxy Resins / chemistry*
  • Humans
  • In Vitro Techniques
  • Microscopy, Confocal
  • Microscopy, Electron, Scanning
  • Molar
  • Polymers / chemistry
  • Polysorbates / chemistry
  • Random Allocation
  • Root Canal Filling Materials / chemistry
  • Root Canal Irrigants / chemistry*
  • Smear Layer


  • Biguanides
  • Epoxy Resins
  • MTAD (intracanal irrigant)
  • Polymers
  • Polysorbates
  • QMix root canal irrigant
  • Root Canal Filling Materials
  • Root Canal Irrigants
  • epoxy resin-based root canal sealer
  • Citric Acid
  • Edetic Acid
  • Doxycycline