The influence of the irrigating solution on the percentage of dentinal tubule sealer penetration: evaluation with Rhodamine B

Abstract

Introduction: The main objectives of endodontic therapy are the complete removal of residual pulpal tissue, the elimination of bacteria from the root canal system and the prevention of recontamination after the treatment that could lead to unsuccessful outcomes. Chemical irrigants such as Sodium Hypochlorite or Chlorhexidine are needed to aid in the debridement of the root canals. Furthermore, the use of chelating agents has been advocated. Sealer penetration into the dentinal tubules could influence the sealing ability of the root filling considering that an increase of the contact surface between dentin and filling material is accompanied by an improvement of sealability. Additionally, sealer penetration can contribute to an antimicrobial effect in the tubules. In search for endodontic sealers that combined the ideal properties, new materials have been proposed such as MTA Fillapex. Aim: The purpose of this study was to investigate and compare the percentage of sealer penetration into dentinal tubules using different endodontic irrigating solutions under in vitro conditions. Methods: twenty-nine extracted human single-rooted teeth were divided into 3 groups according to the main irrigating solution used: (1) the Sodium Hypochlorite group: 3,0% Sodium Hypochlorite + 17% Ethylenediamine tetraacetic acid, (2) the Chlorhexidine group: 2,0% Chlorhexidine + 17% Ethylenediamine tetraacetic acid and (3) the Control group: Saline Solution + 17% Ethylenediamine tetraacetic acid. All teeth were obturated using cold lateral condensation technique with gutta-percha and MTA Fillapex sealer labeled with rhodamine B. The teeth were sectioned at the apical and middle thirds. Total percentage of sealer penetration was measured using confocal laser scanning microscopy. Results: The Kruskal-Wallis analysis results showed that there was no significant difference in the percentage of sealer penetration among all groups in all sections (p < 0,05). The Group G1 and the Control Group obtained a higher mean percentage of sealer penetration in the apical section (Graphic 4). The Group G2 obtained a higher mean percentage of sealer penetration in the middle section. Conclusions: The results of this study suggest that there appears to be no significant difference in the percentage of sealer penetration between the irrigants tested, when smear layer was removed with 17% EDTA (p = 0.05).