Influence of smear layer on depth of penetration of three endodontic sealers: an SEM study

Abstract

Abstract— The purpose of this study was to examine the effect of the smear layer on the penetration depth of Sealapex, Roth 811, and CRCS root canal sealers into the dentinal tubules. Forty recently extracted, human single‐rooted teeth were used. The crowns were cut and removed at the cemento‐enamel junction level and the root canals were prepared to a #60 K‐file. The teeth were then randomly divided into two groups of 20, group A and group B. The smear layer was removed from all teeth in group A with EDTA and NaOCl. The smear layer remained in all teeth in group B. Two roots in each group were used as controls. Six roots from each group were obturated with Roth 811 sealer and gutta‐percha through lateral condensation. The same process was repeated using sealers CRCS and Sealapex. Each root was then divided in two and prepared for scanning electron microscope observation. The removal of the smear layer allowed penetration of all three sealers into the dentinal tubules to a depth of between 35 μm and 80 μm. Although the CRCS sealer penetrated only up to the 35 mm point, it offered better or complete obturation of the dentinal tubules. The presence of smear layer at the root canal walls obstructed the penetration of all sealers into the dentinal tubules.

Completeness of Root Canal Obturations: Epiphany Techniques versus Gutta-Percha Techniques

“…Many studies have concluded that it is mandatory for its removal to attain proper penetration into dentinal tubules (17)(18)(19). Various regimens have been suggested for smear layer removal.…”

Time-dependent effects of chitosan on dentin structures

“…The presence of smear layer in the root canal favors the adhesion and colonization of microorganisms (1), in addition to impairing the action of disinfectant solutions (2) and the penetration of sealing cements through the dentinal tubules (3). For the effective removal of organic and inorganic components from the smear layer, irrigation with EDTA combined with different concentrations of sodium hypochlorite (NaOCl) has been recommended (4).…”

Comparative evaluation of push-out bond strength of a MTA-based root canal sealer

“…Some studies have shown that removal of the smear layer enhances the adhesion of sealers to the root canal wall [15][16] . The smear layer can act as a reservoir or substrate for microorganisms 17 , and can also block the extension of sealer tags into the dentinal tubules, thereby decreasing micromechanical adhesion 18 . In the current study, 17% EDTA was used after instrumentation to remove the smear layer.…”