Quality of Root-Dentin Sealing Provided by Resin-Based Endodontic Fillings

Objective: This study evaluated the immediate and long-term ability of conventional versus “adhesive” root canal filling materials to seal the root-dentin. Methods: Eighty-two human root canals received chemo-mechanical preparation and irrigation with 5.25% NaOCl+17% EDTA. Root canal filling was performed with non-adhesive materials (AH Plus/gutta-percha) or with an adhesive, resin-based system (Epiphany/Resilon). After filling, teeth were coronally sealed with a temporary material (Coltosol) or with adhesive/resin composite (Clearfil SE Bond/Filtek Z250). Negative controls were left without coronal seal. Quality of root-dentin sealing was assessed by a fluid conductance (FC) method, performed either after sealer setting (immediate) or after 6-month storage at 37^oC in humid environment. Results: Mean FC of Epiphany/Resilon obturated specimens was higher than AH Plus/gutta-percha filled specimens (ANOVA R, Tukey`s post hoc, p<0.05), regardless of coronal sealing condition or period of FC evaluation. Specimens without any coronal sealing presented higher FC than those sealed with Coltosol or Clearfil/Filtek Z250 (p<0.05). No difference was observed for the coronal sealing provided by Coltosol and Clearfil/Filtek Z250. Significant decrease (paired observations test, p<0.05) in FC after 6-month storage was observed for roots filled with AH Plus/gutta-percha either without coronal sealing or sealed with Coltosol, as well as for roots filled with Epiphany/Resilon without coronal sealing. Conclusions: Conventional non-adhesive sealer/gutta-percha provides better immediate and long-term seal than the so-called adhesive, resin-based endodontic system. The presence of a coronal seal reduced significantly the FC of the specimens. Storage of root-filled specimens for 6 months did not cause loss of sealing ability of the tested materials. Supported, in part, by CAPES, FAPESP-05/53996-0 and CNPq473164/2007-8.