Effects of an endodontic auxiliary chemical substance on the bond strength of two methacrylate-based endodontic sealers to dentin.
OBJECTIVE
To evaluate the influence of irrigation protocols and drying procedures on the bond strength of two methacrylate-based sealers to dentin and the associated failure pattern using scanning electron microscopy (SEM).


METHODS
Fifty single-rooted human teeth were prepared with an irrigation protocol using either 5.25% sodium hypochlorite (NaOCl) or 2% chlorhexidine (CHX) and 17% EDTA (ethylenediaminetetraacetic acid) for smear layer removal. The following subgroups were also created based on drying of the root canal walls: paper points, the canals were blot dried with paper points with the last one appearing dry; or, ethanol, excess distilled water was removed with paper points followed by dehydration with 95% ethanol for 1 min and blotting with paper points. Each group was divided into two subgroups on the basis of the root canal sealer: EndoREZ and RealSeal SE. Bond strength was measured by the push-out test. The data were analyzed by ANOVA/Tukey HSD (α = 0.05). Failure patterns were classified as adhesive, cohesive, and mixed in the SEM analysis. The failure mode was evaluated by the chi-squared test (α = 0.05).


RESULTS
The roots irrigated with NaOCl showed significantly lower bond strength than the roots irrigated with CHX (p < .05). RealSeal SE showed higher bond strength when compared with EndoREZ (p < .05). The highest values of bond strength were in the CHX and ethanol groups with RealSeal SE (p < .05). An increase in adhesive failure was observed in the NaOCl and EDTA group.


CONCLUSIONS
The bond strength of both methacrylate-based sealers is influenced by the irrigant protocol.
Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Rio Grande do Sul, Brazil.
Roger Nicolini
RN
Fuzinatto
Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Rio Grande do Sul, Brazil.
Ana Paula
AP
Farina
Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Rio Grande do Sul, Brazil.
Matheus Albino
MA
Souza
Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Rio Grande do Sul, Brazil.
Daniela Cristina
DC
Miyagaki
Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, UNICAMP, Piracicaba, São Paulo, Brazil.
Caio Cézar
CC
Randi Ferraz
Department of Restorative Dentistry, Passo Fundo Dental School, University of Passo Fundo, UPF, Rio Grande do Sul, Brazil.
Doglas
http://orcid.org/0000-0001-8851-5233
D
Cecchin
D002710:Chlorhexidine / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D003786:Dental Pulp Cavity; D003804:Dentin / Q000737:chemistry; D006801:Humans; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010895:Pit and Fissure Sealants / Q000737:chemistry*; D012387:Root Canal Filling Materials / Q000737:chemistry; D012388:Root Canal Irrigants / Q000737:chemistry*; D012390:Root Canal Therapy / Q000379:methods*; D012973:Sodium Hypochlorite / Q000737:chemistry*; D014070:Tooth / Q000502:physiology; D014092:Tooth Root / Q000502:physiology
D003188:Composite Resins; D008689:Methacrylates; D010895:Pit and Fissure Sealants; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite; D002710:Chlorhexidine
chlorhexidine; ethanol; root canal filling materials; scanning electron microscopy; sodium hypochlorite