Adhesion of an endodontic sealer to dentin and gutta-percha: shear and push-out bond strength measurements and SEM analysis
AUTOR(ES)
Teixeira, Cleonice Silveira, Alfredo, Edson, Thomé, Luis Henrique de Camargo, Gariba-Silva, Ricardo, Silva-Sousa, Yara T. Correa, Sousa-Neto, Manoel Damião
FONTE
Journal of Applied Oral Science
DATA DE PUBLICAÇÃO
2009-04
RESUMO
The use of an adequate method for evaluation of the adhesion of root canal filling materials provides more reliable results to allow comparison of the materials and substantiate their clinical choice. The aims of this study were to compare the shear bond strength (SBS) test and push-out test for evaluation of the adhesion of an epoxy-based endodontic sealer (AH Plus) to dentin and gutta-percha, and to assess the failure modes on the debonded surfaces by means of scanning electron microscopy (SEM). Three groups were established (n=7): in group 1, root cylinders obtained from human canines were embedded in acrylic resin and had their canals prepared and filled with sealer; in group 2, longitudinal sections of dentin cylinders were embedded in resin with the canal surface smoothed and turned upwards; in group 3, gutta-percha cylinders were embedded in resin. Polyethylene tubes filled with sealer were positioned on the polished surface of the specimens (groups 2 and 3). The push-out test (group 1) and the SBS test (groups 2 and 3) were performed in an Instron universal testing machine running at crosshead speed of 1 mm/min. Means (±SD) in MPa were: G1 (8.8±1.13), G2 (5.9±1.05) and G3 (3.8±0.55). Statistical analysis by ANOVA and Student's t-test (a=0.05) revealed statistically significant differences (p<0.01) among the groups. SEM analysis showed a predominance of adhesive and mixed failures of AH Plus sealer. The tested surface affected significantly the results with the sealer reaching higher bond strength to dentin than to gutta-percha with the SBS test. The comparison of the employed methodologies showed that the SBS test produced significantly lower bond strength values than the push-out test, was skilful in determining the adhesion of AH Plus sealer to dentin and gutta-percha, and required specimens that could be easily prepared for SEM, presenting as a viable alternative for further experiments.
Documentos Relacionados
- Bond strength of different endodontic sealers to dentin: push-out test
- Effect of calcium hydroxide dressing on push-out bond strength of endodontic sealers to root canal dentin
- Correlation between Bond Strength to Dentin and Sealers Penetration by Push-Out Test and CLSM Analysis
- Effect of different endodontic sealers on push-out bond strength of fiber posts
- Push-out bond strength of different tricalcium silicate-based filling materials to root dentin