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A study of the rheological properties of endodontic sealers
Author(s) -
Lacey S.,
Pitt Ford T. R.,
Watson T. F.,
Sherriff M.
Publication year - 2005
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/j.1365-2591.2005.00953.x
Subject(s) - materials science , grossman , composite material , capillary action , rheology , rheometer , significant difference , viscosity , mathematics , statistics , keynesian economics , economics
Aim To test the hypothesis that there would be no statistically significant difference in viscosity‐related measures of endodontic sealers or change in these with strain rate, internal diameter or powder : liquid ratio in a capillary system. Methodology Materials used were Apexit, Tubliseal EWT, Grossman's sealer and Ketac‐endo. Viscosity‐related measures were tested in a two‐plate test, and in a capillary rheometer. The mean values ( n = 12) for thickness and diameter of material formed between two glass plates were tested with one‐way analysis of variance. Pressure was applied to a capillary rheometer at strain rates 5 and 10 mm min −1 in tubes of internal diameter 0.6 and 1.2 mm. Results Tubliseal EWT had a thinner film thickness than the other sealers ( α = 0.05). The difference in diameter between Tubliseal EWT and the other sealers was significant apart from Apexit. Increased strain rate gave a significant increase ( α = 0.05) in the flow of all sealers. Narrower tubes produced increased velocity, which was significant for all sealers, and reduced volumetric flow, which was significant for all sealers except Grossman's 2 : 1 (Wilcoxon signed rank test). Reduction in powder : liquid ratio of Grossman's significantly increased flow in narrow tubes and at higher strain rate (Mann–Whitney test). Conclusion There was a significant difference between the flow of Tubliseal EWT and the other sealers tested in the two‐plate test; capillary flow was affected by sealer, internal diameter, strain rate and powder : liquid ratio. The null hypotheses were rejected.