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Temperature‐dependent rheological property changes of thermoplastic gutta‐percha root filling materials
Author(s) -
Moon H. J.,
Lee J. H.,
Ahn J. H.,
Song H. J.,
Park Y. J.
Publication year - 2015
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/iej.12349
Subject(s) - gutta percha , materials science , composite material , penetration (warfare) , thermoplastic , rheology , materials testing , dentistry , medicine , mathematics , root canal , operations research
Aim To compare the penetration resistance ( PR ) of six thermoplastic gutta‐percha ( GP ) materials against needle penetration at different temperatures. Methodology The PR of the following materials based on warm gutta‐percha techniques, Beefill GP Cartridge (Beefill), GP Obturator‐Hard/Medium/Soft (Dia‐H, Dia‐M, Dia‐S), Obtura (Obtura) and Tactendo Gutta (Tactendo), was measured as a function of temperature change (from 30 °C to 200 °C). The PR was measured using a force gauge, mounted on a motor‐driven micrometre stage, which pushed the penetration needle against GP in a glass cylinder at the designated temperatures. Data were analysed using Kruskal–Wallis anova and Duncan's multiple range tests at 5% significance. Results The mean PR values for all assessed materials ranged from 15.55 MP a to 26.02 MP a at 30 °C, decreased to 0.18–1.61 MP a at 60 °C, and finally reached 0.02–0.12 MP a at 200 °C. The Obtura had the highest PR values at most of the measured temperatures. At 40–60 °C, Obtura had the highest PR value ( P < 0.05), and Tactendo had the lowest amongst the tested materials. At 70–200 °C, both the mean PR values and melt flow temperature ( MFR ) of Obtura, Dia‐H and Dia‐M were significantly higher than those of other materials ( P < 0.05). Conclusions The PR values were changed by both the heating temperature and the brand or type of GP materials tested. Each material was associated with drastic decreases before reaching 60 °C in different degrees, and Obtura had the highest PR at most of the measured temperatures.