TY - JOUR
T1 - A method for assessing force/work parameters for stickiness of unset resin-composites
AU - Kaleem, Muhammad
AU - Satterthwaite, Julian D.
AU - Watts, David C.
PY - 2011/8
Y1 - 2011/8
N2 - Objectives: To evaluate the stickiness of unset resin-composites, at different speeds and temperatures, in terms of maximum probe separation-force (Fmax) and work-of-separation (Ws). Materials and methods: Eight commercial light-cured resin-composites were selected. Each material was placed in a cylindrical mold (φ = 7 mm × 5 mm depth) held at 25 °C or 37 °C. The maximum force (Fmax, N) and work probe separation (Ws, N mm) were measured by using a texture analyzer to register force/displacement. A flat-ended stainless-steel probe (φ = 6 mm) was mechanically lowered onto and into the surface of the unset sample. When a 'trigger' compressive force of 0.05 N was registered, data-acquisition commenced. Descent continued until a compressive force of 1 N was reached, which was held constant for 1 s. Then the probe was moved vertically upward at constant speed. This was varied over the range 2, 4, 6 and 8 mm/s. The tensile force produced on the probe by the sticky resin-composite was plotted against displacement and the maximum value was identified (Fmax). W s was obtained as the integrated area. Data was analyzed by multivariate ANOVA and multiple pair wise comparisons was done by using a Tukey post hoc test to establish homogenous subsets (at p = 0.05). Results: F max and Ws were taken as potential measures of stickiness. They ranged from 0.47 to 3.68 N and from 0.11 to 2.84 N mm, respectively. Multivariate ANOVA showed a strong interaction of withdrawal speed, temperature and materials on both Fmax and Ws (p <0.001). Conclusion: Fmax and Ws are useful parameters for characterizing the handling-stickiness of resin-composite materials, additional to previously reported stickiness-strain or 'peak-height'. The resin-composites investigated could be differentiated, mostly showing increases in F max and Ws stickiness with increased temperature and probe-withdrawal speed. © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
AB - Objectives: To evaluate the stickiness of unset resin-composites, at different speeds and temperatures, in terms of maximum probe separation-force (Fmax) and work-of-separation (Ws). Materials and methods: Eight commercial light-cured resin-composites were selected. Each material was placed in a cylindrical mold (φ = 7 mm × 5 mm depth) held at 25 °C or 37 °C. The maximum force (Fmax, N) and work probe separation (Ws, N mm) were measured by using a texture analyzer to register force/displacement. A flat-ended stainless-steel probe (φ = 6 mm) was mechanically lowered onto and into the surface of the unset sample. When a 'trigger' compressive force of 0.05 N was registered, data-acquisition commenced. Descent continued until a compressive force of 1 N was reached, which was held constant for 1 s. Then the probe was moved vertically upward at constant speed. This was varied over the range 2, 4, 6 and 8 mm/s. The tensile force produced on the probe by the sticky resin-composite was plotted against displacement and the maximum value was identified (Fmax). W s was obtained as the integrated area. Data was analyzed by multivariate ANOVA and multiple pair wise comparisons was done by using a Tukey post hoc test to establish homogenous subsets (at p = 0.05). Results: F max and Ws were taken as potential measures of stickiness. They ranged from 0.47 to 3.68 N and from 0.11 to 2.84 N mm, respectively. Multivariate ANOVA showed a strong interaction of withdrawal speed, temperature and materials on both Fmax and Ws (p <0.001). Conclusion: Fmax and Ws are useful parameters for characterizing the handling-stickiness of resin-composite materials, additional to previously reported stickiness-strain or 'peak-height'. The resin-composites investigated could be differentiated, mostly showing increases in F max and Ws stickiness with increased temperature and probe-withdrawal speed. © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.
KW - Handling characteristics
KW - Resin-composite
KW - Rheology
KW - Stickiness
UR - https://www.scopus.com/pages/publications/79959734012
U2 - 10.1016/j.dental.2011.04.005
DO - 10.1016/j.dental.2011.04.005
M3 - Article
VL - 27
SP - 805
EP - 810
JO - Dental Materials
JF - Dental Materials
IS - 8
ER -