Objectives: The aims of this study are to evaluate the influence of aging conditions on the elastic properties of resin-based materials over the narrow mouth temperature range, and to establish a relation between percentages of fillers and elastic moduli.

Methods: Five specimens of Arabesk Top (56%)*, Grandio (87%)* and Vita Zeta LC (44.3%)* were prepared for each stock medium and storage time. The samples were stored in air or distilled water at 37°C, for 7 or 90 days, or immediately tested (Control).

The Dynamic Mechanical Analysis of the composite materials was carried out using a TA Instruments DMA Q800. The samples were subjected to an stepped isothermal test with frequency sweep, where a series of pre-selected frequencies (0.1, 1, 2, 5 and 10 Hz) was scanned at constant temperatures between 5-55°C.

* Wt.% filler.

Results: Means (SD) of storage modulus (GPa) at 1 Hz.

 

Material	Control		7 Days				90 Days
			Air		Water		Air		Water
	5°C	55°C	5°C	55°C	5°C	55°C	5°C	55°C	5°C	55°C
Arabesk	10.4a (0.2)	6.3b (0.5)	12.0 (0.2)	7.4c (0.4)	11.3 (0.1)	6.6b (0.3)	12.6 (0.4)	8.6  (0.8)	10.5a (0.1)	6.6b,c (0.6)
Grandio	16.1 (0.2)	12.9d  (0.8)	18.6 (0.2)	15.0e (0.2)	17.0 (0.2)	13.5d (0.2)	17.9f (0.3)	14.8e,g   (0.3)	17.6f (0.4)	14.3g (0.5)
Vita        Zeta	4.4 (0.1)	2.3  (0.0)	6.5h (0.3)	3.1i (0.2)	5.6 (0.2)	2.9i  (0.2)	7.0 (0.0)	4.6  (0.1)	6.1h (0.3)	3.5  (0.1)

 

Statistical significance between all aging groups was tested for each material by t-tests at a test level of p=0.05. Also the association between percentages of fillers and elastic moduli was assessed by calculating correlations. Same superscripts indicate no statistical significance. 

Conclusions: The elastic moduli correlated significantly with the percentages of fillers, generally increased with air storage and were negatively affected by water aging and higher temperatures.

Supported by Vita Zahnfabrik and CAPES.