Influência do envelhecimento artificial acelerada sobre a estabilidade de cor, opacidade e densidade das ligações cruzadas de compósitos odontológicos armazenados em diferentes ambientes e tempos de armazenagem / Influence of artificial accelerated aging on color stability, opacity and cross-link density of dental composites stored in different environment and over different times
AUTOR(ES)
Fabrício Mariano Mundim
DATA DE PUBLICAÇÃO
2007
RESUMO
The evolution of composite resins, allied to their characteristic of restoring the natural appearance of teeth regarding color and opacity, makes them one of the main materials of choice among the restorative materials used in dentistry. Color and opacity stability assume a crucial role in a successful aesthetic restoration treatment, since changes in these characteristics may indicate the replacement of aesthetic restorations. These properties are associated with these materialsdegree of conversion at the moment of polymerization. The purpose of this study was to evaluate the influence of artificial accelerated aging on color stability, opacity, and density of cross-links in composites stored for 30 and 90 days in different environments (room temperature/refrigerator). Five dental composites were used, with two shades: light and dark. Composite packages were kept in room temperature (+/- 25ºC) and in a refrigerator (+/- 8ºC), for 30 and 90 days, for posterior specimen fabrication (12 mm in diameter / 2 mm thick). Specimens were subjected to readings for color change ( E), opacity (OP), and cross-link density, before and after artificial accelerated aging. Statistical analysis (2-way ANOVA - Tukey - level of significance at p<0.05), revealed that QuiXfil Universal, Tetric EvoCeram C3, and SR Adoro A2 composites presented clinically unacceptable color changes ( E 3.3). Regarding opacity, light shade direct resins presented less opacity compared to dark shades, whereas light shade indirect resins presented more opacity than dark ones. As to cross-link density, artificial accelerated aging increased crosslink density in direct resins. It is concluded that the materials did not behave homogenously, in terms of the studied properties, under the effects of storage time and environment. This suggests that the effects of aging are imperative and more relevant to material changes over time.
ASSUNTO(S)
artificial accelerated aging compósito opacidade opacity color stability estabilidade de cor densidade das ligações cruzadas crosslink density envelhecimento artificial acelerado composite
Documentos Relacionados
- Evaluation of color and opacity of direct composites protected with surface sealants submitted to accelerated artificial aging
- Color stability of modern composites subjected to different periods of accelerated artificial aging
- "In vitro" study of color stability and opacity of five ceramic systems under influence of accelerated aging
- Influence of ethanol concentration on softening tests for cross-link density evaluation of dental composites
- "Envelhecimento artificial acelerado - Influência na alteração de cor e rugosidade superficial de resinas indiretas"