Influence of artificial aging: mechanical and physicochemical properties of dental composites under static and dynamic compression

Abstract

Objective The aim of the study was to evaluate the influence of filler content, degradation media and time on the mechanical properties of different dental composites after in vitro aging. Materials and Methods Specimens (1 mm3) of three commercially available composites (GrandioSO®, Arabesk Top®, Arabesk Flow®) with respect to their filler content were stored in artificial aging media: artificial saliva, ethanol (60%), lactic acid (pH 5) and citric acid (pH 5). Parameters (Vickers microhardness, compressive strength, elastic modulus, water sorption and solubility) were determined in their initial state (control group, n = 3 for microhardness, n = 5 for the other parameters) and after 14, 30, 90 and 180 days (n = 3 for microhardness, n = 5 for the other parameters for each composite group, time point and media). Specimens were also characterized with dynamic-mechanical-thermal analysis (compression tests, F = ± 7 N; f = 0.5 Hz, 1 Hz and 3.3 Hz; t = 0–170 °C). Results Incorporation of fillers with more than 80 w% leads to significantly better mechanical properties under static and dynamic compression tests and a better water sorption behavior, even after chemical degradation. The influence of degradation media and time is of subordinate importance for chemical degradation. Conclusion Although the investigated composites have a similar matrix, they showed different degradation behavior. Since dentine and enamel occur only in small layer thickness, a test specimen geometry with very small dimensions is recommended for direct comparison. Moreover, the use of compression tests to determine the mechanical parameters for the development of structure-compatible and functionally adapted composites makes sense as an additional standard. Clinical relevance Preferential use of highly filled composites for occlusal fillings is recommended.

Effect of contamination of bulk-fill flowable resin composite with different contaminants during packing on its surface microhardness and compressive strength: in vitro study

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Shade matching potential of one-shade resin composites used for restoration repair

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Disinfection and Isotonic Drinks’ Influence on Hardness and Color Stability of Ethylene-Vinyl-Acetate Copolymer Mouthguards Used in Martial Arts: An In Vitro Study

“…The environment of the oral cavity is difficult to replicate by in vitro experimental conditions-saliva has protective effects in moderating the extent of wear, abrasion and fatigue of restorative materials by interfering with the hydrolytic degradation process. The use of artificial saliva may be considered in material studies to mimic oral conditions [84][85][86]. However, the natural changes in saliva composition are still hard to duplicate in the research study, and solutions used in the literature have a different composition which may influence the achieved results [87].…”