In vitro aging of dental composites in water-Effect of degree of conversion, filler volume, and filler/matrix coupling

• Published in: Journal of biomedical materials research 1998-12, Vol.42 (3), p.465-472
• Main Authors: Ferracane, J. L., Berge, H. X., Condon, J. R.
• Format: Article
• Language: English
• Subjects: aging; Biological and medical sciences; Composite Resins - chemistry; dental composite; elastic modulus; Ent and stomatology; fracture toughness; hardness; Materials Testing; Medical sciences; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Stomatology; strength; Technology. Biomaterials. Equipments. Material. Instrumentation; Water - chemistry
• ISSN: 0021-9304; 1097-4636
• DOI: 10.1002/(SICI)1097-4636(19981205)42:3<465::AID-JBM17>3.0.CO;2-F

The purpose of this study was to evaluate the long‐term effect of aging in water on the physical properties of experimental composites having systematically controlled differences in degree of conversion (DC), filler volume fraction (Vf), and percentage of silane‐treated fillers. Composites were made with a 50% Bis‐GMA:50% TEGDMA light‐cured resin and a 1–2 μm (average size) strontium glass filler (+ 5 wt% SiO2 microfiller). For composites A–E, the DC was varied from 56–66% by changing the curing time; for D and F–I, the Vf was varied from 28–62 vol%; and for D and J–M, the percent of fillers with a silane coupling agent (γ‐MPS) was varied from 20–100%. Fracture toughness (KIc), flexure strength (FS), elastic modulus (E), and hardness (KHN) were tested after soaking in water at 37°C for 1 day, 6 months, 1 year, and 2 years. The KIc was reduced 20–30% for all composites after 6 months, with minimal changes thereafter. The FS was reduced for several composites at 6 months, but only those with poor cure (A and B) were lower at 2 years than they were initially. The E was not reduced for most composites. Hardness was reduced for most composites after 6 months, but many returned to their original levels at 2 years. Long‐term aging in water caused a reduction in the KIc, independent of composition, but had little effect on other properties, suggesting limited degradation of composites in water. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 42, 465–472, 1998.