This study evaluated the effects of nanofiller surface treatment and resin viscosity on the early and long-term properties of experimental hybrid composites. Three resin formulations (low, medium and high viscosity) were prepared by varying the ratio of TEGDMA:UDMA:bis-GMA (47:33:16wt%; 30:33:33wt%; 12:33:51wt%). Composites contained 71.3wt% silanated strontium glass (1-3μm) and 12.6wt% of either silanated or unsilanated silica (OX-50; 0.04μm). Specimens (n=10) for flexural strength, flexural modulus, fracture toughness and Knoop hardness were tested after 24h, 1 and 6 months exposure to water at 37°C. Degree of conversion (DC) was determined 24h after photoinitiation using FTIR. Resin viscosity only had a marginal influence on the mechanical response of composites but it can be adjusted to achieve a balance between DC and mechanical properties. Adding non-bonded nanofiller to hybrid composites had no systematic effect on DC. Non-bonded nanofillers had no significant effect on the long-term properties of hybrid composites.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Aug 1 2004|
ASJC Scopus subject areas
- Ceramics and Composites
- Mechanics of Materials