Abstract
Objectives. The objective of this study was to report on a novel phenomenon that occurs when resin-modified glass-ionomer cements (RMGICs) are bonded to moist human dentine. Methods. Dentine surfaces from extracted third molars were abraded with 180-grit SiC paper. Ten teeth were prepared for each of the two RMGICs tested (Fuji II LC, GC Corp. and Photac-Fil Quick, 3M ESPE). RMGIC buildups were made according to the manufacturers' instructions. After storage at 37°C, 100% humidity for 24 h, the bonded specimens were cut occlusogingivally into 0.9×0.9 mm beams. Dentine surfaces bonded with the two RMGICs were examined along the fractured RMGIC/dentine interfaces. Additional beams fractured within the RMGICS and at 3 mm away from the interfaces were used as controls. The fractured beams were examined using scanning electron microscopy (SEM), field emission-environmental SEM (FE-ESEM) and transmission electron microscopy (TEM). Results. SEM and FE-ESEM revealed numerous solid spherical bodies along the RMGIC/dentine interfaces. By contrast, no spherical bodies could be identified within the RMGIC fractured 3 mm distant from the bonded interface. TEM and energy dispersive X-ray analyses performed on carbon-coated ultrathin sections showed that these solid spherical bodies consisted of a thin aluminum and silicon-rich periphery and an amorphous hydrocarbon core within the air voids of the original resin matrix. Conclusion. The spherical bodies probably represent a continuation of GI reaction and poly(HEMA) hydrogel formation that results from water diffusion from the underlying moist dentine. Their existence provides evidence for the permeation of water through RMGIC/dentine interfaces.
Original language | English (US) |
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Pages (from-to) | 521-530 |
Number of pages | 10 |
Journal | Journal of Dentistry |
Volume | 32 |
Issue number | 7 |
DOIs | |
State | Published - Sep 2004 |
Externally published | Yes |
Keywords
- Dentine
- Interface
- Permeability
- Resin-modified glass-ionomer cement
- Water movement
ASJC Scopus subject areas
- General Dentistry