Interaction of glass-ionomer cements with moist dentin.
Glass-ionomer cements (GICs) are regarded as aqueous gels made up of polyalkenoic acid salts containing ion-leachable glass fillers. The consequence of water permeation across the GIC-dentin interface is unknown. This study used SEM, field-emission/environmental SEM (FE-ESEM), and TEM to examine the ultrastructure of GIC-bonded moist dentin. Dentin surfaces bonded with 6 auto-cured GICs were examined along the fractured GIC-dentin interfaces. Additional specimens fractured 3 mm away from the interfaces were used as controls. SEM revealed spherical bodies along GIC-dentin interfaces that resembled hollow eggshells. FE-SEM depicted similar bodies with additional solid cores. Energy-dispersive x-ray analysis and TEM showed that the spherical bodies consisted of a silicon-rich GIC phase that was absent from the air-voids in the controls. The GIC inclusions near dentin surfaces result from a continuation of the GI reaction, within air-voids of the original polyalkenoate matrix, that occurred upon water diffusion from moist dentin.
Yiu
C K Y
CK
Paediatric Dentistry and Orthodontics, Faculty of Dentistry, University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong SAR, China.
Tay
F R
FR
King
N M
NM
Pashley
D H
DH
Sidhu
S K
SK
Neo
J C L
JC
Toledano
M
M
Wong
S L
SL
D000268:Adhesiveness; D001840:Dental Bonding; D018772:Dental Marginal Adaptation; D003804:Dentin / Q000737:chemistry* / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D004058:Diffusion; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D008863:Microspheres; D013499:Surface Properties; D014867:Water / Q000737:chemistry
D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D014867:Water