The morphology and stability of resin-modified glass-ionomer adhesive at the dentin/resin-based composite interface.
OBJECTIVE
To evaluate the interface with tooth structure, mode of failure and stability of Fuji Bond LC (FBLC) resin-modified glass-ionomer bonding system.


METHODS
The study was in three main parts. The first part with interfacial characteristics of FBLC. The micropermeability of the FBLC/dentin interface of restored cavities in extracted teeth, after fluorescent dye was introduced into the pulp chamber, was assessed by confocal microscopy. In other teeth, confocal microscopy was also used to examine trhe failure of FBLC bonded to flat dentin surfaces, on shear loading. In the second part, cervical cavities restored with FBLC (with and without light-curing) and a resin-based composite were examined for stability of the interface over the first 15 minutes. In the last part of the study, a new fluorescent dye was mixed with FBLC for restoration of cavities and subsequent examination using 2-photon imaging techniques.


RESULTS
FBLC adapted well to tooth structure, had an interface with dentin that was permeable to fluid and displayed the absorption layer. Shear loading at the dentin interface resulted in complex failure with areas of cohesive failure where the absorption layer was present. Light-curing of FBLC seemed to produce a stable restorative while "co-curing" resulted in an unstable situation, with the appearance of an emmisable exudate from the FBLC. Advanced fluorescent imaging of the material itself seemed to suggest that there was a movement of aluminum ions in a manner similar to other glass-ionomer cements. The presence of HEMA in the matrix of the cement associated with the absorption layer was also demonstrated.
Sidhu
Sharanbir K
SK
Department of Restorative Dentistry, Dental School, University of Newcastle, Newcastle upon Tyne, UK. S.K.Sidhu@ncl.ac.uk
Pilecki
Peter
P
Cheng
Ping-Chin
PC
Watson
Timothy F
TF
D000042:Absorption; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D000535:Aluminum / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation; D003782:Dental Pulp / Q000648:ultrastructure; D003804:Dentin / Q000648:ultrastructure*; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005456:Fluorescent Dyes; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008689:Methacrylates / Q000737:chemistry; D018613:Microscopy, Confocal; D010539:Permeability; D019279:Resin Cements / Q000737:chemistry*; D012235:Rhodamines; D013267:Stilbenes; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D019237:Tooth Cervix / Q000648:ultrastructure
C103290:4-(N-(2-hydroxyethyl)-N-(methyl)aminophenyl)-4'-(6-hydroxyhexylsulfonyl)stilbene; D000180:Acrylic Resins; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D005456:Fluorescent Dyes; D005899:Glass Ionomer Cements; D008689:Methacrylates; D019279:Resin Cements; D012235:Rhodamines; D013267:Stilbenes; C065770:Herculite XR; C084541:Fuji glass-ionomer lining cement; C006903:carbopol 940; C005044:hydroxyethyl methacrylate; D000535:Aluminum; C029773:rhodamine B