The ultrastructure of a compomer adhesive interface in enamel and dentin, and its marginal adaptation under dentinal fluid as compared to that of a composite.
OBJECTIVE
To visualise the ultrastructure of the interface of SCA compomer adhesive and of Optibond composite adhesive in enamel and dentin, and to relate the findings to the marginal adaptation of these two products in mixed class V restorations.


METHODS
The ultrastructure was investigated using a scanning electron microscope (SEM) with and without prior argon ion etching, an environmental SEM, a field emission SEM, a confocal laser scanning microscope, and a transmission electron microscope. The marginal adaptation was quantified in mixed class V restorations by using the replica technique and a SEM under simulated dentinal fluid before and after simultaneous mechanical and thermal loading.


RESULTS
The ultrastructure of the compomer adhesive interface differed from those of the composite. However, no significant difference was discerned as regards the percentage of "continuous margin" in the enamel marginal area before loading, and in the dentin area before and after loading (p < 0.05; unpaired t-test). Only after loading, the percentage of "continuous margin" in enamel was significantly (p < 0.05; unpaired t-test) better than that of the compomer.


CONCLUSIONS
The results indicated that the ultrastructure of the adhesive interface allowed no clear conclusions to be drawn as to the quality of marginal adaptation.
Krejci
I
I
University of Geneva, Dental School, Division of Cariology, Endodontology and Pediatric Dentistry, Switzerland. ivo.krejci@medecine.unige.ch
Schüpbach
P
P
Balmelli
F
F
Lutz
F
F
D020770:Compomers / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008963:Molar; D019279:Resin Cements / Q000737:chemistry
C105428:Compoglass; D020770:Compomers; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; C092987:Optibond; D019279:Resin Cements; C078484:Syntac dentine adhesive; C065770:Herculite XR