Resin-dentin interface of Scotchbond Multi-Purpose dentin adhesive.
OBJECTIVE
To evaluate the interface between dentin, Scotchbond Multi-Purpose (SMP), and resin composite (Z100) using confocal fluorescence microscopy.


METHODS
Novel techniques were employed to view and record at video rate the application of the SMP primer and adhesive onto the dentin surface. The subsurface morphology of the dentin/restorative interface was also studied. To facilitate this study, the components of the adhesive system were labeled with fluorescent dyes.


RESULTS
In an ideal situation, the primer and adhesive penetrated the dentin tubules, a distinct hybrid zone was formed and a thin layer of adhesive was observed at the interfacial region. However, the primed dentin surface was sensitive to disruption by the adhesive application brush during its placement, so that parts of the primer layer could be incorporated into the adhesive. This disruption could only be seen using confocal microscopy and a fluorescence labeling technique. Delamination of the primer layer was not observed when the adhesive film was thinned by air blowing. The application of an air stream to the cavity surface increased the penetration of the primer and adhesive along the dentin tubules, but also increased the thickness of the adhesive within irregularities on the cavity surface and at the cavity line angle. The cause of the problems in the handling properties of SMP may be the difference in viscosity between the two components (primer and adhesive) at the adhesive interface.
Griffiths
B M
BM
Department of Conservative Dentistry, United Medical and Dental Schools, Guy's Hospital, London, United Kingdom.
Watson
T F
TF
D003188:Composite Resins; D003804:Dentin / Q000378:metabolism; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D019279:Resin Cements; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D014783:Viscosity; D015040:Zirconium / Q000737:chemistry*
D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; D012822:Silicon Dioxide; D015040:Zirconium