Effect of the seating pressure on the adhesive bonding of indirect restorations.
OBJECTIVE
To evaluate the effect of two different techniques of seating pressure application on the adhesive-dentin bond of indirect restorations.


METHODS
Eight non-carious human third molars were randomly divided in two treatment groups (four teeth each). Cylindrical composite blocks were luted with a resin cement (Panavia F). In Group 1, the seating pressure was applied for 5 seconds. In Group 2, the resin cylinder was maintained under constant pressure during the entire 3-minute polymerization period of the resin cement. After storing in distilled water for 24 hours, 0.9 x 0.9 mm sticks were produced from these luted specimens for microtensile bond testing and SEM examination.


RESULTS
The Student t-test showed a significant difference (P < 0.05) in bond strength between Groups 1 and 2. SEM revealed the presence of structural defects and resin globules on the seating surface of the composites. These features were exclusively identified from Group 1 specimens and were probably caused by fluid transudation from the underlying dentin through the simplified self-etch adhesive (ED primer).
Chieffi
Nicoletta
N
Department of Restorative Dentistry and Dental Materials, University of Siena, Italy.
Chersoni
Stefano
S
Papacchini
Federica
F
Vano
Michele
M
Goracci
Cecilia
C
Davidson
Carel L
CL
Tay
Franklin R
FR
Ferrari
Marco
M
D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D003804:Dentin / Q000648:ultrastructure; D019234:Dentinal Fluid; D006801:Humans; D007284:Inlays; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D044367:Phase Transition; D011312:Pressure; D019279:Resin Cements; D013718:Tensile Strength
C438843:Panavia-Fluoro; D019279:Resin Cements