A comparison of the shear bond strength of composite resin bonded by a fourth and a fifth generation dental adhesive to bovine teeth.
OBJECTIVE
This study compared the shear bond strengths, to bovine enamel and dentine, of composite resin bonded using an established bonding agent (Syntac) and the more recent Syntac SC.


METHODS
A total of 24 adult bovine incisors were divided into two equal groups and prepared by roughening the enamel surfaces with a medium-grit, high-speed diamond. The enamel was etched and 24 x 5 mm diameter composite discs were light-cured and bonded using Syntac and 24 using Syntac SC, following the manufacturer's instructions. The samples were shear tested 72 hours later at a crosshead speed of 50 mm/min using a Howden Universal Testing Machine. The labial enamel and 1 mm of dentine were removed and the experiment was repeated.


RESULTS
The mean shear bond strengths (MPa) for the Syntac and Syntac SC bonded composite to enamel were 10.9 +/- 4.5 and 8.9 +/- 5.7, and to dentine 6.4 +/- 3.2 and 5.5 +/- 3.1, respectively. The differences between the values for each material on enamel and between each material on dentine were not significant (P > 0.01). However, nine (19%) Syntac SC bonded composite discs debonded during build-up and had to be remade, prior to testing.


CONCLUSIONS
When a bond between composite and resin was achieved, no significant difference was found between the mean shear bond strengths of Syntac and Syntac SC bonded composite to either enamel or dentine. However, lack of composite adherence to the Syntac SC was noted during the preparation of specimens.
Davies
B
B
Conservation Department, GKT Dental Institute, King's College, London.
Dunne
S M
SM
Mokhtari
M
M
Nicholson
J
J
D000818:Animals; D002417:Cattle; D003188:Composite Resins; D001840:Dental Bonding; D017220:Dentin-Bonding Agents; D008422:Materials Testing; D019279:Resin Cements; D013718:Tensile Strength
D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C078484:Syntac dentine adhesive