Background: The purpose of this study was to determine the effect of water
on the tensile strength of three bonding resins (All Bond 2, Scotchbond Mul
ti-Purpose Adhesive, Clearfil LB Bond) and a low viscosity resin composite
(Protect Liner F) after 1, 7, 28, 84 and 168 days of storage.
Methods: Cylinders of bonding resin 2.4 +/-0.2mm diameter and 9.5mm long we
re made and stored at 37 degreesC for 24 hours. The specimens were milled i
nto dumb-bell shapes and stored in either air or water at 37 degreesC. Five
specimens of each material were stressed in tension after the specified st
orage times at a crosshead speed of 1mm/min in a testing jig attached to a
universal testing machine. The mean tensile strengths of bonding resins wer
e calculated and analysed statistically using one-way analysis of variance,
lower standard deviation and student t-tests.
Results: Comparison of the air and water samples at all test periods showed
the tensile strengths of specimens stored in water were significantly less
than those stored in air (P <0.001).
Conclusion: The effect of water on the tensile strength of bonding resins i
ndicated a slight decrease in strength of each material over the 168 day te
st period, whereas the air samples showed little change over the test perio
d.