T. Brosh et al., EFFECT OF COMBINATIONS OF SURFACE TREATMENTS AND BONDING AGENTS ON THE BOND STRENGTH OF REPAIRED COMPOSITES, The Journal of prosthetic dentistry, 77(2), 1997, pp. 122-126
Statement of problem. Enhancement of bond strength between new and old
composite usually requires increasing the surface roughness to promot
e mechanical interlocking and coating of old composite with unfilled r
esin bonding agents to advance surface wetting and chemical bonding. P
urpose. The purpose of this study was to evaluate the effect of combin
ations of surface treatments and bonding agents on the shear bond stre
ngth between new and old composite. Material and methods. Sis surface
treatments, two bonding agents, and an untreated control comprised 18
different subgroups. Results. The use of unfilled resin, alone or comb
ined with silane, was the most effective procedure to enhance the shea
r bond strength of the repaired composite specimens, irrespective of t
he surface pretreatment processes. Silanation and unfilled resin sligh
tly but not significantly improved the repair strength compared with u
nfilled resin alone. Conclusions. Different combinations of surface tr
eatments and bonding agents affect shear bond strength differently. Th
e highest shear bond strength values were achieved by grinding the sur
face with green Carborundum stone or sandblasting, whereas the lowest
values were obtained with hydrofluoric acid as the surface treatment a
gent.