Introduction: Lingual fixed retainers are one of the commonest retention appliances used today. However, wires may debond or break causing relapse. Sandblasting was introduced as a method of enhancing bonding of wires to avoid these shortcoming. Aim: The aim of this study was to evaluate the effect of enamel sandblasting before acid etching and wire sandblasting on the retention of two different lingual fixed retainers.
Materials and Methods: Fifty six acrylic blocks, each one contained two primary bovine incisor teeth contacting each others, were used in testing shear bond strength of 0.016x0.022 multistranded st.st. dead soft wire and twisted 0.032 coaxial wire. Blocks were divided equally into 2 main groups according to type of wire used; Each group was subdivided into 4 subgroups of 7 blocks to test the effect of sandblasting to either the wire or enamel on the shear bond strength of rectangular and round wire. Wires were bonded on lingual surfaces of teeth using Reliance LCR adhesive. Shear bond strength was tested using Instron testing machine.
Results: It was found that there was statistically significant difference between sandblasted wire bonded to non-sandblasted enamel and non-sandblasted wire bonded to sandblasted enamel for both types of wires. This showed that enamel sandblasting before acid etching didn't increase bond strength of non- sandblasted wires.
Conclusions: Sandblasted wires bonded to non-sandblasted enamel showed highest mean shear bond strength values over other groups. There was no significant difference in shear bond strength between both types of wires. Sandblasting enamel before acid etching didn't increase shear bond strength of the wires.