Shear bond strength of adhesive to KrF excimer laser treated enamel

The bond strength of resin composite bonded to enamel surfaces treated with KrF excimer laser radiation, acid-etched surfaces and laser treated surfaces subjected to acid-etching was studied using a single plane shear method. Enamel specimens were prepared from freshly extracted healthy incisors. The specimens were subjected to laser treatment with a KrF excimer laser (248 nm) using a fluence of 4 J/cm². The bond strength to acid-etched specimens was greater than laser treated specimens. In contrast, bond strength to laser treated specimens subjected to acid-etching was comparable to those obtained with acid-etched specimens. The analogous bond strength to these specimens as compared to acid etched specimens was probably due to a shift from adhesive to mixed rupture mechanism.