Bracket Bond Strength with Transillumination of a Light Activated Orthodontic Adhesive and the Effect of Curing Time and Tooth Thickness on it: An in vitro Study

Abstract

Objective: This study was conducted to compare the shear bond strength of brackets bonded with the conventional technique, transillumination technique and the combination of both the techniques; the effect of curing time on the bond strength of the brackets bonded with the transillumination method; and the amount of light passing through different thickness of teeth. Materials and methods:The study was conducted in vitro on 175 extracted human teeth (50 incisors and 125 premolars). In the first part of the study, the amount of light passing through different thickness of teeth was studied and, for second part, brackets were bonded with transillumination method and conventional method followed by shear bond strength testing using an instron machine. Results:The amount of light passing through the tooth depends on the thickness of the tooth. Only a small fraction of the original light intensity passes through the tooth but this is adequate to achieve clinically acceptable bond strengths.The bond strength achieved with transillumination method is comparable to the conventional light cure technique. Ten seconds of transillumination followed by conventional curing leads to an increase in bond strength and this increase is clinically significant. Conclusion:Transillumination technique is a viable method for bonding orthodontic attachments.