Assessment of Shear Bond Strength of Orthodontic Brackets Bonded by Trans-illumination Method

Objective: To assess the clinical effectiveness of trans-illumination technique in bonding orthodontic brackets. Materials and method:  Forty premolars were arbitrarily divided into 4 groups. Bonding of brackets was done with 40- and 80-s light curing from the buccal or lingual aspect with different intensities. Shear bond strengths of brackets were measured using a universal testing machine. Collected data were analyzed statistically. Result: The highest shear bond was observed in group 2 (high intensity, 40 s, buccal) and the lowest found in group 3 (low intensity, 40 s, lingual). Conclusion:  In all experimental groups except group 2, shear bond strength was below the clinically accepted values. Doubling the curing time and increasing the light intensity during trans-illumination are recommended for achieving acceptable bond strengths