The effect of the blue light diode laser on shear-peel bond strength of orthodontic brackets with varying curing time and distance

THE EFFECT OF THE BLUE LIGHT DIODE LASER ON SHEAR-PEEL BOND STRENGTH OF ORTHODONTIC BRACKETS WITH VARYING CURING TIME AND DISTANCE Kamran Shaikh, DDS June 17,2010 Background: Light cured composite resin can be time consuming for bonding orthodontic brackets. A new Blue light diode laser may reduce curing times for composite resins. Hypothesis: The laser will achieve similar bond strengths in half the time and at greater distances as the LED. Methods: 90 extracted premolars will be bonded and cured using Laser and LED curing units at varying times, another 120 extracted premolars will be bonded and cured at varying distances. An Instron machine will be used to test shear bond strength. Results: The laser was not able to achieve similar bond strengths as the LED curing light in half of the curing time. At 5 seconds, the laser had 35% lower bond strengths but was still in the clinically acceptable range. The laser achieved similar bond strengths when the curing tip was at greater distances as when it was close to the bracket-adhesive-tooth interface.