Effect of DPSS laser on the shear bond strength of orthodontic brackets.

PURPOSE

To test the bonding of orthodontic brackets to teeth using a diode-pumped solid state (DPSS) laser.

METHODS

A total of 60 extracted human teeth were divided randomly into four groups: Group 1 (control)--he brackets were bonded to teeth using the quartz-tungsten-halogen (QTH) light (800 mW/cm2) for 40 seconds; Groups 2-4--the brackets were bonded to teeth using the DPSS laser (500 mW/cm2) for 40 seconds, 20 seconds, and 10 seconds, respectively. The teeth were debonded using shear force in a universal testing machine, and the amount of residual adhesive remaining on each tooth was evaluated. Statistical analysis was carried out for the shear bond strength (SBS) and Adhesive Remnant Index (ARI).

RESULTS

The brackets bonded using the DPSS laser for 40 seconds showed the highest mean SBS (13.1 +/- 1.2 MPa) among the groups. Furthermore, the DPSS laser with 10 seconds light-curing could achieve 83% of the mean SBS obtained using the QTH light for 40 seconds. The ARI scores showed no differences among all four groups suggesting a similar failure mode.