Comparison of bond strength by plasma-xenon arc curing system in relation to L.E.D and conventional light curing system for orthodontic attachments: An in-vitro study

Abstract

Aim : The study was aimed to evaluate efficacy of plasma arc curing light in reducing curing time as claimed by manufacturer, without compromising bond strength and compare it with LED and Tungsten Halogen Light (conventional light cure) at different curing times. Methods : One hundred and twenty human premolars extracted for orthodontic treatment purpose were taken and divided into three groups: group 1(conventional cure, 45 teeth), group 2(LED, 30 teeth) and group 3(plasma arc, 45 teeth). The groups were further subdivided into subgroups of 15 samples each for different curing periods.The shear bond strength was tested on a universal testing machine. Results : Shear bond strength for the three groups were; Group 1A(conventional cure 20sec):7.71MPa, Group 1B (conventional cure 40sec):12.56MPa,Group 1C(conventional cure 60sec):13.20MPa ,Group 2A(LED 20sec):12.27MPa ,Group 2B(LED 30 sec):14.90MPa ,Group 3A(plasma arc 4sec):9.39MPa, Group 3B(plasma arc 6 sec): 13.11 MPa, Group 3C(plasma arc 10sec):16.7 MPa. The total exposure time required by different curing systems was evaluated. Analyses of variance indicated no significant difference in intra group or inter group values. Student ttest were performed to evaluate the difference in the means of different subgroup.Z test was done to check the difference in the total exposure times of different light curing units. The mean shear bond strengths of different subgroups were more than the minimal required bond strength. Conclusion : plasma arc curing system saved a significant amount of time without compromising on bond strength.