A comparison of three light curing units for bonding adhesive pre-coated brackets

Abstract

Objective: To compare the effectiveness of three curing lights of different types.

Design: Prospective randomized laboratory investigations.

Materials and method: Adhesive pre-coated orthodontic brackets were bonded to 9 groups of extracted premolars and the adhesive was cured using three different curing lights, each at three different times. Bond strength was tested using a shear/peel method.

Results: The plasma light had 3 times the light intensity of the standard quartz halogen light. The curing times recommended by the manufacturers were 2 seconds for the plasma light, 10 seconds for the high intensity quartz halogen light and 20 seconds for the standard one. Mean debond stresses with these cure times were 9.36, 11.77 and 12.00 MPa, respectively, p<0.04. Increasing the plasma light cure to 4 seconds increased the mean debond stress to 11.19 MPa, similar to that for the other lights, p=0.62.

Conclusions: Use of a plasma light confers worthwhile time savings when bonding orthodontic brackets, whilst producing bonds of equivalent strength to those found with quartz halogen lights.

Keywords:

• Orthodontic adhesive
• light cure

Acknowledgments

We are grateful to 3M Unitek for providing materials used in this study. The Optilux 501 light was lent by Kerr UK.