Light curing in orthodontics : should we be worried?

There were four aims to this study; to assess the profile of orthodontists, their light curing processes and knowledge of the appliances they use. To calculate the maximum permissible daily exposure times for a number of different types of currently available light curing units. To evaluate the effect of orthodontic brackets to the blue light hazard. To test the hypothesis that routine use of dental curing units may lead to problems with colour discrimination in clinicians, namely orthodontists, when compared with a non- dental control. A self administered questionnaire was designed to assess the profile of orthodontists and the procedures used for light curing. This was completed by 104 orthodontists. The maximum permissible daily exposure times of a variety of curing lights (8 LED, 2 Quartz Tungsten Halogen, and 1 plasma) were calculated at distances of 2cm, 10cm, 20cm, 30cm, 40 cm, 5Ocm and 60 using a spectroradiometer. A phantom head unit with acrylic teeth was used to assess the effect of different bracket materials (metal and aesthetic) on reflected light and the maximum daily exposure limits. The Farnsworth Munsell l00 hue test was used to assess the colour discrimination and deficiency of 15 orthodontists and 15 controls. The results demonstrate that Orthodontists knowledge about the properties of light curing units that are important for orthodontic bonding and safety is low. Blue light hazard decreases as distance from the eye increases. Current light curing units a-re unlikely to reach maximal daily exposure for blue light at normal working distances . • Orthodontic bracket materials do affect reflected light but the differences are unlikely to be of clinical significance. Continued use of current dental light curing units does not lead to problems with colour discrimination.EThOS - Electronic Theses Online ServiceGBUnited Kingdo