A Survey Of Power Density Of Clinical Curing-light Units Used In Changchun

Light-cured resin composites is a material widely used in oral clinical treatment and restorative.It has good physical and chemical properties such as beautiful color and strong plasticity.With the wide application of light-cured resin composites in oral clinical practice,research on light-curing technology is continually deepening,and the types and performances of light curing units are constantly being updated.At present,the quartz-tungsten-halogen,has been gradually replaced by light-emitting diode.Compared with the traditional curing lights,light-emitting diode lights has the advantages of portability,long life,less heat production and high curing efficiency.There are many factors affecting the curing effect of the resin composites,sufficient power density,sufficient curing time,and appropriate visible wavelength are three key factors for fully curing the resin composites.Therefore,sufficient power density is a key factors that doctors need to pay special attention during the clinical work.There have been many surveys on the power density of light curing units around the world.In 2010,our research team had reported the application of light curing units in Changchun.And this survey was designed to examine the types of curing lights and the power density in the same areas in Changchun after 8 years.Comparing with the results in 2011,this will be of great significance for the review and development of oral clinical use of light curing units in domestic cities.A total of 285 LED light curing units were investigated in 4 stomatology hospitals,10 department of stomatology in general hospitals,55 private dental offices.The investigation involved 56 brands,25 foreign brands and 3 1 domestic brands.The distribution of power density was from 121 to 1794 mW/cm2.The mean power density was 796 mW/cm.Most of the curing lights were equipped with only one light guide,and only 21 curing lights were equipped with two.The investigation showed that the mean number of years usage of the curing lights was 2.85 years,and the bivariate correlations of power density and the age of the light confirmed a negative correlation(r=-0.306,P<0.001).The mean operating frequency of the curing lights is 3.6 times every day.A positive correlation was recorded between the power density and operating frequency(r=0.105,P<0.05).90%of doctors fail to realize that the light curing units need regular testing and maintenance.They also lack of the relevant knowledge,such as the standard of the power density for clinical application,matters need attention,and the possible consequences of incomplete light curing,and so on.A survey of the efficiency of power density,the following conclusion could be drawn:1.LED curing lights is now commonly used in Changchun.2.The mean power density of light-curing units in Changchun was adequate for normal clinical requirements.The pass rate of power density is 93%(>400 mW/cm2),and the failure rate is 1%(<200 mW/cm2).3.At present,dentists are lack of the relevant knowledge of light curing units.The light guides are more seriously stained,and lack of the daily detection and maintenance.