Light Intensity Decay in Quartz-Tungsten-Halogen Polymerization Units

摘要

>Objectives: The aim of this study was to determine the effect of ageing on the light intensity of quartz-tungsten-halogen (QTH) polymerization units in dental schools and dental clinics.>Materials & Methods: Two dental schools and multiple public health dental clinics were visited and the light intensity of curing units was assessed. The age, make, model and service history were recorded. A calibrated radiometer (range 0-1000 nm) was used to measure the light intensity of 171 QTH units. At the end of each visit, the team members provided each dental clinic with a verbal report of the test results and recommendations on maintenance of light polymerization units.>Results: The 171 units tested were from seven different manufacturers. The mean light intensity was 373.1 mW/cm², the lowest intensity being 95.3 and the highest 526.60 mW/cm². Only 29 QTH units recorded more than 500 mW/cm²; 102 units showed readings that ranged between 300 and 500 mW/cm² and 39 units recorded readings below 300 mW/cm². It was not able that one unit had light intensity reading of less than 100 mW/cm². The age distribution was as follows: 35 units were more than 10 years old, 79 were from 5 to 10 years old and 57 were less than 5 years old. There was a high statistical significant relation between the mean light intensity and age (P = 0.001).>Conclusion: Light intensity values used in some dental clinics were to be found lower than what is recommended for optimum polymerization of resin-based composite restorations. Awareness among dentists of the value of QTH light curing units and their commitment to care and maintenance are crucial to achieving optimum restoration properties.>How to cite this article: Al-Samadani KH, Al-Dharrab A, Wahbi MA , Algizani L. Light Intensity Decay in Quartz-Tungsten-Halogen Polymerization Units. J Int Oral Health 2013; 5(1):23-30.