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EFFECT OF LIGHT CURING UNIT CHARACTERISTICS ON LIGHT INTENSITY OUTPUT, DEPTH OF CURE AND SURFACE MICRO-HARDNESS OF
B A Kassim1, B K Kisumbi, W R Lesan
1Department of Conservative and Prosthetic Dentistry, College of Health Sciences, University of Nairobi, PO Box 19676-00202, Nairobi, Kenya.
East African Medical Journal
|February 11, 2016
Summary
The age of dental light curing units (LCUs) significantly impacts light intensity, but LCU type and maintenance history do not affect composite cure depth or surface hardness. Older LCUs show reduced performance.
Area of Science:
- Dental Materials Science
- Biomaterials Engineering
- Restorative Dentistry
Background:
- Dental composite restorations rely heavily on visible light curing devices.
- The performance characteristics of these light curing units (LCUs) can impact the quality of dental restorations.
Purpose of the Study:
- To evaluate the characteristics of light curing units (LCUs) used in Nairobi dental clinics.
- To determine the effect of LCU characteristics on light intensity, depth of cure (DOC), and surface micro-hardness (SMH) of dental resin composites.
Main Methods:
- A cross-sectional analytical study was conducted in public and private dental clinics in Nairobi, Kenya.
- Eighty-three in-use LCUs (43 LED, 39 QTH, 1 PAC) and resin composite specimens were analyzed.
- Light intensity, DOC, and SMH were measured and correlated with LCU type, age, and maintenance history.
Main Results:
- No significant difference in mean light intensity or DOC was found between Quartz-Tungsten-Halogen (QTH) and Light Emitting Diode (LED) LCUs.
- LED LCUs showed higher surface micro-hardness (SMH) compared to QTH.
- LCUs aged 5 years or less exhibited significantly higher light intensity compared to older units (>5 years).
Conclusions:
- LCU age is a significant factor influencing light intensity output.
- The type of LCU (LED vs. QTH) and its maintenance history did not significantly affect light intensity, DOC, or SMH.
- Older light curing units may compromise the quality of dental composite restorations due to reduced light intensity.
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