In-vitro determination of residual monomer leaching by high performance liquid chromatography: light emitting diode versus halogen light

Abstract

Introduction: The long life span of light emitting diode (LED) and more consistent light output compared with halogens has resulted in greater use of LED in Orthodontics. Aim of present research was to compare the mean residual monomer (RMo) released from composites cured with LED or halogen lights.

Material and Methods: This in-vitro study was conducted at Department of Orthodontics, de’Montmorency College of Dentistry, Lahore. 150 extracted teeth were randomly divided into 2 groups of 75 teeth each, by lottery method. The selected teeth were cleansed of any debris, rinsed in distilled water and were stored in distilled water container. All teeth were embedded in cold cure fast set acrylic resin jig. In group 1, teeth brackets were cured with LED light source and in group 2, by halogen light. High performance liquid chromatography (HPLC) was used for estimating the mean amount of RMo release.  Independent t-test was used for comparison of mean release of RMo in both groups.  Level of significance was determined at p≤0.05.

Results: The mean value of RMo leaching was statistically greater in adhesives cured with halogen light group (94.67±3.13 ppm) then the LED source group (37.91±1.86 ppm). (P = 0.012)

Conclusions: LED lights are recommended in Orthodontic practice as the residual monomer leaching was significantly less as compared to the halogens.