engleski

Polymerization kinetics of composites cured by low intensity blue superbright LED's

Previous studies have shown many disadvantages of standard curing units influencing some important clinical properties of composite fillingsThe objective of this investigation was to evaluate the degree of conversion and temperature rise in composite samples illuminated by blue superbright light emitting diodes (LED) (Nichia, Japancompared to the conventional halogen lamps Heliolux GTE and Elipar Highlight. The temperature rise in the specimens was tested after 20 and 40 seconds polymerization using METEX Model M-3850D multimetar. The temperature rise of samples cured by blue LED varied from 4 to 11°C while for halogen lamps ranged from 8 to 17°C. The results of degree of conversion were obtained on the surface and at the deepth of 1.0 mm and were lower approximately 10% in case of even 66 times weaker blue LED. All the measurements were repeated five times. Statistics were performed using analysys of variance. The results obtained with experimental light source of minimal intensity were promising especially concerning low temperature rise in the samples.However, it is necessary to use more blue LEDs of 470 nm and focusing their light to ensure sufficient light intensity for improved curing. This study was supported by the Ministry of Science and Technology of the Republic of the Croatia.

degree of conversion; composite resin; polymerization

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