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In addition to halogen (HL) and plasma lamps, LED lamps (LED) claimed to be suitable for polymerizing composite are commercially available. The aim of the study was to compare the hardness profiles of test specimens made of composite. 92 test specimens (3x6x6mm) made of Herculite XRV® and 92 made of Filtec Supreme® were polymerized with a HL (Elipar II®) and with a LED (Elipar FreeLight II®), for a period of 40 sec. The Barcol hardness (BH) was measured after 5 min of polymerization and after 24 h, after 3 days and 20 days storage in Ringer solution at 37°C in the dark. The measuring points were 1 mm, 1.5 mm, 2 mm, 2.5 mm and 3 mm below the point at which light impacted the test specimen. The composite Herculite XRV® exhibited a significant (p≤0,05) to most significant (p≤0,001) higher BH with the polymerization of the HL at all times of the measurements than with the polymerization of the LED. Only with the polymerization after one day Herculite XRV® at two measuring points showed no significant (p>0,05) differences BH and at one measuring point showed the LED a significant (p≤0,05) higher BH. The composite Filtec Supreme® exhibited a very significant (p≤0,01) to most significant (p≤0,001) higher BH with the measurements after 5 min and 24 hours with the polymerization of the HL. The measurements after 3 days and 20 days showed to a large extent no significant (p>0,05) differences of the BH. Altogether the LED polymerization could not achieve equal results with the comparison of the hardness profiles.