This study aimed to investigate multiple aspects of composite resin polymerization as the degree of monomer conversion (DC), the kinetic parameters of polymerization and the determination of residual monomers TEGDMA and BisGMA, and evaluate the performance of light curing units. The experimental composites were manipulated by varying the photoinitiators R1-) camphorquinone/amine, R2-) PPD/amine, R3-) PPD + camphorquinone/ amine) and two devices were used for the polymerization I-) halogen lamp (Demetron LC / SDS Kerr, USA) and II-) LED (Poly 600/Kavo-Brasil) both with 600 mW cm -2 for 40 s. DC after 300 s and the kinetic parameters such as maximum rate of polymerization conversion (Rp max ), time of occurrence of the maximum rate of polymerisation (t max ) and the conversion occurred when Rp max were determined by infrared absorption spectroscopy in real time (RT-FTIR), the infrared spectrum was collected from the specimen (n=5) in order kinetics for 305 s, between 1680 and 1550 cm -1 . The first 5 scans were used to provide the collected absorption spectrum of the uncured resin (calculated DC). In the sixth scan, the curing unit was connected (by 40 seconds) while the spectrum continued to be collected up to 300 s after activation of the light. The presence of residual monomers (TEGDMA and BisGMA) was assessed by high performance liquid chromatography (HPLC), and the specimens (n=6) were immersed in acetonitrile (5 mL-24 h) with mechanical stirring, the method developed used: HPLC, C18 column, mobile phase A: water with triethylamine (0,05%) acidified with acetic acid (pH 4) and phase B: acetonitrile, gradient elution mode (40-85% -17 min/55 o C), flow 1 mL/min, UV detector at 210 nm, injection of 20 μL. Regarding the results of DC after 300s were the highest values for both R1 resin polymerized with LED (65.90% ±1.81) and with a halogen lamp (64.40% ±0.83), and lower values when the resin was found that R2 was polymerized by LED (35.64% ±1.73) and the only resin that showed significant differences in the sources of light was the R2. The values of the resins decreased Rp max who had PPD photoinitiator. The time of occurrence of the maximum rate of conversion (t max ) occurred more rapidly for the resin with CQ. And all resins showed values similar degree of conversion in t max . For HPLC results, the amount of monomer extracted (M/M%) ranged from 1.98% ±0.16 to 3.34% ±0.07 for the monomers of TEGDMA and 3.57% ±0.30 to 7.57% ±0.40 for the monomers BisGMA. Resin R2 showed the highest amount of residual monomers as polymerized with both sources, especially when polymerized with LED. Resins R1 and R3 had similar behavior for both curing units. In conclusion, the resin R3 can be a good choice, as compared with the resin obtained R1 advantages as reduction in Rp max as well as the time it occurred (t max ), and be suitably photoactivated with LED devices.