Polymerisation characteristics of resin composites polymerised with different curing units

Objectives. The aim of this study was to compare the plasma arc light source Apollo 95E and the conventional halogen lamp Elipar Visio regarding a number of polymerisation characteristics of different resin composites. Methods. Four different resin composites (Arabesk Top, Herculite XRV, Pertac II, Tetric) were irradiated using the Apollo 95E unit for one, two or three cycles of 3 s and using the Elipar Visio unit for 40 s. The investigated polymerisation characteristics were: flexural strength and modulus of elasticity, bond strength to dentine, depth of polymerisation, and quantity of remaining double bonds. The data were treated statistically by analysis of variance and by Scheffé test. Results. The modulus of elasticity and the flexural strength resulting from curing with Apollo 95E for 1×3 s were equal to or less than those resulting from curing with Elipar Visio. The bond strength to dentine and the depth of polymerisation with Apollo 95E used for 1×3 s were equal to or less than that obtained with the conventional lamp, depending on the resin composite. Irradiation of Herculite XRV resulted in a higher quantity of remaining double bonds than did Elipar Visio. In general, two or three curing cycles of 3 s with Apollo 95E were necessary to produce mechanical properties not significantly worse than with 40 s of conventional curing. Conclusions. The efficiency of plasma arc curing with Apollo 95E strongly depends on the resin composite. For most resin composites tested, plasma arc curing for 3 s resulted in inferior mechanical properties as compared to conventional curing.