Effectiveness of four different light-activated composites cure with different curing modes

Abstract EN

Background: Light-activated resin composites, introduced in the 1970s, revolutionized clinical dentistry by maximizing working time and minimizing setting time.

This study investigated the influence of different new curing modes on the effectiveness of cure of different light- activated composites to examine their efficacy in satisfying composite adequate polymerization.

Materials and methods: This study investigated the hardness of the top/bottom surfaces and hardness ratio of two mm thick composite specimens after exposure to different curing modes.

Parameters included six curing modes: Control (C), Pulse Delay I (PDI), Pulse Delay II (PDII), Soft-start (SS), Pulse Cure I (PCI), and Pulse Cure II (PCII) plus three experimental curing modes of higher energy density: Prolonged low-intensity pulse cure mode (PLPC), Prolonged moderate-intensity pulse cure mode (PMPC) and Rapid high-intensity continues cure mode (RHCC) for each of the four different light-activated composite materials (Tetric Ceram, Heliomolar, Herculite XRV and Degufill Mineral).

Results: There was very high significant difference for all the hardness ratios with the curing modes except the hardness ratio of Heliomolar composite where, there was an insignificant difference because, the mean hardness ratio of Heliomolar composite with the first six curing modes (control, PDI, PDII, SS, PCI, PCII) was not calculated because of the poor polymerization of Heliomolar bottom surfaces with these six curing modes.

Conclusion: This study indicated that, clinical usage of Control, PDI, PDII, SS, PCI and PCII curing-modes is not advocated to cure Heliomolar and Degufill Mineral composites while the experimental curing modes (PLPL, PMPC and RHCC) satisfied effectiveness of composite cure for all the composites being tested.

Key words: Resin composite, light curing modes, microhardness.

(J Bagh Coll Dentistry 2007; 19(1)11-15)