Influência da unidade de fotoativação na conversão de monômeros e alteração de cor de resinas compostas

Abstract

Introduction: The performance of resin based restorations is directly related to color stabilization after the curing process. When different types of light control units (LCU), polywave or monowave, are combined with composites containing different photoinitiators, such as camphorquinone (CQ) or diphenyl (2,4,6-trimethybenzoyl) phosphine oxide (TPO), the aestethic outcomes of the curing method can affect the longevity of direct restorations. Objectives: This study aimed to evaluate the color stability and the degree of conversion (DC) of two resin composites, containing different photoinitiators, cured with four different light sources. Methods: The units chosen were: Bluephase® G2 (IVOCLAR), Elipar ™ DeepCure (3M), Radii-cal ™ (SDI) and Valo ™ Grand (ULTRADENT). The composites evaluated were: Vit-L-Escence® (ULTRADENT) and Charisma® (Heraeus Kulzer), separated in 16 groups (n=5) of 2mm and 4mm thick. The samples were measured for color stability using a spectrophotometer (Vita Easyshade IV. Vita Zahnfabrik, BadSackingen, Germany). The DC was measured by Fourier-transformed infrared spectroscopy (FTIR), using a spectrometer (PerkinElmer Spectrum ONE FT-IR Spectrometer). The results were evaluated immediately after curing, 24 hours and 30 days later. Results: Valo™ Grand e Elipar™ showed the best results regarding ΔE mean values at 30 days analysis.: 1,8765 e 2,3120, respectively. Their performance were superior compared to Bluephase® G2 e Radii-cal™ (p<0,05). Conclusion: The combination of Valo ™ Grand and Elipar ™ LEDs, curing both resins at 2mm thick, showed the best color stability results on the follow-up periods