Does an additional UV LED improve the degree of conversion and Knoop Hardness of light-shade composite resins?

• Published in: European journal of dentistry 2012-10, Vol.6 (4), p.396-401
• Main Authors: Giorgi, Maria Cecília Caldas, Aguiar, Flávio Henrique Baggio, Soares, Luís Luís, Martin, Airton Abrahão, Liporoni, Priscila Christiane Suzy, Paulillo, Luís Alexandre Maffei Sartini
• Format: Article
• Language: English
• Subjects: Original Article
• ISSN: 1305-7456; 1305-7464
• DOI: 10.1055/s-0039-1698978

ABSTRACT Objective: The purpose of this study was to evaluate the degree of conversion (DC) using FTRaman spectroscopy and the Knoop hardness (KHN) of composites cured by second and third-generation LED light curing-units (LCU), Radii Cal and Ultralume 5. Methods: Three composites (Filtek Supreme XT, Filtek Z350, and Esthet X) were selected for this study. KHN testing (n=10) was performed with 10 indentations for the top (T) and bottom (B) surfaces. For DC (n=10), both the T and B surfaces were analyzed. Results: For KHN, the three composites differed in hardens. There was a “LCU-surface” interaction, in which Radii Cal showed significantly greater hardens in the B surface. For DC, there was a “composite-surface-LCU” interaction. For the “composite” factor, there was no significant difference between the groups, except for Supreme XT-Radii Cal (T or B surfaces). For the “LCU” factor there was a significant difference for Supreme XT T surface, Ultralume 5 obtained a higher DC. For the Z350 T surface, a significant difference in the DC in which Radii Cal obtained better results. For the “surface” factor, all groups presented T surfaces with a higher DC than the B surfaces, the sole exceptions involved Esthet X-Radii Cal and Z350-Ultralume 5. Conclusion: Knowledge regarding composite composition and the characteristics of LCUs are important for effective polymerization. (Eur J Dent 2012;6:396-401)