Objectives: The aim of this study was to evaluate how different light curing sources influence the degree of conversion (DC) of two composite cements used to lute indirect composite restorations of increasing thickness. Methods: 120 cylindrical onlays (Signum composite – Heraeus - shade A2, 6mm of diameter) of different thickness (2mm, 3mm, 4 mm) were prepared in a custom template. The specimens were divided into three groups (N=40) and luted with different LED light sources (Bluephase C8-Ivoclar Vivadent 800mW/cm2*s for 60s, Bluephase G2-Ivoclar Vivadent 1200 mW/cm2*s for 40 s, Valo-Ultradent, 1000mW/cm2*s for 48s). In each group, 20 inlays were cemented with MultilinkAutomix (Ivoclar-Vivadent), while 20 were cemented with Calibra (Dentsply) interposing the cement between a glass plate and a restoration; the curing tip was shielded so that the light reached the composite material only through the onlay. Each sample was examinated using the Micro-Raman Dilor HR LabRam spectrometer to evaluate the polymer DC. Statistical analysis was carried out using ANOVA test and Tukey's and Fisher's test. Results: Multilink Automix DC is significantly higher (p=<0.05) than that of Calibra, regardless of the radiation source used for curing. Bluephase C8 allows to obtain DC values significantly lower (p=<0.05) than those obtained with Valo, while there are no significant differences with Bluephase G2. 1200 mW/cm2*s for 40 s 800mW/cm2*s for 60s 1000mW/cm2*s for 48s A B A B A B 2 mm 82,2 75,4 85,8 67,8 89 76 3 mm 75,07 70 79,87 61,4 88,4 75 4 mm 71,87 62 75,33 58,4 86,6 66,8 Conclusions: High radiation power allows a higher degree of conversion in both tested materials. Greater collimation of the light beam allows, even in lamps with medium power, to obtain high DC and a reduced standard deviation.
Light source influences the conversion degree of dual-curing luting materials
CERUTTI, Francesca;MADINI, Lorenzo;CERUTTI, Antonio
2012-01-01
Abstract
Objectives: The aim of this study was to evaluate how different light curing sources influence the degree of conversion (DC) of two composite cements used to lute indirect composite restorations of increasing thickness. Methods: 120 cylindrical onlays (Signum composite – Heraeus - shade A2, 6mm of diameter) of different thickness (2mm, 3mm, 4 mm) were prepared in a custom template. The specimens were divided into three groups (N=40) and luted with different LED light sources (Bluephase C8-Ivoclar Vivadent 800mW/cm2*s for 60s, Bluephase G2-Ivoclar Vivadent 1200 mW/cm2*s for 40 s, Valo-Ultradent, 1000mW/cm2*s for 48s). In each group, 20 inlays were cemented with MultilinkAutomix (Ivoclar-Vivadent), while 20 were cemented with Calibra (Dentsply) interposing the cement between a glass plate and a restoration; the curing tip was shielded so that the light reached the composite material only through the onlay. Each sample was examinated using the Micro-Raman Dilor HR LabRam spectrometer to evaluate the polymer DC. Statistical analysis was carried out using ANOVA test and Tukey's and Fisher's test. Results: Multilink Automix DC is significantly higher (p=<0.05) than that of Calibra, regardless of the radiation source used for curing. Bluephase C8 allows to obtain DC values significantly lower (p=<0.05) than those obtained with Valo, while there are no significant differences with Bluephase G2. 1200 mW/cm2*s for 40 s 800mW/cm2*s for 60s 1000mW/cm2*s for 48s A B A B A B 2 mm 82,2 75,4 85,8 67,8 89 76 3 mm 75,07 70 79,87 61,4 88,4 75 4 mm 71,87 62 75,33 58,4 86,6 66,8 Conclusions: High radiation power allows a higher degree of conversion in both tested materials. Greater collimation of the light beam allows, even in lamps with medium power, to obtain high DC and a reduced standard deviation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
