Objectives: Adhesive luting affects the long-term outcomes of composite inlays; dual-curing materials are broadly employed for this procedure. However light contribution still plays a key-role when luting thick inlays. Aim of this study was to evaluate the degree of conversion (DC) of two dual-curing luting materials cured below composite inlays by means of four LED lamps. The null hypothesis was to find no difference among the materials DC, independently from the inlay thickness and the LCU power/time combinations. Methods: 120 inlays (Signum–Heraeus–shade A2) of increasing thickness (2mm-3mm-4mm) were prepared in a custom template, then split into 24 groups (n=5) and luted on glass slides with two dual-cure luting composites (transparent): A) a self-curing luting composite with light- curing option (Multilink Automix, Ivoclar-Vivadent, Schaan, Liechtestein batchL42296) and B) a visible light-cured, dual-cured/self-cured material (Calibra-Dentsply-Konstanz, Germany batch5, 304,586; 4,920,082). Light-curing was performed, according to the programs reported in Tab1, with four LCUs (Bluephase G2 and C8, DemiLight and VALO) whose tip was shielded providing a constant energy density (48J). DC was assessed with a micro-Raman Dilor-HR-Labram spectrometer (laser He:Ne; 50X magnifications, exposure time 60s, resolution 0.6cm-1), then ANOVA and Turkey's test were performed (α=0.05). Results: Mean DC and SD are shown in Tab.2. As expected, DC decreases as the inlay thickness increases, but the datum is not significant. The statistical analysis stressed that the material A reaches significantly higher DCs than B. Considering LCUs, 3 and 4 allow to obtain the highest DCs, probably due to the high power output of 3 and of the high collimation of the light peculiar of 4. Conclusions: The dual-curing materials employed are reliable even when luting thick inlays. High-power polymerization allows obtaining the highest DCs in both materials. In addition, a great collimation of the light allows, even at lower powers, to obtain high DCs.
Light-curing-unit influences the conversion of dual-curing composites in inlays luting / F. Cerutti, M. Bottone, N. Barabanti, D. Re, A. Cerutti. - In: JOURNAL OF DENTAL RESEARCH. - ISSN 0022-0345. - 90:(2011 Mar). ((Intervento presentato al 89. convegno General Session of the IADR tenutosi a San Diego nel 2011.
Light-curing-unit influences the conversion of dual-curing composites in inlays luting
D. RePenultimo
;
2011
Abstract
Objectives: Adhesive luting affects the long-term outcomes of composite inlays; dual-curing materials are broadly employed for this procedure. However light contribution still plays a key-role when luting thick inlays. Aim of this study was to evaluate the degree of conversion (DC) of two dual-curing luting materials cured below composite inlays by means of four LED lamps. The null hypothesis was to find no difference among the materials DC, independently from the inlay thickness and the LCU power/time combinations. Methods: 120 inlays (Signum–Heraeus–shade A2) of increasing thickness (2mm-3mm-4mm) were prepared in a custom template, then split into 24 groups (n=5) and luted on glass slides with two dual-cure luting composites (transparent): A) a self-curing luting composite with light- curing option (Multilink Automix, Ivoclar-Vivadent, Schaan, Liechtestein batchL42296) and B) a visible light-cured, dual-cured/self-cured material (Calibra-Dentsply-Konstanz, Germany batch5, 304,586; 4,920,082). Light-curing was performed, according to the programs reported in Tab1, with four LCUs (Bluephase G2 and C8, DemiLight and VALO) whose tip was shielded providing a constant energy density (48J). DC was assessed with a micro-Raman Dilor-HR-Labram spectrometer (laser He:Ne; 50X magnifications, exposure time 60s, resolution 0.6cm-1), then ANOVA and Turkey's test were performed (α=0.05). Results: Mean DC and SD are shown in Tab.2. As expected, DC decreases as the inlay thickness increases, but the datum is not significant. The statistical analysis stressed that the material A reaches significantly higher DCs than B. Considering LCUs, 3 and 4 allow to obtain the highest DCs, probably due to the high power output of 3 and of the high collimation of the light peculiar of 4. Conclusions: The dual-curing materials employed are reliable even when luting thick inlays. High-power polymerization allows obtaining the highest DCs in both materials. In addition, a great collimation of the light allows, even at lower powers, to obtain high DCs.
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