Document Detail


Effect of different photo-initiators and light curing units on degree of conversion of composites.
MedLine Citation:
PMID:  20877961     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The aim of this study was to evaluate: (i) the absorption of photo-initiators and emission spectra of light curing units (LCUs); and (ii) the degree of conversion (DC) of experimental composites formulated with different photo-initiators when activated by different LCUs. Blends of BisGMA, UDMA, BisEMA and TEGDMA with camphorquinone (CQ) and/ or 1-phenyl-1,2-propanedione (PPD) were prepared. Dimethylaminoethyl methacrylate (DMAEMA) was used as co-initiator. Each mixture was loaded with 65 wt% of silanated filler particles. One quartz-tungsten-halogen - QTH (XL 2500, 3M/ESPE) and two lightemitting diode (LED) LCUs (UltraBlue IS, DMC and UltraLume LED 5, Ultradent) were used for activation procedures. Irradiance (mW/cm²) was calculated by the ratio of the output power by the area of the tip, and spectral distribution with a spectrometer (USB 2000). The absorption curve of each photo-initiator was determined using a spectrophotometer (Varian Cary 5G). DC was assessed by Fourier transformed infrared spectroscopy. Data were submitted to two-way ANOVA and Tukey's test (5%). No significant difference was found for DC values when using LED LCUs regardless of the photo-initiator type. However, PPD showed significantly lower DC values than composites with CQ when irradiated with QTH. PPD produced DC values similar to those of CQ, but it was dependent on the LCU type.
Authors:
William Cunha Brandt; Luis Felipe Jochims Schneider; Elisabete Frollini; Lourenço Correr-Sobrinho; Mário Alexandre Coelho Sinhoreti
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Brazilian oral research     Volume:  24     ISSN:  1807-3107     ISO Abbreviation:  Braz Oral Res     Publication Date:    2010 Jul-Sep
Date Detail:
Created Date:  2010-09-29     Completed Date:  2011-01-14     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101307187     Medline TA:  Braz Oral Res     Country:  Brazil    
Other Details:
Languages:  eng     Pagination:  263-70     Citation Subset:  D; IM    
Affiliation:
Departamento de Dentística Restauradora, Área de Materiais Dentários Faculdade de Odontologia de Piracicaba, UNICAMP Av. Limeira, 901 Piracicaba - SP - Brazil. williamcbrandt@yahoo.com.br
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MeSH Terms
Descriptor/Qualifier:
Camphor / analogs & derivatives
Chalcones / chemistry,  radiation effects
Composite Resins / chemistry,  radiation effects*
Curing Lights, Dental*
Materials Testing
Methacrylates / chemistry,  radiation effects*
Phase Transition
Photochemical Processes
Polyethylene Glycols / chemistry,  radiation effects
Polymethacrylic Acids / chemistry,  radiation effects
Spectroscopy, Fourier Transform Infrared
Time Factors
Chemical
Reg. No./Substance:
0/Chalcones; 0/Composite Resins; 0/Methacrylates; 0/Polyethylene Glycols; 0/Polymethacrylic Acids; 76-22-2/Camphor

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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