Chemical and morphological features of dental composite resin: influence of light curing units and immersion media.
OBJECTIVE
The study evaluated the influence of light curing units and immersion media on superficial morphology and chemistry of the nanofilled composite resin Supreme XT (3M) through the EDX analysis and SEM evaluation. Light curing units with different power densities and mode of application used were XL 3000 (480 mW/cm(2)), Jet Lite 4000 Plus (1230mW/cm(2)), and Ultralume Led 5 (790 mW/cm(2)) and immersion media were artificial saliva, Coke((R)), tea and coffee, totaling 12 experimental groups. Specimens (10 mm x 2 mm) were immersed in each respective solution for 5 min, three times a day, during 60 days and stored in artificial saliva at 37 degrees C +/- 1 degrees C between immersion periods. Topography and chemical analysis was qualitative.


RESULTS
Groups immersed in artificial saliva, showed homogeneous degradation of matrix and deposition of calcium at the material surface. Regarding coffee, there was a reasonable chemical degradation with loss of load particles and deposition of ions. For tea, superficial degradation occurred in specific areas with deposition of calcium, carbon, potassium and phosphorus. For Coke((R)), excessive matrix degradation and loss of load particles with deposition of calcium, sodium, and potassium.


CONCLUSIONS
Light curing units did not influence the superficial morphology of composite resin tested, but the immersion beverages did. Coke((R)) affected material's surface more than did the other tested drinks.
Department of Dentistry, University Center of Araraquara (UNIARA), São Paulo, Brazil.
Patrícia Aleixo
PA
Dos Santos
Patrícia Petromilli Nordi Sasso
PP
Garcia
Ana Luisa Botta Martins
AL
De Oliveira
Michelle Alexandra
MA
Chinelatti
Regina Guenka
RG
Palma-Dibb
D003041:Coca; D003069:Coffee; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects; D006801:Humans; D008027:Light; D008855:Microscopy, Electron, Scanning; D012463:Saliva; D013052:Spectrometry, X-Ray Emission; D013662:Tea
D003069:Coffee; D003188:Composite Resins; D013662:Tea