engleski

Influence of mechanical and chemical degradation on surface gloss of composite resin materials

Composite materials are increasingly being used in anterior aesthetic restorations. In this indication not only color, translucency and opalescence, but also surface gloss is of paramount importance. The purpose of this study was to determine the changes in surface gloss of different composite materials after simulation of mechanical and chemical ageing mechanisms. Thirty six specimens were fabricated for each material and polished with 120-, 220-, 500-, 1200-, 2400- and 4000- grit SiC abrasive paper, respectively. Gloss measurements were made with a glossometer (Novocurve) prior to testing procedures. Specimens of each material were randomly divided into three groups. First group was conditioned for seven days at 37° C in 75% ethanol aqueous solution. Second was immersed in fluoride gel (Elmex gelée® ; ) at 37° C for 1 hour. Third was subjected to simulated toothbrushing with an electrical toothbrush while being immersed in toothpaste. Surface gloss measurements were made subsequently. Surface gloss of all the materials was affected by simulated toothbrushing and the decrease of gloss was material dependent. Following immersion in Elmex gelée® , surfaces of Enamel HFO, Miris 2, CeramX and Clearfill Photo Posterior presented a severe decrease in gloss. There was no significant drop of surface gloss values after 7 days of storage in 75% ethanol. Artificial materials available nowadays try to mimic natural enamels' appearance without reaching a complete success. New developments in nanotechnology, however, let us to imagine that in the future more tooth-like materials could be developed which will present better optical properties and allow enhanced esthetic outcomes.

composite resin; surface gloss; degradation

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