الفهرس 
List of Contentsيوجد فقط 14 صفحة متاحة للعرض العام
 |  | from | 94 |  |  |
| | | from | 94 | | |
المستخلص
The aim of this in vitro study was to evaluate and compare the effect of a chemical and light-activated bleaching agents on color stability of three different resin composite restorative materials. There was color change among all groups after bleaching regardless of bleaching material, however the change not detected by naked eye as ΔE<3.3. There was significant difference between two bleaching agents used regardless of composite type. Color change between composite types was non significantly different regardless of bleaching agent. Material and methods: The materials tested were a nanofilled (Filtek Z350 XT - 3M ESPE, St Paul, USA), a nanohybrid (Tetric–N–Ceram, Ivoclar-Vivadent, Schaan, Liechtenstein), and a microhybrid (Herculite Classic, Kerr/Sybron, Orange, CA, USA) resin composites. from each material, 20 cylindrical specimens were prepared according to the manufacturer instructions using specially designed Teflon mold (10 mm diameter and 2 mm thickness), finished and polished. A baseline color measurements were assessed for all the specimens using spectrophotometer (Vita Easyshade, Zahnfabrik, Germany). from each material, half of the specimens (n=10) were subjected to chemically- activated teeth bleaching agent (Power Whitening YF, WHITE smile GMBH, Birkenau, Germany), while the remaining specimens were subjected to light-activated bleaching agent (Light whitening AC, WHITE smile GMBH, Birkenau, Germany). A second color assessment were done after bleaching procedures. The data were statistically analyzed and data were described using range (minimum and maximum), mean, standard deviation and median. The level of significance was set at p<0.05.