| چکیده انگلیسی مقاله |
Effect of Tea on Color Change of Silorane and Methacrylate based Composite Resins Dr. Heshmat H .,1 Dr. Hajian M., 2 Dr. Hoorizad Ganjkar M . ,1 Dr. Emami Arjomand M.3 1 Assistant Professor, Department of Restorative Dentistry , School of Dentistry, Dental Branch, Islamic Azad University. Tehran , Iran . 2 Dentist . 3 Resident, Department of Restorative Dentistry , School of Dentistry, Dental Branch, Islamic Azad University. Tehran , Iran . (Received 22 Mey, 2012 Accepted 10 Jan, 2013) Abstract Background and Aim : At present, stainability and color instability of tooth-colored restorations following the consumption of colored beverages are among the problems commonly encountered in restorative dentistry. Filtek P90 composite resin comprising of Oxirane and Siloxanefunctional moietieswas recently introduced aiming at reducing the polymerization shrinkage. The aim of this study was to evaluate the effect of tea on color change of P90 and Z250 composite resins using spectrophotometry . Materials and Methods : For this experimental study, 20 composite discs were fabricated in metal molds from Z250 and P90 composite resins and light cured using LED light-curing unit. Specimens were stored in distilled water at 37 ° C for 24 hours to allow completion of polymerization. Color of specimens was then measured at baseline and after 5 days of storage in water and tea solution using spectrophotometer. Data were analyzed using independent sample t-test and two-way ANOVA . Results : The color change of P90 and Z250 composites after storage in distilled water was not significant in comparison to their baseline color (P>0.05). However, both composite resins showed a significant change in color after storage in tea solution (P< 0.05). Stainability of Z250 composite in tea was significantly greater than that of P90 but in distilled water P90 showed greater color change than Z250 . Conclusion: Within the limitations of this study, Z250 composite demonstrated significantly greater color change in comparison to P90 after immersion in tea solution . Key words : Low-shrinkage composite resin , color stability , stainability , spectrophotometer Corresponding Author: Dr. Hoorizad Ganjkar M ., Assistant Professor, Department of Restorative Dentistry , School of Dentistry, Dental Branch, Islamic Azad University. Tehran , Iran . e.mail: Mahoorizad@yahoo.com |