TY - BOOK AU - Sara Bassam Abdelfattah Mohamed Elhelw AU - Mai Mahmoud Yousry , AU - Rasha Raafat Abdelaziz , TI - Color stability and stain resistance of different types of machinable ceramic and composite blocks / PY - 2015/// CY - Cairo : PB - Sara Bassam Abdelfattah Mohamed Elhelw , KW - Color stability KW - Composite blocks KW - Stain resistance N1 - Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine - Department of Operative Dentistry; Issued also as CD N2 - This study was conducted to evaluate the effect of coffee staining on the color. 2 stability and stain resistance of three types of CADCAM blocks. M and M: A total of 30 specimens were sectioned, 10 of the ceramic blocks (B1), 10 of the hybrid blocks (B2) and 10 of the composite (B3). A spectrophotometer was used to assess the color four times throughout the study; the baseline color, after primary coffee staining for 12 days(S), after polishing (P) and after secondary coffee staining for another 12 days (SS). Results: The ceramic specimens showed the highest color stability and stain resistance, followed by the hybrid and finally the composite specimens. Conclusion: All the materials tested could not resist the coffee staining, while the ceramic material showed the least color change {u2206}E ER -