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2. Luminescent veneers;McLaren;J Esthet Dent,1997
3. Artificial opals as effect pigments in clear-coating;Egen;Macromol Mater Eng,2004
4. Light and color in anterior composite restorations;Vanini;Pract Periodont Aesthet Dent,1996
5. Fundamentals of opal porcelain;Chizick;Trends Tech Contemp Dent Lab,1994