Tooth Discoloration

• Egyptian Russian University — Badr, Cairo Governorate, Egypt

• Clinical Research Facility of the Center for Oral Health and Research, UTHSA — San Antonio, Texas, United States

• University Hospital Bordeaux — Bordeaux, France
• University Hosptial Caen — Caen, France
• University Hospital Lille — Lille, France
• Hospices Civils de Lyon — Lyon, France

• Clínica Universitària d'Odontologia UIC Barcelona — Sant Cugat del Vallès, BARCELONA, Spain

• Jordan University of Science and Technology — Irbid, Jordan

• Universidad Rey Juan Carlos — Alcorcón, Madrid, Spain

• Misr University for science and technology — Giza, Egypt

• Hacettepe University — Altındağ, Ankara, Turkey (Türkiye)

• Marmara Üniversitesi Recep Tayyip Erdoğan Külliyesi Sağlık Yerleşkesi, Diş Hekimliği Fakültesi — Istanbul, MALTEPE, Turkey (Türkiye)

Not specified