The aim of the study was to assess the visual and radiographic changes in teeth subjected to various high temperatures. An in-vitro observational study was conducted on 45 extracted teeth in the Department of Oral Medicine & Radiology, Sri Sai College Of Dental Surgery, Vikarabad. A burnout furnace was used for heating the teeth. The teeth were then categorized into three groups based on the degree of thermal stress, subjected to (150 o C, 450 o C and 950 o C). The teeth were then visually and radiographically analyzed for any changes. Teeth samples with caries, fractures and restorations were excluded from the study. The visual changes appreciated were development of cracks, crazing lines at 150o C, to progressive discoloration at 450o C, followed by fractures of crowns and roots at 950o C. The radiographic changes appreciated at 150 o C were not so appreciable, radiographic fissures were seen between enamel and dentin at 450 o C to large factures spreading through the dentin and crown en bloc fractures at 950 o C.

Keywords : Temperature, In-Vitro, Thermal Stress, Extracted Teeth.