4 interchangeable inserts show progressive stages of caries on this Dental model Our largest tooth model, molded of unbreakable plastic, portrays a molar from the upper jaw 15 times normal size for ease of study. Divide the molar longitudinally to expose its interior from crown to root. Next remove the pulp from one half of the tooth. Then extract a section of the crown, from the other half. Finally insert any of three additional interchangeable sections exhibiting advancing stages of caries. Principal structures, hand numbered on the model are identified in the accompanying key. The tooth pivots on a hardwood base and measures 7 x 7 x 13 inches (18 x 18 x 33 cm).