[A microradiographic and histological study of a case of dentinogenesis imperfecta type I]

Four temporary teeth, extracted for periodontal infection reasons, from a 53-months-old child with osteogenesis imperfecta, have been coated in methyl metacrylate and prepared for microradiographic analysis and light microscopic study. The enamel and dentin of three teeth (51, 65 and 85) don't show any particularity, some how the cementum is remarkably thin. Pulp chambers was large and contain a great number of calcifications. Some of them present a radial striation around a radio-transparent center, and when coloured with blue of methylen, they revealed inflammatory or fibroblastic cells. The fourth tooth (55) shows a dentinogenetic overproduction which closed the major part of the pulp chamber. The dentin presents two rows of different aspect, separated with a calcified bond. The mantle dentin contains sinuous tubules with a type I arrangement of SIAR classification (1986). But, in the deepest dentin, they are very little size and joined together while approaching the center of the tooth and coast along cellular inclusions, pathognomonic sign of dentinogenesis imperfecta. The pulpal space not obliterated contains a calcification with radial and microlacunary aspect.