The effect of glucocorticosteroid treatment on dentine formation in the Lewis rat, a histological study

Glucocorticosteroids are widely used in the treatment of chronic illnesses and have been reported to cause premature obliteration of the pulp space. D uring the active stages of dentinogenesis, odontoblasts are growth hormone receptor (GHr) positive. The aims of this study were to determine if the gl ucocorticosteroid, prednisone, affected the rate of dentine deposition and odontoblast expression of GHr in the rat molar. Following subcutaneous inje ction of 0.05 mg/kg, 1.0 mg/kg or 5.0 mg/kg prednisone for 20 days, immatur e and mature molars from rats aged 3 and 6 weeks respectively, were examine d histologically. Distribution of GHr expression was determined immunohisto chemically. No morphological differences were observed in molars from predn isone treated animals. Prednisone did not appear to enhance dentine deposit ion in immature molars but in mature molars significantly increased dentine deposition on the roof of the pulp chamber at a dosage of 5.0 mg/kg (p < 0 .001), In all immature molars, odontoblasts and pulp cells expressed GHr im munoreactivity. In mature molars, odontoblasts and pulpal cells from contro ls did not show GHr immunoreactivity, However, odontoblasts and pulp cells were GHr immunoreactive in mature molars from animals treated with predniso ne.