Effect of Artificially Induced Hyperpyrexia on Tooth Structure of the Rabbit

Abstract

The increasing therapeutic importance of artificially induced fever raises the question of its effect on developing tooth structure. Damage to the enamel by infections accompanied by high fever during the period of tooth formation has been recognized clinically for many years. It is evidenced as a hypoplastic condition with superficial pits and grooves, often markedly disfiguring the anterior teeth. Detrimental effects in the dentin would be an internal dystrophy and would escape clinical notice but might well be expected under conditions which would affect the enamel.

Normal dentin is a homogeneously calcified tissue produced by the dental pulp. It is laid down around the periphery of the pulp in periodic increments as an organic matrix which is subsequently calcified to a bone-like consistency. Unlike bone, dentin once formed is not subject to further physiologic change to any marked degree, and hence it affords a permanent record of any variations in the calcification process. The dentin of the continuously growing teeth of the rabbit, therefore, affords a suitable medium for the recording of any effect which might be caused by artificially induced hyperpyrexia.

In the same series of rabbits used for observations on other tissues by the Departments of Medicine and Pathology and reported elsewhere, 1 2 3 histologic studies were made on thin ground sections cut longitudinally through the incisor teeth. Schour and Hoffman, 4 reporting on dentin deposition in growing mammalian teeth, state that it is laid down at the approximate rate of 16 micra in 24 hours. Their work included, among other animals, a series of rabbits. Thus, any periodic interference with calcification would be characterized by the presence in the dentin of alternate layers of normal and abnormal tissue, the latter coinciding with the periods of disturbance.