The Regeneration of Rodent Peridental Membrane.

Abstract

The work, in which one of us (W. C. F.) has participated indicates that a certain degree of repair of peridental fibrous tissue in man may follow careful treatment of the pyorrheal pocket. Many points regarding the sequence of events in regeneration of peridental membrane, however, were left without explanation. Thus, it was decided to examine the possibilities of repair of this peridental structure in the experimental animal. If a dental bur be passed through the gum and alveolar process into the incisor tooth there is produced a local injury which includes destruction of the external soft tissue, alveolus, peridental membrane, cementum and dentine in order of sequence. If a series of animals be subjected to this operation, they may be sacrificed at varying periods afterwards, in order that an appropriate spacing may be obtained for subsequent examination regarding the various steps of destruction and repair which follow in each of the structures included. For this purpose we selected the rabbit and the guinea pig for a particular reason. The rodents are provided with continuously growing teeth. As a result the various structures will change in relationship for as the tooth continues to grow, an uninjured tooth surface will come opposite to the site of injury to the alveolar bone. For histological examination this presents advantages, since peridental repair is more likely to take place from an intact dental surface than from one which is fractured. Two series of rabbits and two series of guinea pigs have been submitted to operation as described in the preceding paragraph. Animals thus treated have been sacrificed at semi-weekly intervals over a period of 6 weeks. The tooth with its adjacent structures was sawed out immediately after death, fixed, and then prepared in serial longitudinal sections in celloidin by methods which are described by one of us (A. W.).