Influence of Occlusal Wear and Age on Formation of Dentin and Size of Pulp Chamber

¹ Athens, Greece

Dentin formation and size of the pulp chamber were studied in 168 sound, left, permanent mandibular first molars of both sexes, belonging to contemporary individuals, and ancient skeletal material of different age groups suffering varying degrees of occlusal wear. These teeth were examined clinically and radiographed so as to show their cross-sectional anatomy from the buccal aspect under identical standard conditions. The resultant radiographs were enlarged ten times, and diagrams were drawn. Measurements were then taken by means of eight defined indexes and analyzed. The data were tabulated separately for the contemporary and ancient skeletal observations, according to age groups and assessed degrees of occlusal wear. Dentin formation and the size of the pulp chamber under the influence of the two factors—age and occlusal wear—were investigated. The material was subjected to statistical analysis.

The main findings were as follows: (1) There appeared to be no significant change in the dentin at the roof of the pulp chamber with increasing age over the entire spans of age and occlusal wear studied. (2) The dentin at the floor of the pulp chamber showed a definite increase in thickness with increasing age, this being chiefly responsible for the reduction in size of the pulp chamber occlusogingivally. (3) The mesial and distal walls of dentin increased in thickness with increasing age, causing the reduction in size of the pulp chamber mesiodistally. (4) Both the height and the width of the pulp chamber showed a definite decrease with advancing age, regardless of the degree of occlusal wear studied.

It thus appears that, regardless of occlusal wear up to degree V, dentin formation goes on uninterruptedly throughout the life of the sound tooth, faster in the early years but more slowly later on. It is this continuous formation of dentin with age that is responsible for the decrease in size of the pulp chamber.