MORPHOMETRIC ANALYSIS OF MOLAR WEARING AND ITS EFFECTS UPON ENDODONTAL SPACE

Tooth abrasion, or wearing away, significantly changes relationships b etween external tooth surface and oral cavity. The study included 150 extracted lower second molars. Fifty of these had visible abrasion (gr oup II), 50 had advanced abrasion (group III) and the remaining 50 mol ars were the control group (group I). The teeth were bored in their me siodistal direction and dyed in special technique following which thre e vertical and one horizontal measurements were made in carefully sele cted points. In this way a large number of relevant parameters was obt ained. The results show that advanced abrasion is often (group II) is often combined with reduced or completely disappeared mesial apex of t ooth pulp and decrease in total height of tooth chamber measured along the median line. It is interesting to notice marked depositing of sec ondary dentine at the bottom of pulp chamber i.e. in the part of the t ooth that is not directly affected by forces acting upon tooth surface . The finding is accounted for by the summing up of reversible forces acting in combination that are transferred from occlusal plate through out the whole tooth structure until the apex of the root and are forme d. by joint action of osseous matter periodontal ligament and root cem ent. This knowledge calls for further biomechanical research.