The role of root wall thickness in stress distribution in dentin after endodontic treatment

BACKGROUND: predicting possible complications in the form of fractures and fractures of the root of the tooth makes it relevant to study the distribution of stresses in the root of the tooth in different biomechanical circumstances, in particular, with changes in the magnitude of the functional load, its direction, as well as the dimensional and mechanical parameters of the tooth.

AIM: three-dimensional mathematical modeling of functional stresses in the root of the tooth depending on the thickness of the dentinal wall.

MATERIALS AND METHODS: using the mathematical program SolidWorks (Dassault Systems), an analysis of the magnitude and propagation of stresses in the root of a devitalized tooth under an inclined load of 30 ° with a force of 150 N. For the purposes of this study, the stresses in three tooth models were compared: with a root wall thickness of 1.0 mm, 1.5 mm and 2.0 mm. Integral stresses were analyzed, as well as tensile stresses propagating in the vertical, buccal-lingual and medio-distal directions.

RESULTS: a pattern of increasing stresses in the dentine of a devitalized tooth was obtained depending on a decrease in the thickness of the root wall. This pattern is especially evident when modeling the 1.0 mm thick root wall, where stresses become limiting for dentin strength. Stress distribution patterns show the localization of maximum values in the area of the tooth neck.

CONCLUSION: evidence of an increase in functional stresses in the dentine of a devitalized tooth with a decrease in the thickness of the root wall has been obtained. The main localization of maximum stresses was revealed – the tooth neck. It has been established that devitalized dentin is subject to stresses in excess of the ultimate strength at a root thickness of 1 mm.