THE EFFECT OF CONVERGENCE ANGLE OF TOOTH PREPARATION IN PATIENTS WITH GENERAL PERIODONTITIS ACCORDING FINITE ELEMENT ANALYSIS
DOI:
https://doi.org/10.35220/2078-8916-2022-45-3.12Keywords:
finite element method, displacement and stress distribution, tooth preparation, general periodontitis.Abstract
Purpose of the research. To study the character of displacement and stress distribution after prosthetics of the lower central incisor with the metal-ceramic crown, depending on the convergence angle of preparation and the degree of resorption of alveolar septa using finite element analysis. Research methods. The computer models have been studied using the calculated software complex “Lira 9.6” to reproduce intact (before preparation) and treated teeth, taking into account subsequent imposition of a metal-ceramic crown. Calculations have been made for different convergence angles, from 20 to the maximum possible, for four types of loads (constant from own weight; vertical from food biting off; at an angle of 300 to vertical; at an angle of 450 to vertical) and for different degrees of preservation of alveolar septa: 100 %, 75 % and 50 %. Scientific novelty. It has been established that in the calculated model the increase of the convergence angle of tooth surfaces, as well as the decrease in alveolar septa height, cause the increase in displacements in the biomechanical system “crown – tooth – alveolar bone”, the maximum of which are localized in the neck area of the tooth on its lingual surface. The increase in the angle of preparation causes the increase in stresses in the same area, while the increase in the degree of resorption of alveolar septa results with the displacement of the maximum stress zone from the tooth neck to the apical part of the root. Conclusions. The obtained results indicate the need for tooth preparation with the minimum convergence angle of surfaces in patients with general periodontitis. It could prevent the risks of the progression of the pathological process in periodontal tissues due to the increase of stresses and displacements.
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Антомонов М.Ю. Математическая обработка и анализ медико-биологических данных. Киев: [б.и.], 2017. 558 с.
