Experimental and Mathematical Determination of Deformation Risks of Dental Matrices During Anatomical Adaptation to the Proximal Surface of the Tooth

Abstract

Introduction. Creating high-quality interdental contacts is the most important and difficult step in the treatment of proximal caries. In modern dentistry, most methods for restoring the proximal wall of teeth involve the use of dental matrices. The choice of matrix and the peculiarities of working with it are the determining factor in the formation of the proximal contour of the tooth and often causes difficulties, especially for young specialists.
 The aim of the study is to conduct an experimental-mathematical determination of the tensile strength of dental matrices to elastic deformation based on the curvature of the proximal surface of the chewing teeth.
 Materials and methods. The work consisted of 2 stages. Initially, a test bench was developed to assess the deformation capabilities of dental matrices, consisting of a strain gauge and a model of the proximal tooth wall with the possibility of fixing the matrix and imitating pushing. The model was created in SolidWorks software and 3D printed from light-cured polyamide. At the second stage, computer models of teeth and matrices were created, as well as an analysis of data from x-rays and other sources.
 Results. In the course of the work, the strength characteristics of dental matrices were obtained, the limits of their deformation capabilities were determined depending on the thickness of the material and the area of impact on it. Titanium matrices have the best strength characteristics, withstanding a force of 70 N, with an impact area of 2.25 mm2. An analysis of the curvature of the proximal surfaces of the chewing teeth revealed the best match between the matrix contour and the tooth contour on the medial surface of the first molars of the upper and lower jaws.
 Conclusions. To achieve high results in the restoration of the proximal walls of the teeth, in most cases it is recommended to press the matrix with an instrument with a working area of at least 2 mm2.