Three-dimensional analysis of cavity wall deformation after composite restoration of masticatory teeth

Abstract

AIM: The aim of the present work was to study the size of cavity wall deformation in eight class I and II defects after composite restoration. MATERIALS AND METHODS: 1. Creating a geometric model - data on the size of the left maxillary second premolar were obtained from a routine craniofacial scanning of a 20-yearold patient with a 2,5 Dental CT scanner (General Electric), with high resolution and 0.625mm-thin slices. The contour of each of the 33 cross-sections of tooth 25 was delineated using graphics software (CorelDraw 7.0) and transferred to a specialized product for engineering design (SolidWorks Offi ce Premium 2010, SolidWorks Corp. USA). The pulp cavity and periodontal ligament were created in the same manner and were integrated in the premolar body; 2. Generation of a fi nite element method - the geometric model was exported to specialized software for analysis by the fi nite element method - COSMOSWorks 2010, which automatically builds a 3D fi nite elements mesh. Based on the generated model, eight additional models of class I and II cavities with different geometries, adhesive layer and nanofi lled composite restorations were constructed. The polymerization shrinkage was modelled by thermal deformation, with a negative temperature difference (cooling), corresponding to the actual volume shrinkage of the composite materials by 2.1%. RESULTS: In models A and B, the maximum cavity wall displacement was small - 0.014 mm and 0.015 mm, respectively. In models A1, B1, C1 and C, the displacement was at the expense of large deformation of the dental tissues. The maximum cavity wall displacements were 0.020 mm, 0.026 mm, 0.020 mm, 0.035 mm, respectively. The least cavity wall displacement was in models A2 and B2 with 0.008 mm and 0.017 mm, respectively. CONCLUSIONS: The least displacement resulting from cavity wall deformation is found in patient-friendly class I and II preparations. Preservation of the dental tissues reduces the risk of mechanical pressure on the dentinal lymph and the likelihood of post-operative sensitivity.

Two-Dimensional Analysis of Digital Images through Vector Graphic Editors in Dentistry: New Calibration and Analysis Protocol Based on a Scoping Review

“…The selected papers date between 2006 and 2019 [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ], are written in English, and are from the following countries: Brazil ( n = 8), Bulgary ( n = 1), Canada ( n = 1), China ( n = 1), Estonia ( n = 1), Japan ( n = 1), Jordan ( n = 1), India ( n = 2), Poland ( n = 1), Saudi Arabia ( n = 1), and Turkey ( n = 3). Supplemental Table S1 shows the results of the variables analysed in the selected papers.…”

“…The registered studies were: in vitro study ( n = 4) [ 22 , 23 , 29 , 31 ], fine element study ( n = 1) [ 27 ], cross-sectional study ( n = 9) [ 20 , 21 , 25 , 30 , 32 , 34 , 35 , 37 , 39 ], case–control ( n = 4) [ 24 , 28 , 33 , 36 ], and cohort study ( n = 3) [ 26 , 38 , 40 ].…”

“…The dental specialties covered in the research were: endodontics ( n = 3) [ 22 , 23 , 31 ], restorative dentistry ( n = 3) [ 27 , 33 , 36 ], orthodontics ( n = 8) [ 24 , 25 , 29 , 30 , 32 , 37 , 38 , 39 ], and prosthodontics ( n = 7) [ 20 , 21 , 26 , 28 , 34 , 35 , 40 ].…”

“…CorelDRAW (Corel Corp and Coral Ltd., Ottawa, ON, Canada) ( n = 19), in its different versions, was the most used VGE among the included works [ 20 , 21 , 22 , 23 , 24 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 38 , 39 , 40 ]. Adobe Illustrator (Adobe Systems Inc, San Jose, CA, USA) was used in two studies [ 25 , 37 ], and none of the selected articles described applications with Inkscape.…”

“…Radiological images were the most frequently used, such as: periapical radiographs ( n = 7) [ 22 , 23 , 26 , 33 , 36 , 38 , 40 ], cross-sectional images of CBCT (Cone Beam Computed Tomography) ( n = 3) [ 27 , 31 , 39 ], cephalometric radiographs ( n = 2) [ 24 , 25 ], and panoramic radiographs ( n = 3) [ 26 , 28 , 40 ]. The second-most used source of images was standardised photographs of the smile ( n = 3) [ 20 , 21 , 35 ], face ( n = 1) [ 34 ], and dental casts or typodonts ( n = 2) [ 29 , 37 ].…”