CUSTOMIZED POST-AND-CORE DESIGN AND STRESS ANALYSIS FOR POSTERIOR TOOTH PROSTHESIS

2019 ◽  
Vol 19 (07) ◽  
pp. 1940038
Author(s):  
QIUDONG YU ◽  
SHUXIAN ZHENG ◽  
WEIZHEN WANG
Keyword(s):  
Root Canal ◽  
Core Structure ◽  
Tooth Root ◽  
Canal Surface ◽  
Element Analysis ◽  
Root Fracture ◽  
Similar Shape ◽  
Posterior Tooth ◽  
Structure Formula ◽  
Post And Core

A post-and-core crown is widely used in prosthetic dentistry; however, in clinical treatment, it easily causes root fracture and tooth penetration. To address these problems, this study aimed to present a customized post-and-core design for the posterior tooth implant. First, a residual tooth and its root canal were reconstructed. Then, the root canal surface was extracted, the surface curvature and length parameters were defined, and the customized post-and-core design was developed. Finally, the tooth, root canal, and post-and-core with different implant lengths in five masticatory directions were analyzed using finite element analysis to evaluate the stress distribution. The results showed that, with the similar shape of the post-and-core structure and the root canal, the tooth stress trend was uniform. When the length of the post-and-core structure [Formula: see text] was 0[Formula: see text]mm, that is, it was two thirds of the root canal length, the root canal stress was minimum. Therefore, the customized design of the post-and-core structure could well adapt to any kind of root canal, and the length of the post-and-core structure [Formula: see text] provided guidance for the post-and-core crown prosthesis in clinic.

scholarly journals Effect of different restorative crown design and materials on stress distribution in endodontically treated molars: A finite element analysis study

2020 ◽  
Author(s):  
Jie Lin ◽  
Zhenxiang Lin ◽  
Zhiqiang Zheng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Root Canal ◽  
Alveolar Bone ◽  
Tissue Loss ◽  
Stress Distributions ◽  
Principal Stresses ◽  
Element Analysis ◽  
Root Fracture ◽  
Post And Core

Abstract Background: The purposes of this simulation study were to evaluate the stresses in the roots of endodontically treated molars with extensive coronal tissue loss which were restored by endocrowns (all-in-one core and crown) and traditional crowns with post-cores, during masticatory simulation using finite element analysis. Methods: A mesio-distal cross-section of a lower right first molar was digitized and used to create 2-dimensional models of the teeth and supporting tissue; different crown designs, viz., endocrown with 2 mm occlusal clearance, endocrown with 4 mm occlusal clearance and post-core crown; different crown materials, viz., zirconia (Zr) and lithia-disilicate reinforced glass ceramic (LDRGC), and different post and core materials, viz., glass fiber (GF), stainless steel (SS) and metal cast (MC). An axial load of 600 N was applied to the central fossa of occlusal surface. Results: The stress distributions were similar between Zr and LDRGC for periodontal ligament and alveolar bone. The root canal inner wall maximum principal stresses of SS post (70.8 MPa) and MC post (71.4 MPa) were higher than that of GF post (36.0 MPa) and endocrown (2.4 MPa).Conclusion: The endocrowns reduced stress concentration for the root canal inner wall in comparison with the conventional post-core crown. Molars restored with endocrowns are less prone to root fracture than those with posts.

scholarly journals Effect of different restorative crown design and materials on stress distribution in endodontically treated molars: A finite element analysis study

2020 ◽  
Author(s):  
Jie Lin ◽  
Zhenxiang Lin ◽  
Zhiqiang Zheng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Root Canal ◽  
Alveolar Bone ◽  
Tissue Loss ◽  
Stress Distributions ◽  
Principal Stresses ◽  
Element Analysis ◽  
Root Fracture ◽  
Post And Core

Abstract Background The purposes of this simulation study were to evaluate the stresses in the roots of endodontically treated molars with extensive coronal tissue loss which were restored by endocrowns (all-in-one core and crown) and traditional crowns with post-cores, during masticatory simulation using finite element analysis. Methods A mesio-distal cross-section of a lower right first molar was digitized and used to create 2-dimensional models of the teeth and supporting tissue; different crown designs, viz ., endocrown with 2 mm occlusal clearance, endocrown with 4 mm occlusal clearance and post-core crown; different crown materials, viz ., zirconia (Zr) and lithia-disilicate reinforced glass ceramic (LDRGC), and different post and core materials, viz. , glass fiber (GF), stainless steel (SS) and metal cast (MC). An axial load of 600 N was applied to the central fossa of occlusal surface. Results The stress distributions were similar between Zr and LDRGC for periodontal ligament and alveolar bone. The root canal inner wall maximum principal stresses of SS post (70.8 MPa) and MC post (71.4 MPa) were higher than that of GF post (36.0 MPa) and endocrown (2.4 MPa). Conclusion The endocrowns reduced stress concentration for the root canal inner wall in comparison with the conventional post-core crown. Molars restored with endocrowns are less prone to root fracture than those with posts.

scholarly journals Effect of different restorative crown design and materials on stress distribution in endodontically treated molars: A finite element analysis study

2020 ◽  
Author(s):  
Jie Lin ◽  
Zhenxiang Lin ◽  
Zhiqiang Zheng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Root Canal ◽  
Alveolar Bone ◽  
Tissue Loss ◽  
Stress Distributions ◽  
Principal Stresses ◽  
Element Analysis ◽  
Root Fracture ◽  
Post And Core

Abstract Background The purposes of this simulation study were to evaluate the stresses in the roots of endodontically treated molars with extensive coronal tissue loss which were restored by endocrowns (all-in-one core and crown) and traditional crowns with post-cores, during masticatory simulation using finite element analysis. Methods A mesio-distal cross-section of a lower right first molar was digitized and used to create 2-dimensional models of the teeth and supporting tissue; different crown designs, viz ., endocrown with 2 mm occlusal clearance, endocrown with 4 mm occlusal clearance and post-core crown; different crown materials, viz ., zirconia (Zr) and lithia-disilicate reinforced glass ceramic (LDRGC), and different post and core materials, viz. , glass fiber (GF), stainless steel (SS) and metal cast (MC). An axial load of 600 N was applied to the central fossa of occlusal surface. Results The stress distributions were similar between Zr and LDRGC for periodontal ligament and alveolar bone. The root canal inner wall maximum principal stresses of SS post (70.8 MPa) and MC post (71.4 MPa) were higher than that of GF post (36.0 MPa) and endocrown (2.4 MPa). Conclusion The endocrowns reduced stress concentration for the root canal inner wall in comparison with the conventional post-core crown. Molars restored with endocrowns are less prone to root fracture than those with posts.

3D Analysis for Identification of the Proper Type of Post to Restore the Endodontic Treated Teeth

2014 ◽  
Vol 658 ◽  
pp. 441-446
Author(s):  
Ruxandra Margarit ◽  
Stefan Sorohan ◽  
Alice Tanasescu ◽  
Constantin Dăguci ◽  
Oana Cella Andrei
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Root Canal ◽  
3D Analysis ◽  
Analysis Method ◽  
Element Analysis ◽  
Root Fracture ◽  
Finite Element Analysis Method ◽  
Endodontic Retreatment ◽  
Posterior Area

Abstract. The problem of root fracture in case of prosthetically restored non-vital teeth is a common concern among clinicians. These fractures are caused by increasing the diameter of the root canal during the endodontic retreatment and occure on the dental arches in both the anterior and posterior area. Such treatment failures lead to extraction, therefore the physician’s goal is to limit as much as possible their occurrence. We used finite element analysis method to find out what type of corono-radicular restoration is more appropriate in order to avoid fractures. We selected two of the most commun posts used in our country: metallic NiCr casted RCR (corono-radicular reconstruction) and prefabricated fiberglass endodontic posts of various diameters and we analyzed the existing tensions in the dental structures that would predispose the root to fracture.

scholarly journals Effect of different restorative crown design and materials on stress distribution in endodontically treated molars and peripheral bone: A finite element analysis study

2019 ◽  
Author(s):  
Jie Lin ◽  
Zhenxiang Lin ◽  
Zhiqiang Zheng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stainless Steel ◽  
Cross Section ◽  
Root Canal ◽  
Tissue Loss ◽  
Element Analysis ◽  
Analysis Study ◽  
Post And Core ◽  
Peripheral Bone

Abstract Background: The purposes of this simulation study were to evaluate the stresses in the roots of endodontically treated molars with extensive coronal tissue loss which were restored by endocrowns (all-in-one core and crown) and traditional crowns with post-cores, during masticatory simulation using finite element analysis. Methods: A mesio-distal cross-section of a lower right first molar was digitized and used to create 2-dimensional models of the teeth and supporting tissue; different crown designs, viz ., endocrown with 2 mm occlusal clearance, endocrown with 4 mm occlusal clearance and post-core crown; different crown materials, viz ., zirconia (Zr) and lithia-disilicate reinforced glass ceramic (LDRGC), and different post and core materials, viz. , glass fiber (GF), stainless steel (SS) and metal cast (MC). A simulated 100 N vertical occlusal load was applied to the distal marginal ridge of the crown. Results: The root canal inner wall stresses of SS post (maximum 33.7 MPa) and MC post (maximum 36.3 MPa) were higher than that of GF post (maximum 19.1 MPa) and endocrown (maximum 8.9 MPa). Conclusion: Endocrown showed reduced stresses at its root canal inner wall but increased stresses at the coronal cavity inner wall when compared to post-core crowns.

scholarly journals 3D Finite Element Analysis of Rotary Instruments in Root Canal Dentine with Different Elastic Moduli

2021 ◽  
Vol 11 (6) ◽  
pp. 2547 ◽  
Author(s):  
Carlo Prati ◽  
João Paulo Mendes Tribst ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alexandre Luiz Souto Borges ◽  
Maurizio Ventre ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Root Canal ◽  
Elastic Moduli ◽  
Reaction Force ◽  
Von Mises Stress ◽  
Elastic Behavior ◽  
Element Analysis ◽  
Heat Treated ◽  
Von Mises

The aim of the present investigation was to calculate the stress distribution generated in the root dentine canal during mechanical rotation of five different NiTi endodontic instruments by means of a finite element analysis (FEA). Two conventional alloy NiTi instruments F360 25/04 and F6 Skytaper 25/06, in comparison to three heat treated alloys NiTI Hyflex CM 25/04, Protaper Next 25/06 and One Curve 25/06 were considered and analyzed. The instruments’ flexibility (reaction force) and geometrical features (cross section, conicity) were previously investigated. For each instrument, dentine root canals with two different elastic moduli(18 and 42 GPa) were simulated with defined apical ratios. Ten different CAD instrument models were created and their mechanical behaviors were analyzed by a 3D-FEA. Static structural analyses were performed with a non-failure condition, since a linear elastic behavior was assumed for all components. All the instruments generated a stress area concentration in correspondence to the root canal curvature at approx. 7 mm from the apex. The maximum values were found when instruments were analyzed in the highest elastic modulus dentine canal. Strain and von Mises stress patterns showed a higher concentration in the first part of curved radius of all the instruments. Conventional Ni-Ti endodontic instruments demonstrated higher stress magnitudes, regardless of the conicity of 4% and 6%, and they showed the highest von Mises stress values in sound, as well as in mineralized dentine canals. Heat-treated endodontic instruments with higher flexibility values showed a reduced stress concentration map. Hyflex CM 25/04 displayed the lowest von Mises stress values of, respectively, 35.73 and 44.30 GPa for sound and mineralized dentine. The mechanical behavior of all rotary endodontic instruments was influenced by the different elastic moduli and by the dentine canal rigidity.

scholarly journals Analysis of the Morpho-Geometrical Changes of the Root Canal System Produced by TF Adaptive vs. BioRace: A Micro-Computed Tomography Study

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 531
Author(s):  
Loai Alsofi ◽  
Muhannad Al Harbi ◽  
Martin Stauber ◽  
Khaled Balto
Keyword(s):  
Surface Area ◽  
Root Canal ◽  
Type I ◽  
Structure Model ◽  
Canal Surface ◽  
Canal System ◽  
Structure Model Index ◽  
Continuous Rotation ◽  
Before And After ◽  
Root Canal System

We aimed to analyze the morpho-geometric changes of the root canal system created by two rotary systems (TF Adaptive and BioRace) using micro-CT technology. Two concepts of rotary file system kinematics, continuous rotation and adaptive kinematics, were used in root canal preparation. Twenty mandibular molars (n = 20) were selected with the following criteria: the teeth have mesial roots with a single and continuous isthmus connecting the mesiobuccal and mesiolingual canals (Vertucci’s Type I configuration) and distal roots with independent canals. Teeth were scanned at a resolution of 14 μm. Canals were divided equally into two groups and then enlarged sequentially using the BioRace system and TF Adaptive system according to manufacturer protocol. Co-registered images, before and after preparation, were evaluated for morphometric measurements of canal surface area, volume, structure model index, thickness, straightening, and un-instrumented surface area. Before and after preparation, data were statistically analyzed using a paired sample t-test. After preparation, data were analyzed using an unpaired sample test. The preparation by both systems significantly changed canal surface area, volume, structure model index, and thickness in both systems. There were no significant differences between instrument types with respect to these parameters (p > 0.05). TF Adaptive was associated with less straightening (8% compared with 17% for BioRace in the mesial canal, p > 0.05). Both instrumentation systems produced canal preparations with adequate geometrical changes. BioRace straightened the mesial canals more than TF Adaptive.

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