scholarly journals Stress Analysis of a Maxillary Central Incisor Restored with Different Posts

2007 ◽  
Vol 01 (02) ◽  
pp. 067-071 ◽  
Author(s):  
Necdet Adanir ◽  
Sema Belli
Keyword(s):  
Stress Distribution ◽  
Glass Fiber ◽  
Gold Alloy ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Maxillary Incisor ◽  
Central Incisor ◽  
Cross Sectional ◽  
Maxillary Central Incisor

ABSTRACTObjectives: To evaluate the effects of different post materials on the stress distribution in an endodontically treated maxillary incisor.Materials and Methods: A pseudo 3-dimensional finite element model was created in a labiolingual cross-sectional view of a maxillary central incisor and modified according to five posts with different physical properties consisting stainless steel, titanium, gold alloy, glass fiber (Snowpost), and carbon fiber (Composipost). A 200 N force was then applied from two different directions; a) vertical load on the incisal edge, b) 45 degree diagonal load above the cingulum location. Stress distribution and values were then calculated by considering the pseudo three dimensional von Mises stress criteria.Results: Under two loading conditions, post made of steel showed greatest stress concentration at the post/dentin interface followed by titanium, gold alloy, Snowpost and Composipost. However, Composipost, which elastic modulus was closer to the dentin, produced highest stress values at 1/3 cervical area.Conclusions: Within the limitation of this simulated mechanical analysis, we can conclude that the physical characteristics of posts were important on stress distributions in post and core applications. Glass fiber post revealed more balanced stress distribution under functional forces. (Eur J Dent 2007;2:67-71)

scholarly journals Stress distributions in maxillary central incisors restored with different high-stiffness post models: 3-D FEA

2018 ◽  
Vol 6 (1) ◽  
pp. 45
Author(s):  
Bassam Srayeddin ◽  
Ali Almuntashri
Keyword(s):  
Stress Distribution ◽  
Root Canal ◽  
Gold Alloy ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Distribution Profile ◽  
Maxillary Central Incisor ◽  
Group I ◽  
Group Ii ◽  
Restoration Failure

Background: Dental root posts are recommended for endodontically treated weakened teeth.Objectives: The present computational FEA study aims to evaluate the effect of material and design of the post on the stress distribution under load in different root canal shapes of endodontically treated maxillary central incisor (MCI).Methods: Three-dimensional models of (MCI) were created by using CAD modeling software and divided into two groups. Group-I comprised five models of a weakened root restored using different post materials (stainless steel, titanium, gold-alloy, Ni-Cr, and zirconium). Group-II: involved four models of (MCI) with two different root canal shapes (small and wide) restored using cylindrical (C-Post) and two-stage tapered (T-Post) posts. Each tooth model was subjected to a 100 N oblique load at the palatal surface of the crown. Von Mises equivalent stresses on dentin and post, as well as shear stresses on the post cement, were evaluated.Results: In Group-I: Ni-Cr produced the lowest stress values on the dentin, where titanium and gold-alloy posts produced the lowest stresses in the post and post/root interfaces. In Group-II: Roots restored with a T-Post showed a lower concentration stress in the dentin and lower shear stresses in the cement layer compared with those restored with a C-Post.Conclusion: The geometry of the post and the corresponding material play an important role in the stress behavior of restored teeth. The use of titanium or gold-alloy T-Posts seems a good way to improve the stress distribution profile and reduce the risk of restoration failure.   

SEXUAL DIMORPHISM OF MINANGKABAUNES’ MAXILLARY CENTRAL INCISOR’S WIDTH

2017 ◽  
Vol 20 (1) ◽  
pp. 8-12
Author(s):  
Nila Kasuma ◽  
Susi Susi ◽  
Haria Fitri ◽  
Fildzah Nurul Fajrin
Keyword(s):  
Sexual Dimorphism ◽  
Sampling Technique ◽  
Simple Random Sampling ◽  
Maxillary Incisor ◽  
Central Incisor ◽  
Cross Sectional ◽  
Average Width ◽  
Maxillary Central Incisor ◽  
Biological Damage ◽  
Significant Difference

Teeth are known as organs made up of the hardest mineral tissue that is resistant to decay and physical, thermal, mechanical, chemical or biological damage. Tooth crown dimensions are reasonably accurate predictors of genders especially to young individuals whose secondary skeletal characteristics are yet developed. This research aims to analyse the influence of genders to the width of maxillary central incisor Minangkabaunese. The study was conducted using cross-sectional method in Luhak Agam, Luhak Tanah Datar and Luhak Lima Puluh Kota, West Sumatra using simple random sampling technique to a total of 120 samples. Teeth width was measured in mesiodistal dimension with 0.01 mm calibrated sliding digital caliper. The measurement was done on a tooth mould at ⅓ incisal as the position of mesial and biggest distar. T-test independent statistic test was done to determine the relationship between the 2 variables. Sexual dimorphism was determined with Garn formula. The research shows significant difference (p=0.001) between the width of left and right central incisor in males and females. The average width of the male and female right maxillary incisor is 8.545 mm and 8.370 mm, while the left central incisor width is 8.877 mm in male and 8.283 mm in females. Sexual dimorphism on the right central incisor is 2.09% and 3.43% on the left side. The conclusion of the study is that maxillary central incisor width can distinguish different genders in the identification process.

Finite Element Analysis for the Mega Columns for XRL West Kowloon Terminus

2013 ◽  
Vol 405-408 ◽  
pp. 1139-1143
Author(s):  
Wei Su ◽  
Ying Sun ◽  
Shi Qing Huang ◽  
Ren Huai Liu
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Parametric Design ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element

Using ANSYS parametric design language, a three-dimensional finite element model is developed to analyze the stress distribution and the strength of the mega columns for XRL West Kowloon Terminus. The detailed von Mises stress distribution in each column, vertical stiffener plates and the diaphragm plates is obtained. From the analysis, the phenomenon of stress concentration is obvious in both upper and lower diaphragm plates. The local value of von Mises stress in them is higher than the yield stress value, which must be avoided by more detailed local structural design.

scholarly journals Analysis of colorimetric parameters of international commission on illumination L*a*b* system in the color of maxillary central incisors

2020 ◽  
Vol 73 (9-10) ◽  
pp. 309-314
Author(s):  
Aleksandra Maletin ◽  
Milica Jeremic-Knezevic ◽  
Daniela Djurovic-Koprivica ◽  
Tanja Veljovic ◽  
Bojana Ramic ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Spectrophotometric Analysis ◽  
International Commission ◽  
Maxillary Incisor ◽  
Blue Color ◽  
Central Incisor ◽  
Color Tone ◽  
Tooth Color ◽  
Maxillary Central Incisor ◽  
Significant Difference

Introduction. Tooth color can be represented in a three-dimensional color system by applying L* (lightness), a* (red-green color tone) and b* (yellow-blue color tone) coordinates. Clinically significant color difference, Delta-E, can be expressed in units that are correlated with visual perception using the International Commission on Illumination L*a*b* system. The aim of the study was spectrophotometric analysis of the natural maxillary central incisor color, and to establish any gender-related differences in lightness, red-green tone, and yellow-blue tone coordinates. Material and Methods. The study included 80 students (40 male and 40 female, with an average age of 22 years). The color of the maxillary right central incisor was determined using an intraoral spectrophotometer and VITAPAN Classical and VITA 3D-Master color shade guides. Lightness, red-green tone, and yellow-blue tone values were recorded for each result. The obtained data were processed by using ?2, Student?s t-test and Mann-Whitney test. Results. Results showed no statistically significant gender-related difference in color according to the VITApan Classical and VITA 3D-Master color key. No difference was found in the lightness of the central maxillary incisor between genders, or in terms of red-green tone (p = 0.860573). A statistically significant difference was found when observing the sex-related yellow-blue tone of the color of the central maxillary incisor. Conclusion. The analysis of colorimetric parameters of the International Commission on Illumination L*a*b* system provides useful information about the tooth color in the examined population, while potentially revealing differences in lightness, red-green tone and yellow-blue tone between genders.

scholarly journals The effect of type post, crown, and ferrule presence on stress distribution of maxillary central incisors with weakened roots: Finite Element Analysis

2013 ◽  
Vol 1 (2) ◽  
pp. 154 ◽  
Author(s):  
Paulo César de Freitas Santos-Filho ◽  
Crisnicaw Verissimo ◽  
Cristhiane Leão Queiroz ◽  
Rebeca Carniello Saltarelo ◽  
Carlos José Soares ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Glass Fiber ◽  
Numerical Models ◽  
Central Incisor ◽  
Fiber Post ◽  
Maxillary Central Incisor ◽  
Biomechanical Behavior ◽  
Glass Fiber Post ◽  
Root Dentin ◽  
Post And Core

The aim of this study was to evaluate the biomechanical behavior, by means FEA, of maxillary central incisor with weakened roots restored with different posts, crowns and ferrule presence. A digital image of an intact maxillary central incisor section plane around the alveolar bone was obtained in order to build the model of sound tooth. A sound tooth and eight two-dimensional numerical models were generated from the protocol of image processing. The studied factors were: crown type - metal-ceramic crown (MC) and alumina-reinforced ceramic (CC); post type - glass fiber post (GFP) and cast post and core (CPC); and ferrule - absence of ferrule (AFE) and 2,0 mm ferrule (FE2). A 2N static and oblique load with a 135° inclination to the tooth longitudinal axis was applied at the level of palatal surface of the crown. The displacement was restricted and stress of tensile and compression within the tooth structure was recorded. Cast post and core models concentrated stresses in post dentin interface and glass fiber post models had homogeneous stresses distribution within the root dentin similar to sound tooth. The restorative complex GFP-CC concentrated higher stress in coping than GFP-MC, both models with or without ferrule. The ferrule presence improved the stress distribution regardless of the crown and post types. Therefore, cast post-and-cores concentrate too much stresses within a root dentin and post interface; glass fiber post has more homogeneous stress distribution in dentin than cast post-and-cores; the presence of 2 mm ferrule improves the mechanical behavior.

scholarly journals Evaluation of Stress Generated with Different Abutment Materials and Angulations under Axial and Oblique Loading in the Anterior Maxilla: Three-Dimensional Finite Element Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Sumedha Kapoor ◽  
Shobha Rodrigues ◽  
M. Mahesh ◽  
Thilak Shetty ◽  
Umesh Pai ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
The Body ◽  
Von Mises Stress ◽  
Central Incisor ◽  
Element Analysis ◽  
Anterior Maxilla ◽  
Maxillary Central Incisor ◽  
Von Mises

Purpose. The aim of this study was to assess and correlate the stress distribution in an anterior maxillary implant-supported prosthesis with 0°(degree), 15°, and 25° angulated titanium and zirconia abutments using a three-dimensional (3D) finite element analysis (FEA). Materials and Methods. Six FEA models consisting of a dentate anterior maxilla with a single bone-level implant of dimension 4.2 × 10 mm placed in the region of left maxillary central incisor and abutments of dimension 4.2 mm made of titanium and zirconia each with angulation 0° (IA and IB), 15° (IIA and IIB), and 25° (IIIA and IIIB) and ANSYS Workbench software were utilized to design a layered zirconia crown. Unilateral axial and oblique loads of 178 N were applied on the palatal aspect of the crown of left maxillary central incisor. Average von Mises stress values were evaluated in the implant and the peri-implant bone quantitatively and qualitatively. Results. Stress was shown to increase with an increase in angulation in all the areas that were examined. Zirconia abutments showed lesser stress in the implant and surrounding bone than titanium abutments. When compared with the body and apex of the implant, the implant neck values were higher in all models. In between cortical and cancellous bone, the stress recorded was higher in the cortical bone. Conclusion. Within the limitations of this study, straight abutments generated a more uniform and minimal stress in implant and peri-implant bone than angulated abutments. Titanium abutments generated higher stress levels than zirconia abutments. The stresses generated are directly proportional to an increase in abutment angulation, and therefore, straight abutments are most suitable for favourable stress transmission.

scholarly journals A Comparative Evaluation of Stress Distribution by Three Different Designs of Prefabricated Metal Posts on Endodontically Treated Permanent Maxillary Central Incisor: A Three-dimensional Finite Element Study

2015 ◽  
Vol 5 (3) ◽  
pp. 123-130
Author(s):  
Jyoti Nadgere ◽  
Ganesh Pandurang Mengal
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Comparative Evaluation ◽  
Three Dimensional ◽  
Central Incisor ◽  
Maxillary Central Incisor ◽  
Finite Element Study ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Element Study

ABSTRACT Purpose of the study: This study intends to evaluate and compare the stress distribution by three designs of prefabricated metal posts, parallel post (EG post), parallel post with coronal flare (i-post) and a tapered post (Filpost) in endodontically treated permanent maxillary central incisor. This study will help the dentists to choose the post that would generate the least stress in endodontically treated teeth. Procedure Three-dimensional (3D) finite element models were developed. The physical models include composite resin core material, dentin, endodontic post, luting cement and guttapercha. They were subjected to compressive load of 100 N at 135° angle with respect to longitudinal axis of tooth, above the level of cingulum, simulating the load condition in oral cavity and the effects of three posts on stress distribution, in endodontically treated maxillary central incisor was evaluated. Results Stress distribution was found to be better in the models having parallel post and parallel post with the coronal flare. Coronal flare has an added advantage of better fit in the root canal. Conclusion It was found that the stresses in maxillary central incisor with the parallel post with coronal flare were well distributed. How to cite this article Mengal GP, Nadgere J, Ram SM, Shah N. A Comparative Evaluation of Stress Distribution by Three Different Designs of Prefabricated Metal Posts on Endodontically Treated Permanent Maxillary Central Incisor: A Three-dimensional Finite Element Study. J Contemp Dent 2015;5(3):123-130.

scholarly journals Effects of intracorneal ring segments implementation technique and design on corneal biomechanics and keratometry in a personalized computational analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Niksa Mohammadi Bagheri ◽  
Mahmoud Kadkhodaei ◽  
Shiva Pirhadi ◽  
Peiman Mosaddegh
Keyword(s):  
Clinical Data ◽  
Three Dimensional ◽  
Element Model ◽  
Von Mises Stress ◽  
Patient Specific ◽  
Average Error ◽  
Constant Thickness ◽  
Arc Length ◽  
Implementation Techniques ◽  
Von Mises

AbstractThe implementation of intracorneal ring segments (ICRS) is one of the successfully applied refractive operations for the treatment of keratoconus (kc) progression. The different selection of ICRS types along with the surgical implementation techniques can significantly affect surgical outcomes. Thus, this study aimed to investigate the influence of ICRS implementation techniques and design on the postoperative biomechanical state and keratometry results. The clinical data of three patients with different stages and patterns of keratoconus were assessed to develop a three-dimensional (3D) patient-specific finite-element model (FEM) of the keratoconic cornea. For each patient, the exact surgery procedure definitions were interpreted in the step-by-step FEM. Then, seven surgical scenarios, including different ICRS designs (complete and incomplete segment), with two surgical implementation methods (tunnel incision and lamellar pocket cut), were simulated. The pre- and postoperative predicted results of FEM were validated with the corresponding clinical data. For the pre- and postoperative results, the average error of 0.4% and 3.7% for the mean keratometry value ($$\text {K}_{\text{mean}}$$ K mean ) were predicted. Furthermore, the difference in induced flattening effects was negligible for three ICRS types (KeraRing segment with arc-length of 355, 320, and two separate 160) of equal thickness. In contrast, the single and double progressive thickness of KeraRing 160 caused a significantly lower flattening effect compared to the same type with constant thickness. The observations indicated that the greater the segment thickness and arc-length, the lower the induced mean keratometry values. While the application of the tunnel incision method resulted in a lower $$\text {K}_{\text{mean}}$$ K mean value for moderate and advanced KC, the induced maximum Von Mises stress on the postoperative cornea exceeded the induced maximum stress on the cornea more than two to five times compared to the pocket incision and the preoperative state of the cornea. In particular, an asymmetric regional Von Mises stress on the corneal surface was generated with a progressive ICRS thickness. These findings could be an early biomechanical sign for a later corneal instability and ICRS migration. The developed methodology provided a platform to personalize ICRS refractive surgery with regard to the patient’s keratoconus stage in order to facilitate the efficiency and biomechanical stability of the surgery.

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