scholarly journals Stress Distribution in Roots Restored with Different Types of Post Systems with Composite Resin

2008 ◽  
Vol 27 (4) ◽  
pp. 605-611 ◽  
Author(s):  
Daizo OKADA ◽  
Hiroyuki MIURA ◽  
Chikako SUZUKI ◽  
Wataru KOMADA ◽  
Chiharu SHIN ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Composite Resin ◽  
Different Types

Mandibular Implant-Supported Overdenture: An In Vitro Comparison of Ball, Bar, and Magnetic Attachments

2013 ◽  
Vol 39 (3) ◽  
pp. 302-307 ◽  
Author(s):  
V. Manju ◽  
T. Sreelal
Keyword(s):  
Stress Distribution ◽  
Strain Gauge ◽  
Load Transfer ◽  
Implant Surface ◽  
Transfer Characteristics ◽  
Ball Bar ◽  
Different Types ◽  
Dial Gauge ◽  
In Vitro Comparison

In an implant-supported overdenture, the optimal stress distribution on the implants and least denture displacement is desirable. This study compares the load transfer characteristics to the implant and the movement of overdenture among 3 different types of attachments (ball-ring, bar-clip, and magnetic). Stress on the implant surface was measured using the strain-gauge technique and denture displacement by dial gauge. The ball/O-ring produces the optimal stress on the implant body and promotes denture stability.

Stress Distribution Analysis of Different Types of Blade for a Fermentation System

2013 ◽  
Vol 479-480 ◽  
pp. 319-323
Author(s):  
Cheng Chi Wang ◽  
Po Jen Cheng ◽  
Kuo Chi Liu
Keyword(s):  
Stress Distribution ◽  
Maximum Stress ◽  
Effective Means ◽  
Materials Processing ◽  
Distribution Analysis ◽  
Stress Distributions ◽  
Fermentation System ◽  
Different Types ◽  
Inclined Angle ◽  
Key Parameter

Fermentation system is widely used for food manufacturing, materials processing and chemical reaction etc. Different types of blade in the tank for fermentation cause distinct stress distributions on the surface between fluid and blade, and appear various flow fields in the tank. So, this paper is mainly focused on analyzing the stress field of blades under different scales of blade with fixing rotational speed. The results show that the ratio of blade length to width influences stress distribution on the blades. At the same time, the inclined angle of blade is also the key parameter for the consideration of design and appropriate design will decrease the maximum stress. The results provide an effective means of gaining insights into the stress distribution of fermentation system.

The Strength Evaluation and Reliability Analysis of Periodic Symmetric Struts Support

2011 ◽  
Vol 462-463 ◽  
pp. 1164-1169
Author(s):  
Jing Xiang Yang ◽  
Ya Xin Zhang ◽  
Mamtimin Gheni ◽  
Ping Ping Chang ◽  
Kai Yin Chen ◽  
...  
Keyword(s):  
Distribution Function ◽  
Probability Distribution ◽  
Stress Distribution ◽  
Least Squares ◽  
Reliability Analysis ◽  
Least Squares Method ◽  
Nonlinear Least Squares ◽  
Distribution Model ◽  
Different Types ◽  
Nonlinear Least Squares Method

In this paper, strength evaluations and reliability analysis are conducted for different types of PSSS(Periodically Symmetric Struts Supports) based on the FEA(Finite Element Analysis). The numerical models are established at first, and the PMA(Prestressed Modal Analysis) is conducted. The nodal stress value of all of the gauss points in elements are extracted out and the stress distributions are evaluated for each type of PSSS. Then using nonlinear least squares method, curve fitting is carried out, and the stress probability distribution function is obtained. The results show that although using different number of struts, the stress distribution function obeys the exponential distribution. By using nonlinear least squares method again for the distribution parameters a and b of different exponential functions, the relationship between number of struts and distribution function is obtained, and the mathematical models of the stress probability distribution functions for different supports are established. Finally, the new stress distribution model is introduced by considering the DSSI(Damaged Stress-Strength Interference), and the reliability evaluation for different types of periodically symmetric struts supports is carried out.

scholarly journals Evaluation of maxillary anterior endodontically treated teeth restored with different types of crowns

2017 ◽  
Vol 5 (2) ◽  
pp. 163
Author(s):  
Mohammed Al Moaleem ◽  
Abdulrahman A Mobaraky ◽  
Hassan A Madkhali ◽  
Muneera R Gohal ◽  
Amna M Mobaraki ◽  
...  
Keyword(s):  
Composite Resin ◽  
Clinical Performance ◽  
Rank Test ◽  
Endodontically Treated Teeth ◽  
Exact Test ◽  
Color Changes ◽  
Anterior Teeth ◽  
Different Types ◽  
The One ◽  
Composite Restoration

Statement of the problem: restoring endodontically treated teeth (ETT) is one of the major treatments provided by a dentist. Glass fiber posts (GFP) showed good clinical performance during last few years.Aim of the study; to assess and compare the clinical as well as the radiographic performance of different types of ceramic crown systems used in restoration of maxillary anterior teeth over a cemented GFP and composite resin core.Materials and methods: 50 ETT with GFP were included in this study. These teeth were divided into four gropes (composite resin. Porcelain fused to metal (PFM), e. max and zirconia restorations). Both the clinical and radiographic assessments were done for the restoration at a period of one week, 3, 6, 9, and 12 months after composite build up and crown's cementations. All data were registered and analyzed by SPSS program using percentages and Kaplan-Meyer analysis. Fisher’s exact test was used for categorical values while log-rank test was used for descriptive statistical analysis.Results: the clinical assessment showed no changes in the one week, 3 and 6 months in the four groups. While during the 9 and 12 months, a movement of the crown margin under finger pressure was present in one case, loss or retention in 2 cases of zirconia, the periodontal status with violation of biological width was present in one case of PFM and finally the color changes were obvious in one case of PFM and 2 cases of composite restoration. All the restorations in the four groups had no radiographic changes in the one week and three-month assessments. While during six-month follow-up, a loosed of retention in one case of the zirconia crown was detected. At the 9 and 12 months, two cases showed recurrent caries at the cervical margin of the composite restoration, cases with periapical infection and other with loss of retention of the post were recorded in the PFM restoration.Conclusion: e. Max and zirconia all ceramic crowns showed better clinical and radiographic performance than the PFM and composite restorations over 12 months recall.

scholarly journals Polymerization Shrinkage of Different Types of Composite Resins and Microleakage With and Without Liner in Class II Cavities

2014 ◽  
Vol 39 (3) ◽  
pp. 325-331 ◽  
Author(s):  
E Karaman ◽  
G Ozgunaltay
Keyword(s):  
Composite Resin ◽  
Glass Ionomer Cement ◽  
Class Ii ◽  
Composite Resins ◽  
Imaging Device ◽  
Polymerization Shrinkage ◽  
Resin Modified Glass Ionomer ◽  
Different Types ◽  
Composite Resin Restorations

SUMMARY Aim To determine the volumetric polymerization shrinkage of four different types of composite resin and to evaluate microleakage of these materials in class II (MOD) cavities with and without a resin-modified glass ionomer cement (RMGIC) liner, in vitro. Materials and Methods One hundred twenty-eight extracted human upper premolar teeth were used. After the teeth were divided into eight groups (n=16), standardized MOD cavities were prepared. Then the teeth were restored with different resin composites (Filtek Supreme XT, Filtek P 60, Filtek Silorane, Filtek Z 250) with and without a RMGIC liner (Vitrebond). The restorations were finished and polished after 24 hours. Following thermocycling, the teeth were immersed in 0.5% basic fuchsin for 24 hours, then midsagitally sectioned in a mesiodistal plane and examined for microleakage using a stereomicroscope. The volumetric polymerization shrinkage of materials was measured using a video imaging device (Acuvol, Bisco, Inc). Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U-tests. Results All teeth showed microleakage, but placement of RMGIC liner reduced microleakage. No statistically significant differences were found in microleakage between the teeth restored without RMGIC liner (p>0.05). Filtek Silorane showed significantly less volumetric polymerization shrinkage than the methacrylate-based composite resins (p<0.05). Conclusion The use of RMGIC liner with both silorane- and methacrylate-based composite resin restorations resulted in reduced microleakage. The volumetric polymerization shrinkage was least with the silorane-based composite.

scholarly journals The Effects of Cavity Preparation and Composite Resin on Bond Strength and Stress Distribution Using the Microtensile Bond Test

2018 ◽  
Vol 43 (1) ◽  
pp. 81-89 ◽  
Author(s):  
SSL Braga ◽  
LRS Oliveira ◽  
RB Rodrigues ◽  
AA Bicalho ◽  
VR Novais ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Bond Strength ◽  
Failure Modes ◽  
Composite Resin ◽  
Shrinkage Stress ◽  
Cavity Preparation ◽  
Chi Square ◽  
Chi Square Test ◽  
Post Hoc ◽  
Made In

SUMMARY Objectives: To evaluate the effect of flowable bulk-fill or conventional composite resin on bond strength and stress distribution in flat or mesio-occlusal-distal (MOD) cavity preparations using the microtensile bond strength (μTBS) test. Methods: Forty human molars were divided into two groups and received either standardized MOD or flat cavity preparations. Restorations were made using the conventional composite resin Z350 (Filtek Z350XT, 3M-ESPE, St Paul, MN, USA) or flowable bulk-fill (FBF) composite resin (Filtek Bulk Fill Flowable, 3M-ESPE). Postgel shrinkage was measured using the strain gauge technique (n=10). The Z350 buildup was made in two increments of 2.0 mm, and the FBF was made in a single increment of 4.0 mm. Six rectangular sticks were obtained for each tooth, and each section was used for μTBS testing at 1.0 mm/min. Polymerization shrinkage was modeled using postgel shrinkage data. The μTBS data were analyzed statistically using a two-way analysis of variance (ANOVA), and the postgel shrinkage data were analyzed using a one-way ANOVA with Tukey post hoc test. The failure modes were analyzed using a chi-square test (α=0.05). Results: Our results show that both the type of cavity preparation and the composite resin used affect the bond strength and stress distribution. The Z350 composite resin had a higher postgel shrinkage than the FBF composite resin. The μTBS of the MOD preparation was influenced by the type of composite resin used. Irrespective of composite resin, flat cavity preparations resulted in higher μTBS than MOD preparations (p<0.001). Specifically, in flat-prepared cavities, FBF composite resin had a similar μTBS relative to Z350 composite resin. However, in MOD-prepared cavities, those with FBF composite resin had higher μTBS values than those with Z350 composite resin. Adhesive failure was prevalent for all tested groups. The MOD preparation resulted in higher shrinkage stress than the flat preparation, irrespective of composite resin. For MOD-prepared cavities, FBF composite resin resulted in lower stress than Z350 composite resin. However, no differences were found for flat-prepared cavities. Conclusions: FBF composite resin had lower shrinkage stress than Z350 conventional composite resin. The μTBS of the MOD preparation was influenced by the composite resin type. Flat cavity preparations had no influence on stress and μTBS. However, for MOD preparation, composite resin with higher shrinkage stress resulted in lower μTBS values.

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