scholarly journals Stress Analysis of Endodontically Treated Anterior Teeth Restored with Different Types of Post Material

2006 ◽  
Vol 25 (1) ◽  
pp. 145-150 ◽  
Author(s):  
Takashi NAKAMURA ◽  
Tatsuo OHYAMA ◽  
Tomonori WAKI ◽  
Soichiro KINUTA ◽  
Kazumichi WAKABAYASHI ◽  
...  
Keyword(s):  
Stress Analysis ◽  
Anterior Teeth ◽  
Different Types

Photoelastic stress analysis of different types of anterior teeth splints

2020 ◽  
Author(s):  
Murilo Baena Lopes ◽  
Klissia Romero Felizardo ◽  
Ricardo Danil Guiraldo ◽  
Karina Fancio Sella ◽  
Sérgio Ramos Junior ◽  
...  
Keyword(s):  
Stress Analysis ◽  
Anterior Teeth ◽  
Different Types ◽  
Photoelastic Stress

scholarly journals Assessment of the Prevalence of the Different Types of Vertucci’s Root Canal Configurations in Mandibular Anterior Teeth

2021 ◽  
Vol 12 (2) ◽  
pp. 5-8
Author(s):  
Sachin Passi ◽  
Amit Bhagat ◽  
Preeti Choudhary ◽  
Aiyana Parthi ◽  
Sourabh Bhagat ◽  
...  
Keyword(s):  
Root Canal ◽  
Anterior Teeth ◽  
Different Types

scholarly journals Do NiTi Instruments show Defects before Separation? Defects caused by Torsional Fatigue in Hand and Rotary Nickel-Titanium (NiTi) Instruments which Lead to Failure during Clinical Use

2012 ◽  
Vol 13 (6) ◽  
pp. 867-872 ◽  
Author(s):  
Sudhir Kumar ◽  
P Ratnakar ◽  
NV Murali Krishna Chakka ◽  
Sanjib Das ◽  
Anandamy Bagchi ◽  
...  
Keyword(s):  
Nickel Titanium ◽  
Clinical Use ◽  
New Classification ◽  
Torsional Fatigue ◽  
Anterior Teeth ◽  
Microscopic Evaluation ◽  
Different Types ◽  
Before And After ◽  
The Difference ◽  
Niti Instruments

ABSTRACT Aims Visual and microscopic evaluation of defects caused by torsional fatigue in hand and rotary nickel titanium (NiTi) instruments. Materials and methods Ninety-six NiTi greater taper instruments which were routinely used for root canal treatment only in anterior teeth were selected for the study. The files taken include ProTaper for hand use, ProTaper Rotary files and Endowave rotary files. After every use, the files were observed visually and microscopically (Stereomicroscope at 10×) to evaluate the defects caused by torsional fatigue. Scoring was given according to a new classification formulated which gives an indication of the severity of the defect or damage. Statistical analysis Data was statistically analyzed using KruskallWallis and Mann-Whitney U test. Results Number of files showing defects were more under stereomicroscope than visual examination. But, the difference in the evaluation methods was not statistically significant. The different types of defects observed were bent instrument, straightening/stretching of twist contour and partial reverse twisting. Endowave files showed maximum number of defects followed by ProTaper for hand use and least in ProTaper Rotary. Conclusion Visible defects due to torsional fatigue do occur in NiTi instruments after clinical use. Both visual and microscopic examinations were efficient in detecting defects caused due to torsional fatigue. This study emphasizes that all files should be observed for any visible defects before and after every instrumentation cycle to minimize the risk of instrument separation and failure of endodontic therapy. How to cite this article Chakka NVMK, Ratnakar P, Das S, Bagchi A, Kumar S, Anumula L. Do NiTi Instruments show Defects before Separation? Defects caused by Torsional Fatigue in Hand and Rotary Nickel-Titanium (NiTi) Instruments which Lead to Failure during Clinical Use. J Contemp Dent Pract 2012;13(6):867-872.

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.

The Stress Analysis for the Trenchless Pipeline Rehabilitation

2005 ◽  
Author(s):  
Kuang-Chyi Lee ◽  
Rong-Yuan Jou ◽  
Hsin Her Yu ◽  
Yuan-Cheng Liang ◽  
Chien-Chang Lin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Analysis ◽  
Heavy Traffic ◽  
Element Model ◽  
Hydraulic Pressure ◽  
Optimal Thickness ◽  
Plastic Sheet ◽  
Different Types ◽  
The Finite Element Model

Most of the pipelines will get aging year after year and then they will need to be rehabilitated. Because of the heavy traffic on the ground or the congested pipelines under the ground, the replacement of old pipes will be very difficult in the cities. The dig-free (trenchless) method is a revolutionary pipelining method which uses air pressure, hydraulic pressure or mechanical drag force to pull the flexible piping plastic sheet into the old pipe. This research proposes a stress analysis for trenchless pipeline method by the finite element model with CATIA. The material of piping sheet is combined of two different types of epoxy with the anionic harder. We do the stress analysis of the trenchless rehabilitated pipelines to decide the optimal thickness of flexible piping plastic sheet and whether the material is available or not by finite element method.

scholarly journals Frequently affected teeth by different types of iatrogenic perforations made during dental training in Bulgaria

2021 ◽  
pp. 47
Author(s):  
◽  
◽  
Keyword(s):  
Treatment Failure ◽  
Root Canal ◽  
Entire Period ◽  
Patient Records ◽  
Posterior Teeth ◽  
Iatrogenic Perforation ◽  
Anterior Teeth ◽  
Different Types ◽  
Molar Teeth ◽  
Made In

Background: One of the reasons for endodontic treatment failure is iatrogenic perforation. That is why it is important to provide adequate endodontic education for graduating young practitioners. Aim: The aim of this study is to determine the most common locations of the iatrogenic perforations made by last year students in the Dental Faculty in Sofia, Bulgaria, to note the association of particular errors with particular teeth and to determine how this information can improve their education. Methods: All patient records of last-year students for 2015 and 2016 were examined. Perforations were diagnosed by radiography, and also confirmed clinically. Results: From all 778 teeth 30 incidents of root perforations were found: 10 in 2015 and 20 in 2016. More perforations were found in upper posterior teeth- 80% of all the perforations made in 2015, and 45% of all registered perforations in 2016. For the entire period of the research perforation frequency in upper molars, and in upper anterior teeth were found to be significantly higher than in other group of teeth. In academic 2015 year, 8 of the perforations (80%) were furcal. In 2016 year, 11 (55%) of all perforations were apical. Conclusions: More in-depth knowledge of endodontic anatomy , and also more strict supervision on students’ tasks are needed, especially regarding standard root canal treatment on molar teeth.

scholarly journals Guided endodontics: accuracy of access cavity preparation and discrimination of angular and linear deviation on canal accessing ability—an ex vivo study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yinghui Su ◽  
Chenghui Chen ◽  
Chiahua Lin ◽  
Huina Lee ◽  
Kerkong Chen ◽  
...  
Keyword(s):  
Roc Curve ◽  
Ex Vivo ◽  
Predictive Ability ◽  
Angular Deviation ◽  
Cavity Preparation ◽  
Apical Position ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Different Types ◽  
3D Printed

Abstract Background Guided endodontics technique has been introduced for years, but the accuracy in different types of teeth has yet to be assessed. The aim of this study is to evaluate the accuracy of three dimensional (3D)-printed endodontic guides for access cavity preparation in different types of teeth, and to evaluate the predictive ability of angular and linear deviation on canal accessibility ex vivo. Method Eighty-four extracted human teeth were mounted into six jaw models and categorised into three groups: anterior teeth (AT), premolar (P), and molar (M). Preoperative cone beam computed tomography (CBCT) and surface scans were taken and matched using implant planning software. Virtual access cavity planning was performed, and templates were produced using a 3D printer. After access cavities were performed, the canal accessibility was recorded. Postoperative CBCT scans were superimposed in software. Coronal and apical linear deviations and angular deviations were measured and evaluated with nonparametric statistics. The receiver operating characteristic (ROC) curve was used to evaluate the predictive ability of angular and linear deviation for canal accessibility in SPSS v20. Results A total of 117 guided access cavities were created and 23 of them were record as canal inaccessibility, but all canals were accessible after canal negotiation. The average linear deviation for all groups was 0.13 ± 0.21 mm at coronal position, 0.46 ± 0.4 mm at apical position, and 2.8 ± 2.6° in angular deviation. At the coronal position, the linear deviations of the AT and P groups were significantly lower than M group deviation (P < 0.05), but no statistically significant difference between AT group and P group. The same results were found in linear deviation at the apical position and in angular deviation. The area under the ROC curve was 0.975 in angular deviation, 0.562 in linear deviation at the coronal position, and 0.786 at the apical position. Statistical significance was noted in linear deviation at the apical position and in angular deviation (P < 0.001). Conclusions In conclusion, this study demonstrated that the accuracy of access cavity preparation with 3D-printed endodontic guides was acceptable. The linear and angular deviations in the M group were significantly higher than those in the other groups, which might be caused by the interference of the opposite teeth. Angular deviation best discriminated the canal access ability of guided access cavity preparation. Graphical Abstract

A Unified Analytical Method of Stress Analysis for Tubesheet—Part II: Case Study

2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Hongsong Zhu
Keyword(s):  
Stress Analysis ◽  
Analytical Method ◽  
Heat Exchangers ◽  
Numerical Comparison ◽  
Element Analysis ◽  
Comparison Results ◽  
Different Types ◽  
The Unified Method ◽  
Unified Method

Based on the unified analytical method of stress analysis for fixed tubesheet (TS) heat exchangers (HEX), floating head and U-tube HEX presented in Part I, numerical comparisons with ASME method are performed in this paper as Part II. Numerical comparison results indicate that predictions given by the unified method agree well with finite element analysis (FEA), while ASME results are not accurate or not correct. Therefore, it is concluded that the unified method deals with thin TS of different types of HEX in equal detail with confidence to predict design stresses.

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