scholarly journals Effect of different bracket types on streptococcus mutans count in orthodontic patients using fluoridated toothpaste

2020 ◽  
Vol 32 (2) ◽  
pp. 1-4
Author(s):  
Hala Jasim ◽  
Dhiaa Al-Dabagh ◽  
Maha Mahmood
Keyword(s):  
Stainless Steel ◽  
Streptococcus Mutans ◽  
Bacterial Count ◽  
Test Results ◽  
Plaque Sample ◽  
Counting Method ◽  
Orthodontic Therapy ◽  
Orthodontic Patients ◽  
The Right ◽  
Colony Counter

Background: Plaque retention during fixed orthodontic therapy is an important cause of developing enamel demineralization. The purpose of this study was to evaluate the effect of different brackets types on the count of Streptococcus Mutans in orthodontic patients using conventional fluoridated toothpaste. Materials and Methods: Plaque samples were collected from maxillary 1st premolar teeth of twenty right handed patients (using split mouth technique) before bonding, after 48 hrs of bonding using tooth brush only, and after 2 weeks of using fluoridated toothpaste. Stainless steel bracket was bonded on right first premolar while the left one was bonded with sapphire bracket. The calculation of the Streptococcus Mutans count was done using the plate counting method utilizing colony counter. The differences between the two types of brackets were determined using the Wilcoxon signed ranks test. Results: The median bacterial count on the right side was insignificantly higher than the left side; streptococcus mutans in the plaque sample around the sapphire brackets showed insignificantly less counts than around the stainless steel one, when the patients used tooth brush only or fluoridated toothpastes. Fluoridated toothpastes reduced streptococcus mutans insignificantly around both types of brackets. Conclusion: Fluoridated toothpaste acts effectively in reducing streptococcus mutans colony counts around sapphire and stainless steel brackets. Keywords: Streptococcus mutans, Stainless steel brackets, Sapphire brackets.

scholarly journals Virulence modulation of Streptococcus mutans biofilms by metal ions released from orthodontic appliances

2013 ◽  
Vol 83 (6) ◽  
pp. 987-993 ◽  
Author(s):  
Alinne Ulbrich Mores Rymovicz ◽  
Maiara Medeiros Ronsani ◽  
Ana Maria Trindade Grégio ◽  
Odilon Guariza Guariza-Filho ◽  
Orlando Tanaka ◽  
...  
Keyword(s):  
Metal Ions ◽  
Streptococcus Mutans ◽  
Metal Ion ◽  
Laboratory Data ◽  
Sugar Metabolism ◽  
Orthodontic Appliances ◽  
Orthodontic Therapy ◽  
Orthodontic Patients ◽  
The Impact

ABSTRACT Objectives: To evaluate the impact of metal ions commonly shed from orthodontic appliances on the virulence of Streptococcus mutans ATCC®25175™ biofilms. Materials and Methods: Biofilms were grown in the presence of Ni2+, Fe3+, Cr3+, Co2+, and a metal ion pool at concentrations similar to those released in saliva of orthodontic patients for 72 hours. Once mature, biofilms were treated for up to 12 hours with 5% glucose. Results: Ions interfered with the growth of S mutans by reducing its biomass (Ni2+, Fe3+, Cr3+), raising its rates of sugar metabolism (Ni2+, Fe3+, Cr3+), and raising its secretion of lactate (Ni2+, Fe3+, Cr3+, pool). Conclusion: The laboratory data presented here point to the possibility of virulence increase of S mutans by metal ions commonly released during orthodontic therapy.

Biomechanical characteristics of allogeneic cortical bone pins designed for fracture fixation

2008 ◽  
Vol 21 (02) ◽  
pp. 140-146
Author(s):  
M. R. Edwards ◽  
S. P. James ◽  
W. S. Dernell ◽  
R. J. Scott ◽  
A. M. Bachand ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Cortical Bone ◽  
Fracture Fixation ◽  
Impact Testing ◽  
Left Tibia ◽  
Four Point Bending ◽  
And Gender ◽  
The Right ◽  
Biomechanical Comparison ◽  
Better Than

SummaryThe biomechanical characteristics of 1.2 mm diameter allogeneic cortical bone pins harvested from the canine tibia were evaluated and compared to 1.1 mm diameter stainless steel pins and 1.3 mm diameter polydioxanone (PDS) pins using impact testing and four-point bending. The biomechanical performance of allogeneic cortical bone pins using impact testing was uniform with no significant differences between sites, side, and gender. In four-point bending, cortical bone pins harvested from the left tibia (204.8 ± 77.4 N/mm) were significantly stiffer than the right tibia (123.7 ± 54.4 N/mm, P=0.0001). The site of bone pin harvest also had a significant effect on stiffness, but this was dependent on interactions with gender and side. Site C in male dogs had the highest mean stiffness in the left tibia (224.4 ± 40.4 N/mm), but lowest stiffness in the right tibia (84.9 ± 24.2 N/mm). Site A in female dogs had the highest mean stiffness in the left tibia (344.9 ± 117.4 N/mm), but lowest stiffness in the right tibia (60.8 ± 3.7 N/mm). The raw and adjusted bending properties of 1.2 mm cortical bone pins were significantly better than 1.3 mm PDS pins, but significantly worse than 1.1 mm stainless steel pins (P<0.0001). In conclusion, cortical bone pins may be suitable as an implant for fracture fixation based on initial biomechanical comparison to stainless steel and PDS pins used in clinical practice.

Evaluation of Mandibular Arch Width Changes following Fixed Retention in Post Orthodontic Patients - a Randomized Clinical Trial

2020 ◽  
Author(s):  
Nasreen Iqbal Nagani
Keyword(s):  
Stainless Steel ◽  
Steel Wire ◽  
P Value ◽  
Chi Square ◽  
Mandibular Arch ◽  
Arch Width ◽  
Orthodontic Patients ◽  
Mean Differences ◽  
One Year ◽  
The Stability

Background: Retention is an integral phase in which teeth are maintained in their newly adapted position for which retainers are inserted. Retainers are generally of two types: removable and fixed. Fixed retainers are indicated in the mandibular arch for an indefinite period specifically in the non-extraction cases. Changes in intercanine and intermolar widths are valuable parameters to evaluate the stability. The objectives of this study were to assess and compare the mandibular intercanine and intermolar width changes following orthodontic treatment after insertion of two types of fixed lingual retainers for one year. Methods: Total 54 subjects were recruited in which two types of fixed lingual retainers were inserted in the mandibular arch randomly. Intercanine and intermolar arch widths were measured by digital caliper of 0.01 mm accuracy. Data was analyzed by using Statistical Package of Social Sciences (SPSS V-21). Chi-square and independent t tests were used to compare baseline characteristics. Intercanine and intermolar widths were assessed and compared using independent t test, p-value ≤ 0.05 is considered as statistically significant. Results: Intercanine width increased from baseline to T4 in both retainers. When mean differences of intercanine width were compared between two retainers significant differences were observed at T1, T2, T3 and T4 with significant p-values (< 0.05) and increased intercanine width with multistranded stainless steel wire (MSW) retainers. Conclusion: Mandibular intercanine width increases significantly in post retention phase with multistranded stainless steel retainers. Thus, fiber reinforced composite retainers are more effective in preserving the arch width changes.

scholarly journals Technical efficiency of pesticide application on tomato, chinese cabbage and cauliflower in simpang empat sub-district Karo Regency

2018 ◽  
Vol 52 ◽  
pp. 00045
Author(s):  
Sri Fajar Ayu ◽  
Destanul Aulia
Keyword(s):  
Technical Efficiency ◽  
Chinese Cabbage ◽  
Quantitative Method ◽  
Protective Device ◽  
Test Results ◽  
Pesticide Application ◽  
Vegetable Farmers ◽  
The Right ◽  
North Sumatra ◽  
Mild Toxicity

Prior research by authors on the use of pesticides and their impact on 75 vegetable farmers in Simpang Empat subdistrict, Karo district, North Sumatra showed that 60% of respondents applied pesticides in excess of the packaging instructions. Respondents were also found not to use a complete protective device. Almost 70% of respondents have mild toxicity complaints, and based on blood cholinesterase levels are also found most respondents have mild toxicity. Pesticide residue test results also found 0.728 residues of chlorpyrifos and 0.321 profenofos in vegetables produced in this area. This led to continued review by checking the technical efficiency in the use of pesticides. The method used is a quantitative method with the Data Envelope Analysis (DEA) approach to analyze technical efficiency of pesticide on each commodity. The population is the whole vegetable farmer who grew tomatoes, Chinese cabbage and cauliflower at the time of the study. The entire population is used to be a sample of 35 tomato and cauliflower farmers and 20 Chinese cabbage farmers. The results of the study indicate that the uses of pesticide as production inputs on tomato commodities, Chinese cabbage and cauliflower are not technically efficient. It is suggested to farmers to use pesticide input according to the rules, proper dosage, on target, on time, the right way so that pesticide used is technically efficient.

Investigation on Material Selection in Missan Oilfields Similar Environment

2014 ◽  
Vol 641-642 ◽  
pp. 427-433
Author(s):  
Shuang Cheng ◽  
Feng Lin ◽  
Pei Long Yang ◽  
Pei Ke Zhu ◽  
Jin Gen Deng ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Nickel Alloy ◽  
Martensitic Stainless Steel ◽  
Material Selection ◽  
Pressure Ratio ◽  
Service Condition ◽  
Corrosion Mechanism ◽  
Test Results ◽  
Chrome Steel

This paper analyzed the corrosion environment of Missan oilfields and investigated the oilfield country tubular goods used in other similar oilfields. Summarized the effect of partial pressure ratio of H2S/CO2 and Cl-to the corrosion behavior of OCTG. This paper concluded the service condition, test results and anti-corrosion mechanism of carbon steel, low-chrome steel, modified martensitic stainless steel and nickel alloy. Finally arrived at conclusion that the nickel alloy can meet the requirement of Missan oilfields, some literature reported that the modified martensitic stainless steel can apply in H2S/CO2 environment. In the condition that be easy to replace the tubular, carbon steel and low-chrome steel tubular can meet the requirement with corrosion inhibitor.

Effects of Surface Finish and Loading Conditions on the Low Cycle Fatigue Behavior of Austenitic Stainless Steel in PWR Environment for Various Strain Amplitude Levels

2009 ◽  
Author(s):  
Jean Alain Le Duff ◽  
Andre´ Lefranc¸ois ◽  
Jean Philippe Vernot
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Strain Amplitude ◽  
Surface Finish ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Complex Loading ◽  
Loading Conditions ◽  
Test Results ◽  
Cycle Fatigue

In February/March 2007, The NRC issued Regulatory Guide “RG1.207” and Argonne National Laboratory issued NUREG/CR-6909 that is now applicable in the US for evaluations of PWR environmental effects in fatigue analyses of new reactor components. In order to assess the conservativeness of the application of this NUREG report, Low Cycle Fatigue (LCF) tests were performed by AREVA NP on austenitic stainless steel specimens in a PWR environment. The selected material exhibits in air environment a fatigue behavior consistent with the ANL reference “air” mean curve, as published in NUREG/CR-6909. LCF tests in a PWR environment were performed at various strain amplitude levels (± 0.6% or ± 0.3%) for two loading conditions corresponding to a simple or to a complex strain rate history. The simple loading condition is a fully reverse triangle signal (for comparison purposes with tests performed by other laboratories with the same loading conditions) and the complex signal simulates the strain variation for an actual typical PWR thermal transient. In addition, two various surface finish conditions were tested: polished and ground. This paper presents the comparisons of penalty factors, as observed experimentally, with penalty factors evaluated using ANL formulations (considering the strain integral method for complex loading), and on the other, the comparison of the actual fatigue life of the specimen with the fatigue life predicted through the NUREG report application. For the two strain amplitudes of ± 0.6% and ± 0.3%, LCF tests results obtained on austenitic stainless steel specimens in PWR environment with triangle waveforms at constant low strain rates give “Fen” penalty factors close to those estimated using the ANL formulation (NUREG/6909). However, for the lower strain amplitude level and a triangle loading signal, the ANL formulation is pessimistic compared to the AREVA NP test results obtained for polished specimens. Finally, it was observed that constant amplitude LCF test results obtained on ground specimens under complex loading simulating an actual sequence of a cold and hot thermal shock exhibits lower combined environmental and surface finish effects when compared to the penalty factors estimated on the basis of the ANL formulations. It appears that the application of the NUREG/CR-6909 in conjunction with the Fen model proposed by ANL for austenitic stainless steel provides excessive margins, whereas the current ASME approach seems sufficient to cover significant environmental effects for representative loadings and surface finish conditions of reactor components.

Friction-Instability: A New Design Parameter for Brakes

1971 ◽  
Vol 93 (4) ◽  
pp. 1225-1228 ◽  
Author(s):  
W. L. Starkey ◽  
T. G. Foster ◽  
S. M. Marco
Keyword(s):  
Quality Control ◽  
Coefficient Of Friction ◽  
Design Parameter ◽  
Control Device ◽  
Experimental Facility ◽  
Test Results ◽  
Effective Manner ◽  
The Coefficient Of Friction ◽  
Brake Lining ◽  
The Right

A new design parameter, friction-instability, is defined in this paper. Friction-instability is a variation in the coefficient of friction which may occur at any time during the life of a brake lining. A friction-index is defined which measures this variation. A lining which has a high friction index may tend to cause an automobile to swerve either to the right or to the left. A unique experimental facility is described by means of which the friction-instability characteristics of brake linings can be measured. Test results using this facility are presented and interpreted. The friction-index is proposed as a new parameter which should be taken into consideration when brakes are designed and, developed. This index should be particularly useful as a quality control device to insure that machines which use mass-produced braking systems will perform in a safe and effective manner.

Study on Conventional Domed Bursting Disc Material and Burst Pressure Test

2013 ◽  
Vol 690-693 ◽  
pp. 2371-2378
Author(s):  
Wei Pu Xu ◽  
Yi Ting Liu
Keyword(s):  
Stainless Steel ◽  
Tensile Test ◽  
316L Stainless Steel ◽  
Performance Test ◽  
Test Method ◽  
Burst Pressure ◽  
Test Results ◽  
Manufacturing Method ◽  
Pressure Test ◽  
Disc Material

A brief overview is given in the conventional domed bursting disc structure and manufacturing method. 316L stainless steel as a template is selected. With the investigation on bursting disc material tensile test method, the test results are summarized,also the burst results of disc burst pressure in different sizes. With the help of bursting disc material performance test and bursting disc burst pressure test of 316L , the test results provide a reference for other types of bursting disc.

scholarly journals The Relationship between Palatal Displacement of Upper Canines and Incisors Widths in a Syrian Sample of Patients with Uncrowded Arches

2015 ◽  
Vol 16 (11) ◽  
pp. 873-875 ◽  
Author(s):  
Luai Mahaini
Keyword(s):  
Orthodontic Treatment ◽  
Matched Control ◽  
Control Sample ◽  
Tooth Size ◽  
Orthodontic Patients ◽  
Treatment Plans ◽  
The Right ◽  
The Relationship ◽  
Mandibular Incisors ◽  
Dental Casts

ABSTRACT The aim of this study investigates mesiodistal crown size of the maxillary and mandibular incisors of patients with palatally impacted canines (PDC). Pretreatment dental casts of orthodontic patients with PDC of one or both maxillary canines (N: 33) were collected. This PDC sample was matched according to age and sex with pretreatment dental casts from unaffected orthodontic patients. For the PDC and matched control samples, maximum mesiodistal crown diameters were recorded for the four incisors on the right side only. The results showed that, on average, the mesiodistal crown diameters for the maxillary and mandibular incisors measured smaller in the PDC sample than in the control sample. These findings of statistically significant tooth-size reductions associated with PDC occurrence indicate a generalized pattern of reduced tooth size as a characteristic associated with the PDC anomaly. Further, the presence of generalized tooth-size reduction in cases with palatally displaced canines help explain why most orthodontic treatment plans for PDC patients are of the nonextraction type. How to cite this article Mahaini L. The Relationship between Palatal Displacement of Upper Canines and Incisors Widths in a Syrian Sample of Patients with Uncrowded Arches. J Contemp Dent Pract 2015;16(11):873-875

scholarly journals Study on Suitability and Behaviour of Ferrocement in Folded Plates

2021 ◽  
Vol 9 (VI) ◽  
pp. 3540-3546
Author(s):  
Mr. V. Karthick
Keyword(s):  
Stainless Steel ◽  
Compressive Strength ◽  
Cross Section ◽  
Test Results ◽  
Logical Investigation ◽  
Second Stage ◽  
Concrete Application ◽  
Extended Range ◽  
Properties Of Materials ◽  
Low Consumption

Ferro concrete is one of the developments arising material an alternative for the traditional RCC in numerous viewpoints. Ferro concrete is the fate of the minimal expense houses and precast houses. Folded plates are answer for the more extended range rooftops in prudent and aesthetical manner. This project consolidates the upsides of both Ferro concrete and collapsed plate. The box type Ferro concrete collapsed plates of size 0.6 m x 1.80 m x 0.15 m are casted by thinking about various diaries and RCC collapsed plates in thought while fixing dimensions. In first period of trial various properties of materials utilized for projecting are tried and compressive strength of the mortar utilized is tried, the test is done at 1:2 of concrete: sand proportion and 0.35 water concrete ratio. In second stage the example is casted with Stainless Steel cross section of 2 mm opening is utilized and 2 layers on front and posteriors of 6mm width 150m divided skeleton steel is laid. The projected examples is tried for 28 days strength in stacking outline and the outcomes are contrasted and logical investigation Using ANSYS for load versus redirection and reasonableness of Ferro concrete application in collapsed plates are studies. The test results are shown acceptable outcomes, at last with low consumption and low self-weight Ferro concrete constructions are acceptable substitute for RCC.

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