scholarly journals A COMPARASION OF BRACKET DEBONDING FORCES BETWEEN THE TWO ADHESIVES: CON TEC LC AND CON TEC DUO

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Vladan Mirjanić ◽  
Đorđe Mirjanić ◽  
Slobodan Čupić
Keyword(s):  
Tooth Enamel ◽  
Vertical Axis ◽  
Mean Value ◽  
Tooth Surface ◽  
Axial Stretch ◽  
Mean Values ◽  
Average Value ◽  
Different Types ◽  
Orthodontics Brackets ◽  
Debonding Process

Fixed technique for applying brackets would be impossible without using adhesives for their fixation to the tooth enamel. However, the use of adhesives entails a number of problems which are a consequence of their imperfection, besides the fact that they have been actually applied for a number of decades already. The paper will analyze the debonding force values for bracket-tooth interface by using Con Tec LC and, Con Tec Duo. For comparative analysis of the strength of bracket-tooth interface, with the application of different types of adhesives, 80 extracted teeth of the frontal region were used (maxillary and mandibular incisors and canines). For the debonding process of applied orthodontics brackets, single-axial Stretch system for examination of tissues was applied to determine the value of the force necessary to separate the bracket from tooth surface, i.e. it was used to test debonding force. The direction of the used force for debonding was under angle of 90 degrees to the vertical axis of the tooth. By comparison of mean values of the strength of interface among the tested groups, it was determined that the highest average value of bond strength was with the group of teeth with which Con Tec Duo was used, a little lower mean value was recorded with the use of Con Tec LC adhesive.

The analysis of temperature fluctuations by pulse-counting techniques

1959 ◽  
Vol 6 (2) ◽  
pp. 261-271 ◽  
Author(s):  
A. A. Townsend
Keyword(s):  
Time Derivative ◽  
Temperature Fluctuations ◽  
Mean Value ◽  
Time Intervals ◽  
Mean Values ◽  
Average Value ◽  
Electrical Pulses ◽  
The Mean ◽  
The Stability ◽  
Better Than

To determine experimentally the mean value of a randomly fluctuating quantity, it may be necessary to measure the average value over a considerable interval of time. This problem arose in a recent study of the temperature fluctuations over a heated horizontal plate, and a system was used that depended on the counting of electrical pulses generated at a rate proportional to the quantity being measured. The advantage of this technique is that mean values may be measured over time intervals of almost unlimited length with little added difficulty for the experimenter. Circuits are described which measure: (a) the mean square of a fluctuating quantity and of its time-derivative, (b) the statistical distribution of the fluctuations, (c) the mean frequency of the fluctuation assuming a particular value, and (d) the mean product of two fluctuating quantities. Over the range of use, the stability and linearity of the calibrations is better than 1%, more than sufficient for work on natural convection. In its present form, the equipment responds uniformly to all frequencies below 100 c/s, but it would not be difficult to extend this range of response to higher frequencies.

scholarly journals Comparative evaluation of the effectiveness in plaque removal from the tooth surface by electric toothbrushes with different types of bristle movement

2018 ◽  
pp. 58-63
Author(s):  
V.G. Atrushkevitch ◽  
V.N. Tsarev ◽  
L.U. Orekhova ◽  
L.A. Elizova ◽  
E.S. Loboda
Keyword(s):  
Tooth Enamel ◽  
Head Rotation ◽  
Tooth Surface ◽  
Microbial Biofilms ◽  
Mechanical Removal ◽  
Supportive Periodontal Therapy ◽  
Different Types ◽  
Manual Toothbrush ◽  
Plaster Models

Supportive periodontal therapy (SPT) is an important factor in maintaining the results of active treatment of periodontal disease. Selection of effective personal hygienic tools is very important in addition to the formation of sustainable hygienic skills in patients. The aim of the study is a comparative assessment of the quality of mechanical removal of a native microbial biofilm with toothbrushes with different types of head rotation and a manual toothbrush. Objects and methods. The extracted teeth were fixed in plaster models, and the vestibular surface of the three teeth was processed for 10 seconds without the use of toothpaste. Tooth № 1 was a control (biofilm was not removed), tooth № 2 was cleaned with a manual toothbrush with an imitation of the Brass method, tooth № 3 was cleaned with a brush with oscillating-rotating movements of bristles. Tooth №4 was brushed with a toothbrush with vibrating types of bristles motion. The enamel-cementum junction of the tooth was taken strictly from the vestibular surface along the central axis of the tooth for studying in a scanning electron microscope. Conclusions. A complete cleaning of the tooth enamel surface from microbial biofilms is not achieved after using a manual toothbrush. Toothbrushes with oscillating-rotating movements of bristles create the phenomenon of “sweeping” of the biofilm fragments into the area of the cementum-enamel junction. The vibrating types of bristles motion maximally clean the cervical area of the tooth.

scholarly journals Influence of different types of whitening tooth pastes on the tooth color, enamel surface roughness and enamel morphology of human teeth

F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1764
Author(s):  
Mohamed Shamel ◽  
Mahmoud M. Al-Ankily ◽  
Mahmoud M. Bakr
Keyword(s):  
Surface Roughness ◽  
Tooth Enamel ◽  
Morphological Changes ◽  
Enamel Surface ◽  
Tooth Surface ◽  
Tooth Whitening ◽  
Sem Images ◽  
Human Teeth ◽  
Tooth Color ◽  
Different Types

Background: Tooth whitening usually includes the direct use of gels containing carbamide or hydrogen peroxide on the tooth enamel surface through a wide variety of products formulas. A generally new advancement in whitening of teeth uses the significant importance of the tooth color shift from yellow to blue in delivering a general enhancement in the observation of tooth whiteness. The aim of the current work was to measure the tooth whitening effects, surface roughness and enamel morphology of six different types of blue covarine-containing and blue covarine-free toothpastes using in vitro models. Methods: A total of 70 sound extracted human premolars were randomly and equally divided into seven groups, and each subjected to tooth brushing using different toothpastes. Tooth color and enamel surface roughness were measured before and after the brushing procedure using a white light interferometer, and scanning electron microscopy (SEM) was used to assess tooth surface after the procedure. Results: Toothpaste containing blue covarine resulted in the greatest improvement in tooth color amongst all groups as well as a statistically significant color difference when compared to blue covarine-free toothpaste.  Furthermore, blue covarine-containing toothpaste resulted in fewer morphological changes to the enamel surface. This was confirmed with SEM images that showed smooth enamel surfaces with fine scratches.   Conclusions: The results from the present study show that blue covarine containing toothpastes are reliable, effective in tooth whitening and produce less surface abrasion when compared to blue covarine-free toothpastes.

scholarly journals Verification of the method of equivalent amplitude determination based on two - parameter fatigue characteristic

2018 ◽  
Vol 182 ◽  
pp. 02022
Author(s):  
Karolina Karolewska ◽  
Bogdan Ligaj
Keyword(s):  
Fatigue Life ◽  
Mean Value ◽  
Structural Components ◽  
Counting Method ◽  
Fatigue Characteristic ◽  
Mean Values ◽  
Average Value ◽  
Extensive Range ◽  
Two Parameter ◽  
Over Time

In the most causes the loads which are affected on structural components are various over time and their character changes is stochastic. The stochastic character of operational loads of construction elements in various machine types is depended on many factors, included : work forces variability, environmental conditions, physical properties of components etc. Fatigue life calculation for this type of loads are conducted on the basis of determined sinusoidal cycles set through to use of the cycles counting method. The cycles which are contained to the sinusoidal cycles set are characterized by extensive range of amplitude Sai variation and mean values Smi. Application of Sa-N curve in fatigue life calculations caused disregard of the cycle mean value. This may affect the accuracy of calculations. Taking into account the cycle mean value Sm in the calculations may be realized by determining a substitute cycle with an average value Sm=0 and a substitute amplitude Saz≠Sa.

scholarly journals Survey of indoor radon (Rn-222) entry and concentrations in different types of building in Kalisz, Poland

2020 ◽  
Vol 326 (2) ◽  
pp. 1299-1306
Author(s):  
H. Bem ◽  
S. Janiak ◽  
B. Przybył
Keyword(s):  
Residential Buildings ◽  
Indoor Radon ◽  
Local Population ◽  
Mean Value ◽  
Arithmetic Mean ◽  
Mean Values ◽  
High Rise ◽  
Different Types ◽  
Average Effective Dose ◽  
Calculated Average

Abstract Indoor radon (222Rn) was surveyed in a total of 141 individual houses and apartments used precalibrated passive PicoRad Detectors. The radon activity in the soil gas around the dwellings was simultaneously measured. The arithmetic mean values of indoor radon concentrations for detached houses, old buildings (up to four-stories), prefabricated blocks of flats (mostly five stories) and high-rise residential buildings (10-stories) were:, 70.9; 46.5; 38.4, and 56.6 Bq m−3, respectively. The average arithmetic mean value for all measured rooms equals 51.8 Bq m−3. The calculated average effective dose from indoor radon for the local population was equal to 2.2 mSv.

scholarly journals Diagnostic Potential of Calprotectin for Spontaneous Bacterial Peritonitis in Patients Withliver Cirrhosis and Ascites

PRILOZI ◽  
2021 ◽  
Vol 42 (3) ◽  
pp. 97-106
Author(s):  
Fana Lichoska Josifovikj ◽  
Kalina Grivcheva Stardelova ◽  
Beti Todorovska ◽  
Magdalena Genadieva Dimitrova ◽  
Nenad Joksimovikj ◽  
...  
Keyword(s):  
Liver Cirrhosis ◽  
Antibiotic Treatment ◽  
Spontaneous Bacterial Peritonitis ◽  
Mean Value ◽  
Mean Values ◽  
Average Value ◽  
Bacterial Peritonitis ◽  
Diagnostic Potential ◽  
The Mean ◽  
The Difference

Abstract The development of spontaneous bacterial peritonitis (SBP) is a serious and life-threatening condition in patients with cirrhosis and ascites. The aim of this study was to determine the diagnostic potential of calprotectin in ascites, for SBP in patients with liver cirrhosis and ascites before and after antibiotic treatment and to compare the mean values of calprotectin in ascites in patients with and without SBP. This prospective-observational study was comprised of 70 patients with cirrhosis and ascites, divided into two groups, the SBP and the non-SBP group. Quantitative measurements of calprotectin in ascites was completed with the Quantum Blue Calprotectin Ascites test (LF-ASC25), using the Quantum Blue Reader. The average value of calprotectin in the SBP group was 1.5 ± 0.40 μg / mL, and in the non-SBP group it was lower (0.4 ± 0.30). The difference between the mean values was statistically significant with p <0.05. The mean value of calprotectin in ascites before therapy among the SBP group was 1.5 ± 0.4, and after antibiotic therapy, the value decreased significantly to 1.0 ± 0.6; the difference between the mean values was statistically significant with p <0.05. ROC analysis indicated that calprotectin contributed to the diagnosis of SBP with a 94.3% sensitivity rating (to correctly identify positives), and the specificity was 62.5%, which corresponded to the value of 0.275. Our research confirmed that ascitic calprotectin was a good predictor, and is significantly associated with the occurrence of SBP in patients with liver cirrhosis. By monitoring the value of calprotectin in ascites on the 7th day of antibiotic treatment, the effectiveness of antibiotic treatment in patients with SBP can be determined.

Accuracy and Reproducibility of the Assessment of the Global Ejection Fraction Using 195mAu and a Single-Crystal Digital Gamma Camera: Influence of Collimator Design

1987 ◽  
Vol 26 (04) ◽  
pp. 167-171
Author(s):  
G. Zatta ◽  
M. Gallazzi ◽  
A. De Agostini ◽  
A. Albertini ◽  
Maria Radice ◽  
...  
Keyword(s):  
Count Rate ◽  
Gamma Camera ◽  
High Sensitivity ◽  
Mean Value ◽  
Global Ejection Fraction ◽  
Average Value ◽  
Different Types ◽  
First Pass ◽  
Sequential Studies ◽  
Peak Count

A sequence of RAO first-pass studies (first with 99mTc and then twice with 195mAu) was performed in 18 normal volunteers and in 12 CAD patients using two different types of collimator for medium energy: a standard collimator (MEMS) and a special high-sensitivity collimator (MEHS). The following data were compared: the peak count rate, the net LV end-diastolic counts and the LVEF. Using MEMS the end-diastolic counts acquired were so low (12% of 99mTc average value) that EF standard deviation had a mean value of 0.061 (range 0.045-0.081). With MEHS the following results were obtained: 1. the peak count rate and LV net end-diastolic counts with 195mAu were 55% and 50% respectively, of 99mTc values; 2. a good correlation was shown between LVEF values either with 99mTc and 195mAu (r =.97), or with 195mAu sequential studies (r =.98).

scholarly journals Radon levels in different types of bottled drinking water and carbonated drinks in Iraqi markets

2016 ◽  
Vol 17 (1) ◽  
pp. 206-211 ◽  
Author(s):  
Ali Abid Abojassim ◽  
Suha H. Kadhim ◽  
Hussien Abid Ali Mraity ◽  
Rua R. Munim
Keyword(s):  
Drinking Water ◽  
Effective Dose ◽  
Radon Concentration ◽  
Mean Value ◽  
World Health ◽  
The European Union ◽  
Mean Values ◽  
Bottled Drinking Water ◽  
Different Types ◽  
Carbonated Drinks

In the present work, radon concentration was measured for different types of bottled drinking water and carbonated drink samples that are available in Iraqi markets. Radon measurements were carried out using a RAD-7 electronic radon detector. Annual effective dose was also calculated. The measured radon concentration in samples of bottled drinking water ranged from 0.0354 to 0.248 Bq/l with a mean value of 0.11265 Bq/l and the measured radon concentration in the samples of the carbonated drinks lay between 0.0354 and 0.283 Bq/l with a mean value of 0.1418 Bq/l. The mean values of the effective dose in all samples of bottled drinking water and carbonated drinks were found to be 0.410844 and 1.022 μSv/y respectively. The results of this work revealed that the radon concentrations were lower than the recommended limits indicated by the World Health Organization and by the regulatory bodies of the European Union.

scholarly journals The influence of size and structure of metal orthodontic bracket base on bond strength on tooth enamel

2009 ◽  
Vol 137 (11-12) ◽  
pp. 601-606 ◽  
Author(s):  
Vladimir Mitic ◽  
Mirjana Janosevic ◽  
Tatjana Tanic ◽  
Mirjana Sasic
Keyword(s):  
Bond Strength ◽  
Tooth Enamel ◽  
Mean Value ◽  
Middle Part ◽  
Orthodontic Brackets ◽  
Tooth Surface ◽  
Adhesive Material ◽  
Orthodontic Bracket ◽  
Bracket Base ◽  
Size And Structure

Introduction. The factors which may influence the bond strength of the applied orthodontic brackets on the tooth surface are the size and structure of the bracket base. Objective. The aim of the paper was to investigate the influence of size and shape of different types of brackets on bond strength on the enamel and analyze the remaining quality of adhesive material on the tooth surface after debonding of orthodontic brackets (adhesive remnant index - ARI). Methods. In this study, three types of metal brackets of different sizes and shapes of Dentaurum manufacturer were used (Utratrimm, Equilibrium 2, Discovery, Dentaurum, Inspringen, Germany). The brackets were applied onto the middle part of the anatomic crowns of buccal surfaces of 30 premolars extracted for orthodontic reasons. In addition, the pre-treatment of teeth by 37% orthophosphoric acid and adhesive material System1+ (Dentaurum, Germany) were used. Results. The mean value of the bonded brackets bond strength of Discovery type after debonding was 8.67?0.32 MPa, while the value of the bonded brackets bond strength of Equilibrium 2 type amounted to 8.62?0.22 MPa. The value of the bonded brackets bond strength of Ultratrimm type after debonding was 8.22?0.49 MPa. There were no statistical differences in the values of bond strength regarding all three groups of the investigated orthodontic brackets (F=4.56; p<0.05). Conclusion. The base size and design of metal orthodontic brackets did not play a significant role in bond strength, while the values of ARI index were identical in all three investigated groups.

scholarly journals The Effect of 10 Weeks Game Experience Learning (Gel) Based Training on Teamwork, Respect Attitude, Skill and Physical Ability in Young Football Players

2021 ◽  
Vol 21 (2) ◽  
pp. 173-179
Author(s):  
Sulistiyono Sulistiyono ◽  
Andry Akhiruyanto ◽  
Nawan Primasoni ◽  
Fatkurahman Arjuna ◽  
Nurhadi Santoso ◽  
...  
Keyword(s):  
Hypothesis Test ◽  
Intervention Group ◽  
Young Male ◽  
Mean Value ◽  
Football Players ◽  
Attitude Score ◽  
Physical Ability ◽  
Mean Values ◽  
Average Value ◽  
Fitness Tests

This study aims to examine the effectiveness of the games experience learning-based training against teamwork, respect attitude, skills, and physical ability of young footballers. Materials and methods. Participants consisted of young male football players who had participated in matches at the district, provincial and national levels. The number of participants involved amounted to 46 divided into control and intervention groups of 23 parties each. Footballers aged 10-12 years old have a height of 140.98 ± 7.23 cm, an average body weight of 34.33 ± 8.64 kg. Instruments in this study consist of instruments to measure teamwork and respect attitude in the form of expert validated observation rubrics, passing, and dribbling skill tests, 30-meter sprints, vertical jumps, and multistage fitness tests to measure physical ability of speed, leg power, and aerobic endurance.  Results. Descriptive data showed mean values and standard deviations of control and intervention groups there were differences, the intervention group had a mean value and better deviation standards, while the hypothesis test using the Mann-Whitney test obtained a teamwork attitude score of 0.039 <0.05; respect attitude of 0.009 <0.05; passing skills of 0.039 <0.05; dribbling skills of 0.000 <0.05; speed ability of 0.004 <0.05; leg power of 0.002 <0.05; Endurance of 0.020 <0.05. That from the significance value of the control and intervention group (p < 0.05) it can be concluded that the variables of teamwork, respect attitude, passing, dribbling, speed, power, and endurance on the posttest value are not the same and the average value of all variables descriptively the intervention group has a higher average value. Conclusions. There is a significant influence statistical analysis on teamwork, respect attitude, skill techniques, and physical ability for young football players thus training with the game experience learning model can be one solution to improve the performance of youth football.

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