scholarly journals Avaliação da Diminuição da Força de Ativação de Elásticos Correntes de Diferentes Cores: Estudo in Vitro

2020 ◽  
Vol 24 (4) ◽  
pp. 396-401
Author(s):  
Larissa Gomes ◽  
Renata Almeida-Pedrin ◽  
Victor Ladewig ◽  
Victor Didier ◽  
Joel Santiago ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
Statistical Tests ◽  
Significance Level ◽  
Oral Environment ◽  
The Mean ◽  
The Difference ◽  
Continuous Use ◽  
Elastomeric Chains ◽  
Calculated Analysis

O objetivo deste estudo consistiu em comparar a degradação de força de cinco cores diferentes de elásticos corrente, a fim de buscar parâmetros clínicos para o uso desses elásticos nas terapias ortodônticas. Foram avaliados 10 segmentos com 6 elos de elásticos corrente de força média da marca Morelli, das cores preto, cinza, azul, rosa e transparente, provenientes de embalagens seladas e dentro do prazo de validade. Os elásticos foram distendidos até o dobro de seu comprimento e mantidos por dispositivos simples com duas pontas de metal, simulando o uso contínuo dos elásticos por parte dos pacientes. Esses dispositivos foram submersos em saliva artificial a 370C dentro de recipientes mantidos em estufa.  As forças dos segmentos de elásticos foram mensuradas com um dinamômetro ortodôntico de precisão ao início e nos intervalos de 1, 7,14, 21 e 30 dias após a imersão, e a média de força para cada grupo e tempo foi calculada. A Análise de variância (ANOVA) a dois critérios (tempo e grupos) e o teste de Tukey foram utilizados para a análise dos dados. Em todos os testes estatísticos foi adotado um nível de significância de 5%. Todas as cores de elásticos degradaram com o tempo, sendo a porcentagem média de degradação após 1 dia de 40,4%; 7 dias 48,2%; 14 dias 56,8%; 21 dias 65% e 81% após 30 dias. Entretanto, há diferença de degradação de força entre as cores dos elásticos. Os elásticos Transparente e Azul apresentaram menor degradação da força, sendo que após 30 dias o elástico Transparente se mostrou mais efetivo, seguido do Azul, Cinza, Preto e Rosa. Mesmo com a diferença na degradação de força entre as cores dos elásticos, esses dados não apresentam relevância clínica se utilizados por até 14 dias, após esse período seria melhor a utilização do elástico Transparente.   Palavras-chave: Ortodontia. Látex. Elasticidade   Abstract The aim of this study was to compare the force degradation of five different colors of elastomeric chains, in order to achieve clinical parameters for the use of these elastics in orthodontic therapies. The sample was composed by 10 segments with 6 links (medium force) for each color of elastomeric chain (Morelli); black, gray, blue, pink and transparent, from sealed packages and within the expiration date. The elastics were stretched twice their length and maintained by simple devices with two metal tips, simulating the continuous use of the elastics by the patients. These devices were submerged in artificial saliva at 370C to simulate the oral environment. The  elastic segments strengths were measured with a precision orthodontic dynamometer at the beginning and at intervals of 1, 7, 14, 21 and 30 days after immersion, and the mean strength for each group and time was calculated. Analysis of variance (ANOVA) with two criteria (time and groups) and the Tukey test were used for data analysis. In all statistical tests, a significance level of 5% was adopted. All the  elastics colors degraded over time, with the average  degradation percentage after 1 day being 40.4%; 7 days 48.2%; 14 days 56.8%; 21 days 65% and 81% after 30 days. However, there is a difference in force degradation among the  elastics colors. The Transparent and Blue elastics showed less force degradation, and after 30 days the Transparent elastic was more effective, followed by Blue, Gray, Black and Pink. Even with the difference in force degradation among the  elastics colors, these data are not clinically relevant they are used for up to 14 days, after that period it would be better to use the Transparent elastic.   Keywords: Orthodontics. Latex. Elasticity

scholarly journals An in vitro comparison of the force decay generated by different commercially available elastomeric chains and NiTi closed coil springs

2007 ◽  
Vol 21 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Ana Cristina Soares Santos ◽  
André Tortamano ◽  
Sandra Regina Frazatto Naccarato ◽  
Gladys Cristina Dominguez-Rodriguez ◽  
Julio Wilson Vigorito
Keyword(s):  
Artificial Saliva ◽  
Testing Machine ◽  
In Vitro Study ◽  
Original Length ◽  
Force Decay ◽  
Decay Pattern ◽  
The Mean ◽  
Initial Force ◽  
Elastomeric Chains

This in vitro study was designed to compare the forces generated by commercially available elastomeric chains and NiTi closed coil springs, and to determine their force decay pattern. Forty elastomeric chains and forty NiTi closed coil springs were divided into 4 groups according to the following manufacturers: (1) Morelli®, (2) Abzil®, (3) TP Orthodontics® and (4) American Orthodontics®. The specimens were extended to twice their original length and stored in artificial saliva at 37°C. Initial force was measured by means of an Instron universal testing machine and then at 1, 4, 7, 14, 21, and 28 days. The results revealed that the elastomeric chains delivered a mean initial force of 347 g for Morelli®, 351 g for American Orthodontics®, 402 g for Abzil®, and 404 g for TP Orthodontics®. The NiTi closed coil springs generated a mean initial force of 196 g for American Orthodontics®, 208 g for TP Orthodontics®, 216 g for Abzil®, and 223 g for Morelli®. The mean percentage of force decay observed after 28 days for the elastomeric chains was 37.4% for TP Orthodontics®, 48.1% for American Orthodontics®, 65.4% for Morelli®, and 71.6% for Abzil®. After 28 days, the NiTi closed coil springs presented a mean percentage of force decay of 22.6% for American Orthodontics®, 29.8% for Abzil®, 30.6% for Morelli®, and 45.8% for TP Orthodontics®. At the end of the study, significant differences were observed between the elastomeric chains and the NiTi closed coil springs. The results indicated that the studied NiTi closed coil springs are more adequate for dental movement than the elastomeric chains.

scholarly journals Force Decay Characteristics of commonly used Elastomeric Chains on Exposure to various Mouth Rinses with different Alcohol Concentration: An in vitro Study

2017 ◽  
Vol 18 (9) ◽  
pp. 812-820
Author(s):  
M Mohamed Ramees ◽  
Esther A Abraham ◽  
KK Manjusha ◽  
A Nishad ◽  
S Ramachandraiah
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Total Sample ◽  
Alcohol Concentration ◽  
Alcohol Mixture ◽  
Mouth Rinses ◽  
Force Decay ◽  
The Difference ◽  
Elastomeric Chains

ABSTRACT Aim The aim of this study was to test the effect of varying alcohol concentrations of various commercially available mouthwashes on force decay of elastomeric chains in prestretched and unstretched condition. Materials and methods A total of five specimen groups were tested with a total sample size of 180 specimens. A specimen is described as a three-link, short module, clear elastomeric chain (3M Unitek, Ortho Plus, Ortho Organizer). The control and test groups were independently submerged in separate 37°C artificial saliva to simulate the oral conditions. Effects of different solution groups and time (initial, 1, 7, 14, 21, and 28 days) on three different elastomeric chains and force (cN) are analyzed with two-way analysis of variance; pair-wise comparisons are done by t-test. Results Higher mean force was recorded initially followed by 24 hours >7 days >14 days >21 days and 28 days respectively. The difference in mean force decay among the different time intervals was found to be statistically significant (p < 0.001). Among the different solutions, higher mean force was recorded in 21.6% alcohol mixture > Listerine 8.38% > Wokadine > alcohol mixture 8.38% > artificial saliva. Conclusion In conclusion, alcohol-containing mouth rinses cause an increase in force decay of elastomeric chain over time. Clinical significance These mouth rinses are commonly recommended during orthodontic treatment. The orthodontist can know better that the alcohol content of the mouth rinses and the structural and molecular modification results in the decay of elastomeric chain. How to cite this article Ramachandraiah S, Sridharan K, Nishad A, Manjusha KK, Abraham EA, Ramees MM. Force Decay Characteristics of commonly used Elastomeric Chains on Exposure to various Mouth Rinses with different Alcohol Concentration: An in vitro Study. J Contemp Dent Pract 2017;18(9):812-820.

scholarly journals Effect of Bleaching Mouthwash on Force Decay of Orthodontic Elastomeric Chains

2018 ◽  
Vol 19 (2) ◽  
pp. 221-225 ◽  
Author(s):  
Mohammad Behnaz ◽  
Fatemeh Namvar ◽  
Setareh Sohrabi ◽  
Mina Parishanian
Keyword(s):  
Sodium Fluoride ◽  
Artificial Saliva ◽  
Test Group ◽  
Clinical Problem ◽  
Control Group ◽  
Force Decay ◽  
Custom Made ◽  
The Difference ◽  
Elastomeric Chains

ABSTRACT Introduction Force decay elastomeric chains are significant, and it is a clinical problem. Aim The aim of this study was to evaluate the effects of bleaching agent in the mouthwash on the force decay of orthodontic chains. Materials and methods In this experimental study, 160 gray closed elastomeric chains were randomly divided into three groups (one control and two test groups). Four loops of chains were stretched for 25 mm on custom-made jig. Control group specimens were immersed in artificial saliva during the test period. Test group specimens were immersed twice a day for 30 seconds in the whitening (LISTERINE® HEALTHY WHITE™) and daily sodium fluoride (LISTERINE® TOTAL CARE ZERO) mouthwashes. All specimens were immersed in artificial saliva at 37°C. Force was measured at different time points (initial, 1, 7, 14, 21, 28 days). Statistical analysis was performed by two-way analysis of variance (ANOVA) and Bonferroni methods (α = 0.05). Results Force of elastomeric chains was decreased dramatically in all groups during the experiment. After 24 hours, force was decreased by 42.18, 48.34, and 53.38% in control group, daily, and bleaching mouthwash groups respectively. The corresponding numbers after 4 weeks were 66.30, 76.73, and 86.48. The difference between three groups at days 1 and 28 was statistically significant (p < 0.05). Conclusion Within the limitations of the current in vitro study, bleaching and sodium fluoride mouthwashes could cause force decay of orthodontic elastomeric chains. Whitening mouthwash is more weakening for elastomeric chains. Clinical significance Use of whitening mouthwash by orthodontic patients could decrease the force of elastomeric chains, so it could be recommended to use them for a short time. How to cite this article Behnaz M, Namvar F, Sohrabi S, Parishanian M. Effect of Bleaching Mouthwash on Force Decay of Orthodontic Elastomeric Chains. J Contemp Dent Pract 2018;19(2):221-225.

Effect of Sodium Fluoride Mouth Rinse on Elastic Properties of Elastomeric Chains

2009 ◽  
Vol 34 (2) ◽  
pp. 189-192 ◽  
Author(s):  
Barat Ali Ramazanzadeh ◽  
Arezoo Jahanbin ◽  
Nadia Hasanzadeh ◽  
Neda Eslami
Keyword(s):  
Elastic Properties ◽  
Sodium Fluoride ◽  
Artificial Saliva ◽  
Mouth Rinse ◽  
Original Length ◽  
Entire Duration ◽  
The Difference ◽  
Orthodontic Forces ◽  
Elastomeric Chains

Objective: This study evaluated Sodium Fluoride mouth rinse effects on elastic properties of different elastomeric chains. Study design: In this in vitro experiment, two orthodontic chains were tested. In the first group, they were stored in artificial saliva for the entire duration, and in the second group they were immersed daily in 0.05% NaF mouth rinse for 1 minute, artificial saliva–NaF mixture for 30 minutes, and then in artificial saliva for the rest of the day. Specimens were tested at baseline, 1 hour, 24 hours, 1, 2 and 3 weeks and then the displacement of specimens to obtain 150g and 300g, also the applied force after stretching them to 100% of their original length were evaluated. Results: In contrast to force degradation,chains of both companies required more displacement to achieve both forces in the saliva- NaF mixture than saliva itself; however, the difference was only significant for the 300g force (P = 0.020). American Orthodontics chains required more displacement than Dentaurum chains to obtain both forces, also they had more load relaxation (P&lt;0.001). Conclusions: Daily use of NaF mouth rinse does not affect force degradation and the displacement of both chains to achieve conventional orthodontic forces, but for higher force levels the displacement increase is statistically significant.

scholarly journals Force degradation of nickel-titanium closed coil springs: an in vitro

2020 ◽  
Vol 9 (10) ◽  
pp. e2669108488
Author(s):  
Ana Claudia de Castro Ferreira Conti ◽  
Caroline de Vitto ◽  
Leonardo Filipe Conceição ◽  
Gregório Bonfim Dourado ◽  
Graziela Hernandes Volpato ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Treatment Time ◽  
Artificial Saliva ◽  
Statistical Tests ◽  
Objective Evaluation ◽  
Nickel Titanium ◽  
Significance Level ◽  
Total Treatment Time ◽  
T1 And T2

Objective: evaluation of the forces resulting from the initial stretching of closed Nickel-titanium springs and the degradation of these forces after 28 days of stretching. Methodology: The sample comprised 80 Morelli Nickel-titanium closed coil springs, divided into 4 groups of 20 according to their length, 7, 9, 12 and 15mm. In each group, 10 spring coils suffered distension in 50 and 100% of its original length and were maintained in devices to simulate the distension. The resulting forces were measured with a tensiometer and compared with the force described by the manufacturer on the spring packaging (200 grams force). Measurements were performed in 2 time-points; right after the initial strain (T1) and after 28 days (T2), when the devices were kept in artificial saliva at a temperature of 37°C. For the statistical analysis, the Mann-Whitney test was applied to compare the forces in T1 with the manufacturer's value and the paired t test to compare the forces between T1 and T2. In all statistical tests, a significance level of 5% was adopted. Result: In T1 the springs of 9, 12 and 15mm stretched by 50% showed significantly lower values ​​and the springs of 7 and 15mm stretched by 100% showed significantly higher values, both compared with the manufacturer's recommendation. All groups of springs showed significant degradation of forces between T1 and T2, with percentage rates of force degradation from 7.1 to 21.9%. Conclusion: It is necessary to measure the forces of the springs during orthodontic treatment, aiming to establish an optimal force for tooth movement and thus optimizing the total treatment time.

scholarly journals Comparative Analysis of Different Local Anesthetic Solutions Available in Market: An In Vitro and Clinical Study

2021 ◽  
Author(s):  
Eisha Imran ◽  
Faisal Moeen ◽  
Beenish Abbas ◽  
Bakhtawar Yaqoob ◽  
Mehreen Wajahat ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Local Anesthetic ◽  
Compositional Analysis ◽  
Bacterial Activity ◽  
Similar Composition ◽  
Ph Values ◽  
Significant Difference ◽  
The Mean ◽  
The Difference

Abstract Objectives The study aimed to evaluate and compare various commercially available local anesthetic solutions. Materials and Methods A total of 150 commercially available local anesthetic cartridges of similar composition (2% lidocaine with epinephrine 1:100,000) were randomly collected and divided into 3 groups. The designations of groups were selected from their product names such that each group consisted of 60 cartridges. Group S (Septodont, France) Group M (Medicaine, Korea) and Group H (HD-Caine, Pakistan). The samples were divided into five sub-groups, each consisting of 10 cartridges from each group to investigate each parameter. Results The acquired data was statistically analyzed and compared (using SPSS version 12). Compositional analysis revealed a non-significant (P>0.05) difference when the three Groups were compared with standard lidocaine and epinephrine solutions. The mean pH values of samples from group S, M and H respectively fell within the range of pH values of commercially available solutions. Non-significant difference in EPT values of Group S and H was found when efficacy was compared (p = 0.3), however a significant difference (p < 0.01) was observed in contrast to Group M. Anti-bacterial activity was observed in all the group and a non-significant difference in cell viability values of Group S and M was found (p = 0.6), while the difference was significant in comparison to Group H. Conclusion Within the limitations of these investigations, it appears that the properties of different manufacturers fall within the recommended ranges as mentioned in literature and do not appear to be statistically different in the variables we have tested.

scholarly journals Microtubule minus-end stability is dictated by the tubulin off-rate

2019 ◽  
Vol 218 (9) ◽  
pp. 2841-2853 ◽  
Author(s):  
Claire Strothman ◽  
Veronica Farmer ◽  
Göker Arpağ ◽  
Nicole Rodgers ◽  
Marija Podolski ◽  
...  
Keyword(s):  
Dynamic Instability ◽  
In Vitro Reconstitution ◽  
Primary Determinant ◽  
Mean Size ◽  
The Mean ◽  
The Difference ◽  
Insight Into ◽  
Dynamic Organization ◽  
In Cells

Dynamic organization of microtubule minus ends is vital for the formation and maintenance of acentrosomal microtubule arrays. In vitro, both microtubule ends switch between phases of assembly and disassembly, a behavior called dynamic instability. Although minus ends grow slower, their lifetimes are similar to those of plus ends. The mechanisms underlying these distinct dynamics remain unknown. Here, we use an in vitro reconstitution approach to investigate minus-end dynamics. We find that minus-end lifetimes are not defined by the mean size of the protective GTP-tubulin cap. Rather, we conclude that the distinct tubulin off-rate is the primary determinant of the difference between plus- and minus-end dynamics. Further, our results show that the minus-end–directed kinesin-14 HSET/KIFC1 suppresses tubulin off-rate to specifically suppress minus-end catastrophe. HSET maintains its protective minus-end activity even when challenged by a known microtubule depolymerase, kinesin-13 MCAK. Our results provide novel insight into the mechanisms of minus-end dynamics, essential for our understanding of microtubule minus-end regulation in cells.

Relative Adherence of Bacteroides Species and Strains to Actinomyces viscosus on Saliva-coated Hydroxyapatite

1989 ◽  
Vol 68 (9) ◽  
pp. 1308-1312 ◽  
Author(s):  
J. Li ◽  
R.P. Ellen
Keyword(s):  
Liquid Scintillation ◽  
Mineral Surface ◽  
Standard Strain ◽  
Input Concentration ◽  
Bacteroides Species ◽  
In Vitro Simulation ◽  
Independent Variable ◽  
The Mean ◽  
The Difference

The study was designed to compare the adherence of several Bacteroides species to A. viscosus. Using 3H, we labeled 24 laboratory strains, including 13 Bacteroides species and I I fresh clinical isolates of three Bacteroides species. Their adherence to A. viscosus bound to a saliva-coated mineral surface was quantified by liquid scintillation. Adherence relative to a standard strain, B. gingivalis 2561, was compared. Among the lab bacteroides, those of B. gingivalis (eight strains) were the greatest binders (mean, 80.5 ± 12.4%). Strains of other lab bacteroides bound less well (mean, 33.4 ± 6.3%). The difference in means was statistically significant (p<0.01). The mean for B. gingivalis strains was also significantly greater than that for strains of B. intermedius (51.7 ± 6.2%). Attachment of B . gingivalis was saturable in experiments in which either input concentration or time was the independent variable, indicating that B. gingivalis cells do not accumulate in this in vitro simulation of plaque formation by binding to each other. Subculture did not seem to affect the degree of binding.

The Effect of Casein Phosphopeptide-Amorf Calcium Phosphate and Acidulated Phosphate Fluoride Gel on Dental Erosion in Primary Teeth: An in Vitro Study

2017 ◽  
Vol 41 (4) ◽  
pp. 275-279 ◽  
Author(s):  
Eda Arat Maden ◽  
Özge Acar ◽  
Ceyhan Altun ◽  
Günseli Güven Polat
Keyword(s):  
Surface Roughness ◽  
Protective Effect ◽  
Primary Teeth ◽  
Artificial Saliva ◽  
Soft Drink ◽  
Dental Erosion ◽  
The Other ◽  
The Mean ◽  
Casein Phosphopeptide

Objective: This study aimed to investigate the effect of acidulated phosphate fluoride (APF) gel and casein phosphopeptide/amorphous calciumphosphate (CPP-ACP) on the dental erosion produced by carbonated soft drink in primary teeth. Study Design: This study evaluated by an in vitro model the effect of APF gel and CPP-ACP on the dental enamel previously subjected to erosive challenge with carbonated soft drink. Sixty sound human primary molars were prepared by embedding the crown sections in acrylic resin blocks leaving the enamel surfaces exposed. The surface roughness of the enamel was measured with prophilometry at baseline. Specimens were randomly divided into three treatment groups (n:20): artificial saliva, CPP-ACP, 1.23% APF gel. All specimens were then exposed to an erosive challenge of carbonated soft drink and artificial saliva for 20 cycles of 20 seconds each. Demineralization-remineralization cycles was repeated twice at eight-hour intervals and roughness values were measured. Enamel samples were treated with artificial saliva, CPP-ACP, 1.23% APF gel applied for 10 min after erosive challenge. The arithmetic average roughness (Ra) readings were recorded after remineralization agents were applied. Results: The mean surface roughness in all groups increased significantly after erosion process and decreased after remineralization treatment. After treatment, the mean surface roughness of the 1.23% APF gel group was significantly less than the other groups and the mean surface roughness of the artificial saliva group was significantly more than the other groups. 1.23% APF gel showed the highest protective effect against erosive enamel loss. Conclusions: Under the conditions of this study, artificial saliva, CPP-ACP and 1.23% APF treatments were able to reduce erosive enamel loss produced by carbonated soft drink in primary teeth. However, 1.23% APF gel showed the highest protective effect against erosive enamel loss.

scholarly journals Cochran’s Q-Test on Soil Helminth Prevalence

2021 ◽  
Vol 58 (2) ◽  
pp. 169-185
Author(s):  
I. J. David ◽  
M. U. Adehi ◽  
P. O. Ikwuoche
Keyword(s):  
Soil Samples ◽  
The Other ◽  
Significance Level ◽  
Comparison Test ◽  
The Mean ◽  
The Difference ◽  
Comparison Technique

Summary A study was made of the prevalence of nine geohelminth egg types in 184 soil samples from 16 recreational parks in Abuja metropolis, Nigeria. Cochran’s Q-test was applied to determine whether the difference in the proportions of the egg types found in the soil samples was significant. At a 5% significance level, it was found that the prevalence of the egg types was significantly different in the 184 soil samples from 16 parks. To identify which of the geohelminth eggs had a significantly larger mean proportional prevalence, a minimum required difference mean comparison technique was applied. The mean comparison test showed that Taenia and Coccocidia eggs were highly prevalent, with significantly larger mean proportions than the other analyzed geohelminth eggs in the 184 examined soil samples.

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