scholarly journals In vitro evaluation of force degradation of elastomeric chains used in Orthodontics

2013 ◽  
Vol 18 (1) ◽  
pp. 55-62 ◽  
Author(s):  
André Weissheimer ◽  
Arno Locks ◽  
Luciane Macedo de Menezes ◽  
Adriano Ferreti Borgatto ◽  
Carla D'Agostini Derech
Keyword(s):  
Constant Temperature ◽  
Artificial Saliva ◽  
Clinical Use ◽  
Time Intervals ◽  
In Vitro Evaluation ◽  
Significant Difference ◽  
Initial Force ◽  
Elastomeric Chains ◽  
Over Time

OBJECTIVE: To analyze the in vitro force degradation of four different brands of elastomeric chains: American Orthodontics, Morelli, Ormco and TP Orthodontics. METHODS: The sample consisted of 80 gray elastomeric chains that were divided into four groups according to their respective manufacturers. Chain stretching was standardized at 21 mm with initial force release ranging from 300 g to 370 g. The samples were kept in artificial saliva at a constant temperature of 37°C and the degradation force was recorded at the following time intervals: initial, 1, 3, 5, 7 and 9 hours, and 1, 7, 14, 21, 28, and 35 days. RESULTS: There was a statistically significant difference between the groups regarding the force degradation, mainly within the first day, as a force loss of 50-55% was observed during that time in relation to the initial force. The force delivered at 35 days ranged from 122 g to 148 g. CONCLUSION: All groups showed force degradation over time, regardless of their trademarks, a force loss of 59-69% was observed in the first hour compared to baseline. However, because the variation in force degradation depends on the trademark, studies such as the present one are important for guiding the clinical use of these materials.

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 Evaluation of Force Degradation Characteristics of Orthodontic Latex Elastics in Vitro and In Vivo

2007 ◽  
Vol 77 (4) ◽  
pp. 688-693 ◽  
Author(s):  
Tong Wang ◽  
Gang Zhou ◽  
Xianfeng Tan ◽  
Yaojun Dong
Keyword(s):  
Artificial Saliva ◽  
Statistical Significance ◽  
Repeated Measure ◽  
Control Groups ◽  
Time Intervals ◽  
Room Condition ◽  
In Vivo Testing ◽  
Initial Force

Abstract Objective: To evaluate the characteristics of force degradation of latex elastics in clinical applications and in vitro studies. Materials and Methods: Samples of 3/16-inch latex elastics were investigated, and 12 students between the ages of 12 and 15 years were selected for the intermaxillary and intramaxillary tractions. The elastics in the control groups were set in artificial saliva and dry room conditions and were stretched 20 mm. The repeated-measure two-way analysis of variance and nonlinear regression analysis were used to identify statistical significance. Results: Overall, there were statistically significant differences between the different methods and observation intervals. At 24- and 48-hour time intervals, the force decreased during in vivo testing and in artificial saliva (P < .001), whereas there were no significant differences in dry room conditions (P > .05). In intermaxillary traction the percentage of initial force remaining after 48 hours was 61%. In intramaxillary traction and in artificial saliva the percentage of initial force remaining was 71%, and in room conditions 86% of initial force remained. Force degradation of latex elastics was different according to their environmental conditions. There was significantly more force degradation in intermaxillary traction than in intramaxillary traction. The dry room condition caused the least force loss. Conclusions: There were some differences among groups in the different times to start wearing elastics in intermaxillary traction but no significant differences in intramaxillary traction.

Effects of Different Commercially Available Mouth Rinses on The Force Degradation of Orthodontic Elastomeric Chain

2020 ◽  
Vol 23 (2) ◽  
pp. 41-48
Author(s):  
Halima Mohammed Hassan ◽  
Anees Mahmood Mudhir
Keyword(s):  
Artificial Saliva ◽  
Testing Machine ◽  
Control Group ◽  
Time Intervals ◽  
Mouth Rinses ◽  
Force Decay ◽  
Significant Difference ◽  
Mouth Wash ◽  
And Control ◽  
Elastomeric Chains

Aim of the study: To evaluate the effects of different commercial type of mouthwashes on the force decay of the orthodontic elastomeric chain. Materials and methods: two hundred pieces of the elastomeric chains with two different configurations were divided into five groups (one control group and four different mouthwashes groups). after one-day immersion in artificial saliva then immersion in the specific mouthwashes (kin, Vitis, perio_aid, splat) for one minute twice daily and time intervals after 7 days, 14 days, 21 days, and 28 then washed and kept in artificial saliva at 37°C again. Force decay was calculated by Instron measured, digital force gauge - Instron universal testing machine then compared different force decay of elastic types. Results: A significant difference was found among between the four types of mouth wash and control group, according to close and short elastic chain the kin mouth wash was shows a significant difference (0.002), while splat mouthwash was shown a no significant difference. Conclusion: splat mouth wash groups showed no significant influence on the force degradation of the chain elastics tested. Kin mouthwash exhibit the highest force decay and found different significant effects.

scholarly journals Force Degradation of Elastomeric Chains after Storage Time and Mechanical Brushing

2021 ◽  
Vol 32 (4) ◽  
pp. 55-61
Author(s):  
Antonio Carlos da Silva Chaves-Filho ◽  
Ana Rosa Costa ◽  
Lincoln Pires Sousa Borges ◽  
Eduardo Cesar Almada Santos ◽  
Marcus Vinicius Crepaldi ◽  
...  
Keyword(s):  
Storage Time ◽  
Mixed Model ◽  
In Vitro Study ◽  
Deionized Water ◽  
Time Intervals ◽  
Mixed Model Anova ◽  
Post Hoc ◽  
Elastomeric Chains ◽  
Over Time

Abstract The purpose of this in vitro study was to evaluate the force decrease of different elastomeric chains after different times: initial, 10 minutes, 1 day, 28 days and after mechanical brushing. Twenty orthodontic elastomeric chains segments were utilized for each commercial brand. Initially, the elastomeric chain of 15mm long were immediate stretched up to 20 mm in an Instron and the force was measured in gf. After all specimens were placed stretched on rectangular acrylic jigs with distance of 20 mm, immersed in deionized water at 37oC for 10 minutes and the force (gf) was measured again. Five test measurements of remaining force were made at the following time intervals: initial, 10 minutes, 1 day, 28 days and mechanical brushing. After 28 days, the acrylic plates with the specimens were adapted in the mechanical brushing machines (MSCT 3) and the elastomeric chains were submitted to mechanical brushing and the force (gf) measure again. The force (gf) was submitted to mixed-model ANOVA and Sidak post-hoc test (α=0.05). A statistically significant reduction in the force was found for all orthodontic elastomeric chain types after 1 day, 28 days and mechanical brushing (p<0.05). Morelli and 3M Unitek elastomeric chains showed significantly higher force than Abzil and GAC (p<0.05) after 1 day, 28 days and mechanical brushing. In conclusion, the force delivered by all elastomeric chains decayed rapidly over time. Morelli and 3M Unitek elastomeric chains consistently had a significantly greater force after mechanic brushing, while GAC the lowest.

scholarly journals Generation I and Generation II Elastomeric Chains Characteristics Comparison in Artificial Saliva Immersion

2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Marisa Icha Aisya Subroto ◽  
Anindita Permata Hardarini Putri ◽  
Leliana Sandra Devi Ade Putri ◽  
Lusi Hidayati
Keyword(s):  
Artificial Saliva ◽  
Orthodontic Force ◽  
Force Decay ◽  
Significant Difference ◽  
Chain Force ◽  
Cie Lab ◽  
Elastomeric Chains ◽  
Research Period ◽  
Color Reader

Objective: To determine the force decay and discoloration in Generation I and Generation II elastomeric chain on artificial saliva immersion. Material and methods: Generation I and Generation II elastomeric chains stretched on an acrylic board and immersed in artificial saliva for 1, 7, 14, 21, and 28 days according to the group of days. On each specified day, the force of each sample measured by an orthodontic force gauge and the magnitude of the force obtained is entered to the formula to find out the force decay in percentage, whereas discoloration of each sample analyzed by the color reader with CIE Lab analysis. Results: The force decay between Generation I and Generation II elastomeric chains showed a statistically significant difference in every group of days, in which Generation II is more effective in maintaining stretch force. Similar to force decay, the discoloration in Generation I elastomeric chains on the 14th day showed significant value and Generation II elastomeric chains were more stable in maintaining color compared to Generation I. Conclusions: over the entire research period time, Generation II elastomeric chains are more stable in maintaining stretch forces and color compared to Generation I elastomeric chains. KEYWORDS Discoloration; Elastomeric chain; Force decay; Generation I; Generation II.

scholarly journals Comparative Time-Dependent Evaluation of Dimensional Accuracy of Dies Using Different Tray Adhesives: An In Vitro Study

2018 ◽  
Vol 6 (02/03) ◽  
pp. 106-111
Author(s):  
Ramandeep Kaur ◽  
Manjit Kumar ◽  
Shailesh Jain ◽  
Neha Jindal
Keyword(s):  
Bond Strength ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Time Dependent ◽  
Time Intervals ◽  
Crosshead Speed ◽  
Significant Difference ◽  
Different Types ◽  
Separation Failure

Abstract Statement of Problem The adhesion of impression material to impression tray is very important. Tray adhesive plays a major role in making accurate impression. Although manufactures recommend the use of particular tray adhesives, comparison of their affective adhesiveness has not been reported. The effect of use of tray adhesives on dimensional accuracy of dies has not been established. Purpose The aim of this study was to compare the dimensional accuracy of dies using different tray adhesives at different time intervals. Materials and Methods First part of study comprised 120 samples in six groups with 20 samples in each group. First group comprised samples with no tray adhesive, and in other five groups, different types of tray adhesives were applied. The dies obtained were evaluated for upper diameter, lower diameter, and occlusogingival height. In the second part, there were a total of 125 samples in five groups with 25 samples in each group. Five different types of tray adhesive were applied for five different time intervals 5, 10, 15, 20, and 25 minutes, respectively. The specimens were tested in tensile mode for its debonding force at a crosshead speed of 5 mm/min, until separation failure occurred. Results Significant difference was seen for upper and lower diameters when compared with the group without any tray adhesive. The maximum bond strength was found in the group in which tray adhesive was applied for 20 minutes.

scholarly journals Effect of Er,Cr:YSGG on Remineralization Using CPP - ACPF (MI - Paste Plus) after Enamel Erosion Caused by Carbonated Soft Drink in Primary Teeth: In-Vitro Study

2019 ◽  
Vol 7 (7) ◽  
pp. 1184-1192 ◽  
Author(s):  
Ghada Ezzeldin Elwardani ◽  
Tarek Abdel Hamid Harhash ◽  
Ahmed Abbas Zaky
Keyword(s):  
Primary Teeth ◽  
Artificial Saliva ◽  
Soft Drink ◽  
Combined Treatment ◽  
Laser Application ◽  
Mi Paste Plus ◽  
Group I ◽  
Significant Difference ◽  
Mi Paste

BACKGROUND: Erosion is a widespread phenomenon with higher predilection in primary dentition. AIM: The aim of the present study is to assess the remineralising effect of Er,Cr:YSGG laser application combined with CPP-ACPF after erosive demineralisation by Coca-Cola in primary teeth. METHODS: Fifty teeth (n = 10) were divided into; Group I: Artificial saliva, (Saliva natural, Medac, UK), Group II: CPP-ACPF (MI Paste Plus, GC Corp, USA), Group III: Er,Cr:YSGG (Waterlase iPlus, USA), Group IV: CPP-ACPF + Er,Cr:YSGG, Group V: Er,Cr:YSGG + CPP-ACPF. Teeth were immersed in Coca-Cola for 10 min, 5 times/day for 5 days. DIAGNOdent (DD) measurements were taken before and after the experiment. RESULTS: There was a significant increase in DD readings after erosive-treatment cycles in all test groups. The highest reading was in samples immersed in artificial saliva, and the lowest was in those subjected to combined CPP-ACPF and Er,Cr:YSGG laser application, regardless of the sequence used. There was no significant difference between samples immersed in artificial saliva, and after CPP-ACPF application. Similarly, there was no significant difference between samples treated by combined treatment of CPP-ACPF and Er,Cr:YSGG application. However, there was a significant difference between samples immersed in artificial saliva or treated with CPP-ACPF application and those subjected to combined treatment CPP-ACPF along with Er,Cr:YSGG. CONCLUSION: Combining Er,Cr:YSGG laser and CPP-ACPF paste significantly increased enamel remineralisation, regardless of the sequence implemented. Saliva naturally and CPP-ACPF application had a comparable effect on remineralisation.

scholarly journals 541 Turning novices into experts: can artificial intelligence transform echocardiography training?

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
H Langet ◽  
M Bonopera ◽  
M De Craene ◽  
A Popoff ◽  
E Denis ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Median Time ◽  
Significant Contribution ◽  
Cost Effective ◽  
Matched Pair ◽  
Rank Test ◽  
Clinical Use ◽  
Real Time Analysis ◽  
Significant Difference ◽  
Over Time

Abstract Funding Acknowledgements Philips BACKGROUND Developing new training tools for TransThoracic Echocardiography (TTE) is more important than ever, as the use of ultrasound expands with the advent of mobile devices, both reducing costs and increasing the number of sites and operators. Two major challenges are the lack of experts to meet the growing demand for training and the risk of unnecessary examinations and misdiagnosis by users who lack proper training. PURPOSE To evaluate Artificial Intelligence (AI)-assisted TTE for assessing and improving novices" echocardiography skills. METHODS AI-assisted TTE relies on real-time analysis of the ultrasound stream by AI algorithms (e.g. for automated view recognition) to provide adaptive feedback to the user. It was compared to standard TTE in a prospective study including 40 medical students with no prior ultrasound experience ("novices") and 40 healthy volunteers of varying echogenicity. Novices received a standardized 10-minute presentation of the basic machine controls and requirements of an apical 4-chamber (AP4) acquisition. They were then asked to perform three consecutive AP4 acquisitions on a randomly assigned healthy volunteer: 1) "initial" standard TTE, 2) AI-assisted TTE and 3) "repetition" standard TTE, with a maximum of 3 minutes per acquisition. Additionally, for reference purposes, an AP4 acquisition was performed by an expert. Both the performance over time and the final acquisition performance were assessed by an AI-based AP4 quality score and expressed relatively to the reference score. The suitability for clinical use was assessed by an expert on a 0-3 semi-quantitative scale. RESULTS Kaplan-Meier analysis of the probability to match reference performance over time (see left part in figure below) validated the positive and significant contribution of AI-assisted TTE wrt initial TTE (median time = 16.1s vs. 45.7s, p = 0.026). There was also a positive, though non-significant, contribution wrt repetition TTE (median time = 25.7s, p = 0.20), while the difference between standard TTEs was non-significant (p = 0.24). A majority of novices (70%, resp. 72.5%) improved their final acquisition with AI-assisted TTE wrt initial TTE, resp. repetition TTE. The final performance gain (81.7 ± 29.7% vs. 60.8 ± 40.4%, resp. 70.4 ± 33.9%, see right part in figure below) was shown to be significant by Wilcoxon matched-pair signed-rank test (p &lt; 0.001, resp. p = 0.003). There was no significant difference between standard TTEs (p = 0.34). AI-assisted TTE was also associated with improved suitability for clinical use (2.53 ± 0.79 vs. 2.00 ± 1.03, resp. 2.08 ± 0.98). Among these acquisitions, 50% were found fully suitable for clinical use (vs. 22.5%, resp. 27.5%). CONCLUSION AI-assisted TTE can assess and improve novices" echocardiography skills. Developing and embedding AI-assistance in ultrasound devices could be a cost-effective way to support the training of novices and key to acquisition standardization. Abstract 541 Figure.

Brushing Effect of Abrasive Dentifrices during At-home Bleaching with 10% Carbamide Peroxide on Enamel Surface Roughness

2006 ◽  
Vol 7 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Luís Roberto Marcondes Martins ◽  
Claudia Cia Worschech ◽  
José Augusto Rodrigues ◽  
Gláucia Maria Bovi Ambrosano
Keyword(s):  
Surface Roughness ◽  
Artificial Saliva ◽  
Enamel Surface ◽  
Tooth Bleaching ◽  
Carbamide Peroxide ◽  
Peroxide Bleaching ◽  
Human Enamel ◽  
Over Time ◽  
At Home

Abstract During tooth bleaching abrasive dentifrices might change the outer superficial enamel. The aim of this in vitro study was to evaluate the roughness of human enamel exposed to a 10% carbamide peroxide bleaching agent at different times and submitted to different superficial cleaning treatments. The study consisted of 60 sound human enamel slabs, randomly assigned to different treatment groups: G1 - not brushed; G2 - brushed with a fluoride abrasive dentifrice; G3 - brushed with a non-fluoride abrasive dentifrice; and G4 - brushed without a dentifrice. There were 15 enamel slabs per group. Slabs of molar teeth were obtained and sequentially polished with sandpaper and abrasive pastes. A perfilometer was used to obtain the mean of Ra value on the surface of each specimen to initial and experimental times. Bleaching was performed on the enamel surface for six hours daily. After that, each slab received a cleaning surface treatment and was stored in artificial saliva. Analysis of variance (ANOVA) and Tukey's HSD hoc analysis (α =0.05) revealed significant differences in roughness values over time for enamel bleached and treated with different superficial cleaning methods. G1 and G4 showed no significant differences in roughness over time, G2 and G3 showed a significant increase in the surface roughness values. This in vitro investigation showed the sole use of 10% carbamide peroxide did not alter the enamel surface roughness, but the cleaning treatments that employed the use of brushing with abrasive dentifrices resulted in a significant increase of enamel surface roughness. Citation Worschech CC, Rodrigues JA, Martins LRM, Ambrosano GMB. Brushing Effect of Abrasive Dentifrices during At-home Bleaching with 10% Carbamide Peroxide on Enamel Surface Roughness. J Contemp Dent Pract 2006 February;(7)1:025-034.

Acceleration of hemoglobin C crystallization by hemoglobin S

Blood ◽  
1989 ◽  
Vol 74 (5) ◽  
pp. 1823-1825
Author(s):  
MJ Lin ◽  
RL Nagel ◽  
RE Hirsch
Keyword(s):  
Gel Electrophoresis ◽  
Phosphate Buffer ◽  
Potassium Phosphate ◽  
Potassium Phosphate Buffer ◽  
Time Intervals ◽  
Agar Gel ◽  
Hemoglobin C ◽  
Agar Gel Electrophoresis ◽  
Over Time

We previously reported that circulating hemoglobin (Hb) CC erythrocytes contain oxygenated HbC crystals with little or no HbF and that HbF inhibits in vitro crystallization of HbC. We now report that HbS accelerates in vitro crystallization of HbC. Crystals were formed in 1.8 mol/L potassium phosphate buffer, pH 7.4, at 30 degrees C and were counted in several time intervals with a hematocytometer. The hemoglobin composition of Millipore-isolated crystals and supernatant were also analyzed. Under the conditions selected, 100% HbS formed needle-shaped crystals only after two hours. Pure HbC does not form crystals within 15 minutes, whereas a ratio of 10% HbS:90% HbC forms 1,100 crystals/mm3, 20% HbS:80% HbC forms 370 crystals/mm3, and 30% HbS:70% HbC forms 5 crystals/mm3. Crystals formed in the presence of HbS are tetragonal, as are pure HbC crystals. As compared with 100% HbC, HbA or albumin mixed with HbC showed a decreased number of crystals as a result of dilution. Analysis of the Hb content of isolated crystals by citrate agar gel electrophoresis showed that HbS was rapidly incorporated into the crystal in the same ratio over time. These results demonstrate that HbS accelerates crystallization of HbC with respect to the rates of crystallization of any of these two Hbs separately, through a mechanism that involves cocrystallization. These results may be significant in understanding SC disease.

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