Force decay of intermaxillary orthodontic elastics: in vitro study

2019 ◽  
Vol 88 (2) ◽  
pp. 91-95
Author(s):  
Hubert Kardach ◽  
Aneta Olszewska ◽  
Ewa Firlej ◽  
Agnieszka Bogdanowicz ◽  
Ewelina Golusińska-Kardach ◽  
...  

Introduction. Orthodontic elastics are widely used in orthodontic treatment. It’s been proved that they have advantages such as low cost, ease of use, but also disadvantages, mainly force decay in time and increased entrapment of biofilm. Amount of the force is of extreme significance. This force can be altered by physical or chemical factors. Material and Methods. Latex elastics in 3 different diameters were selected for this study. Each elastic was stretched and placed on hooks that are at specified distances that equal 3 times the diameter of each elastic. The forces produced by stretching was measured using tension gauge and the measurement were taken at specific time intervals of 0h, 3h, 12h, 24h. The same process was repeated for elastics in dry and artificial environment. Results. Elastics in the dry environment showed progressive force decay cause by stretching over time. Just after 3 hours force decay between 6,07% and 8,75% was observed. The biggest loss of force between 13,61 — 16,13 % was measured after 24 hours. Compared to the dry environment, an even more significant force decay was observed in the artificial saliva. After first 3 hours force loss was between 4,99% — 9,22%. The biggest force decay was observed after 24 hours and it was 5 % higher compared to dry environment. Conclusions. 1) The artificial saliva environment and time of exposure to it, have a negative effect on the properties of elastomeric. 2) To maintain the effective orthodontic strength of elastics, they should be replaced every 12 hours.

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

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.


2013 ◽  
Vol 11 (1) ◽  
pp. 60-70 ◽  
Author(s):  
Abdelali Halimi ◽  
Mohamed-Faouzi Azeroual ◽  
Anas Doukkali ◽  
Khalid El Mabrouk ◽  
Fatima Zaoui

2017 ◽  
Vol 18 (9) ◽  
pp. 812-820
Author(s):  
M Mohamed Ramees ◽  
Esther A Abraham ◽  
KK Manjusha ◽  
A Nishad ◽  
S Ramachandraiah

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.


2015 ◽  
Vol 40 (5) ◽  
pp. 492-502 ◽  
Author(s):  
GC Oliveira ◽  
AP Boteon ◽  
FQ Ionta ◽  
MJ Moretto ◽  
HM Honório ◽  
...  

SUMMARY Resin-based materials that show promising effects for preventing the progression of erosion have been studied. This in vitro study evaluated the effects of applying resin-based materials, including resin infiltration, on previously eroded enamel subjected to erosive challenges. The influence of enamel surface etching prior to application of the material was also studied. Bovine enamel blocks were immersed in hydrochloric acid (HCl), 0.01 M (pH 2.3), for 30 seconds in order to form a softened erosion lesion. The blocks were then randomly divided into nine groups (n=12) and treated as follows: C = control without treatment; Hel = pit & fissure resin sealant (Helioseal Clear); Adh = two-step self-etching adhesive system (AdheSe); Tet = two-step conventional adhesive system (Tetric N-bond); and Inf = infiltrant (Icon). The Helno, Adhno, Tetno, and Infno groups received the same materials without (or with no) surface conditioning. The depth of the material's penetration into softened erosion lesions was qualitatively analyzed using reflection and fluorescence confocal microscopy. After application of the materials, the blocks were immersed in HCl for two minutes; this step was followed by immersion in artificial saliva for 120 minutes four times a day for five days (erosive cycling). Both the enamel alteration and material thickness were analyzed using profilometry, and the results were submitted to Kruskal-Wallis and Dunn tests (p&gt;0.05). Images from the confocal microscopy showed minimal penetration of Adh/Adhno and deep penetration of Inf/Infno into the erosive lesions. The groups Hel, Adh, Inf, Tetno, and Infno resulted in the formation of a layer of material over the enamel, which was effective in inhibiting the progression of erosion. In conclusion, the infiltrant, with or without etching, was able to penetrate and protect the enamel against dental erosion. The other resin-based materials, except for the two-step conventional adhesive, were able to penetrate and inhibit the progression of erosive lesions only when they were applied after enamel etching.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Philipp Körner ◽  
Luca Georgis ◽  
Daniel B. Wiedemeier ◽  
Thomas Attin ◽  
Florian J. Wegehaupt

Abstract Background This in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear. Methods Surface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1–5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2–5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test. Results The overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047). Conclusions After 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.


2021 ◽  
Vol 10 (3) ◽  
pp. 391
Author(s):  
Rani D’haese ◽  
Tom Vrombaut ◽  
Geert Hommez ◽  
Hugo De Bruyn ◽  
Stefan Vandeweghe

Purpose: The aim of this in vitro study is to evaluate the accuracy of implant position using mucosal supported surgical guides, produced by a desktop 3D printer. Methods: Ninety implants (Bone Level Roxolid, 4.1 mm × 10 mm, Straumann, Villerat, Switzerland) were placed in fifteen mandibular casts (Bonemodels, Castellón de la Plana, Spain). A mucosa-supported guide was designed and printed for each of the fifteen casts. After placement of the implants, the location was assessed by scanning the cast and scan bodies with an intra-oral scanner (Primescan®, Dentsply Sirona, York, PA, USA). Two comparisons were performed: one with the mucosa as a reference, and one where only the implants were aligned. Angular, coronal and apical deviations were measured. Results: The mean implant angular deviation for tissue and implant alignment were 3.25° (SD 1.69°) and 2.39° (SD 1.42°) respectively, the coronal deviation 0.82 mm (SD 0.43 mm) and 0.45 mm (SD 0.31 mm) and the apical deviation 0.99 mm (SD 0.45 mm) and 0.71 mm (SD 0.43 mm). All three variables were significantly different between the tissue and implant alignment (p < 0.001). Conclusion: Based on the results of this study, we conclude that guided implant surgery using desktop 3D printed mucosa-supported guides has a clinically acceptable level of accuracy. The resilience of the mucosa has a negative effect on the guide stability and increases the deviation in implant position.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2998
Author(s):  
Mohammed Nadeem Bijle ◽  
Manikandan Ekambaram ◽  
Edward Lo ◽  
Cynthia Yiu

The in vitro study objectives were to investigate the effect of arginine (Arg) incorporation in a 5% sodium fluoride (NaF) varnish on its physical and chemical properties including F/Arg release. Six experimental formulations were prepared with L-arginine (L-Arg) and L-arginine monohydrochloride at 2%, 4%, and 8% w/v in a 5% NaF varnish, which served as a control. The varnishes were subjected to assessments for adhesion, viscosity, and NaF extraction. Molecular dynamics were simulated to identify post-dynamics total energy for NaF=Arg/Arg>NaF/Arg<NaF concentrations. The Arg/F varnish release profiles were determined in polyacrylic lactate buffer (pH-4.5; 7 days) and artificial saliva (pH-7; 1 h, 24 h, and 12 weeks). Incorporation of L-Arg in NaF varnish significantly influences physical properties ameliorating retention (p < 0.001). L-Arg in NaF varnish institutes the Arg-F complex. Molecular dynamics suggests that NaF>Arg concentration denotes the stabilized environment compared to NaF<Arg (p < 0.001). The 2% Arg-NaF exhibits periodic perennial Arg/F release and shows significantly higher integrated mean F release than NaF (p < 0.001). Incorporating 2% L-arginine in 5% NaF varnish improves its physical properties and renders a stable matrix with enduring higher F/Arg release than control.


2019 ◽  
Vol 13 (4) ◽  
pp. 305-310
Author(s):  
Mina Biria ◽  
Sajedeh Namaei Ghasemi ◽  
Seyedeh Mahsa Sheikh-Al-Eslamian ◽  
Narges Panahandeh

Background. This in vitro study aimed to evaluate the microshear bond strength (μSBS), microhardness and morphological characteristics of primary enamel after treating with sodium fluoride (NaF) and acidulated phosphate fluoride (APF). Methods. Forty-eight primary canines were cut into mesial and distal sections and assigned to five groups randomly: group 1 (immersed in saliva as a control), group 2 (treated with NAF and immersed in saliva for 30 minutes), group 3 (treated with APF and immersed in saliva for 30 minutes), group 4 (treated with NAF and immersed in saliva for 10 days), and group 5 (treated with APF and immersed in saliva for 10 days). Composite resin (Filtek Z250) was bonded on the specimens (n=15) for measuring the μSBS. After storage in 37°C artificial saliva for 24 hours, µSBS and Vickers hardness tests (10 readings) were performed. The data were analyzed using one-way ANOVA and Kolmogorov-Smirnov, Levene’s and Tukey HSD tests (P<0.05). Morphological analysis of enamel and modes of failure were carried out under a scanning electron microscope (SEM) on two remaining specimens. Results. Significant differences in μSBS were only noted between groups 2 and 4 (P=0.024). Group 3 showed a significant decrease in hardness after storage in artificial saliva (P<0.001), with a significantly lower hardness than the other groups (P<0.001). The SEM observations showed irregular particles in groups 3 and 5; uniform, smooth and thin coats were seen in groups 2 and 4. Conclusion. Fluoride therapy with NaF and APF gels prior to restorative treatments had no adverse effects on the microshear bond strength.


2000 ◽  
Vol 66 (4) ◽  
pp. 1720-1723 ◽  
Author(s):  
J. Pratten ◽  
R. Bedi ◽  
M. Wilson

ABSTRACT Microcosmic dental plaques were grown in artificial saliva and supplemented with either milk or fluoridated milk. The presence of fluoride in the milk increased the pH of the biofilms and reduced the proportions of streptococci, demonstrating that in this model, fluoridation of milk produces biofilms with reduced cariogenic potential.


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