Latex Orthodontic Elastics Research Articles

Does mouthwash degrade the force of orthodontic latex elastics?

With the surge of COVID-19 pandemic, orthodontists have recommended the use of mouthwashes. However, this product frequently contains ingredients that can modify the mouth's pH and elastic force. This study examined the influence of mouthwashes on latex elastic force deterioration. One hundred orthodontic latex elastics (1/4”) were separated into five groups: control, zinc sulfate 0.2%, chlorhexidine 0.2%, sodium fluoride 0.2%, and povidone–iodine 1%. The samples were stretched to 19.05 mm, stored in artificial saliva solutions, and incubated. Groups 2–5 tested mouthwashes for 60 seconds every 12 hours and then reverted to artificial saliva. Force was measured using a five-times-activated tension gauge. Elastic force was tested at five-time intervals: baseline, 1, 6, 12 and 24 hours. The statistical analysis included two-way ANOVA and the Tukey post–hoc test. Results showed statistical differences for the time intervals and force degradation of orthodontic latex elastics (p<0.05). The majority of force loss occurred within six hours of extension and immersion. Mouthwashes had no influence on the reduction in elastic force (p>0.05). The force degradation of orthodontic latex elastics was unaffected by mouthwashes. The lowest force degradation was generated by povidone–iodine, followed by zinc sulfate, sodium fluoride, and chlorhexidine.

Influence of Storage Temperature on Orthodontic Elastics

Introduction: Orthodontic elastics are a very significant tool in orthodontics, as it is the most commonly used force delivering unit. Temperature plays a key role in the amount of force that elastics are able to produce. Hence, there is a need to evaluate the influence of storage temperature on the properties of orthodontic elastics before its clinical use. Aim: To evaluate the influence of different storage temperature of latex orthodontic elastics. Materials and Methods: This cross-sectional study was conducted at Sathyabama Dental College and Hospital, Chennai, in November 2019. Sample of 40 latex orthodontic elastics (TP Orthodontics, medium force, standard size of 3/16′′) were divided into four groups with 10 elastics each, based on their storage temperature and stored in closed plastic packages. Group 1 was kept as a Control group and Group 2, Group 3 and Group 4 were stored in three Incubators under the specified storage temperatures such as 26-28°C, 4-8°C, 37°C respectively. The elastics were stretched and their forces measured in six progressive increases of 100% of their inner diameter, starting at a level of 100% stretching, with the Universal Testing Machine, Instron. The samples were also tested for Maximum Stress (MPa), Maximum Force (N), Maximum Elongation (%) and Break Distance (mm). Data were analysed using Statistical Package for the Social Science (SPSS) software version 16.0, one-way Analysis of Variance (ANOVA) and post-hoc test. Results: On evaluating the stress at 100%, 200%, 300%, 400%, 500%, 600% of strain, there was no statistically significant difference between the groups. Maximum Stress MPa was found to be 24.12±3.32, 25.12±3.42, 23.3±3.41, 23.97±3.50 for group1, group 2, group 3 and group 4 respectively. Maximum Elongation (%) was found to be 1369.0±25.108, 1364.0±23.190, 1359.0±35.103, 1363.0±34.657 for group 1, group 2, group 3 and group 4, respectively. Break Distance (mm) was found to be 68.48±1.267, 68.28±1.267, 67.87±1.77 and 68.19±1.727 for group1, group 2, group 3 and group 4, respectively. And none of the parameters tested showed statistical significance between the four groups. Conclusion: Latex elastics may be stored under any of the conditions tested in the present study over a period of one month, since different storage temperatures over a period of one month did not interfere in their mechanical properties.

Force degradation of orthodontic latex elastics analyzed in vivo and in vitro

The objective of this study was to evaluate the characteristics of force degradation of latex elastics of 10 kinds of elastics over 48hours, both invivo and invitro. For the invivo study, 10 different kinds of elastics were randomly chosen for investigation: 1/8-inch (2 oz); 1/8-inch (3.5 oz); 3/16-inch (2 oz); 3/16-inch (3.5 oz); 1/4-inch (2 oz); 1/4-inch (3.5 oz); 5/16-inch (2 oz); 5/16-inch (3.5 oz); 3/8-inch (2 oz); and 3/8-inch (3.5 oz). Ten volunteers (aged 22-24years) were selected to wear personalized clear retainers, which were made to hold the elastics in the mouth and stretched to a specific length. Control samples of 1/4-inch (2 oz) and 1/4-inch (3.5 oz) latex elastics were stretched to the same length and held in dry air conditions (temperature=25°C) and in artificial saliva (temperature=37°C, pH=6.7). Force value and percentage of force degradation were estimated 10 times over a 48-hour period in both the invivo and invitro groups. A 1-way ANOVA and t test were used to identify statistical significance (P<0.05). The force degradation of the latex elastic invivo is greater than invitro. In the invivo groups, during the first hour, the extension rate of all elastics decreased sharply about 13.16%-18.79%, then the rate of force degradation declined. The degradation of initial force was about 29.35%-39.94% after 48hours. The extension range of 2.0-oz elastics reduced less than that of the 3.5-oz elastics invivo. At the same time, with the same initial force, elastics with larger inner diameters decreased more slowly than the smaller elastics (P<0.05). The force degradation of latex elastic invivo is much greater than that in both air and artificial saliva. Invivo, the force value of the orthodontic latex elastics decreased sharply in the first hour. The larger the inner diameter and smaller the setting force value were, the slower the force decay.

Comparison of the Force Released by Intermaxillary Elastics Used for Different Time Periods.

The objective of the present study was to compare the strength degradation of the force of intermaxillary elastic used for different periods. The sample included intermaxillary elastics used for 20 adult patients with bilateral Class II or III malocclusion in orthodontic treatment with fixed appliances, with a mean age of 27.25 years. Latex orthodontic elastics with 3/16 inch of diameter were used, with an average stretching of three times its diameter. The elastics were used in the same patient bilaterally for different periods, with each pair of elastics used for 1, 12, 24, and 48h. Thus, the sample consisted of 200 elastics, with 40 being used in each period (one pair used by each patient) and 40 new elastics without use tested as control. Elastics were tested using a universal testing machine, stretched with a velocity of 30 mm/min, and the force was evaluated in stretches of 15, 20, 25, and 30 mm. The degradation force was compared in the four different times of use and control by one-way ANOVA (analysis of variance) and Tukey tests. There were significant differences among the groups in all evaluated stretches (15, 20, 25, and 30 mm). The control elastics presented higher average forces numerically and statistically significant for all tested times, except for the elastic used for 1h. The elastics used for 1, 12, and 24h had similar forces among them, with a significant difference to the elastics used for 48h. It is recommended to change the intermaxillary elastics after 24 h of use.

Force degradation of orthodontic latex elastics: An in-vivo study

Our objectives were to assess the force degradation of orthodontic latex elastics over 48hours invivo and to study the relationship between the amount of mouth opening and the degree of force decay. Fifty-two orthodontic patients wearing fixed appliances using Class II elastics were asked to wear premeasured-force 3/16-in heavy and medium intermaxillary elastics. The force amounts were measured and compared at different time intervals. Fifty percent of theforce was lost after 3.9hours for the medium elastics and after 4.9hours for the heavy elastics. A continuous significant force drop in all elastics was seen at all time intervals (P<0.05, P<0.001). There was greater force loss in the heavy elastics compared with the medium elastics invivo at all time intervals (P<0.001); the rates of force loss, however, were similar. Fifty percent of force degradation occurred in the first 4 to 5hours. Because of breakage and for oral hygiene purposes, orthodontic elastics should be changed daily; otherwise, elastics can be used for 48hours. Force decay of the elastics was correlated to the lateral distance between the maxillary canine and the mandibular first molar in occlusion.

Synergic effect of salivary pH baselines and low pH intakes on the force relaxation of orthodontic latex elastics.

Latex elastics are still in common use due to their low cost and high flexibility to improve sagittal discrepancies or interdigitation of teeth. Mechanical properties of elastics are influenced by several environmental factors such as pH changes. This study evaluated similar latex elastics to define the influence of synergic effect of intermittent low pH and various baselines pH of saliva. Four groups of latex elastics (3-M Unitek, 3/16 inch) were tested (n = 15 in each group). Two groups of elastics were immersed in two tanks of artificial saliva with different pH levels of 7 and 5, and two groups were immersed in two tanks of artificial saliva with intermittent drop of pH to 4. The force was measured when the elastics were stretched to 25 mm. These measurements were taken in 0, 4, 8, 12, 24, 36, and 48 h for each group. Repeated measures analysis of variance (RMANOVA) and post-hoc Tukey's test were used to assess the findings. The level of significance was 0.05%. The interaction between pH and time analyzed with RMANOVA showed no significant differences (P > 0.05) except in 36 h (P = 0.014). The Tukey's analysis showed that each comparison between any two groups did not indicate significant differences (P > 0.05) except between Groups 1 and 3 and between Groups 2 and 3 (P < 0.05). No significant correlation was seen between fluctuation of pH and force degradation in latex elastic band except in 36 h.

Force relaxation of 3/16 inch heavy orthodontic latex elastics used in maxillofacial trauma in simulated jaw fracture situation

Introduction: Orthodontic elastic has been investigated for tooth movement. Study about their use in treatment of jaw fractures is limited. This study is designed to measure force relaxation of 3/16 inch heavy latex orthodontic elastics in jaw fracture treatment simulated conditions. Materials and Methods: This study is designed to study the force relaxation of 45 heavy 3/16 inch orthodontic elastic (American Orthodontist, AO) (4/8 mm internal diameter) were measured using Zwick testing machine (Zwick GmbH & Ulm Germany) in 0, 1, and 14 days of immersion in simulated oral environment. In each of these three occasions, 15 specimens were placed in jigs with metallic pins that inserted 15 mm and 20 mm apart that is equivalent to the normal inter-arch space in a closed mouth position. The jigs were incubated in 37°C and each 24 hours they received 10 thermal cycles of 55°C and 5°C for 30 seconds in a thermocycle. The distribution of the data was evaluated by Klomogrov-Simirnov test and after confirmation of a normal distribution; data was analyzed using analysis of variance (ANOVA). Results: Mean force decay at 15 mm stretch was significantly differ between 0-1 days and 0-14 days (P < 0.05) but was not significantly differ between 1-14 days. The same relations exist for 20 mm stretch. Conclusions: This study creates scientific basis for use of orthodontic elastics in treatment of fractured jaws.

A study of force extension and force degradation of orthodontic latex elastics: An in vitro study

Introduction: The purpose of this study was to determine the force values of different orthodontic latex elastics at different extensions when subjected to testing in dry and wet conditions. This study also aims to determine and compare the force degradation of the elastics produced by four manufacturers at different extensions and at regular intervals. Materials and Methods: 5/16 inch lumen medium (Green) and ¼ inch lumen medium elastics (blue) of 4 companies were used. The elastics were stretched on a correx gauge to two times and three times the inner lumen diameter and at a fixed distance of 25 mm (dry test).The elastics were stretched at the specific distances and then immersed in artificial saliva and checked after 24 and 48 h (wet test). The data was analyzed using Student's t-test. Results: Force degradation increases with time. Force degradation percentage values vary from 5% to a maximum of 25%. Conclusions: Thus from the study, the clinician can know the force degradation rates of elastics of two different sizes, manufactured by four different companies. This study also shows that though, the force degradation during the 2 nd day was found to be significant in most of the elastics, it is not sufficient to justify daily change of elastics.

Comparison of the Mechanical Properties of Thai Nonlatex with Commercial Latex Orthodontic Elastics for Orthodontic Application

Natural rubber latex products are used as orthodontic elastics but the increased incidence of latex allergies has led to the development of nonlatex orthodontic products. In Thailand, commercial nonlatex orthodontic elastics are not readily available and the cost of imported non latex products is relatively high. Thai non latex elasticshave been developedas alternative orthodontic products for latex-allergic patients and their costs are affordable.Objective: Tocomparethe mechanical properties of Thai nonlatex elastics with commercial natural latex orthodontic elastics for orthodontic application. Materials and Methods: Samples of imported latex orthodontic elastics [Ormco(USA), G&amp;H (USA), Creative Orthodontics (China), Tomy Elastics (Japan)]were selected to compare their dimensional characteristics and mechanical properties with Thai non latex elastics. The dimensional characteristics of the elastics (i.e., inner diameter, cross-sectional thickness and cross-sectional area) were determined and their mechanical properties [(i.e., initial extension force (F0), 24 h- residual force (F24), percentage of force loss, force exerted at 3x the specified inner diameter(F3xID) and breaking force] were tested next. The data were analyzed with One-way ANOVA and multiple comparison by Tukey’s test was used among groups (p&lt;0.05). Results:Significant differences of dimensional characteristics and mechanical properties were found among each brand of elastics. Thai non latex elastics had significantly different mechanical properties from natural latex elastics as reported in previous studies(p&lt;0.05). Thai non latex elastics had the lowest initial extension force (0.82N), 24-h residual force (0.56 N) and breaking force (19.63 N, 8.183 MPa) but the highest percentage of force loss after 24 h (32.62%).However, the percentage of force loss was higher than commercial non latexelastics as previously reported. Conclusion:Thai nonlatex elastics were not comparable to those of the latex elasticsregardingmechanical properties;however,these are acceptable for orthodontic application. Therefore, the clinical selection of elastics should be based on the patient’s medical history and the specific mechanical properties of the type of elastic. Thai nonlatex orthodontic elastics can be a valid alternativefor patients with latex allergy in Thailand and this study contributes to the continuous development of Thai nonlatex orthodontic elastics.

Force Relaxation Characteristics of Medium Force Orthodontic Latex Elastics: A Pilot Study

To evaluate force extension relaxation of different brands and diameters of latex elastics subjected to static tensile testing under an apparatus designed to simulate oral environments, sample sizes of 5 elastics from American Orthodontics (AO), Tp, and Morelli Orthodontics (Mo) of equivalent medium force, (3/16, 1/4, and 5/16 inch size) were tested. The forces were read after 1-, 3-, 6-, 12- and 24-hour periods in Emic testing machine with 30 mm/min cross-head speed and load cell of 20 N. Two-way ANOVA and Bonferroni tests were used to identify statistical significance. There were statistically differences among different manufacturers at all observation intervals (P < 0.0001). The relationships among loads at 24-hour time period were as follows: Morelli>AO>Tp for 3/16, 1/4, and 5/16 elastics. The force decay pattern showed a notable drop-off of forces until 3 hours, a slight increase in some groups from 3–6 hours and a more homogeneous force pattern over 6–24 hours.

Force extension relaxation of medium force orthodontic latex elastics

To evaluate the force extension relaxation of different manufacturers and diameters of latex elastics subjected to static tensile testing under dry and wet conditions. Sample sizes of 15 elastics from American Orthodontics (AO) (Sheboygan, Wis), TP (La Porte, Ind), and Morelli Orthodontics (Sorocaba SP, Brazil) were used. Equivalent medium force products were tested--3/16, 1/4, and 5/16 inch lumen size from each manufacturer--making a total of 1080 specimens. An apparatus was designed to simulate oral environments during elastics stretching. Forces were read after 1, 3, 6, 12, and 24 hour periods using the Emic Testing Machine (Emic Co., Sao Paulo, Brazil) with 30 mm/min cross-head speed and load cell of 20 N (Emic Co). Kruskal-Wallis and Dunn's tests were used to identify statistical significance. Statistical differences between AO and the other brands were noted for all testing times. Significant variation in mechanical properties was observed in latex elastics from Morelli. Relationships among loads at the 0 hour time period were as follows: Morelli>AO>TP for 3/16 elastics (P = .0016), 1/4 elastics (P = .0016), and 5/16 elastics (P = .0087). Significant differences in force extension relaxation were noted for elastics from these manufacturers. Force relaxation over the 24 hour time period was AO>Morelli>TP for 3/16 elastics, AO>TP>Morelli for 1/4 elastics, and TP>AO>Morelli for 5/16 elastics. The force decay pattern showed a notable drop-off of forces during 0 to 3 hours, a slight increase in force values from 3 to 6 hours, and a progressive force reduction over 6 to 24 hours.

In Vitro Cytotoxicity of Latex Orthodontic Elastics

El latex natural no entra en la categoria de materiales que se sabe del todo inofensivo. El objetivo del presente estudio in vitro es poner a prueba la hipotesis de que no hay diferencia en la citotoxicidad entre elasticos de latex natural de diferentes colores. El presente articulo compara diferentes elasticos intraorales de latex (5/16 =7,9 mm). La muestra se dividio en cuatro grupos segun su fabricante: Grupo N (elastico latex, Morelli), Grupo I (elastico de color rojo, Morelli) Grupo Y (elastico de color amarillo, Morelli) y el Grupo G (elastico color verde, Morelli). Pruebas de citotoxicidad se realizaron mediante el uso de medio de cultivo celular que contiene lineas celulares L-929 (fibroblastos de raton). La citotoxicidad se evaluo mediante el test “dye-uptake”, que se empleo en dos momentos diferentes (1 y 24 h). Los datos se compararon mediante analisis de varianza (ANOVA) y test de Tukey (p 0,05) en 1 y 24 h. Elasticos intraorales Morelli resultaron ser altamente citotoxicos, independientemente de su color y tiempo de inmersion.

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

To evaluate the characteristics of force degradation of latex elastics in clinical applications and in vitro studies. 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. 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. There were some differences among groups in the different times to start wearing elastics in intermaxillary traction but no significant differences in intramaxillary traction.

Orthodontic latex elastics: a force relaxation study.

The objectives of this study were to assess the force relaxation of latex elastics occurring within 24 hours of extension and to estimate the extension required to reach the reported force. Five specimens of various manufacturers' latex elastics size and force levels were mounted on a custom-made setup capable of monitoring force levels in real time with a continuous mode and without operator intervention. The percentage of force relaxation was estimated from the initial and 24-hour levels, and the results were analyzed with one-way analysis of variance and the Tukey test at alpha = 0.05 level of significance. The elastics showed force relaxation in the order of 25%, which consisted of an initial high slope component and a latent part of decreased rate. Most relaxation occurred within the first 3-5 hours after extension, regardless of size, manufacturer, or force level of the elastic. The overall as well as the initial relaxation curves were fitted to equations, which described the variation of force with time. Elastic extension to achieve the reported force was found to range between 2.7 and five times the original length. Latex elastics show force relaxation in the order of 25%, which consists of an initial high slope component and a latent part of decreased rate. Most relaxation occurs within the first 3-5 hours after extension, regardless of size, manufacturer, or force level of the elastic. The empirical rule of "3" shows remarkable variation, ranging from 2.7 to five.

An in vitro study simulating effects of daily diet and patient elastic band change compliance on orthodontic latex elastics.

This project investigated the effects of food exposure and patient compliance with elastic-band change on the degradation of forces in 3/16-inch, medium-wall, latex elastic bands during a simulated day of clinical wear. Six levels of daily diet/patient compliance were chosen as representative of orthodontic patients and a quasicontrol group. The groups differed with respect to how much exposure to artificial saliva and foodstuffs they experienced. After exposure in mild tension to daily diets and based on compliance with instructions about changing orthodontic elastics, the elastics were tested in tensile mode by stretching to 25 mm, where the load was recorded in newtons. The bands of three manufacturers, Rocky Mountain Orthodontics (RMO), 3M Unitek (UNO), and American Orthodontics (AMO), were examined, with 10 bands per group, per manufacturer, forming a cohort. Two-way analysis of variance and the Tukey-Kramer honestly significant difference tests were used to identify statistical significance (P > .05). With respect to bands from a single manufacturer, no differences were found between daily diet/patient compliance levels. However, differences (P < .0001) were found between manufacturers' bands. RMO > UNO > AMO in all environments. Over a 24-hour period, latex elastics maintain their applied load in the simulated oral environments.

Calibration of force extension and force degradation characteristics of orthodontic latex elastics

The force-extension characteristics of orthodontic elastics made of natural rubber latex by 4 manufacturers were subjected to static testing under dry and wet conditions. The elastics consisted of 3 sizes: 3/16, 1/4, and 5/16 inch lumen sizes, each with forces specified according to the standard extension index of three times the lumen diameter. Most of the elastics did not match the specified index using the dry tests, but this should not be a serious clinical concern as all elastics showed acceptable regularity of force-extension characteristics. There was notable force degradation of all elastics when subject to water immersion, approximating 30% during the hour, but with an average less than 7% further loss up to 3 days. There were significant differences in force extension and force degradation characteristics between different extensions and force magnitudes for the elastics of the different manufacturers. It is suggested that the clinician could use the table of force degradation values for different extensions to select an appropriate elastic. (Am J Orthod Dentofacial Orthop 2000;118:280–7)