Comparison Of The Force Deterioration Of Different Orthodontic Elastomeric Materials In Artificial Saliva: An In Vitro Study

The orthodontist must be able to choose an elastic band with force-extension characteristics that are most suitable for the particular tooth movement required. From a clinician view it would be mandatory not only to know the clinical aspect of these elastics but also their basic properties, in order to extract the most out of these polymers. Stretching of elastics are thought to be the primary cause of force degradation of orthodontic elastics but there is evidence of in-creased force degradation of elastics when exposed to various types of substances like artificial saliva, phosphoric acid and citric acid. Orthodontic elastics have received mixed reactions of practitioners as reported by the vendors of ortho-dontic supplies. The present study is designed to compare the force deterioration of different orthodontic elastomeric materials in artificial saliva medium. There was a force deterioration over time in all materials, being greatest on the seventh day of the experiment, especially more in the chains; From the third to the fourth week there was no noticea-ble force degradation in either group; By the end of the experiment, modules showed less deterioration of the force compared to the chains and threads.

Does acidic drinks vs. controls differents interfere with the force of orthodontic chain elastics? / Bebidas ácidas versus diferentes controles interferem com a força de elásticos ortodônticos em cadeia?

This study aimed to investigate alterations in physical properties of orthodontic elastomeric chains when in contact with different controls and acidic beverages. Elastomeric chains were divided into 6 groups (n=18) of elastic chain segments, distributed as follows: Group CW (Deionized water) Group CS (Artificial saliva), Group CC (Coca-Cola®) Group SP (Sprite®) Group GA (Guaraná Antártica®) and Group FA(Fanta®). Elastics were stretched in 50% of the initial length and were held for initial, 1, 7, 14, 21 and 28 day time intervals. Force magnitudes were measured at 23.5 mm of activation using a digital meter. Force decay were assessed using analysis of variance(ANOVA) and Tukey's test(p<.05). Control Group CS saliva demonstrated the highest elastic decay values, with statistical difference between time of 24h with time intervals of 14, 21 and 28 days (p<.05). In comparison between groups, there was statistical difference between Group CS and Groups CW and FA in all experimental time-intervals, with group CC in time-intervals 7, 14, 21 and 28 days and with Group GA in time-intervals 7, 14 and 21 days (p<.05). In decreasing order: Coca-cola®, Fanta®, Guarana Antartica® and Sprite® demonstrated capacity to influence elastomeric chain decay, however with less influence than the saliva medium.

Este estudo objetivou investigar as alterações das propriedades físicas de cadeias elastoméricas ortodônticas quando em contato com diferentes controles e bebidas ácidas. Cadeias elastoméricas foram divididas em 6 grupos (n=18) de segmentos de elásticos em cadeia, assim distribuídos: Grupo CW (água deionizada), Grupo CS (saliva artificial), Grupo CC (Coca-Cola®), Grupo SP (Sprite®), Grupo GA (Guaraná Antártica®) e Grupo FA (Fanta®). Os elásticos foram esticados em 50 % do comprimento inicial e mantidos pelos intervalos de tempo inicial, 1, 7, 14, 21 e 28 dias. Magnitudes de força foram medidos em 23.5 mm de ativação usando um medidor digital. Degradação da Força foi avaliada através da análise de variância (ANOVA) e teste de Tukey (p<.05). Grupo Controle CS saliva demonstrou os maiores valores de degradação elástica, com diferença estatística entre o tempo de 24 h com intervalos de tempo de 14, 21 e 28 dias (p<.05). Na comparação entre os grupos, houve diferença estatística entre o Grupo CS e os Grupos CW e FA em todos os intervalos de tempos experimentais, com grupo CC nos intervalos de tempo de 7, 14, 21 e 28 dias e com o Grupo GA nos intervalos de tempo de 7, 14 e 21 dias (p<.05). Em ordem decrescente: Coca-cola®, Fanta®, Guaraná Antartica® e Sprite® demonstraram capacidade de influenciar a degradação da cadeia elastomérica, porém com menos influência do que o meio de saliva.

An in-vitro study to compare the force degradation of pigmented and non-pigmented elastomeric chains.

Aim: The purpose of the study was to compare the force delivery and force decay property of pigmented and non-pigmented elastomeric chains, widely used in orthodontic practice. Materials and Methods: Force delivered by the samples consisting of pigmented and non-pigmented elastomeric chains obtained from 3 manufacturers were tested at 3 time intervals (as received, after 24 hours and 21 days of stretching) to measure the force delivered by the test samples, as well as the force decay over time. Results: The force delivered by the non-pigmented samples was significantly greater than the pigmented ones at all 3 time intervals irrespective of the brand. Force decay was more significant in case of pigmented samples. Force decay was greater noticed in first 24 hours of testing and a gradual decrease in force was observed from 24 hours to 21 days in all test samples irrespective of the brand or color. Conclusion: Non-pigmented elastomeric chains exhibited better force delivery and less force decay percentage when compared to pigmented chains. Though colored elastomeric chains are widely used in present day orthodontic practice to satisfy the younger age group patients, the study ascertains the prudential use of pigmented and non-pigmented chains for efficient and faster orthodontic treatment.

Force degradation of different elastomeric chains and nickel titanium closed springs

Aim: The purpose in this study was to evaluate the degradation force of conventional synthetic orthodontic elastics and synthetic orthodontic elastics with memory properties. Methods: Specimens of each material (Plastic chain, Memory chain and Closed spring NiTi) were stretched and adapted to the test specimens composed of resin plates and orthodontic wires, simulating retraction units. Degradation force was verified in an Instron universal test machine at the following intervals: 1, 2, 18, 24, 48 h; 7, 14, 21, and 28 days. Data (gF) were analyzed statistically using Friedman and Kruskal-Wallis tests at 5% significance level. Results: It was observed a significant force reduction of Plastic chain and Memory chain after 2 h (p<0.05). For NiTi spring significantly force reduction was observed after 18 h, but no significant change was showed up to 21 days. NiTi spring showed force significantly higher than synthetic elastomeric materials (p<0.05). There was no significant difference between Memory chain and Plastic chain up to 24 h. However, from 48 h to 21 days Memory chain showed force significantly higher than Plastic chain. Conclusions: There was higher force degradation in the synthetic elastomeric materials in comparison with NiTi springs, which allows the preferential indication of these space closure jigs for clinical use.