ABSTRACT
INTRODUCTION: The main objective of this study was to reexamine the mechanical properties of elastomeric chains after stretching in various artificial saliva solutions and in air. MATERIALS AND METHODS: Five brands of elastomeric chain manufactured by different companies were selected. For each brand, four types were tested in different artificial media. A dismountable test kit was used to stretch the chains up to various initial force levels. They were then immersed in pre-prepared solutions, with control samples exposed to air only. Residual force was measured at multiple time points using a hand-held dynamometer. RESULTS AND DISCUSSION: The force delivered by the elastomeric chains decayed rapidly and differently over time. This decay varied depending on multiple factors, discussed here.
Subject(s)
Dental Stress Analysis , Elastomers , Orthodontic Appliances , Saliva, Artificial/adverse effects , Elasticity , Equipment Failure , Materials Testing , Mechanical Phenomena , Tensile StrengthABSTRACT
INTRODUCTION: Elastomeric chains are one of several devices used to provide force for orthodontic tooth movement, but the force they exert diminishes over time and can thus be difficult to control. The objective of this investigation was to provide a systematic review of publications pertinent to force decay in orthodontic elastomeric chains. MATERIALS AND METHODS: A systematic review was performed via electronic querying of multiple databases for the period 1970-2011. Queries were limited to a set of specific keywords in two languages (English and French). Five main reviews were consulted manually to identify relevant publications. Two investigators sorted out those studies that complied with selection criteria. RESULTS AND DISCUSSION: A total of 53 studies were found to be relevant to force decay in elastomeric chains, including 22 on force decay over time, seven on the force consequences of pre-stretching, 12 on the impact of the environment on the force delivered, and 11 on clinical efficacy. CONCLUSION: The force delivered by elastomeric chains decays rapidly over time, affecting their mechanical properties and clinical efficacy when studied in either human saliva or laboratory test media.
