Evaluation of plasticity and radiopacity of elastic separators by means of traction tests and radiography

摘要

INTRODUCTION: Elastic separators are widely used in the orthodontic clinic, in different sizes and thicknesses. Their function is to promote the separation between the teeth that will receive orthodontic bands, however, when subgingivally lost, they may cause periodontal problems and, ultimately, cause tooth extraction. OBJECTIVE: Concerned not only about their function but also about their properties, this experimental work was performed in order to evaluate, with a clinical perspective, the plasticity and radiopacity of the elastic separators, usually used in orthodontic clinic, through physical traction tests and radiographs. METHODS: Six different brands were analyzed and divided in two groups: extruded separators (American Orthodontics, GH, Morelli Blue and Morelli Green) and modular separators (Abzil, Dentaurum, GAC, Blue Modular Morelli and Green Modular Morelli). The plasticity was evaluated after physical traction tests, stretching the separators to 3 times their initial diameter. While the radiopacity was assessed using x-rays. RESULTS: When stretched to three times their inner diameter (ID), the extruded separators American Orthodontics, GH, Morelli Blue and Morelli Green and the modular ones Dentaurum, Morelli Blue Modular and Morelli Green Modular, presented elastic deformation, recovering their original inner diameter. The modular separators from Abzil and GAC showed permanent plastic deformation. With respect to radiopacity, the Abzil, American Orthodontics, Dentaurum, GAC and GH separators were radiopaque. CONCLUSION: Correlating the results concerning the plasticity and radiopacity, the separators which showed the most satisfactory results on both tests were, among the extruded separators, American Orthodontics and GH, and among the modular separators, GAC and Dentaurum.