An investigation into the behavioural characteristics of orthodontic elastomeric modules.

Abstract

The object of the study was to investigate the behavioural characteristics of orthodontic elastomeric modules with regard to their effect on frictional resistance and their failure load forces, and involved the use of an experimental laboratory-based study. Six cohorts were assembled employing five types of module and two bracket types. Straight lengths of 0.018 x 0.025-inch stainless steel were pulled through the ligated brackets and frictional resistance was measured using an Instron universal testing machine. Recordings were repeated over a 4-week period, during which time the cohorts were placed in a simulated oral environment. Failure load forces of new and used modules were also recorded, and frictional resistance and failure load forces. Analysis of variance revealed that the Minitwin cohort exhibited significantly higher frictional resistance and that the clear modules demonstrated the lowest levels of friction. Time soaked in a simulated oral environment had a variable effect on frictional resistance. A wide range of failure load forces was seen for the five types of module and all types showed a reduction in failure load force following their soaking in the simulated oral environment. There was variation in performance of the different modules both in friction testing and failure load testing.

Effect of applied moment on resistance to sliding among esthetic self-ligating brackets

“…This process is known to have a variable effect on RS, and some studies 17 have reported a decreased amount of force delivered by elastic ligatures. Others 18,19 have reported increased amounts of RS depending on the exact storage environment or elastic material used. In a similar fashion to the elastic ligatures, the brackets themselves may become degraded 20 at different rates and stick to the archwire more than in the untreated state.…”

In vivo color changes of esthetic orthodontic ligatures

“…Assessments of the physical properties of elastomeric ligatures have reported significant changes in the structure and composition of these materials after exposure to the oral environment. [1][2][3][4][5][6][7] Variations in the friction force of elastomeric ligatures of different brands were observed after immersion in laboratory solutions in an attempt to reproduce the oral environment. 3 After exposure to the oral environment for 3 weeks and subsequent analysis by optical microscopy and spectroscopy, the elastomeric ligatures exhibited precipitates of calcium and phosphorus with the formation of calcium phosphate on the surface.…”

“…Many studies have evaluated the effects of the oral cavity on the elastic properties of elastomeric ligatures, such as force decay, friction and dimensional changes. [1][2][3][4][5][6][7] However, researchers have shown little concern about the behavior of orthodontic materials after exposure to the oral environment, especially the extent to which these changes interfere with esthetics.…”

Effect of dental arch convexity and type of archwire on frictional forces

“…11 The testing machine was calibrated to measure maximum 2000 g of friction. Static friction was recorded while 5 mm 1,6 of the whole length of the wire was drawn through the brackets at a cross-head speed of 20 mm/min 1,11 and it was defined as the force needed to start the wire moving through the bracket-wire assembly. This force was measured as the maximal initial rise and was analyzed with the software program (TestXpert ® , Zwick ROELL, Ulm, Germany).…”

“…Static friction is the force required to produce the initial movement and it is always stronger than the kinetic force that keeps the body in motion. 6,7 Tooth movement along an arch-wire is not continuous but occurs in a series of intermittent movements. Static friction in this context is considered to have a greater importance in orthodontic applications because it needs to be overcome with movement of each tooth.…”