Forces in stainless steel, TiMolium® and TMA® intrusion arches, with different bending magnitudes

Abstract

, Vbend intrusion arches with different magnitudes of flexion. The sample consisted of rectangular-section wires, caliber .017" x .025", with ten arches of each alloy. All V-bends were made 48 mm from the midline, using the same phantom upper jaw, maintaining the same distance between the tubes fixed to the molars and the midline. Loads necessary to deflect the arches by 5, 10, 15 and 20 mm were measured by means of an Instron dynamometer with a 1 kgf load cell. Calculations for sample size confirmed the suitability of using 10 arches of each alloy. Variance tests (ANOVA) of one factor and three levels, complemented by the Tukey test for multiple comparisons, identified that TMA  intrusion arches required a smaller quantity of load in relation to conventional steel and TiMolium  at all levels of flexion. Furthermore, TiMolium  presented intermediary characteristics between steel and TMA  , and in all alloys increase in distance entailed a significant increase in force between all registered values, and that the increase in load necessary to deflect the arches at the intervals tended to decrease from first to last interval, these differences being more significant in steel, less in TiMolium  and practically non-existent in TMA  . Descriptors: Orthodontic wires; Dental alloys; Biomechanics; Tooth movement.Resumo: O presente estudo comparou as forças em arcos de intrusão com dobra V confeccionados em aço inoxidável, TiMolium  e TMA  , com diferentes magnitudes de deflexão. A amostra constou de fios de secção retangular e calibre 0,017" x 0,025", com dez arcos de cada liga. Todas as dobras em V foram confeccionadas a 48 mm distantes da linha média, e foi utilizado o mesmo manequim de maxila para manter a mesma distância entre os tubos fixados nos molares e a linha média. As cargas necessárias para defletir os arcos em 5, 10, 15 e 20 mm foram mensuradas por meio de dinamômetro com célula de carga de 1 kgf, da marca Instron. O cálculo para o tamanho de amostra confirmou a possibilidade de se utilizar dez arcos de cada liga. Os testes de variância (ANOVA) de um fator e três níveis, complementados com os testes de Tukey para comparações múltiplas, identificaram que os arcos de intrusão de TMA  requereram menor quantidade de carga em relação ao aço convencional e ao TiMolium  em todos os níveis de deflexão; que o TiMolium  apresentou características intermediárias entre o aço e o TMA  ; que em todas as ligas o aumento das distâncias implicou em aumento significativo da força entre todos os valores registrados; e que os incrementos de carga necessários para defletir os arcos nos intervalos tenderam a decrescer do primeiro ao último intervalo, sendo essas diferenças mais significantes no aço, menores no TiMolium  e praticamente inexistentes no TMA  .

Assessment of friction resistance of four orthodontic arch wires using three ligation methods in dry and wet conditions

“…The result of the present study showed that stainless steel arch wire material provide the lowest friction resistance in wet condition followed by titanium molybdenum alloy (β-titanium TMA), then Nitinol (NiTi), and copper nickel titanium (Cu Ni Ti) which reported the highest friction resistance. Many studies (14,(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41) reported the superiority of stainless steel archwires as it was associated with the least amount of friction but followed by Ni Ti while beta titanium exhibited the highest frictional resistance. This was explained by the increased surface roughness of β-titanium wire as compared with stainless steel arch wire as reported by scanning electron microscope and laser spectroscopic picture (26,43) .…”

The Effect of Orthodontic Forces on Calcitonin Gene-related Peptide Expression in Human Dental Pulp

“…Before extraction, premolars in experimental groups were submitted to 24 hours of moderate or severe orthodontic force application. Both experimental groups used a cantilever made of 0.017 Â 0.025 TMA wire, which is ideal for the experiment because of its rectangular shape and its long transverse diameter that allows proper buccolingual control with an adequate elasticity module (17)(18)(19)(20). The activation angle controls the direction of the force exerted by a cantilever.…”

Friction between different wire bracket combinations in artificial saliva: an in vitro evaluation

“…In the present study, the systems using TMA wire had a higher friction coefficient regardless of the type of bracket used. In addition, TMA has been shown to present lower modulus of elasticity, springback greater than that of steel 8 . With regard to the brackets, the slots of metallic brackets exhibited less roughness compared to those of polycarbonate and ceramic ones.…”