Abstract
ObjectiveThe objective this work was to assess the friction coefficient between brackets and wires of different materials under conditions simulating the oral environment.Material and MethodsStainless steel (SS) and titanium-molybdenum alloy (TMA) wires of 0.019x0.025-in diameter (American Orthodontics) and polycarbonate bracket (American Orthodontics), ceramic bracket (American Orthodontics), and metal bracket (3M Unitek) with slots of 0.022x0.030-in were used. The friction coefficient was assessed by means of mechanical traction with the system immersed in artificial saliva. The mean roughness of both wire surface and bracket slots was evaluated by using a surface profilometer.ResultsThe system using TMA wire and polycarbonate bracket had the highest roughness (p<0.05). SS wire with ceramic bracket had the highest friction coefficient, whereas the use of metallic bracket yielded the lowest (p<0.05). However, it was observed a statistically significant difference in the system using TMA wire and ceramic bracket compared to that using TMA wire and polycarbonate bracket (p=0.038).ConclusionCeramic brackets in association with SS wire should be judiciously used, since this system showed a high friction coefficient.
Highlights
A successful orthodontic movement is directly related to the ability of orthodontic wires to slide through brackets slots and tubes, and it is well known that the sliding resistance between the bracket slot and archwire can drastically influence the tooth movement3,22
Comparing the maximum mean friction values for the bracket systems using stainless steel (SS) wire (Table 2), no statistically significant differences were found between metallic (SSB-SS) and polycarbonate (PBSS) brackets
With regard to systems of brackets using titanium-molybdenum alloy (TMA) wire, no statistically significant differences were found between metallic (SSB-TMA) and polycarbonate (PB-TMA) brackets or between metallic (SSB-TMA) and ceramic (CB-TMA) brackets
Summary
A successful orthodontic movement is directly related to the ability of orthodontic wires to slide through brackets slots and tubes, and it is well known that the sliding resistance between the bracket slot and archwire can drastically influence the tooth movement. In an attempt to fulfill an increasingly aesthetic demand, aesthetic accessories consisting of different materials have been developed, among which are the aesthetic ceramic and polycarbonate brackets11 These accessories alleviate the aesthetic problem despite the limitations of their use, such as fracture of the brackets, abrasion of antagonist teeth and, mainly, the increased friction resulting from the mechanical sliding. Friction is defined as the force opposing the movement of two objects in direct contact to each other, and its direction is tangent to a common interface between both surfaces. The intensity of this force is closely related to the surface characteristics and properties of the materials involved. Knowing the influence of different materials on the sliding mechanism, the aim of this study was to assess the frictional force existing between conventional and aesthetic brackets in association with stainless steel (SS) and titanium-molybdenum alloy (TMA) wires by correlating the mean roughness values of wires and bracket slots
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
