Comparison of static friction with self-ligating, modified slot design and conventional brackets

Abstract

O bjective: To compare the static frictional forces generated at the bracket/wire interface of stainless steel brackets with different geometries and angulations, combined with orthodontic wires of different diameters. Material and Methods: The frictional forces were evaluated with three different types of metal brackets: a passive self-ligating (SmartClip™, 3M/Unitek, Monrovia, USA), with a modified slot design (Mini Uni Twin™, 3M/Unitek, Monrovia, USA) and conventional (Kirium, Abzil, São José do Rio Preto, Brazil). The samples were mounted in a testing device with three different angulations and tested with 0.014" and 0.018" stainless steel wires (American Orthodontics, Sheboygan, USA). The static frictional force was measured using a universal testing machine (DL 500, eMIC ® , São José dos Pinhais, Brazil) with a crosshead speed of 1 mm/min. Statistical analysis was performed by two-way ANOVA followed by Bonferroni's post hoc test. Results: There was a significant difference (p<0.05) in static friction when the three types of brackets were tested with the same wire size. The wire diameter influenced friction only when the brackets had a 10° angulation (p<0.05). The angulation influenced friction (p<0.05) when the brackets were associated with a 0.018" wire. Conclusion: Brackets with a modified slot design showed intermediate static frictional force values between the conventional and self-ligating brackets tested.

Antimicrobial action of chlorhexidine digluconate in self-ligating and conventional metal brackets infected with <em>Streptococcus mutans</em> biofilm

“…Presently, metallic brackets are the most widely used 31 , 32 regardless of model or prescription. Although the concept does not characterize a novelty in orthodontics, the SL system was widespread in the early 21st century 11 , 31 by stating the low friction as differential, which facilitates the start of tooth movement by decreasing the initial resistance to movement. This has aroused great interest among orthodontists, since the reduction in friction levels during orthodontic treatment promises faster treatment and less number of dental appointments.…”

Effects of nanostructured, diamondlike, carbon coating and nitrocarburizing on the frictional properties and biocompatibility of orthodontic stainless steel wires

“…Factors affecting friction include the material used, archwire size, and ligation methods, to name a few. 11,26,27 Surface roughness has a positive correlation with friction, while archwire hardness is negatively correlated with friction. In the present study, our DLC-coated wires displayed a smoother and harder surface compared with the control wire (Table 1), which possibly resulted from the larger proportion of sp3 bonds in the DLC coating.…”

Are self-ligating brackets an advantageous alternative for non-extraction treatments?

“…The frictional force is lower with self-ligating brackets than with traditional brackets 8,12 . The friction resistance proved to be lower with ceramic and metal (stainless steel) self-ligating brackets than with conventional ceramic brackets 39 .…”