OBJECTIVE: To determine if the type of ligation influences the frictional resistance between stainless steel wire and brackets when the wire is subjected to repeated vertical displacements. METHODS: Eight different types of ligation were used to secure a length of stainless steel wire in three stainless steel twin brackets. The wire was subjected to repeated vertical displacements in a simulated extraction space. Eighty per cent of the minimum force required to overcome static friction (F-m) between the wire and brackets was applied to the wire for eight minutes and any sliding measured. RESULTS: Frictional resistance to sliding was least when stainless steel ligatures twisted in a figure 8 pattern until taut then untwisted one quarter turn were used, and greatest when elastomeric modules in a figure 8 pattern (EM8) were used. The F-m difference between fully engaged standard and Super Slick elastomeric modules was significantly different (p = 0.007). The frictional resistance to sliding fell when the wire was secured with either of these two methods and subjected to vertical displacement loads. There was no significant difference in the rate of wire movement between these modules. CONCLUSION: Repeated vertical displacement reduced the frictional resistance to sliding for all methods of ligation except EM8.
OBJECTIVE: To determine if the type of ligation influences the frictional resistance between stainless steel wire and brackets when the wire is subjected to repeated vertical displacements. METHODS: Eight different types of ligation were used to secure a length of stainless steel wire in three stainless steel twin brackets. The wire was subjected to repeated vertical displacements in a simulated extraction space. Eighty per cent of the minimum force required to overcome static friction (F-m) between the wire and brackets was applied to the wire for eight minutes and any sliding measured. RESULTS: Frictional resistance to sliding was least when stainless steel ligatures twisted in a figure 8 pattern until taut then untwisted one quarter turn were used, and greatest when elastomeric modules in a figure 8 pattern (EM8) were used. The F-m difference between fully engaged standard and Super Slick elastomeric modules was significantly different (p = 0.007). The frictional resistance to sliding fell when the wire was secured with either of these two methods and subjected to vertical displacement loads. There was no significant difference in the rate of wire movement between these modules. CONCLUSION: Repeated vertical displacement reduced the frictional resistance to sliding for all methods of ligation except EM8.
Authors: Maryam Fathimani; Garrett W Melenka; Dan L Romanyk; Roger W Toogood; Giseon Heo; Jason P Carey; Paul W Major Journal: Prog Orthod Date: 2015-06-04 Impact factor: 2.750
Authors: Fabio Savoldi; Aggeliki Papoutsi; Simona Dianiskova; Domenico Dalessandri; Stefano Bonetti; James K H Tsoi; Jukka P Matinlinna; Corrado Paganelli Journal: Korean J Orthod Date: 2018-07-06 Impact factor: 1.372