title: Effects of different ligature materials on friction in sliding mechanics.
abstract: BACKGROUND
  During orthodontic tooth movement friction occurs at the bracket wire interface. Out of the total force applied to the tooth movement, some of it is dissipated as friction, and the remainder is transferred to the supporting structures of the tooth to mediate tooth movement. However many factors affect friction, and method of arch wire ligation being an important contributing factor. Hence, this study was carried out to evaluate the effects of different ligature materials on friction in sliding mechanics and to compare the effect of environment (dry and wet) on friction produced in sliding mechanics.
  
  
  METHODS
  The evaluation of friction between the bracket and the archwire consisted of a simulated half arch fixed appliance with archwire ligated in a vertical position. Four 0.022" maxillary stainless steel premolar brackets having a - 0° torque and 0° angulation were aligned with a 0.019" × 0.025" stainless steel arch wire onto a rigid Plexiglass sheet. The movable test bracket was fitted with a 10 mm long, 0.045" thick stainless steel power arm on the bonding surface. Testing was performed on a Hounsfield material testing machine. A total of 100 g weight was suspended from the power arm and the load needed to move the bracket over the distance of not <4 mm across the central span was recorded separately. Fifteen representative readings were taken with one reading per test sample.
  
  
  RESULTS
  The results showed that the mean frictional force of different groups in dry and wet state was statistically significantly different. The mean frictional force in a dry state was statistically significantly higher than wet state in elastomeric group.
  
  
  CONCLUSIONS
  The type of ligation material and environment significantly affected the degree of friction generated during sliding mechanics. Teflon coated stainless steel ligatures produced the least friction among the materials tested in both dry and wet conditions and there was no significant effect on friction in this group caused due to lubrication.
authors.affiliation: Assistant Professor, Department of Orthodontics & Dentofacial Orthopedics, DY Patil University School of Dentistry, Navi Mumbai, Maharashtra, India.
authors.forename: Aparna
authors.initials: A
authors.lastname: Khamatkar
authors.affiliation: Associate Professor, Department of Orthodontics & Dentofacial Orthopedics, DY Patil University School of Dentistry, Navi Mumbai, Maharashtra, India.
authors.forename: Sushma
authors.initials: S
authors.lastname: Sonawane
authors.affiliation: Professor, Department of Orthodontics & Dentofacial Orthopedics, DY Patil University School of Dentistry, Navi Mumbai, Maharashtra, India.
authors.forename: Sameer
authors.initials: S
authors.lastname: Narkhade
authors.affiliation: Associate Professor, Department of Orthodontics & Dentofacial Orthopedics, DY Patil University School of Dentistry, Navi Mumbai, Maharashtra, India.
authors.forename: Nitin
authors.initials: N
authors.lastname: Gadhiya
authors.affiliation: Assistant Professor, Department of Orthodontics & Dentofacial Orthopedics, DY Patil University School of Dentistry, Navi Mumbai, Maharashtra, India.
authors.forename: Abhijit
authors.initials: A
authors.lastname: Bagade
authors.affiliation: Professor and Head, Department of Orthodontics & Dentofacial Orthopedics, DY Patil University School of Dentistry, Navi Mumbai, Maharashtra, India.
authors.forename: Vivek
authors.initials: V
authors.lastname: Soni
authors.affiliation: Professor, Department of Orthodontics & Dentofacial Orthopedics, DY Patil University School of Dentistry, Navi Mumbai, Maharashtra, India.
authors.forename: Asha
authors.initials: A
authors.lastname: Betigiri
keywords: Friction; ligature; sliding mechanics