title: Duration of elastomeric separation and effect on interproximal contact point characteristics.
abstract: BACKGROUND
  The common protocol of a week-long duration of elastomeric separators to facilitate band placement usually causes discomfort. In this study, we examined the minimum separation time required to create an interproximal space >0.16 mm (band thickness), the interproximal changes over 24 hours after separator removal, and the mechanical characteristics of various separators.
  
  
  METHODS
  Thirty subjects, ages 28.1 +/- 2.8 years, had an elastomeric separator placed between the mandibular second premolar and first molar (CP5-6) for 1, 4, 12, and 24 hours. After separator removal, CP5-6 was measured for space and tightness of dental contact point (TDCP) changes up to 24 hours after separator removal. The mechanical behaviors of 6 manufacturers' separators were compared.
  
  
  RESULTS
  After 12 and 24 hours of separation, all patients demonstrated space >0.16 mm (P <.001). A significant negative correlation (R = -0.59 to -0.63; P = .001) was found between baseline TDCP and the space measured at separator removal. A biphasic viscoelastic recovery (82%-95%) to baseline tightness level occurred within 24 hours. Variation between manufacturers was low (9%).
  
  
  CONCLUSIONS
  Separators should be placed a day before banding. The patient should arrive 3 to 4 hours before the appointment for separator replacement if the separator is lost. Rapid recovery after separation removal implies the biological soundness of elastomeric separation regardless of the manufacturer used.
authors.affiliation: Department of Orthodontics, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Davidovitch
authors.forename: Sophia
authors.initials: S
authors.lastname: Papanicolaou
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Vardimon
authors.forename: Tamar
authors.initials: T
authors.lastname: Brosh
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D020724:Elastomers; D005260:Female; D006801:Humans; D008297:Male; D009811:Odontometry; D009967:Orthodontic Appliances; D013027:Space Maintenance, Orthodontic / Q000295:instrumentation*; D013997:Time Factors; D014087:Tooth Movement Techniques / Q000295:instrumentation
chemical_list: D020724:Elastomers