Duration of elastomeric separation and effect on interproximal contact point characteristics.
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.
Davidovitch
Moshe
M
Department of Orthodontics, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
Papanicolaou
Sophia
S
Vardimon
Alexander D
AD
Brosh
Tamar
T
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
D020724:Elastomers