Interproximal Contact Point Tightness With Varied Duration of Elastomeric Separation

The insertion of bands as part of orthodontic treatment requires the creation of an interproximal space greater than 0.016mm. Objectives: To determine the minimal time required by elastomeric separators to create a space greater than 0.016mm, and to investigate spontaneous closure of this space across 24 hours following their removal. Methods: 30 subjects ages 25-35 years submitted for placement of an elastomeric separator mesial to the mandibular left first molar for 1, 4, 12, and 24 hours groups 1-4). A tightness of dental contact point device (TDCP) was used to measure changes in interproximal point contact dimensions. Measurements were taken prior to separator placement (T1), at its removal (T2), and four itmes hourly hence (T3-T6), as well as 24 hours after removal (Tz). ANOVA with repeated measures and Post Hoc analysis with Bonferroni corrections, and Pearson's correlation were used to assess intra and inter group data. Results: 12 hours of separator wear were needed to create appropriate band space. Maintenance of this space for one hour occurred in 10% of subjects in groups 1 and 2, 83% in group 3, and 96% in group 4. 24 hours after separator removal no significant differences in TDCP values (p=0.17) were found. Conclusions: A space of 0.16mm was accomplished by 12 hours of separator wear. Tightness of TDCP baseline values were directly associated to duration of maintaining this space, as well as the amount of space created over time. 24 hours after separator removal no differences in TDCP values were found across all groups.