title: Viscoelastic properties of elastomeric chains: an investigation of pigment and manufacturing effects.
abstract: BACKGROUND
  Orthodontic elastomeric chains are commercially available in various colors from many manufacturers. In this study, we investigated the viscoelastic properties of elastomeric chains using dynamic mechanical analysis to perform color and brand comparisons.
  
  
  METHODS
  Ten colors of Sunburst chains (GAC International, Bohemia, NY) were selected for the color study. Three colors of Sunburst, Bobbin Alastik (3M Unitek, Monrovia, Calif), and Energy (Rocky Mountain Orthodontics, Denver, Colo) chains were selected for the brand study. Nine specimens of each type were measured and tested. Dynamic mechanical analysis was performed at room temperature at 8 frequencies ranging from 0.125 to 16.0 Hz. Three variables (storage stiffness, loss stiffness, and tan δ) were analyzed by using repeated-measures analysis of variance (ANOVA) and pairwise t tests, comparing all frequencies for each specimen type and all specimen types for each frequency (with Bonferroni corrections). Significance was set at α = 0.05.
  
  
  RESULTS
  Significant differences were found among all specimen dimensions, all frequencies, and all 3 dynamic mechanical analysis variables in both the color and brand studies. Comparisons focused on tan δ, which does not depend on specimen dimensions as do storage stiffness and loss stiffness.
  
  
  CONCLUSIONS
  Statistically significant differences in tan δ values among colors were relatively small, so the clinical significance is questionable and requires further investigation. Differences in tan δ values among brands were greater and more likely to be clinically significant. Further studies are needed to relate viscoelastic properties to force decay.
authors.affiliation: Private practice, Kansas City, Mo.
authors.forename: Claire L
authors.initials: CL
authors.lastname: Stroede
authors.affiliation: Private practice, St. Catharines, Ontario, Canada.
authors.forename: Hani
authors.initials: H
authors.lastname: Sadek
authors.affiliation: Research associate, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, Ohio.
authors.forename: Anand
authors.initials: A
authors.lastname: Navalgund
authors.affiliation: Assistant professor, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus, Ohio.
authors.forename: Do-Gyoon
authors.initials: DG
authors.lastname: Kim
authors.affiliation: Professor, Division of Restorative and Prosthetic Dentistry, College of Dentistry, Ohio State University, Columbus, Ohio.
authors.forename: William M
authors.initials: WM
authors.lastname: Johnston
authors.affiliation: Associate professor, Division of Restorative and Prosthetic Dentistry, College of Dentistry, Ohio State University, Columbus, Ohio.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Schricker
authors.affiliation: Professor, Division of Restorative and Prosthetic Dentistry, College of Dentistry, Ohio State University, Columbus, Ohio. Electronic address: brantley.1@osu.edu.
authors.forename: William A
authors.initials: WA
authors.lastname: Brantley
mesh_terms: D003116:Color; D004396:Coloring Agents / Q000737:chemistry; D003799:Dental Stress Analysis / Q000295:instrumentation; D055119:Elastic Modulus; D020724:Elastomers / Q000737:chemistry*; D006801:Humans; D008420:Manufactured Materials; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D018583:Pliability; D012408:Rubber / Q000737:chemistry; D013314:Stress, Mechanical; D013696:Temperature; D014783:Viscosity
chemical_list: D004396:Coloring Agents; D020724:Elastomers; D012408:Rubber