title: Colour changes of orthodontic elastomeric module materials exposed to in vitro dietary media.
abstract: OBJECTIVE
  To evaluate the colour stability of orthodontic elastomeric module material exposed to dietary media.
  
  
  METHODS
  An in vitro laboratory study.
  
  
  METHODS
  Coloured and clear orthodontic elastomeric modules from four companies were exposed to coffee, cola, tea and spices for 72 h. The difference in colour components was measured with a Minolta chromameter before and after exposure.
  
  
  RESULTS
  Significant changes in colour, including grey level and chromaticity, both as a function of colour and company of elastomeric ligature module were found following exposure to beverages and spices. Colour change was most affected by Deltab* (yellowness) and most significant in clear modules. Modules made using injection mouldings were more resistant to colour change than those by extrusion. Spice mix had the most effect and cola beverage the least. Clinically, these changes compromised both colour stability and esthetics of the elastomeric module.
  
  
  CONCLUSIONS
  Clinicians should make patients aware of the effect of consuming beverages and spices on the colour stability of their selected ligature modules. Clinicians should favour modules made with injection moulding. Darker colour modules may be preferred to clear modules to avoid excessive colour degradation through dietary media such as beverages and food spices. Patients consuming large amounts of spices or coffee should avoid clear modules made by extrusion processing because of their tendency to discolour.
authors.affiliation: New Jersey Dental School, University of Medicine and Dentistry of New Jersey, NJ, USA. ardeshap@umdnj.edu
authors.forename: Anil P
authors.initials: AP
authors.lastname: Ardeshna
authors.forename: Tritala K
authors.initials: TK
authors.lastname: Vaidyanathan
mesh_terms: D000704:Analysis of Variance; D001628:Beverages; D003116:Color; D003124:Colorimetry; D020724:Elastomers; D004955:Esthetics, Dental; D006801:Humans; D009967:Orthodontic Appliances; D017365:Spices
chemical_list: D020724:Elastomers