This document describes a study that evaluated the color changes of orthodontic elastic ligatures over time using a portable sphere spectrophotometer. The spectrophotometer was used to take initial color readings and subsequent readings of the ligatures placed on standardized backgrounds to measure color variation using CIE L*a*b* parameters. The study aimed to objectively quantify color changes of elastic ligatures during orthodontic treatment.

1. Color evaluation of orthodontic
elastic ligatures using a portable
sphere spectrophotometer
SOLDATI DC ; SILVA RC ; OLIVEIRA AS ; KAIZER MR ; MORAES RR
School of Dentistry, Federal University of Pelotas, Brazil

2. Color
readings:
CIE L*a*b*
parameters
L a b
100
0
+
-
+
-
Color variation: ΔE = (ΔL2 + Δa2 + Δb2)1/2
∆L = L1 – L0 (final reading – baseline)
∆a = a1 – a0 (final reading – baseline)
∆b = b1 – b0 (final reading – baseline)

3. Portable Sphere Spectrophotometer
(SP60 – EX-Rite / Grand Rapids, MI, USA)
Munsell-like neutral value scale sheet backgrounds

4. View of the spectrophotometer with
the reflectance window open
Sample spot

5. Sample spot
Simplified scheme of
the spectrophotometer
Light source
Light
integrating sphere
Reflectance window

6. Sample spot
Guidelines
Guidelines
Specimen
The authors are grateful to Dr. Lisandra Mozzaquatro for support with the pictures