The Effects of Different Spectrophotometric Modes on Colour Measurement of Resin Composite and Porcelain Materials

Objectives: To investigate the influence of a number of controlled modes on the spectrophotometric analysis of the colour of resin composite and porcelain materials.

Methods: A total of 20 samples of commercially available resin composite, and 20 samples of commercially available porcelain materials in four different shades were produced (five samples for each shade). Colour was measured using a spectrophotometer (CM2600-d, Minolta Konica) set with different colour measuring modes namely, small aperture size (SAV) or large aperture size (MAV); specular component included (SCI), or excluded (SCE); 0% (UV-) or 100% UV illumination (UV+). Colour data were then compared using paired T-test.

Results: Colour coordinates measured with spectrophotometric modes set as 2° observation angle, SAV, SCI, and UV- were significantly different from those measured with 10° observation angle, MAV, SCE, and UV+ respectively in most cases for both materials.

Conclusion: Different spectrophotometric modes (2 or 10 degrees observation angle, SAV or MAV aperture size, 0% or 100% UV, and SCI or SCE) significantly influenced the absolute colour measurements of resin composite and porcelain samples.

Clinical significance: Measuring modes should be taken into consideration when comparing the results of absolute colour measurements of resin composite and dental porcelain materials.