Assessment of a prototype computer colour matching system to reproduce natural tooth colour on ceramic restorations
Journal of Dentistry
Abstract
Objectives
The
aim of this study was to assess the accuracy of a prototype computer
colour matching (CCM) system for dental ceramics targeting the colour of
natural maxillary central incisors employing a dental spectrophotometer
and the Kubelka–Munk theory.
Methods
Seventeen
human volunteers with natural intact maxillary central incisors were
selected to participate in this study. One central incisor from each
subject was measured in the body region by a spectrophotometer and the
reflectance values were used by the CCM system in order to generate a
prescription for a ceramic mixture to reproduce the target tooth's
colour. Ceramic discs were fabricated based on these prescriptions and
layered on a zirconia ceramic core material of a specified colour. The
colour match of each two-layered specimen to the target natural tooth
was assessed by CIELAB colour coordinates (ΔE*, ΔL*, Δa* and Δb*).
Results
The average colour difference ΔE* value was 2.58 ± 84 for the ceramic specimen–natural tooth (CS–NT) pairs. ΔL* values ranged from 0.17 to 2.71, Δa* values ranged from −1.70 to 0.61, and Δb* values ranged from −1.48 to 3.81. There was a moderate inverse correlation (R = −0.44, p-value = 0.0721) between L* values for natural target teeth and ΔE* values; no such correlation was found for a* and b* values.
Conclusion
The
newly developed prototype CCM system has the potential to be used as an
efficient tool in the reproduction of natural tooth colour.
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