Using a Computer Color-Matching System in Color Reproduction of Porcelain Restorations. Part 3: A Newly Developed Spectrophotometer Designed for Clinical Application.

This paper reports the development of a newly modified, noncontact spectrophotometer for clinical use. The instrument is capable of accurately measuring the color within small areas (1 × 2 mm) of a tooth. This spectrophotometer used a 45°/0° geometry, a 150W halogen lamp, and fiberoptics to focus the light, together with a lens having a focal point distance of 85 mm. A movable platform was added to the apparatus to automatically scan and measure the color of specific areas. Short-term repeatability indicated the color difference ΔE to be approximately 0.15. [ABSTRACT FROM AUTHOR]