The influence of varying layer thicknesses on the color predictability of two different composite layering concepts.

Objective: Optical properties of teeth are mimicked by composite layering techniques by combining a relatively opaque layer (dentin) with more translucent layers (enamel). However, the replacing material cannot always optically imitate the tooth when applied in the same thickness as that of the natural tissues. The natural layering composite system is available in 2 concepts: (1) dentin (D) and enamel (E) have the same shade but with different translucencies; (2) D and E have different shades where E is always the same high translucent shade.

Perceptibility and acceptability thresholds for colour differences in dentistry.

Introduction: Data on acceptability (AT) and perceptibility thresholds (PT) for colour differences vary in dental literature. There is consensus that the determination of ΔE* is appropriate to define AT and PT, however there is no consensus regarding the values that should be used. The aim of this clinical review was to provide a systematic approach to the topic of colour science of high clinical relevance to dental research.

Clinical success of shade guides arranged according to lightness measured digitally.

The aim of this study was to evaluate whether the VITA Classical shade guide arranged according to lightness allows clinicians to more often obtain a shade match than with an arrangement based on hue groups. A panel of 50 students determined the shade of the maxillary right central incisors of three patients with two differently arranged and blinded shade guides under standardized conditions. The L*a*b* values of the tabs were compared with those of the teeth spectrophotometrically.

Data comparison between two dental spectrophotometers.

Objectives: The objective of this study was to clinically test whether the data from two different spectrophotometers, based on spot and surface measurements, can be compared.

Methods: Under standardized clinical conditions two devices (Vita Easyshade and Spectro Shade-Micro) were used to record the color of three areas (cervical, middle, and incisal) per tooth for three upper maxillary anterior teeth in 102 participants. Each position was measured three times to attain an average for the CIE L*a*b* coordinates and to attain the corresponding Vita Classical shade tab integrated in the software of both devices.

Color coverage of a newly developed system for color determination and reproduction in dentistry.

Objectives: A newly developed system for color determination and reproduction is logically arranged and systematically combines a few components to acquire its broad color range. The objective was to evaluate color coverage of human teeth with the range of the new system and to compare it with other existing systems.

Methods: The systems for color determination used in this study were: New system Standard (NS), New system Expanded (NE), Vita Classical (VC) and Vita 3D-Master (V3D) (Vita Zahnfabriek, Germany), Vintage Halo (VH) (Shofu, Japan), Chromascope (CH) (Ivoclar Vivadent, Lichtenstein).