In-vivo repeatability of three intra-oral spectrophotometers.

OBJECTIVE: The objective was to assess the repeatability of three spectrophotometers, based on the CIELCh factors and shadeguide reference measurements. MATERIALS AND METHODS: Color analysis was performed using three devices: Rayplicker, Easyshade 4, and Easyshade V. Five repeated measures were performed by the same operator, on the right central maxillary incisor of 30 patients. The CIELCh factors were retrieved and the intra-class correlation was calculated. The Vita Classical and Vita 3D Master shadeguides were used to evaluate the respective Fleiss' Kappa factors. RESULTS: Rayplicker and Easyshade V demonstrated strong intra-class correlation based on the CIELCh factors: 0.98, 0.99, and 0.91 for Rayplicker, and 0.95, 0.99, and 0.93 for Easyshade V, for the L*, C*, and h* parameters, respectively. Regarding the repeatability of the shadeguide data, while Easyshade 4 had the best repeatability when using the Vita Classical as a reference, Rayplicker and Easyshade V showed better repeatability when using the Vita 3D Master. CONCLUSION: These findings suggest that both Rayplicker and Easyshade V are reliable devices for measuring CIELCh parameters. In terms of shadeguide references, the reliability of spectrophotometers is generally lower compared to the CIELCh measurements. CLINICAL SIGNIFICANCE: Given their good repeatability, both the Rayplicker and the Easyshade V spectrophotometers are reliable tools for prosthetic dental practices.

Digital evaluation of dental bleaching using a new methodology: an in vivo study.

OBJECTIVE: The objective of the present study was to assess the progress and efficiency of at-home bleaching protocols with 10% carbamide peroxide using a new methodology based on dental photography. MATERIALS AND METHODS: A 4-week overnight at-home bleaching protocol using whitening trays and 10% carbamide peroxide was performed on 52 patients. The tooth color was analyzed using standardized photographs taken every week for 4 weeks and at 4 months posttreatment. The values of the color evolution (ΔE00), L*, a*, and b* were also measured and used to assess the evolution of the chroma, luminosity, and hue using the CIEDE2000 formula. The statistical analyses were conducted at a significance level of P < 0.05 by means of a repeated measures analysis of variance (ANOVA). RESULTS: The tooth color changed the most, and thus the highest ΔE00 was observed, after the first week of treatment. The color continued to change but to a lesser degree during the following weeks. After 4 weeks, the treatment proved to be very effective. Four months after the end of treatment, a color relapse was observed, though it was hardly perceptible to the human eye. The luminosity (L') changed significantly between the beginning and the end of treatment, affecting the maxilla to a greater extent. The chroma evolution showed a high variance and a low relapse for both jaws. The hue was not affected significantly during the treatment and the stabilization. CONCLUSIONS: Within the limitations of the present study, the authors were able to assess the progress and efficiency of at-home bleaching with 10% carbamide peroxide in terms of chroma, luminosity, and hue using a new methodology based on dental photography. CLINICAL SIGNIFICANCE: This new method is effective and enables a reliable analysis of the evolution of a dental bleaching treatment, turning dental photo-graphy into an even more powerful tool for analysis and communication. It can also be used as a proof-of-concept, paving the way for further research on objective monitoring and evaluation of dental treatments using dental photography.

A comparative in vivo study of new shade matching procedures.

AIM: The aim of the present study was to compare six different methods of in vivo color matching: visual shade matching (3D-Master Linearguide shade guide) performed by 1) a novice practitioner, 2) an expert practitioner, 3) the new Rayplicker spectrometer, 4) the Trios III intraoral scanner, and 5) the Omnicam intraoral scanner compared with 6) the Easyshade V spectrophotometer, which was considered as the reference. MATERIALS AND METHODS: Color matching was performed using the 3D-Master references on the sound maxillary right central incisors of 40 subjects. The study first compared the number of colors found using each of the six methods. The references were then converted to the Commission Internationale de l'Eclairage (CIE) L*a*b* values, from which the difference ?E between either two methods ?was derived. Finally, the L* value was used to compare the luminosity measured by each of the six methods. RESULTS: The Rayplicker showed the smallest ?E compared with the Easyshade V. The expert found a closer color to the Easyshade V than did the novice, and both were closer to the Easyshade V than the two intraoral scanners. The intraoral scanners showed notable differences compared with the Easyshade V. The intraoral scanners also offered a reduced choice of colors and recorded the highest luminosities compared with the other methods. CONCLUSION: Within the limitations of this study, the color matching by the Rayplicker was closest to that of the Easyshade V. The good performance of this new device means that it is a challenging competitor for the Easyshade V. Finally, the new methods based on intraoral scanners were less reliable than the spectrophotometers and the visual shade matching.