Evaluation of Use of Digital Image Analysis on Colour Stability of Commercially Available Porcelain.

Introduction: Comparative evaluation in terms of colour stability of glazed and polished porcelains, has been discussed in literatures, but still controversies are present regarding superiority in terms of aesthetics, especially after toothbrushing. Aim: To evaluate the colour stability of three brands of porcelains in glazed and polished state after performing regular brushing and immersing into different staining solutions. Materials and Methods: An in-vitro study was conducted with a total of 30 specimens of glazed porcelain discs comprising of IPS E.max Computer-aided Design (CAD), Zenoster, and Jyodent were fabricated by CAD/Computer-aided Manufacturing (CAM) milling during April, 2018 to March, 2019. Samples were subjected to power tooth brushing and immersed into solutions of coffee, tea, and pan masala, respectively. For colour measurement, digital image analysis was performed using CIELAB colour space. After stipulated time period, glaze layer was removed, chairside polishing was done, and similar procedures were repeated. Results: In terms of colour stability of glazed and polished porcelains, Zenoster was found most colour stable in glazed and polished state (p=0.05). In terms of staining ability, coffee was found the most discolouring agent among 3 solutions at any time period on glazed samples (p>0.05), as well as on polished samples (p<0.05). Conclusion: Zenoster zirconia is the most colour stable in glazed and polished state and regular tooth brushing merely have any effect on glaze layer. Chance of staining is maximum in coffee than tea and pan masala for both glazed and polished porcelains. [ABSTRACT FROM AUTHOR]