Thesis (M.Sc.)-Cairo University- Faculty of Oral and Dental medicine

Bibliography: p. 141-146.

Aim: The aim of this study is to evaluate the shade matching ability of a new single shade universal microhybrid composite Omnichroma (Tokuyama Dental, Tokyo, Japan) compared to a conventional multiple shade microhybrid composite in the restoration of class V restorations using USPHS criteria and image analysis. Methods and Materials: In two parallel groups (n= 38 restorations), 38 participants with class V anterior carious lesions were enrolled in this study and randomly allocated. The intervention group received Omnichroma single shade universal composite (Tokuyama Dental, Tokyo, Japan) and the control group received a universal microhybrid multiple shade composite, 3M Z250(3M ESPE, St. Paul, USA). Shade selection was carried out preoperatively. All cavities and restorations were done under rubber dam isolation. Shade matching was evaluated visually by 1 blinded assessor using Modified USPHS criteria. Calibrated photography was used to record CIELAB color coordinates and calculate color difference using △E formula. Visual and instrumental evaluation were done at baseline (1 week), after 3 months, and after 6 months. Results: There was no statistically significant difference between the tested materials in shade matching both visually using Modified USPHS criteria and instrumentally using calibrated photography. Conclusions: Within the limitations of this study, it could be concluded that using a single shade composite with a structural coloring concept could be promising in the future of esthetic dentistry. Also, eliminating the shade matching procedure could eliminate the errors in shade selection providing a more predictable esthetic outcome, simplify the restorative procedures and save clinical chairside time. Calibrated photography can be a useful and reliable tool for shade evaluation, matching and analysis