One Year Clinical Evaluation of Shade Matching and Patient Satisfaction of New Gradient Technology Monolithic Zirconia (5Y-TZP\3Y-TZP) Compared to Lithium Disilicate Crowns in Dental Esthetic Zone

Restorative dentistry is a mix of science and art. The success of restorative dentistry is determined on the basis of functional and esthetic results. Closely matching natural teeth with an artificial restoration can be one of the most challenging procedures in restorative dentistry. Natural teeth vary greatly in color and shape.The color of a ceramic restoration is affected by the shade of the ceramic material, its thickness, and, the color of the underlying material. The restoration's color is influenced by ceramic firing temperature, the color of the prepared tooth, translucency and thickness of veneering porcelain. The rational of this study is newly introduced gradient technology zirconia (5Y-TZP\\3Y-TZP) (IPS e.max Zircad Prime) with improved optical properties to solve the drawbacks of esthetic properties of zirconia. Null hypothesis of the study will be: * There would be no difference in shade matching of the new gradient technology zirconia (5Y-TZP\\3Y-TZP) and lithium disilicate ceramic crowns used in the esthetic zone. * There would be no difference in patient satisfaction of new gradient technology zirconia (5Y-TZP\\3Y-TZP) and lithium disilicate ceramic crowns at baseline, 3, 6, 9, 12 months used in the esthetic zone.