Aim: The aim of the present study was to evaluate color difference between zirconia reinforced lithium silicate ceramic (Celtra Press) VS lithium disilicate glass ceramic (e.max) in relation to natural tooth structure to determine which monolithic material will provide restoration with exact shade and optical properties as natural tooth structure.

Materials and Methods: 20 teeth esthetic zone requiring full coverage crown -with their adjacent/contralateral are sound and not severely discolored - were prepared to receive an all ceramic crown. The crowns will be divided into two groups , patient satisfaction of the two groups assessed using the Visual Analogue Scale (VAS). Shade matching to the contral lateral tooth was evaluated by 3 experienced evaluators modified United States public health service (USPHS) criteria as Alpha (Excellent), Bravo (Acceptable), Charlie (Acceptable but modifications needed), and Delta (Unacceptable). The color difference ΔE (perceptibility threshold) was measured using intraoral spectrophotometer and evaluated for each group.

Results: Patient satisfaction was graded according to the visual analogue scale (VAS). There was no statistically significant difference between (Group I) and (Group II) where (p=1) as both groups showed (100%) Alpha. Moreover, shade matching was graded according to USPHS. There was no statistically significant difference between (Group I) and (Group II) where (p=1) as both groups showed (100%) Alpha. The results for both materials in terms of patient satisfaction and shade matching were Alpha.

Conclusions: Within the limitations of this clinical study, Celtra Press and IPS e.max press full coverage restorations revealed excellent patient satisfaction and color matching.