The aim of the study is to determine whether Yttria stabilized multilayered zirconia restorations will differ from lithium disilicate restorations in shade matching and patient satisfaction in patients requiring full coverage restorations.

Steps in short: Single tooth in the esthetic zone requiring full coverage crown is prepared to receive an all-ceramic crown, The restorations will be divided into two groups: I: Teeth receiving restorations fabricated from Lithium disilicate II: Teeth receiving restorations fabricated from yttria stabilized multilayered zirconia. Shade will be measured using intraoral spectrophotometer and evaluated. The colour difference (ΔE) will be calculated for each sample using the following equation: ΔE =[(ΔL) ²+(Δa) ² + (Δb) ²] ½, ΔE (perceptibility threshold) will be evaluated for each group. Participant timeline the patient will be treated in visits designated as follows: Visit 1: Preoperative records, face-to-face adherence reminder session, clinical, radiographic for examination, intraoral photographs and primary impression (Alginate impression) diagnostic cast construction. Visit 2: teeth preparation and secondary impression using addition silicone rubber base material and temporary restoration. Visit 3: placement and permanent cementation of the final restoration using resin cement.

Inclusion criteria:

1. Age range of the patients from 20-60 years old; able to read and sign the informed consent document, illiterate patient will be avoided.
2. Patients able physically and psychologically to tolerate conventional restorative procedures.
3. Patients with no active periodontal or pulpal diseases, having teeth with good restorations.
4. Patients with teeth problems indicated for full coverage restoration (coronal fracture where partial coverage would lack retention, malposed or malformed teeth).
5. Patients with root canal treated teeth requiring full coverage restorations.
6. Patients willing to return for follow-up examinations and evaluation.

Exclusion Criteria:

1. Patients in the growth stage with partially erupted teeth.
2. Patients with poor oral hygiene and motivation.
3. Patients with psychiatric problems or unrealistic expectations (patient that has phobia from dental treatments or needle bunch).
4. Patients suffer from parafunctional habits.