Aim of the studyto evaluate the clinical behavior of translucent zirconia crown in dental esthetic zone with biologically oriented preparation technique versus conventional preparation.

Inclusion Criteria:

• All subjects are required to be:

  1. From 21-35 years old, be able to read and sign the informed consent document.

  2. Have no active periodontal or pulpal diseases, have teeth with good restorations

  3. Psychologically and physically able to withstand conventional dental procedures

  4. Patients with teeth problems indicated for single all ceramic restoration in maxillary esthetic zone cr

     1. Badly decayed teeth
     2. Teeth restored with large filling restorations
     3. Endodontically treated teeth
     4. Malformed teeth
     5. Malposed teeth (Tilted, over-erupted, rotated, etc.)
     6. Spacing between maxillary teeth in esthetic zone

  5. Able to return for follow-up examinations and evaluation

Exclusion Criteria:

1. Patient less than 21or more than 35 years
2. Patient with active resistant periodontal diseases
3. Patients with poor oral hygiene and uncooperative patients
4. Pregnant women
5. Patients in the growth stage with partially erupted teeth
6. Psychiatric problems or unrealistic expectations
7. Patient with periodontal problems
8. patients with malocclusion or parafunctional habits