The aim of the present study is to evaluate the wear of enamel opposed by Newly Introduced Gradient Monolithic Zirconia compared to that of enamel opposed by Full Strength Monolithic Zirconia

The aim of the present study is to evaluate the wear of enamel opposed by Newly Introduced Gradient Monolithic Zirconia compared to that of enamel opposed by Full Strength Monolithic Zirconia Teeth preparation and impressions, placement and permanent cementation of the final restoration using resin cement, and optical scanning of both the restoration and the opposing tooth. Follow up postoperatively after six and twelve months, and optical scanning of both the restoration and the opposing tooth.

Inclusion Criteria:

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All subjects are required to be:

1. From 18-50 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 planned for a single coverage restoration in the posterior area.
5. Patients with a natural (not crowned) opposing antagonist.
6. Able to return for follow-up examinations and evaluation.

Exclusion Criteria:

• Patient less than 18 or more than 50 years 2. Patients with severe clenching or bruxing habits. 3. Patient with active resistant periodontal diseases 4. Patients with poor oral hygiene and uncooperative patients 5. Pregnant women 6. Patients in the growth stage with partially erupted teeth 7. Psychiatric problems or unrealistic expectations 8. Lack of opposing dentition at the area of interest. 9. Presence of dental prosthesis in the opposing arch at the area of interest.