The aim of this study is to evaluate the influence of superstructure material on crestal bone resorption and esthetic outcome of dental implants in patients with single missing tooth in the aesthetic zone.

The transfer of occlusal forces to the implant bone interface greatly influence the long term prognosis of implants and crestal bone resorption. Accordingly this study will investigate the influence of metal ceramic crowns and monolithic zirconia crowns on crestal bone resorption under loading. Also these crown materials greatly influence the final aesthetic outcome of the definitive restoration, which will be evaluated using the pink and white aesthetic scoring systems.

Inclusion Criteria:

1. Patients above 18 years old.
2. Patients able to read and sign the informed consent document. 3. Medically free patients or with controlled systemic disease.

4. Patients with good bone quality and quantity evaluated using C.B.C.T. 5. Patients willing to return for follow-up examinations and evaluation. 6. Patients having single missing recently extracted premolar tooth.

Exclusion Criteria:

1. Young patients in growth stage.
2. Patients with unsuitable implantation sites (patients with major boney defects or sever bone resorption)
3. Pregnant women to avoid any complication that may occur in dental office.
4. Patients with uncontrolled systemic disease (hypertensive patient or uncontrolled diabetic patient)
5. Psychiatric problems or unrealistic expectations.
6. Multiple adjacent missing teeth.
7. Patients with bad oral hygiene