(Ph.D)-Cairo University,2022.

Bibliography: p. 187-198.

The completion of root canal treatment does not mean the end of patient management. The restoration of the tooth back to normal is the actual goal and challenge at the same time. The main aim is to protect the weakened teeth from future failure, which is achieved with the help of a wellfitted restoration. For many years, post and core supported restoration was the conventional treatment modality in these cases. Recently the endocrown proved as an alternative more conservative choice and gained great popularity. Since then many studies searched for the best material to fabricate this type of restoration and found that the material of choice was the lithium disilicate glass ceramics yet for being brittle drawbacks were reported. PEEK is a promising material that was used recently with high success in dental restorations but very limited data used it for fabrication of endocrowns. Twnenty six endocrowns were fabricated for the restoration of posterior molar teeth.