Apical Gap Length and Adaptation of Zirconia Post Using Intraoral and Extraoral Scan of Silicon Impression Technique

First, participants will undergo clinical and radiographic examination for taking all the needed preoperative records, then endodontically treated teeth preparation starting with removal of any carious or undermined tooth structure then ferrule preparation then followed by intra-radicular preparation and then placement of the provisional restoration. In the third visit we will take the final impression of the post space for each patient by using the intraoral scan and extraoral scan o f the conventional impression. Then assessment of the apical gap length by using digital periapical radiograph using the paralleling technique and assessment of post adaptation using replica technique followed by placement and permanent cementation of the zirconia custom made post and core restoration that showed less apical gap length and better adaptation then taking the final impression for the extracoronal restoration and finally permanent cementation of the extra coronal fixed restoration.