The dental Unit is Adec 200 U.S.A. The x-ray Machine is ViVi, S.r.I, Italy The x-ray films are Kodac, speed D, size 2. The operator is master degree student in the department of Endodontics. No dental assistant Time: 2016-2017 Diagnosis The diagnostic data will be collected in a case report form by the investigator and confirmed for eligibility with the assistant supervisor and will be enrolled in the study in the same day.