summaryThe purpose of this study was to evaluate the relationship of the quaality of the coronal restoration and of the rot canal obturation on the radiographic periapical status of endodontically treated teeth. Full‐mouth radiographs from randomly selected new patient folders at Temple University Dental School were examined. The first 1010 endodontically treated teeth restored with a permanent rstoration were evaluated independtly by two examiners. Post and core type restorations were excluded. According to a predetermined radiographic standard set of criteria, the technical quality of the root filling of each tooth was scored as either good (GE) or poor (PE), and the quality of the coronal restoration similarly good (GR) or poor (PR). The apical one‐third of the root and surrounding structures were then evaluated radigraphically and the periradicular status categorized as (a) absence of periradicular inflammation (API) or (b) presence of periradicular inflammation (PPI). The rate of API for all endodontically treated teeth was 61.07%, GR resulted in significantly more API cases than GE, 80%, versus 75.7%. PR resulted in significantly more PPI cases than PE, 30.2% versus 48.6%. The combination of GR and GE had the highest API rate of 91.4%, significantly higher than PR and PE with a API rate of 18