The relation between PAI and lesion size on CBCT and periapical status related to the quality of coronal restorations and root fillings

Abstract

The purpose of this study was (1) to examine efficacy of digital periapical (PA) radiographs for identification of PA lesion compared to cone-beam computed tomography (CBCT) and (2) to evaluate the relationship of the quality of the coronal restoration and of the root canal obturation on the radiographic periapical status of endodontically treated teeth.

1. The relationship between PAI and lesion size on CBCT

The CBCT images and periapical radiograph of the 302 roots of the 290 endodontically treated teeth that had previously been obtained in the Dental Hospital of Yonsei University College of Dentistry were examined. On axial CBCT scans, buccolingually the widest length of PA lesion around root apex was measured and the soundness of buccal and lingual cortical bone was recorded. Periapical radiographic images were coded with PAI scoring system by two independent examiners. Statistically significant differences between the PAI score and the PA lesion size on CBCT were evaluated by Spearman’s rank correlation. The results of this study demonstrated that PAI score was positively correlated with PA lesion size on CBCT and 68.2% of 157 PA lesions within cancellous bone were evaluated more than PAI score 2. PAI score was positively correlated with PA lesion size on CBCT and 68% of PA lesions within cancellous bone were detected on digital PA radiographs.

2. Periapical status related to the quality of coronal restorations and root fillings

Full-mouth radiographs and periapical radiographs from new patients at Dental Hospital of Yonsei University College of Dentistry were examined. A total of 1030 endodontically treated teeth restored with a full veneer crown type restoration were evaluated two independent examiners. The quality of endodontic and the periapical status of endodontically treated teeth were evaluated by radiographic criteria. The quality of coronal restorations of endodontically treated teeth were evaluated by radiographic criteria and by reviewing the intraoral examination records as well. Root fillings were categorized as good(GE) or poor(PE), and coronal restorations were categorized as good(GR) or poor(PR). The periapical status were categorized as "absence of periradicular Inflammation"(API) or "presence of periradicular inflammation"(PPI). The API rate for all endodontically treated teeth was 59.1%. Both qualities of the endodontic filling and coronal restoration affected significantly the periapical status and there is no significant difference in the odds of API between 2 parameters. The difference of API rate of the group with good endodontic filling (GE, 75.5%) and the group with poor endodontic filling (PE, 50.1%) was statistically significant. The difference of API rate of the group with good restoration (GR, 65.3%) and the group with poor restoration (PR, 45.7%) was statistically significant. API of the GE+GR group (82.3%) was statistically significantly different from other three groups (GE+PR, 56.3%, PE+GR, 54.7%, PE+PR, 41.2%), and API of the PE+PR group was statistically significantly different from GE+PR and PE+GR. Both technical qualities of the endodontic treatment and the coronal restoration are of equal importance for periapical health.