Periapical tissue evaluation: analysis of existing indexes and application of Periapical and Endodontic Status Scale (PESS) in clinical practice

Aim: To compare different indexes used for periapical pathology investigation and to apply them in clinical practice. Methodology: PAI, CBCT-PAI, and PESS indexes were analyzed in detail using existing literature. Two cases were evaluated using CBCT-PAI and PESS index. Results: Utilization of PESS index gives the possibility to see the status and changes in periapical tissue with more details. Also, using ETTI part of the index helps to understand the possible causes (filling length, condensation, and complications) of the disease and exact number of roots involved. Conclusion: PESS index is complex and different from all other indexes already present in the literature. It permits to evaluate not only the status of periapical tissues, but also endodontic treatment quality. Furthermore, the COPI periapical index has prognostic value due to its suggested AP treatment risk degrees. PESS can be used in epidemiological studies and clinical practice. Future research must validate it. Finally, if universally adopted, this system of evaluation might allow groups worldwide to calibrate and build powerful combined data.