The periapical index: A scoring system for radiographic assessment of apical periodontitis

TLDR

The study presents a scoring system for registering apical periodontitis in radiographs. The periapical index (PAI) is an ordinal 5‑point scale validated using reference radiographs of teeth with confirmed histology. Studies with 11 observers and 47 radiographs show the PAI is accurate, reproducible, discriminates sub‑populations, facilitates cross‑research comparison, and is suitable for epidemiological, clinical trial, and retrospective endodontic analyses.

Abstract

Abstract A scoring system for registration of apical periodontitis in radiographs is presented. The system is termed the periapical index (PAI) and provides an ordinal scale of 5 scores ranging from 1 (healthy) to 5 (severe periodontitis with exacerbating features). Its validity is based on the use of reference radiographs of teeth with verified histological diagnoses. Results from studies involving 11 observers and 47 selected radiographs document that the PAI system is reasonably accurate, reproducible and able to discriminate between sub‐populations. It may also allow for results from different researchers to be compared. The system may be suitable for the analysis of periapical radiographs in epidemiological studies, in clinical trials and in retrospective analyses of treatment results in endodontics.