Relationship between inflammation site and apical periodontitis in patients with severe endodontic pain

Aim: The aim of present study was to investigate the relationship between inflammation and severe endodontic pain using periapical radiographic images and a periapical index (PAI) scoring system.

Methodology: This was a retrospective study of patients who visited the Department of Endodontics, Faculty of Dentistry, X University between January 2020 and December 2021 with the complaint of severe endodontic pain. After application of specific exclusion criteria, 985 patients with severe endodontic pain were included. Inflammation in the patient population was classified as follows: a positive response to the electric pulp test (stage 1), a negative response to the electric pulp test without swelling (stage 2) or a negative response to the electric pulp test with swelling (stage 3). Using the PAI scoring system, periapical status was then classified as healthy (PAI: 1 or 2) or unhealthy (PAI: 3, 4 or 5). The level of significance was set at 5% (p<0.05).

Results: The lowest severity of apical periodontitis (AP) was found in patients with a positive response to the electric pulp test (stage 1) (p<0.05). Among cases with a negative response to the electric pulp test, the incidence of AP was significantly higher in patients with swelling than in those without swelling (p<0.05).

Conclusions: The present study detected a relationship between the main site of inflammation and AP in patients with severe endodontic pain. The presence or absence of AP might serve as a useful indicator in patients with severe endotontic pain.