Associação da presença de canais acessórios com reabsorções perirradiculares utilizando tomografia computadorizada de feixe cônico de alta resolução.

Abstract

Accessory canals (AC) represent a significant challenge in the control of endodontic infection, as the persistence of bacteria within these canals may lead to periodontal repercussions. Therefore, the aim of this thesis was to describe the morphological characteristics of AC observed on cone-beam computed tomography (CBCT) and their association with periradicular bone resorption. Additionally, 7 clinical cases involving intentional instrumentation of AC are reported, with clinical and CBCT follow-up. A total of 3,223 CBCT reports from a private radiology clinic database were reviewed. Through a keyword search system, cases with reported AC were selected and included for data collection and analysis. The following data were recorded: the tooth in which the AC was present; in multirooted teeth, the root where the AC was located; canal location along the root (cervical, middle, or apical third); root surface on which the AC was found; angulation relative to the main canal; and presence or absence of root canal filling. Additionally, data regarding periradicular bone resorption were collected and categorized as absent, apical, associated with a AC, or both apical and lateral. Descriptive statistics were applied. A total of 45 cases of AC were identified. The highest prevalence was observed in upper premolars and upper incisors, with a predominance in the middle third of the root. Most AC were located on the palatal/lingual and buccal root surfaces. The angle between the AC and the main canal ranged from 87° to 147°, with a mean of 102.4°. Periradicular bone resorption was observed in 39 cases (86.7%). Among these, the combination of apical and lateral bone resorption was the most prevalent, followed by resorption exclusively associated with the AC. Seven clinical cases of endodontic treatment and retreatment in teeth with AC identified by CBCT were reported, all associated with pulp necrosis and bone resorption. AC were located in various root regions: palatal surface of the middle third of the buccal root (case 1), apical third of the mesial surface (case 2), apical third of the buccal surface (case 3), middle third of the palatal surface of the buccal root (case 4), distal surface of the middle third of the mesiolingual root (cases 5 and 6), and cervical third of the buccal root toward the palatal surface (case 7). Treatments followed a standardized protocol, including removal of restorations and posts, chemomechanical preparation up to file 40.05 with 2% chlorhexidine gel, irrigation with saline and 17% EDTA activated by ultrasonic agitation. ACs were intentionally debrided with hand files and, when possible, rotary instruments. Obturation was completed using gutta-percha and AH Plus Jet sealer, followed by composite resin restoration. Clinical and tomographic follow-up between 8 and 24 months showed complete or partial healing and absence of symptoms in all cases. Findings reinforce the clinical relevance of AC and their association with periradicular bone resorption.