# Intentional Negotiation and Filling of Accessory Canals: A Case Series With Three‐Dimensional Segmentation and Volumetric Healing Assessment

## TL;DR

This case series shows that intentionally negotiating and filling accessory canals using 3D imaging can lead to successful healing in endodontic treatment.

## Contribution

The study demonstrates intentional mechanical debridement and filling of accessory canals using CBCT-based planning in clinical practice.

## Key findings

- All six accessory canals were successfully negotiated and filled with endodontic sealer.
- Tomographic analysis showed partial or complete periradicular healing in all cases.
- No patients experienced clinical symptoms at follow-up.

## Abstract

Accessory canals (ACs) are anatomical features that may harbour residual infected tissue and contribute to persistent periradicular inflammation. Although filling of these structures is occasionally achieved passively, their intentional mechanical negotiation remains rarely documented in clinical practice. This case series aims to describe the clinical approach, outcomes and imaging strategies used in the intentional debridement and filling of ACs.

Six teeth with identifiable ACs on cone‐beam computed tomography (CBCT), in association with bone resorption, were included. All cases underwent chemomechanical preparation using rotary instrumentation with 2% chlorhexidine gel, active saline irrigation and final EDTA activation with passive ultrasonic irrigation. Intentional mechanical debridement of ACs was performed using small‐diameter hand files. All fillings were performed with gutta‐percha and AH Plus Jet sealer. Follow‐up was performed using CBCT and periapical radiographs after a mean period of 10.16 months. Three‐dimensional segmentation was used to aid localization and planning.

All ACs were successfully negotiated and filled with endodontic sealer. Tomographic analysis confirmed evidence of partial or complete periradicular healing in all six cases. No patients presented with clinical symptoms at follow‐up.

This case series presents successful intentional instrumentation and obturation of ACs, supported by CBCT‐based planning and follow‐up. Although limited by the lack of a control group, the findings highlight the potential role of CBCT imaging and segmentation in identifying and accessing complex anatomy. Further prospective studies are needed to determine the impact of this approach on long‐term clinical outcomes.