CBCT Evaluation of an Ultrasonic-Assisted Root Canal Protocol in Canine Teeth: A 57-Case Series (2012–2024)

Introduction:
Root canal therapy (RCT) has become a standard and conservative alternative to extraction in dogs, allowing preservation of strategic teeth. The success of RCT depends on effective canal disinfection and a dense, three-dimensional obturation. In human dentistry, ultrasonic activation has been shown to improve irrigant penetration and obturation homogeneity, but this technique has not previously been evaluated in veterinary patients.
Objectives:
This study aimed to describe and assess the outcome of a standardized endodontic protocol that combines passive ultrasonic irrigation (PUI) with ultrasonic-assisted thermoplasticised obturation in canine teeth, using cone-beam computed tomography (CBCT) for postoperative evaluation. To our knowledge, this is the first veterinary study to incorporate ultrasonic activation into both cleaning and obturation phases of endodontic treatment.
Materials and Methods:
Medical records and CBCT scans from 47 dogs (53 canine teeth) treated at AzurVet (2012–2024) were reviewed. All teeth had complicated crown fractures diagnosed as irreversible pulpitis or pulp necrosis. Root canal preparation followed standard veterinary endodontic guidelines. Irrigation was performed with 3% NaOCl activated ultrasonically in three 10-second cycles, followed by 17% EDTA. Obturation used ultrasonic spreaders and pluggers for lateral and vertical thermocompaction of gutta-percha cones coated with zinc oxide eugenol sealer. Outcomes were classified on follow-up CBCT (3–24 months) as success, NEF, or failure according to ESE criteria.
Results:
Overall, 87% of treated teeth were classified as successful, 4% NEF, and 9 % as failures. When pulp status was considered, all irreversible pulpitis cases healed completely (100%), while necrotic pulpitis cases achieved 75% success, 6% NEF and 16% Failure. The use of ultrasonic irrigation appeared to improve cleaning of the apical delta, while ultrasonic obturation produced a denser and more homogeneous fill compared to conventional cold lateral condensation. The technique was well tolerated, and no adverse heat effects were recorded.
Conclusion:
Ultrasonic-assisted root canal therapy combining PUI and thermoplasticised ultrasonic obturation provided predictable clinical and radiographic success, particularly in early pulpitis cases. This protocol enhances canal debridement and sealing quality in long, narrow canine roots and may shorten operator time. To our knowledge, this is the first report describing ultrasonic cleaning and obturation as an integrated approach in veterinary endodontics. Further prospective studies are warranted to confirm long-term benefits and to refine clinical application in complex endodontic cases.