Dr. Roberto Aza
• Dental Degree. ISCS-SUL, Lisbon. 1990-1996.
• Post-graduate Education in Clinical Endodontics and Microsurgery. Centro Odontología Microscópica, Bilbao, Dr. Borja Zabalegui. 2004-2005.
• Master’s Degree in Endodontics, UEM. 2010-2012.
• PhD degree in Dentistry. Alfonso X. 2017
• Member of Spanish Association of Endodontics (AEDE).
• Associate Member. American Association of Endodontists (AAE).
• General Private Practice with special dedication to endodontics. Madrid
introduction
introduction
Pulp canal obliteration associated with traumatic injury in anterior teeth can result from accelerated dentin deposition within the root canal space. The exact mechanism of canal obliteration is unknown, but it is believed to be related to damage to the neurovascular supply of the pulp at the time of injury. The inevitable lack of responses to routine sensitivity tests and crown discolouration add uncertainty to its management. However, only approximately 7%–27% of teeth with pulp canal obliteration will develop pulp necrosis with radiographic signs of periapical disease.
The American Association of Endodontics classifies the endodontic treatment of obliterated canals as highly difficult. Potential procedural errors include access cavity overextension, iatrogenic perforation, missed root canals, file separation, and root canal deviation from its original path. Long neck drills, ultrasonics, operating microscopes, and high-resolution CBCT are strategies routinely used in these types of cases. However, even with these technologies, excessive dentin removal occurs.
Guided endodontics with dynamic navigation can potentially overcome
the limitations of static guided systems by enabling real-time visualisation of the position and angulation of the dental handpiece and the patient throughout the procedure and provide a mechanism to accurately locate complicated calcified canals through minimally invasive access.
“Cone-beam computed tomography (CBCT) is a necessary standard in endodontics for the best patient outcomes.”
the case
the case
A 26-year-old male patient was referred by his dentist due to difficulty locating the canal in tooth during endodontic treatment. A clinical examination revealed pain to palpation and percussion of the upper right central incisor and a light discolouration of the tooth compared to the contralateral (Fig. 1a). The periapical radiograph (Fig. 1b) showed a deviated access cavity, a calcified root canal, an internal resorption, and a periapical radiolucency. High-resolution CBCT (CS 8100 3D, Carestream Dental) with a limited FOV (5 × 5) and 75 μm voxel size was indicated. Coronal (Fig. 1c) and sagittal (Fig. 1d) planes of the right central incisor showed the deviation of initial access, a calcification of the canal up to the middle third of the root, an internal resorption, and chronic apical periodontitis with perforation of the buccal cortical plate. The orientation of initial access is evident in the axial planes (Fig. 1e).
A ‘virtual endodontic guide’ (Dr Jose María Malfaz) was designed, simulating the correct orientation of the access (green) compared to the initial access (red; Fig. 1f, 1g, and 1h). Non-surgical endodontic retreatment with Dynamic Navigation was indicated due to the case’s complexity. The X-Guide® system (X-Nav Technologies, LLC, Lansdale, PA, USA; Fig. 2a) was used to locate the canal with minimally invasive access.
The following steps were followed to perform the access preparation under dynamic navigation:
- A thermoplastic device (X Clip, X-Nav Technologies; Fig. 2b) with three radiopaque fiducials was moulded. A CBCT scan (CS 8100 3D) of the maxillary arch was taken with the clip in place (Fig. 2c).
- An intraoral scan (IS 3600, Dexis) of the maxillary arch was taken (Fig. 2d and 2e).
- The Digital Imaging and Communications in Medicine data set from the CBCT and the intraoral scan were uploaded to the X-Guide software and entered into the Dynamic Navigation planning system. The access drilling entry point, angle, pathway, and depth needed to locate the canal
were planned (Fig. 2f).
The patient presented for the procedure, and the system was calibrated according to the manufacturer´s recommendation. Endodontic retreatment was initiated under rubber dam isolation, and the X-Clip was reinserted. Live navigation was initiated with a size #1 Munce bur (CJM Engineering, Inc) following the planned drilling path until the bur reached the end of the planned drill (Fig. 3a). Canal localisation and negotiation were confirmed by a periapical radiograph (Fig. 3b).
Obturation was performed with a warm vertical technique after instrumentation and irrigation of the canal system (Fig. 3c and 3d). The patient was referred to his dentist to complete the definitive restoration.
Follow-ups with periapical radiographs at one (Fig. 3e), three (Fig. 3f), and six (Fig. 3g) months showed the absence of clinical symptoms and a decrease in the periapical radiolucency. The 12-month follow-up periapical radiograph revealed periapical healing without symptoms. A high-resolution CBCT (CS 8100 3D) at the 12-month follow-up confirmed the healing of the periapical pathosis in the coronal (Fig. 4b) and sagittal (Fig. 4c) planes. Volume rendering showed the repair of the buccal cortical plate due to our endodontic retreatment (Fig. 4d).
We compared data obtained at the 12-month follow-up to those obtained at diagnosis with periapical radiographs (Fig. 4e), the CBCT coronal plane (Fig. 4f), the CBCT sagittal plane (Fig. 4g), and CBCT volume rendering (Fig. 4h).
conclusion
conclusion
Using dynamic navigation in the endodontic treatment of calcified canals offers advantages such as more conservative access cavities, a minimally invasive approach, faster operation time, and more predictable treatments.
High-resolution CBCT is needed to make a correct diagnosis and an accurate treatment plan. A high-quality CBCT image is also needed to locate the root canal system in these cases.
NOTES
CARESTREAM DENTAL IMAGING
Dr. Roberto Aza chooses Carestream Dental imaging for its high quality and reliability at his dental office.