Ralf Krug, Julian Volland, Sebastian Reich, Sebastian Soliman, Thomas Connert, Gabriel Krastl

• Background To report the outcome of guided endodontic treatment (GET) of a case of dentin dysplasia with pulp canal calcification (PCC) and apical periodontitis based on the use of a 3D-printed template designed by merging cone-beam computed tomography (CBCT) and surface scan data. Case presentation A 12-year old female with radicular dentin dysplasia type I (DD-1) presented for endodontic treatment. Radiography revealed PCC in all teeth and apical radiolucency in seven teeth (12, 15, 26, 31, 32, 36 and 46). Tooth 36 had the most acuteBackground To report the outcome of guided endodontic treatment (GET) of a case of dentin dysplasia with pulp canal calcification (PCC) and apical periodontitis based on the use of a 3D-printed template designed by merging cone-beam computed tomography (CBCT) and surface scan data. Case presentation A 12-year old female with radicular dentin dysplasia type I (DD-1) presented for endodontic treatment. Radiography revealed PCC in all teeth and apical radiolucency in seven teeth (12, 15, 26, 31, 32, 36 and 46). Tooth 36 had the most acute symptoms and was thus treated first by conventional access cavity preparation and root canal detection. Despite meticulous technique, the distal and mesiolingual canals were perforated. The perforations were immediately repaired with mineral trioxide aggregate, and the decision was made to switch to guided endodontic treatment for the remaining 6 teeth. CBCT and intraoral surface scans were acquired and matched using coDiagnostix planning software (Dental Wings Inc.), the respective drill positions for root canal location were determined, and templates were virtually designed and 3D-printed. The template was positioned on the respective tooth, and a customized drill was used to penetrate the calcified part of the root canal and perform minimally invasive access cavity preparation up to the apical region. All root canals were rapidly and successfully located with the templates. At 1-year follow-up, clear signs of apical healing were present in all treated teeth. Conclusions In patients with dentin dysplasia, conventional endodontic therapy is challenging. GET considerably facilitates the root canal treatment of teeth affected by dentin dysplasia.…