# Print and Try Technique: 3D-Printing of Teeth with Complex Anatomy a Novel Endodontic Approach
## 2 Case Description
### Case 2  
History and physical examination: A 16-year-old otherwise healthy female was seen in emergency because of pain in her right maxillary region. An extraoral examination did not reveal swelling or other abnormalities. An intraoral examination showed immediately the presence of a lump on the buccal aspect of the tooth 26, which appeared not to be completely erupted and with a typical aspect of dilacreated root morphology on 2D radiographic imaging. A curious lesion was present on the same tooth and element 27 was not erupted (Figure 6a-Movie 6). Figure 5: Tissue healing after (**a**) one week and (**b**) six months and (**c**) six-months and (**d**) twelve-months radiographic follow-up. Tooth 26 did not respond to sensitivity testing and it was tender to percussion and palpation, whereas the other elements responded normally. The electric pulp vitality test confirmed the pulpal necrosis of 26. Periodontal pocket values were between 1 mm up to 3 mm, without bleeding on probing. Imaging examination and diagnosis: A pre-operative periapical image (Figure 6b) was carried out by long-cone paralleling technique (CS 2200, Caestream Dental, Rochester, NY, USA). It confirmed the presence of dilacerated mesio- and disto-buccal roots and the diagnosis of chronic periapical periodontitis. The tooth 27 was not erupted because of aberrant root morphology of the mesial element. This radiography had an important role in the preliminary assessment of the irregular morphology of the root canal system, but it provided only a 2D-representation of the complex anatomy. Therefore, a small-FOV CBCT (Figure 6c-Movie 7) was indicated based on the current ESE guidelines. It provided a 3D image of the dilacerated tooth and its surrounding tissues and helped to determine the exact position and angulation of the dilaceration abnormality, which was found to also affect the palatal root. Apical radiolucencies were detected within the woven bone surrounding the apices of all roots. Figure 6: (**a**) Intraoral examination showed a lump on buccal side of element 2.6, which appeared not to be completely erupted and with a carious lesion. Element 2.7 was clinically absent. (**b**) Periapical X-ray showed dilacerated roots of element 2.6, with a periapical lesion on the mesial-buccal one. Element 2.7 was not erupted, but present. (**c**) CBCT confirmed these findings and highlighted a periapical lesion also on the other roots. These diagnostic findings could be obtained only with CBCT imaging. An orthograde primary root canal treatment was recommended to the patient. Print and Try technique and treatment planning: From the CBCT dicom file, an STL file was converted to generate a whole image of the teeth and supporting bone in three planes, thus allowing a better three-dimensional understanding of the structure involved (Figure 7a-l); subsequently a 3D plastic model was obtained with a Stratasys printer, using a clear material (Figure 7m) (Movie 8). Figure 7: (**a-l**) CBCT data were uploaded to an STL software and (**m**) a transparent plastic model was three-dimensionally printed. The 3D model, inclusive of its hollow root canal system, was used to carry out a mock orthograde endodontic therapy, in particular the best access cavity was determined to localize the position of each orifice in anticipation of the actual treatment. The canals were negotiated with a preliminary rotary scout instrument: the clear roots allowed to understand where the instruments were likely to stop or create an inappropriate path. Rotary files with reduced taper were then used and it was possible to reach the full working length and gauge the apical foramen. An irrigation plastic needle could reach within 1 to 2 mm from the working length. Finally, a single cone filling technique, combined with a bioceramic seal, was tried in the model tooth.