This case report was written according to the Preferred Reporting Items for Case Reports in Endodontics (PRICE) 2020 guidelines 21,22. A timeline of events associated with the management of this patient can be found in Fig. 1.
A 13-year-old Hispanic male patient, ASA I, with incomplete permanent dentition and active orthodontic treatment, was referred to the dental clinic at Universidad de Los Andes, Santiago, Chile, for evaluation and orthodontic treatment. His primary concern was to continue orthodontic treatment at another clinic. His medical history was noncontributory. In his dental history, no history of dental trauma was reported. Previous orthodontic appliances had been removed, necessitating a fresh orthodontic assessment. The patient's orthodontic diagnosis included skeletal class I, with a class III ¼ cuspid subdivision left, dolichofacial, in cervical maturation stage CS5. Clinically, he presented a straight profile, upper lip protrusion, and biprotruded incisors, with an overjet of 0.5 mm and an overbite of 0 mm, presenting a mild upper spacing of 2 mm and slight deviation of both dental midlines and agenesis of tooth 29 with persistence of deciduous tooth T. On radiographic examination, an apical lesion was observed in tooth 2.2, and incipient caries were present. Clinically, mild gingivitis associated with bacterial plaque was observed. The therapeutic objectives considered in the first instance involved the endodontic management of tooth 2.2, oral hygiene instruction, and caries preventive management. Given the presence of a periapical osteolytic lesion in tooth 2.2, the patient was referred to the Graduate Endodontic Clinic for the clinical management of this tooth. Once achieved, it was proposed to proceed with orthodontic management to correct sagittal occlusal relationships, improve OJ and OB, and center midlines with the facial midline.
During the initial endodontic consultation, mild vestibular swelling was observed near the left maxillary lateral incisor, which exhibited normal mobility and probing depths. The tooth itself was asymptomatic upon palpation and percussion and showed a negative response to vitality tests, in contrast to control teeth, which responded normally.
Radiographic evaluation of tooth 2.2 revealed complete root development with thin root dentinal walls and an extensive periapical radiolucent area associated with dens invaginatus type I (Fig. 2-A). According to the PAI score, the initial score was 5. The sinus tract was observed, and a periapical radiograph was taken (Fig. 2-B). CBCT of the involved tooth was performed (3D Accuitomo 170® Tomograph, Morita, Kyoto, Japan) at 90 kV, 8 mA and a voxel size of 0.125 mm. The CBCT images revealed an initial CBCT PAI score of 5 + D (Fig. 3A to 3C).
The comprehensive diagnosis concluded that the tooth was afflicted with a necrotic pulp and a chronic apical abscess, which was intricately associated with the dens invaginatus type I anomaly. Following a thorough discussion with the patient and his guardian regarding the risks, benefits, and various treatment options available, the patient agreed to undergo a regenerative endodontic procedure (REP).
REPs Management
Prior to initiating the REP, both the patient and their guardian were provided with an in-depth understanding of the procedure, its potential risks, and the anticipated outcomes. Upon gaining a comprehensive grasp, they provided their acknowledgment and approval by signing an informed consent form. The patient's oral cavity was rinsed with 5 mL of 0.12% chlorhexidine solution for one minute. Subsequently, local anesthetic (2% lidocaine hydrochloride with epinephrine 1:80,000; Septodont, Saint-Maur-des-Fosses, France) was administered by buccal infiltration. The treatment commenced under the meticulous guidance of a surgical operating microscope (OPMI pico; Carl Zeiss AG, Göttingen, Germany).
After achieving proper isolation using a rubber dam (Hygienic; Coltene/Whaledent AG, Altstätten, Switzerland) and access preparation using a size 018 round diamond bur (Dentsply Maillefer, Ballaigues, Switzerland), the affected tooth was treated following the American Association of Endodontists (AAE) guidelines for REPs.
The working length established at 21 mm was determined using an electronic apex locator (Root ZX II, J. Morita Corp, Kyoto, Japan) and confirmed by a working length radiograph employing a #45 K-File (Dentsply Maillefer, Tulsa, OK) (Fig. 2-C). Instrumentation was not carried out. The root canal was irrigated with 20 mL of 1.5% sodium hypochlorite and then irrigated with 20 mL of sterile saline using a positive pressure Endodontic Irrigation Syringe Monoject 513 (Kendall, Mansfield, MA); finally, the canal was dried with sterile paper points (#50) irrigated with 20 mL of 17% ethylenediaminetetraacetic acid (EDTA). Then, the canal was dried with sterile paper points and dressed in a capsule of calcium hydroxide (Hertz Pharmaceutical, Santiago, Chile) mixed in a sterile glass slab with sterile saline. This material was placed in the root canal, which was then sealed with temporary restorative glass ionomer (Vitremer; 3 M ESPE, St Paul, MN, USA).
One week after the procedure, the patient was asymptomatic. The patient was recalled 2 weeks later, the tooth was asymptomatic, and the sinus tract was not present. Local anesthesia without a vasoconstrictor was achieved (mepivacaine 3%; Septodont, Saint-Maur-des-Fosses, France). After rubber dam isolation, the intracanal medication was removed, and the plants were irrigated with 17% EDTA (20 mL/canal for 3 minutes). The root canal was dried with #60 paper points. Bleeding in the canal was induced by laceration of the apical tissues. A resorbable gelatin sponge hemostat (Gelita-Spon, Gelita Medical GmbH, Eberbach, Germany) was placed on the cervical third of the tooth to contain the Biodentine (Septodont, St Maur-des-Fosses, France) and prevent it from entering the root canal. When the setting of Biodentine was verified, a composite restoration (3 M Filtek P60; 3 M ESPE, St Paul, MN, USA) was placed (Fig. 2-D), and the patient was scheduled for follow-up visits.
Follow-up appointments took place at 9 (Fig. 2-E, Fig. 3D to 3F), 24 and 36 months (Fig. 2-F, Fig. 3G to 3I). The outcome was evaluated radiographically and clinically. The patient remained completely asymptomatic during the 36-month follow-up. Clinically, no tenderness to percussion or palpation was noted, mild discoloration was observed, and the periodontal examination revealed no pocket depths > 3 mm or normal physiological mobility. In the last examination, the tooth showed a delayed response to the cold test using 1,1,1,2-tetrafluoroethane. Radiographic examination revealed a normal periapical area. CBCT imaging revealed intact periapical bone structures (CBCT PAI = 0) (Fig. 3), dentin bridge formation in the middle third of the root, calcification of the canal in its coronal third (Fig. 3) and thickening of the canal walls (Fig. 4). Neither the patient nor their guardian expressed any dissatisfaction with the discoloration of the tooth (Fig. <link rid="fig6">2</link>-G and 2-H). The patient is closely monitored at 12-month intervals and will be kept under long-term review to evaluate treatment success and to check any evidence of signs and/or symptoms of inflammation or infection.
Orthodontic Management
Given the clinical characteristics, the patient’s previous history of orthodontic treatment, and the patient’s family’s intention to finish the treatment as soon as possible, orthodontic treatment without extraction was planned. Orthodontic treatment was resumed once the patient was discharged from the Endodontic Clinic, starting in the lower arch in November 2019 and bonding orthodontic appliances in the upper arch in August 2020. The treatment was completed in October 2022.
The orthodontic treatment was performed utilizing a straight wire technique (MBT prescription), using intermaxillary elastics and stripping to consolidate sagittal occlusal relationships, OJ and OB.