|Year : 2017 | Volume
| Issue : 3 | Page : 190-193
Endodontic management of Type III dens invaginatus with the aid of cone-beam computed tomography
Vidya Narayanamoorthy, M Vidya Saraswathi, Shashi Rashmi Acharya, Payaswi Mohata
Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal, Karnataka, India
|Date of Web Publication||21-Aug-2017|
Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal - 576 104, Karnataka
Source of Support: None, Conflict of Interest: None
Dens invaginatus (DI) is a rare developmental anomaly characterized by invagination of the enamel organ into the dental papilla before calcification has occurred. Maxillary lateral incisor is most commonly involved. The complex anatomy of this anomaly presents as a major challenge to the endodontist. The two-dimensional imaging such as intraoral periapical radiographs and bitewing fall short of defining the extent of the defect. The three-dimensional extent of this lesion can be visualized efficiently using a cone-beam computed tomography, which can help in a better understanding and treatment planning. Depending on the extent of the DI, the treatment modalities can be either surgical or nonsurgical. The present case highlights a maxillary central incisor with Type III DI which was managed using contemporary endodontic techniques.
Keywords: Apexification, cone-beam computed tomography, dens invaginatus Type III
|How to cite this article:|
Narayanamoorthy V, Saraswathi M V, Acharya SR, Mohata P. Endodontic management of Type III dens invaginatus with the aid of cone-beam computed tomography. Saudi Endod J 2017;7:190-3
|How to cite this URL:|
Narayanamoorthy V, Saraswathi M V, Acharya SR, Mohata P. Endodontic management of Type III dens invaginatus with the aid of cone-beam computed tomography. Saudi Endod J [serial online] 2017 [cited 2018 Feb 21];7:190-3. Available from: http://www.saudiendodj.com/text.asp?2017/7/3/190/213478
| Introduction|| |
Anatomic variations in root canal systems are a commonly occurring phenomenon. Treatment of teeth presenting with complex root canal morphologic variations has been a constant challenge for endodontists. One such rare developmental anomaly of teeth is dens invaginatus (DI), which results from the invagination of the enamel organ into the dental papilla before calcification has occurred. DI has been described as a tooth within a tooth or as an invagination of an enamel-lined tract extending into the root, with or without exposure of the dental pulp. The etiology of this developmental anomaly is still unclear. Possible etiologic factors include trauma, infection, growth retardation of specific cells, disruption in factors regulating the formation of enamel organ, and links to genetic factors.,, Its prevalence ranges from 0.04% to 10%, with the maxillary lateral incisors being the most commonly affected and less frequently the central incisors.
The complex anatomy of DI makes a conservative endodontic treatment of such teeth difficult and unpredictable; thus, combination with surgical treatment or sometimes extraction of such a tooth is necessary. In most cases, a DI is detected by chance on the radiograph. The clinical appearance of DI varies considerably. The crown of affected teeth can be of normal morphology but can also be associated with unusual forms such as greater labiolingual diameter, peg-shaped, barrel-shaped, conical, and talons cusp. A deep foramen cecum might be the first clinical sign indicating the presence of an invaginated tooth.
Until recently, imaging in endodontics was limited to two-dimensional, standard intraoral radiographs. The advent and feasibility of cone-beam computed tomography (CBCT), a three-dimensional (3D) imaging modality, and its application in clinical cases have helped not only in diagnosis but also in assisting the clinician in better treatment planning of complex cases requiring endodontic therapy.,
The following case report demonstrates the use of CBCT scans in treatment planning as well as the clinical technique using the dental operating microscope for the successful endodontic management of a DI case with a complex root canal system.
| Case Report|| |
A 20-year-old female patient reported at the Department of Conservative Dentistry and Endodontics with the chief complaint of large abnormal appearance of the upper front tooth and occasional mild pain on biting. The pain was dull and intermittent and increased on biting on hard food. The intensity of the pain had increased in the past year.
The patient's medical and family history was noncontributory. The patient's overall general health was good. No abnormalities were seen on extraoral examination. Intraoral examination revealed localized macrodontia with respect to maxillary right central incisor (#11) with abnormal bulbous delineations [Figure 1]a. The tooth responded negatively to cold test and electronic pulp testing (Parkell Inc. Edgewood, NY, USA). A periapical radiograph of tooth #11 revealed the presence of dens in dente, with the invagination inside the tooth extending to the entire length of the root. Asymmetric diffuse periapical radiolucency was seen at the immature apex with a loss in the continuity of lamina dura [Figure 1]b. A diagnosis was made of Oehler's Type III DI with respect to tooth #11 associated with a chronic periapical abscess. The complex anatomy of the tooth was explained to the patient, an informed consent was obtained, and a decision to perform root canal therapy with respect to 11 was made.
|Figure 1: (a) Preoperative clinical view, (b) preoperative intraoral periapical, (c) access opening under rubber dam isolation, (d) working length determination|
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Under rubber dam isolation, an ideal access cavity was prepared to locate the central canal [Figure 1]c. An endodontic file was placed inside the canal and a working length radiograph was taken. However, the radiograph revealed the file location in the pseudocanal formed by the dens tract [Figure 1]d. To avoid further blind exploration of the access cavity, the patient was advised a CBCT scan to locate the actual root canals. The CBCT image revealed an invagination extending along the entire root length, which was entirely embedded in the pulp canal space, and had a separate portal of exit from the root canal space. Two true root canals were situated slightly distal and palatal to this [Figure 2]a,[Figure 2]b,[Figure 2]c. Based on the CBCT findings, the access opening was modified with the aid of the dental operating microscope (Seiler IQ Precision Microscope, St. Louis, MO, USA) to locate the two root canals [Figure 2]d. Working length of the two canals and the dens tract was established radiographically and cleaning and shaping were carried out [Figure 3]a. The main canals were prepared using 4% taper Rotary M two file system (VDW, Antaeus, Munich, Germany) till an ISO size 20 with 17% ethylenediaminetetraacetic acid (RC–Prep, Premier Dental, Philadelphia, PA, USA) and copious irrigation with 1% NaOCl (Medilise Chemicals, Kannur, Kerala, India) solution. The dens tract with a bulbous extension was prepared by circumferential filing using K files (Mani Inc. Tochigi Ken, Japan) with chemical disinfection using NaOCl. Final rinse was done using 2% chlorhexidine solution (Prevest Denpro, Jammu, India). After cleaning and shaping, an intracanal medication of calcium hydroxide (KMC Pharmacy, Manipal) mixed with chlorhexidine was placed in the canal and changed every 10 days for 2 months. A master cone radiograph was taken [Figure 3]b. The two main canals were obturated using 4% gutta-percha points (Diadent Group International, Korea) along with AH plus sealer (De Trey/Dentsply, Germany) using single cone technique. The dens tract was obturated using a 5 mm apical barrier of mineral trioxide aggregate (MTA) (ProRoot MTA, Dentsply, Tulsa) and backfilling was thereafter completed using thermoplasticized gutta-percha (E and Q Master Obturation system, Meta Biomed Korea) after its complete set in the next appointment [Figure 3]c and [Figure 3]d. The access cavity was restored using resin composites (Filtek P250, 3M ESPE, St. Paul, MN, USA) to obtain a coronal seal. A 6-month follow-up radiograph revealed resolution of the periapical lesion [Figure 3]e. At this stage, following a meticulously planned gingival contouring using a 940 nm diode laser (EzLase, Biolase, San Clemente, CA, USA), crown preparation of the tooth was carried out, and a retraction cord was packed (No. 000) and a polyvinyl siloxane impression (Reprosil, Dentsply Caulk, USA) of the tooth was made using the double-mix single impression technique. An all-ceramic crown (Lava, 3M ESPE) was fabricated and cemented using resin-based cement (Variolink II, Ivoclar Vivadent, India) [Figure 4].
|Figure 2: (a-c) Cone-beam computed tomography images, (d) cone-beam computed tomography assisted access opening under dental operating microscope|
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|Figure 3: (a) Working length determination, (b) master cone intraoral periapical, (c) apical barrier using mineral trioxide aggregate, (d) completed obturation, (e) 6 months follow-up|
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| Discussion|| |
Oehlers classified DI into 3 types on the basis of severity:
- Type I: An enamel-lined minor form occurring within the confines of the crown not extending beyond the cement-enamel junction
- Type II: An enamel-lined form that invades the root but remains confined as a blind sac and might or might not communicate with the pulp
- Type III: A form that penetrates through the root perforating at the apical area, showing a second foramen in the apical or in the periodontal area.
In Types I and II, the invagination can be removed, thus transforming the tooth into a single canal followed by conventional treatment. The challenge becomes greater in Type III cases, where the anatomy is more complex. Such cases always pose a challenge to the clinician in diagnosis as well as in treatment. The current case was diagnosed as Oehlers Type III as the dens cavity was communicating with the periapical region. Inability to locate, debride, and obturate the complex root canal spaces can lead to failure in such cases. Because of the inherent limitations of radiographs, they could not reveal the details of the type and extent of the DI. CBCT and 3D CT are advanced diagnostic aids, which help in assessing the root canal anatomy better in challenging cases such as resorption, presurgical assessment, and trauma. Hence, CBCT was used for diagnosis in the present case. The benefits of CT scans were that it gave a sharp, focused, and 3D view of the invaginatus, giving the exact location and anatomy of the root canal system which allowed successful management of the case. The access cavity was modified under a dental operating microscope to allow adequate magnification and visualization of the additional orifices and canals. The conventional cleaning and shaping procedures were difficult in the present case as the shape of the root canal was deformed due to the invaginatus. The anomaly was wide midway to the apex and the access was narrow. The actual canals were also narrow. Hence, effective disinfection relied greatly on the use of chemical agents such as sodium hypochlorite and chlorhexidine. An intracanal medication of calcium hydroxide and chlorhexidine was used taking into consideration the necessity for fast liberation of calcium ions using an aqueous medium. This combination has shown superior disinfection in endodontic treatment cases with periapical lesions  and agent against Candida albicans. One of the major problems in endodontic therapy in teeth with pulp necrosis and open apex is obtaining an adequate closure of the root canal. In the present case, a MTA barrier in the dens canal was used to create and effective apical seal. Furthermore, since the tooth presented a wide and bulky cavity, a flowable material was required for proper obturation. Hence, the thermoplasticized techniques was used to facilitate the procedure and provide a more efficient sealing. A postendodontic restoration using composite resin was given to provide an effective coronal seal. Follow-up radiograph showed resolution of the periapical lesion with formation of trabecular bony pattern. Success was characterized by the absence of signs and symptoms of periapical disease. This was further enhanced with esthetic rehabilitation using all-ceramic crowns.
| Conclusion|| |
With advancement in diagnostic imaging, enhanced magnification aids, rotary endodontics, improved irrigation regimen, and obturation systems, treatment of such challenging cases can be more predictable and rewarding to both the patient and the endodontist.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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