|Year : 2015 | Volume
| Issue : 1 | Page : 37-40
Restoration of an endodontically treated molar taurodont: A 3-year follow-up case
Antoniadou Maria1, Malivitsi Christina1, Margeti Zoi1, Eleutherios-Terry Farmakis2
1 Department of Operative Dentistry, Dental School of Athens, Athens, Greece
2 Department of Endodontics, Dental School of Athens, Athens, Greece
|Date of Web Publication||20-May-2015|
Dr. Antoniadou Maria
Department of Operative Dentistry, Dental School of Athens, Thivon 2, GR-11527, Athens
Source of Support: None, Conflict of Interest: None
Taurodontism is an anomaly or variation of the anatomy of the tooth basic shape, characterized by an enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cement-enamel junction. Due to these characteristics, endodontic treatment and restoration of these teeth is extremely challenging. In this paper, a review of the phenomenon and prevalence of taurodontism is carried out, and interesting clinical case is described in terms of endodontic notification and final crown restoration. In order to achieve longevity, by preventing microleakage, the final restoration is considered provocative, concerning the selection and combination of restorative materials to be used in such cases. Special care should always be given in occlusion and cuspal protection.
Keywords: Crown molar restoration, dentin preservation, endodontic treatment, taurodontic molar, taurodontism
|How to cite this article:|
Maria A, Christina M, Zoi M, Farmakis ET. Restoration of an endodontically treated molar taurodont: A 3-year follow-up case. J Orofac Sci 2015;7:37-40
|How to cite this URL:|
Maria A, Christina M, Zoi M, Farmakis ET. Restoration of an endodontically treated molar taurodont: A 3-year follow-up case. J Orofac Sci [serial online] 2015 [cited 2019 Nov 15];7:37-40. Available from: http://www.jofs.in/text.asp?2015/7/1/37/157378
| Introduction|| |
Taurodontism is defined as an anomaly in tooth shape characterized by an enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cement-enamel junction. Shifman's and Chanannel's classification was the most commonly used [Figure 1]. Nowadays, a tooth is characterized as taurodontic when the ratio between the sum of crown plus body and the root is >1.1. Permanent molar teeth are most commonly affected, unilaterally or bilaterally, and in any combination of teeth or quadrants.  In the relevant literature, no suggestion has been made so far on materials and techniques of the final restoration of endodontically treated molar taurodonts. This paper describes the clinical challenges and restoration's dilemmas faced when treating and restoring a molar taurodont.
|Figure 1: Schematic view of Shifman's and Chanannel's classification for taurodontism. (a) Hypotaurodontism: C + B/R = 1,1– 1,29 (b) mesotaurodontism: C + B/R = 1,3– 2 (c) hypertaurodontism: C + B/R >2|
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| Case Report|| |
A 21-year-old male patient presented himself complaining of intolerance to cold stimuli and toothache on the posterior left part of the maxilla. The medical history was poor. He had been a smoker for the last 6 years averaging about 20 cigarettes/day. Comprehensive clinical examination revealed poor oral hygiene, a white-coated tongue, and signs of gingival inflammation. The patient was also characterized by a high-rate of tooth caries. His occlusion status was undefined on the right side and angle class III on the left. First upper right molar, which did not show any signs of previous treatment, was widely damaged by caries [Figure 2]. An endodontic treatment was performed according to the minimally invasive treatment plans.  Under dental operating microscope, to facilitate visualisation (Global Protégé plus, Global Surgical Corporation, St. Louis, MA, USA), four root canal orifices were located: two narrow orifices, leading to the MB1 and MB2 canals, one distal buccal and a wide palatal one. An apex locator (Bingo 1020, Forum Engineering Technologies, Rishon, Lezion, Israel) was used to estimate the working length, which was verified by a length determining x-ray. Preparation of the root canal system was performed by rotary nickel files (Protaper Universal, Dentsply/Maillefer) and copious irrigation of 2.4% NaOCl solution. The 3 palatal ones were prepared up to F2 and the palatal one up to F3 finishing file. The obturation of root canals was conducted using Continuous Wave of Condensation (System B / Obtura, Sybron Endo, USA) [Figure 3].
|Figure 2: Initial radiographic view of the taurodontic upper left molar |
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|Figure 3: Final radiographic view of the molar just after completion of the endodontic treatment|
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For the coronal restoration, it was decided to perform a conservative layering restoration in two phases. At the first appointment, a 2 mm layer of glass ionomer cement (Fuji I, GC, Europe) was used in order to seal the endodontically filled root canals [Figure 4]. Then, a dispersed phase amalgam alloy was used to fill the cavity up to 1 mm of the alveolar ridge (Dispersalloy, Dentsply Int.), and a temporary filling was placed. 24 h after the condensation of the amalgam the temporary filling was removed, the cavity walls were cleaned with an ultrasonic handpiece and the tooth cavity was prepared for an adhesive resin final coronal restoration according to the manufacturer's directions [Figure 5]. The palatal surface was first constructed with a nanofill resin (Renamel Nanofill, Cosmedent, USA) in order to absorb stresses developed under the palatal cusps. The access cavity was then transformed into a simple class I cavity. This was possible due to the supragingival limits of the preparation. Following, the set amalgam surface was silanized, and a layer of resin was first placed in the cervical portion of the access and cured. Two subsequent increments were then placed with the objective of creating a nearly c-factor-1 cavity. The final increment of resin was finally placed and brushed to the enamel periphery [Figure 6]. Occlusion was adjusted to completely eliminate any excursive contacts. Ideal occlusion in this type of case would be a very light single centric stop on the restorative material. At the 3-year recall, the radiographic and clinical evaluation revealed no signs of pathology [Figure 7].
|Figure 5: Placement of the amalgam layer until the cement-enamel junction |
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| Discussion|| |
When performing an endodontic treatment in a taurodont tooth, the clinician should take into account the wide variation in size and shape of the pulp chamber, the varying degrees of obliteration and canal configuration, the apically positioned canal orifices, and the potential for additional root canal systems. In such cases, a modified filling technique, which consists of combined lateral compaction in the apical region with vertical compaction of the elongated pulp chamber, is proposed. 
For coronal restoration, it was recommended that post placement should be avoided for tooth reconstruction.  Furthermore, the use of a semi-manufactured product consisting of glass fibers and a polymer/resin gel matrix (e.g., EverStick Post, GC Europe) has not yet been documented for use in such specific cases. Furthermore, as less surface area of the tooth is embedded in the alveolus, a taurodont tooth may not have as much stability as a canine when used as an abutment for either prosthetic or orthodontic purposes. The lack of a cervical constriction would deprive the tooth of the anti-stressing effect against excessive loading of the crown. Finally, the solution of a ceramic or composite resin onlay was not considered as a choice due to the invasive destruction of sound tooth structures. 
A conservative approach could have nonetheless used modern materials imitating dentine (e.g., Biodentine, Septodont, France, EverX posterior, GC Europe). Although validated experimentally,  the efficacy of Biodentine as well as that of other similar materials as dentine substitute is yet to be clinically proven for each of their therapeutic indications. Hence, in order to preserve the longevity of the restoration a sandwich technique has to be considered. The most crucial challenge in similar cases seems to be the prevention of microleakage and stress absorption. These phenomena are prevented with proper preparation, hermetic obturation, and sealing of root canal orifices' with a glass-ionomer cement. 
The use of amalgam between the glass ionomer cement layer and the composite resin was used in order to seal the restoration around the cemento-enamel junction properly, as it has been reported that good condensation of the amalgam against all tooth surfaces reduces microleakage in the enamel-cementum junction.  Moreover, teeth restored with bonded amalgam and composite resins seem to show higher fracture resistance than those restored with conventional amalgam.  Finally, amalgam use although diminishing worldwide, still continues to occur under certain indications. 
The longevity of the restoration performed in this case, according to the coronal tooth structure remained, although depending on many general and local factors such as cavity shape, technique of layering, forces applying on the restoration, oral hygiene and diet habits, could be estimated at 5-9 years.  Finally, it seems that the achievement of successful treatment involves analysis of the occlusion, techniques, and occlusal force equilibration at both restoration and the opposing dentition. It should be noted that when restoring a significant amount of occlusal anatomy, the patient's occlusion is a major determining factor in the success of large restorations.  In this young patient since no main occlusal contacts were to be observed from the opposing dentition, the choice of avoiding the full crown coverage of the taurodont molar was considered as a minimally invasive option.
| Aknowledgments|| |
The authors would like to thank the postgraduate student of the Department of Endodontics, Mr. Xenios Petridis, who performed the endodontic treatment of the case.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]