Management of a large, invasive, external, cervical root resorption of a maxillary canine: a case report with a 2-year follow-up

Drs. Purvi D. Pandya, Dhaval P. Pandya, and Prashant D. Shirke illustrate a complicated restoration

Abstract

Introduction

Invasive cervical resorption of teeth is the loss of dental hard tissues. Proper management can be carried out if the etiology and the extent of the pathology are known.

Objective

The objective of this article is to describe the diagnosis and management of a large, invasive, external cervical root resorption associated with the maxillary right canine tooth in a patient in his 70s.

Method

A 73-year-old male patient requested an opinion for mild pain and swelling over his maxillary right canine region. A clinical and radiologic diagnosis of a large idiopathic invasive cervical resorption was established after which the patient was scheduled for surgical endodontic therapy. Subsequent recall visits showed complete repair of the pathology.

Conclusion

A 2-year clinical and radiologic follow-up showed complete absence of the signs and symptoms associated with the resorption pathology and repair of the lesion.

Introduction

External root resorption is a progressive and destructive loss of hard dental tissue, initiated by a demineralized or denuded area of the root surface.¹ Heithersey described one of the frequent types of external root resorption — namely, the invasive cervical resorption in detail. It is a clinical term used to describe a relatively uncommon, insidious, and aggressive form of external tooth resorption, which may occur in any tooth in the permanent dentition. Invasive cervical resorption is defined as a localized resorptive process that begins on the surface of root below the epithelial attachment and the coronal aspect of the supporting alveolar process — namely, the zone of the connective tissue attachment.”¹ This pathology involving the tooth structure is characterized by its cervical location and its invasive nature. The resorbed tooth structure is replaced by a highly vascular tissue, which may become visible through the thin residual enamel as a pink discolored tooth.² The etiologic factors follow:

1. Physical history of orthodontic treatment, traumatic injuries involving the teeth, excessive pressure associated with impacted teeth or with an oral pathology like a large tumor. Some oral habits that may lead to excessive pressure on the teeth like playing a woodwind instrument³ or trauma related to the cementoenamel junction due to interdental wiring⁴
2. A chemical procedure performed like intracoronal bleaching
3. Idiopathic

Patients presenting with root resorptive pathology are usually asymptomatic, and in many situations, the diagnosis may present as an incidental finding on routine radiographic examinations.⁵ To further determine the extent of the pathology, especially in large invasive lesions and to treatment plan the case with an interdisciplinary approach, cone beam computed tomography imaging modality is an important adjuvant tool.

Case report

A 73-year-old male with a noncontributory medical history presented to us with mild pain and gingival swelling over his maxillary right canine region. On clinical examination (Figure 1), mild gingival swelling over the labial aspect and slight tooth discoloration with the cervical third was observed with respect to the maxillary right canine tooth. The marginal gingiva associated with the cervical third of the tooth was inflamed and red in color. A periodontal probing examination at all aspects of the tooth detected the presence of a deep pocket with respect to the labial gingiva with presence of loss of attachment in the area.

Probing under infiltration anesthesia also suggested a loss of the labial cortex of the bone plate with the canine. Endodontic examination that included a vitality test performed with the tooth showed it to be nonvital, and the tooth was not responding to percussion. After the clinical examination, an intraoral digital radiograph was obtained and processed using a phosphor plate system (Durr Dental, GmbH, Germany) (Figure 2). A large radiolucent lesion was detected in the middle third of the tooth extending from the mesial line angle to the distal line angle horizontally involving the pulp chamber of the tooth and from the cervical third up to the middle third of the tooth in the vertical plane of the canine. Minor horizontal bone loss was noted at the mesial and distal aspect of the canine with a periapical radiolucency seen at the apex of the canine. Periodontal ligament widening was also a finding in the periapical radiograph. Based on the preceding findings and the extent of the pathology, a cone beam computed tomography of the maxilla was advised with detailed reading and different views of the maxillary right canine region to further evaluate the extent of the lesion on the canine. This would work as an adjuvant tool to establish the prognosis and treatment plan the case.

A cone beam computed tomography (CBCT) evaluation confirmed the presence of a large cervical resorption pathology of the canine root in all the section views (Figure 3). A volume reconstruction tomography view of the tooth also revealed the absence of the buccal cortical plate with partial denudation of the tooth root structure (Figure 4).

Surgical endodontic treatment was instituted under infiltration anesthesia. An envelope flap incision to open the area cervically from the maxillary right lateral incisor up to the maxillary right first premolar was undertaken with Bard-Parker^® blade No. 15 (Aspen Surgical) (Figure 5). An endodontic access was performed with diamond drills from the lingual surface of the canine tooth. It was decided to perform a single visit endodontic procedure. The cervical one-third was curetted to remove the diseased granulation tissue and understand the extent of the resorption pathology on the root. Once the area was debrided, it was irrigated with normal saline to clear off any remnants of debris over the resorbed root surface. The root canal length was estimated by taking an initial radiograph (Figure 6). The canals were irrigated with 5.25 % of sodium hypochlorite, and final agitation of 17% EDTA was done. The resorbed area was filled internally with MTA repair HP (Angelus, Londrina, Brazil). Filling of the resorbed area was performed by spreading the MTA by way of condensation with radiologic examination to ensure complete sealing of the area and prevent the material leakage to the periodontium (Figure 7). Endodontic obturation followed the vertical condensation technique with gutta-percha points and AH Plus^® cement (Dentsply Sirona). The restorative procedure was completed in the same visit at the end of the endodontic procedure. The inlet ducts were sealed with glass ionomer cement, and then 35% phosphoric acid gel (Ultradent) was applied for 20 seconds. The enamel and dentin surfaces were then washed and dried. The bonding agent (Tetric^® N-Bond, Ivoclar Vivadent) was applied and polymerized according to the manufacturer’s instructions. The pulp chamber was filled with a low viscosity single increment resin, SureFil^® SDR^® (Dentsply Sirona).The flap closure was accomplished by means of a simple interrupted sutures (Figure 8).

Clinical and radiographic examination at recall visits showed decrease in the absence of symptoms (Figure 9), and the subsequent X-ray follow-ups (Figures 10-17) showed resolution of the resorption process with complete repair of the pathology at 2 years.

Discussion

The exact etiology of invasive cervical resorption is still unknown. According to Gold and Hasselgren,⁶ three environmental factors may contribute to root resorption:

1. Absence of protection for the root surface
2. Presence of vascular connective tissue
3. An inflammatory stimulus

The origin of stimulation factor is different for each type of root resorption, and when these factors are identified, it may be possible to reverse the process by removing the etiological factor.⁷ When the infection originates from the gingival sulcus and stimulates the resorption process, removal of the granulation tissue from the resorption lacuna and reliable sealing are necessary for repair since the elimination of microorganisms in the periodontal sulcus is unlikely.⁷ External cervical resorption is most commonly detected in maxillary central incisor teeth, followed by the maxillary canine,  maxillary lateral incisor, mandibular first molar, and the maxillary first molar. This similar pattern of tooth distribution in these studies may be associated with the high prevalence of traumatic injuries (anterior teeth) (Bastone, et al., 2000) and parafunctional habits (molar tooth) in patients (Chatzopoulos, et al., 2017). Patients are generally asymptomatic, and therefore, the diagnosis of this pathology is usually as an incidental clinical or radiologic finding. In more advanced cases, when the pathology has affected the pulp such as in this case, there may be symptoms of irreversible pulpitis and or apical periodontitis. In our case, the patient complained of mild discomfort with the maxillary right canine, mild-to-moderate swelling over the buccal soft tissue of the tooth, and slight discoloration of the tooth, observed over a period of time. There have been attempts to classify the resorption pathology defects of the tooth, but the most recent 3D classification is by Patel, et al.,⁸ which takes into account the exact 3D dimension of the pathology, the degree of circumferential spread, and the proximity of the root canal.

The 3D classification for external cervical resorption of teeth

According to this classification In Table 1, our case is classified as H3 Circ spread B and p with lesion in pulp.

Invasive cervical resorption requires two stages⁹ — injury and stimulation. Injury can be caused by either mechanical or chemical, whereas the origin of stimulation is different for each type of root resorption. When these factors of stimulation are identified, it is possible to reverse the process by removing the etiological factors. Our case report demonstrates the outcome of sealing the resorptive defect with the restorative materials. Although the pathology defect revealed the presence of a granulation tissue inside the defect crater, subsequent recall visits showed the gingiva to be healing, indicating that no further presence of inflammatory stimulus. External cervical resorption (ECR) is a dynamic and evolving process with phases of destruction and repair (Luso and Luder 2012, Mavridou, et al., 2016). The pathogenesis of ECR consists of:

1. Resorption initiation
2. Resorption progression
3. Reparative stage

Mineral trioxide aggregate (MTA) has been considered a promising material in root canal treatment of root resorption. An important biological property is the stimulation of new bone formation, and due to its alkaline pH and biocompatibility, it does not trigger severe inflammation at the local regeneration. This material seems to be advantageous for the repair of perforations and resorption, since it allows the deposition of cement, providing a very effective biological seal, mainly due to its ability to set itself up in the presence of moisture. For these and other characteristics, MTA has several potential clinical applications to possess dimensional stability in the presence of blood and microbial byproducts besides being biocompatible and radiopaque.¹⁰

Conclusion

Accurate diagnosis, case selection, material consideration, and an interdisciplinary planning for root resorption pathology can lead to successful outcomes and prediction of long-term prognosis of the pathologically involved tooth. This case showed the possibility of treating a large invasive cervical resorption defect of a tooth with satisfactory outcome over a 2-year recall period (Figures 14-17) based on clinical and radiologic findings.