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 Table of Contents  
Year : 2022  |  Volume : 34  |  Issue : 4  |  Page : 300-305

Revascularization of an immature necrotic permanent mandibular second premolar with dens evaginatus: A case report with 3 years' follow-up

1 Lau Dental Clinic, Faculty of Dentistry, MAHSA University, Selangor, Malaysia
2 Department of Endodontics, Faculty of Dentistry, MAHSA University, Selangor, Malaysia
3 Department of Oral Pathology, Faculty of Dentistry, MAHSA University, Selangor, Malaysia
4 Department of Conservative Dentistry, Faculty of Dentistry, MAHSA University, Selangor, Malaysia

Date of Submission02-Dec-2021
Date of Decision05-Jul-2022
Date of Acceptance13-Jul-2022
Date of Web Publication28-Dec-2022

Correspondence Address:
Dr. Raghavendra Penukonda
Department of Endodontics, Faculty of Dentistry, MAHSA University, Bandar Saujana Putra, 42610, Selangor
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/endo.endo_216_21

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Dentists face a challenge when treating necrotic immature teeth with periapical pathology because apexification techniques leave the tooth vulnerable to fracture. After all, the roots are not matured, and the canal walls are thin. Pulp revascularization is a regenerative endodontic procedure that emerged as a viable treatment for apical closure, continued root development, and dentinal wall thickening with successful clinical and radiographical outcomes. In this case report, an 11-year-old boy complained of pain and associated swelling in the lower left posterior teeth region, diagnosed as pulp necrosis with acute apical abscess of an immature tooth with dens evaginatus (DE). After periapical radiographs, drainage was done through the access cavity, and a regenerative endodontic procedure was performed with the final restoration of composite resin. This report emphasizes the successful management of an immature necrotic permanent mandibular second premolar with DE using a revascularization procedure.

Keywords: Dens evaginatus, immature tooth, pulp revascularization, regenerative endodontics

How to cite this article:
Kang KZ, Penukonda R, Pattar H, Al-Haddad A. Revascularization of an immature necrotic permanent mandibular second premolar with dens evaginatus: A case report with 3 years' follow-up. Endodontology 2022;34:300-5

How to cite this URL:
Kang KZ, Penukonda R, Pattar H, Al-Haddad A. Revascularization of an immature necrotic permanent mandibular second premolar with dens evaginatus: A case report with 3 years' follow-up. Endodontology [serial online] 2022 [cited 2023 Jan 28];34:300-5. Available from: https://www.endodontologyonweb.org/text.asp?2022/34/4/300/365810

  Introduction Top

Dental caries, acute trauma, and dental anomalies such as dens evaginatus (DE) and dens invaginatus can cause pulp necrosis and periapical pathologies.[1] Treating pulpal lesions that occur during root formation is a challenge to clinicians as conventional endodontic treatment is not recommended for immature permanent teeth due to the increased risk of thin walls-root fracture or accidental injection of fluids or filling materials beyond the open root apex.[2]

The pulp vitality status primarily determines the management method of such teeth. Vital pulp therapy is favored over root canal therapy if the pulp tissue has become irreversibly inflamed. Pulp capping and partial or complete pulpotomy are usually performed depending on the amount of coronal pulp that needs to be preserved and the method of capping used. When an immature tooth's pulp becomes necrotic, the most common preferred treatment is apexification or revascularization of the tooth.[3] Conventionally, the apexification procedure using calcium hydroxide or mineral trioxide aggregate to form an apical barrier was most commonly employed. However, this technique is considered an extended procedure which may take 6–24 months for the apical barrier to be achieved and does not increase the thickness or length of the root wall, in a few cases, tooth becomes more fragile and prone to future fractures.[4]

Pulp revascularization is a regenerative endodontic procedure that relies on the ability of residual pulp and periodontal stem cells to differentiate into highly vascularized and conjunctive-rich living tissue. The potential of stem cells to colonize the available pulp space and subsequently differentiate into newly formed odontoblasts would allow the complete root formation and increase the thickness of the root canal walls through hard tissue deposition.[5]

DE is an extremely rare odontogenic developmental anomaly that often leads to pulp and periapical pathology if not detected and treated early. DE is characterized by an abnormal tubercle, elevation, protuberance, excrescence, extrusion, or bulge on the central groove or on the buccal or lingual cusps of premolars or molars and the palatal or lingual surfaces of anterior teeth, which results in the formation of an accessory cusp. The elevation projects above the adjacent tooth surface, displaying enamel covering a dentinal core that usually contains pulp tissue and may have a slender pulp horn that extends from a few millimeters to the entire length of the tubercle's dentin core. The trauma during mastication fractures or wears the tubercle, resulting in pulp necrosis and periapical infection. Mandibular premolars are most commonly affected, followed by the molars, with the anterior teeth being rarely affected. The prevalence of this pathological condition varies, with a higher prevalence among people of Asian descent and a lower prevalence among Caucasians and other white people, with estimates ranging from 0.5% to 4.3% depending on the population group studied. In addition, males are more likely to be affected than females.[6],[7]

The current case report describes the revascularization procedure of an immature necrotic permanent mandibular second premolar with DE over a 3-year follow-up.

  Case Report Top

An 11-year-old Chinese male patient reported to a Private Specialty Dental Clinic, Kuala Lumpur, Malaysia, with a chief complaint of pain and associated swelling in the lower left posterior teeth region since 2 weeks. The pain was moderate in intensity, intermittent, aggravated on chewing food, and relieved on taking medication. The patient's medical and dental history was noncontributory.

On extra-oral examination, facial asymmetrical was evident with a diffuse swelling involving the left side of the face. An erythematous area measuring approximately 2 cm in diameter was seen along the inferior right border of the mandible, at the first and second premolar region. The associated swelling was dome-shaped, tender on palpation, and fluctuant. The patient was afebrile. Oral hygiene was found to be acceptable during an intraoral examination. An abraded elevation or protuberance from the central groove of the mandibular left second premolar (# 35) was observed. The tooth was tender to percussion, surrounding tissues exhibited swelling, and periodontal pocket depths were normal. The cold test with Endofrost (Coltene Whaledent, Switzerland) and electric pulp test (Digitest, Parkell, New York, USA) showed no response. Radiographs revealed a small, round, flat surface between the buccal and lingual cusps measuring approximately 1–1.5 mm in diameter with a pinpoint dark spot in the center of tooth # 35, which confirmed abraded DE. The periodontal ligament space was slightly enlarged. A discontinuity in lamina dura was seen, along with a small, circumscribed radiolucency resembling a dental follicle around the immature apex of #35 [Figure 1]. Based on clinical and radiographic examination, the diagnosis of pulp necrosis with acute apical abscess was made with tooth #35. Since the tooth had an immature apex and considering the thin root canal walls, it was decided to treat it with a revascularization procedure. After explaining the treatment procedure to the child's parents, informed consent was obtained from the parents before initiating the treatment.
Figure 1: Preoperative radiograph showing an immature apex and periapical radiolucency #35

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First appointment

At the first appointment, a buccal infiltration with 1–1.5 ml of a local anesthetic agent comprising 3% plain mepivacaine was injected into the buccal sulcus adjacent to tooth #35, and rubber dam isolation was done. After disinfecting the occlusal surface of the tooth with 10% povidine iodine, the access cavity was prepared using a long shank round bur (Dentsply Maillefer, Ballaigues, Switzerland) under a dental operating microscope (Zumax, Zumax Ltd., China). The tooth was left open for approximately 20 min following access cavity preparation to allow a significant quantity of pus to drain from the prepared access cavity. A 20-ml of 1% sodium hypochlorite (NaOCl) solution was used to thoroughly and gently irrigate the root canal system, followed by 20 mL of normal saline, with a side vented needle to prevent the chances of irrigant extrusion. A Teflon tape was placed at the entrance of the pulp chamber, and the tooth was temporized with IRM (Dentsply Maillefer, Ballaigues, Switzerland). 250 mg of Amoxicillin and 250 mg of paracetamol twice a day for 5 days were prescribed and the patient was recalled after 2 weeks.

Second appointment

Two weeks later, the patient was asymptomatic, and the swelling had completely subsided. A local anesthetic was injected; the tooth was isolated. After regaining access to the cavity, the canal was clean and dry, with no evidence of abscess drainage. A K-file # 40 (Dentsply Maillefer, Ballaigues, Switzerland) was used to determine the working length and later confirmed using a periapical radiograph. The root canal was cleaned with approximately 20 ml of a 1% NaOCl solution and a 30G single-side vent irrigation needle. This was followed by irrigation with 5 ml of 17% EDTA (SmearClear™, Kerr Dental, Orange, California) and activated with Endoactivator (Dentsply Maillefer, Ballaigues, Switzerland) for 1 min. The canal was then rinsed with normal saline as a final irrigant. Sterile paper points (Dentsply Maillefer, Ballaigues, Switzerland) were used to dry the root canal, and then the coronal section was filled with triple antibiotic paste (TAP). TAP consists of three antibiotics 400 mg metronidazole, 100 mg of minocycline, and 200 mg of ciprofloxacin in a 1:3:3 ratio. After removing the enteric coating, the drugs were pulverized and combined with propylene glycol or normal saline to achieve a paste-like consistency.

Third appointment

Subjective and objective examinations were conducted. Following the procedure, the patient reported no pain, the temporary restoration was in good condition, and percussion and palpation revealed no abnormalities. After injecting the local infiltration anesthesia and isolating the tooth, the provisional restoration was removed using an ultrasonic scaler unit. NaOCl, along with ultrasonic activation of the solution, was done to remove the previously placed TAP from the root canals. Root canals were later irrigated with 5 mL of 17% EDTA (SmearClear™, Kerr Dental, Orange, California), and the solution was activated using an Endoactivator (Dentsply Maillefer, Ballaigues, Switzerland), for 1 min. Subsequently, the canals were rinsed with distilled water and dried with a sterile paper point. The bleeding was induced by passing a sterile K-file #20 (M-Access, Dentsply Maillefer, Ballaigues, Switzerland) over the working length. After the bleeding had nearly reached the orifice, a sterile cotton pellet was inserted to the level of CEJ to aid in clotting. Bioceramic putty material (EndoSequence BC RRM Fast Set Putty, Busseller, USA) was placed in contact with the blood clot about 5–6 mm into the root canal. A plugger was used to compact the Bioceramic putty material. The density of the material was later confirmed using radiography [Figure 2]. A week later, the patient was instructed to return.
Figure 2: Immediate postoperative radiograph taken after placing the Bioceramic putty material placed in contact with the blood induced

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Fourth appointment

Seven days later, the subsequent examination revealed that the patient experienced no pain following the procedure, the temporary restorative material was in good condition, and that percussion and palpation were negative. The provisional restoration was replaced by a composite resin restoration (Dentsply Maillefer, Ballaigues, Switzerland). Thermal and electrical pulp tests (EPTs) revealed a positive response. Periapical radiographs revealed a reduction of periapical radiolucency and decreased periodontal ligament widening at 6, 12, and 36 months of follow-up [Figure 3], [Figure 4], [Figure 5].
Figure 3: Six months follow-up radiograph showing the signs of healing in the periapical area

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Figure 4: Twelve months follow-up radiograph showing the periapical healing with bone deposition and the slight closure of the apex

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Figure 5: Thirty-six months follow-up radiograph showing good periapical healing with adequate bone deposition and complete closure of the apex

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  Discussion Top

The current case demonstrated conceivable pulpal regeneration of an infected mandibular second premolar with DE and an immature apex. The degree of success of regenerative endodontic procedures can be measured by attaining the primary goal of eliminating symptoms and evidence of bony healing.[8] In addition, increased root wall thickness and length, as well as a positive response to pulp testing, are secondary and tertiary desirable goals.[9] Accordingly, the tooth involved in this report demonstrated a high degree of success.

Controlling intracanal infection in the root canal system is critical because it creates a favorable environment for pulp regeneration and continued root maturation induced by Hertwig's root sheath and pulpal and apical papilla stem cells survived the acute periapical infection.[10],[11]

Disinfection in this case report was achieved through chemical preparation with no debridement as it is contraindicated in immature teeth to avoid weakening the immature root wall.[12] A low concentration of NaOCl (1%) was used to allow for microbial control, prevent the destruction of potential stem cells, and prevent the adverse effects of extrusion into the periapical area.[13] TAP was used as intracanal medicaments due to its effectiveness in eliminating bacteria from infected dentine.[14] The high concentration of TAP is associated with clinical tooth discoloration due to the minocycline constituent.[15] However, the lower esthetic value of a mandibular premolar enabled the use of TAP instead of double antibiotic paste. Even if a discoloration was caused, it could have lesser implications on the patient's esthetics. Indeed, no discoloration was detected in the current case.

Dentin matrix contains growth factors that can induce odontoblast-like cell differentiation. These growth factors are released in varying concentrations by endodontic irrigants such as NaOCl, citric acid, and EDTA, while EDTA releases the highest concentrations of transforming growth factor-b1.[16] EDTA was used to remove the smear layer from the dentinal surfaces to facilitate binding sites for stem cells and encourage the differentiation of odontoblast-like cells.[17]

The presence of a scaffold is one of the prerequisites for pulp regeneration. Various scaffolds, such as blood clots, platelet-rich plasma, and platelet-rich fibrin, have been used.[18],[19] The induction of bleeding and subsequent formation of blood clots provide a scaffold for periapical cells, including mesenchymal stem cells, to migrate into the root canal and eventually induce new tissue formation within the space.[20]

The importance of a coronal seal in successful revascularization is well known. MTA is the most commonly reported coronal plug, followed by resin-bonded restorations.[19] Due to its biocompatibility and effectiveness as a coronal plug, bioceramic putty was used in this case.[21] The bond strengths between composite resin and bioceramic materials were lower than dentin. However, failure distribution was frequently cohesive within the bioceramic or mixed, which could indicate a durable interaction. Thus, the bioceramic-composite interface may not be a clinical factor of critical importance.[22] In the present case, the successful clinical and radiographic outcomes demonstrate the efficacy of bioceramic putty and composite in providing a tight seal.

The presence or absence of positive responses after the regenerative procedure depends on the coronal level of tissue grown in the root canal and the thickness of filling materials over this tissue.[23] It was reported that the tooth is more likely to elicit a negative response to cold or EPT if the filling materials were extended inside the root canal beyond the cementoenamel level. In addition, the presence of a thick layer of restorative materials can also prevent the stimulation of vital tissues within the root canal.[24] However, in the current case, the tooth was responded positively to cold and EPT tests even though the coronal plug was extended to 5–6 mm inside the root, which is in accordance with the previous case.[24]

The positive influence of long-term follow-up on the increasing root length and root-wall thickness with time is significant.[23],[25] In the present case, periapical radiographs show a decrease in radiolucency and further root maturation and apical closure within 36 months.

To sum up, applying the protocol proposed by american association of endodontics (AAE) for the regenerative endodontic procedure, to treat an immature tooth with DE and open apex could provide highly successful clinical and radiographical outcomes for regeneration or revascularization of the pulp and further maturation of the root with high potential to regain positive pulp response.

  Conclusion Top

Pulp revascularization is a viable option for the treatment of necrotic immature teeth with apical periodontitis. The revascularization of immature teeth with apical periodontitis is primarily dependent on: (a) canal disinfection; (b) the placement of a matrix in the canal for tissue in-growth; and (c) a bacterial tight seal of the access opening. The clinical and radiographic outcomes, which were evident in this case, can be used to better evaluate treatment outcomes.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

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Boufdil H, Mtalsi M, El Arabi S, Bousfiha B. Apexification with calcium hydroxide versus. Revascularization. Case Rep Dent 2020;2020:1-6.  Back to cited text no. 4
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Martin DE, De Almeida JF, Henry MA, Khaing ZZ, Schmidt CE, Teixeira FB, et al. Concentration-dependent effect of sodium hypochlorite on stem cells of apical papilla survival and differentiation. J Endod 2014;40:51-5.  Back to cited text no. 13
Mohammadi Z, Jafarzadeh H, Shalavi S, Yaripour S, Sharifi F, Kinoshita JI. A review on triple antibiotic paste as a suitable material used in regenerative endodontics. Iran Endod J 2018;13:1-6.  Back to cited text no. 14
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  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


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