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Journal of Indian Society of Pedodontics and Preventive Dentistry Official publication of Indian Society of Pedodontics and Preventive Dentistry
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Year : 2021  |  Volume : 39  |  Issue : 1  |  Page : 106-109

Regenerative endodontic treatment of an immature permanent canine – A case report of a 13-year follow-up

1 Director General, Dental Volunteers for Israel; Department of Pediatric Dentistry, The Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel
2 Department of Pediatric Dentistry, The Hebrew University-Hadassah School of Dental Medicine, Jerusalem, Israel

Date of Submission08-Sep-2020
Date of Decision18-Oct-2020
Date of Acceptance03-Mar-2021
Date of Web Publication22-Apr-2021

Correspondence Address:
Dr. Roy Petel
Department of Pediatric Dentistry, Hadassah School of Dental Medicine, P. O. Box: 12272, Jerusalem 91120
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jisppd.jisppd_1_20

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Data on long term survival and tooth stability after regenerative endodontic treatment are missing. The purpose of the present report is to describe regenerative endodontic treatment of a permanent mandibular canine with extensive coronal hypoplasia, immature root, and a periapical radiolucency. The regenerative endodontic treatment was initiated by irrigation of the root canal, followed by three weeks of triple antibiotic paste dressing and the creation of a blood clot scaffold covered with mineral trioxide aggregate. A one year clinical and radiographic follow-up demonstrated healing of the periapical radiolucency and the tooth remained stable and sound for almost thirteen years post treatment.

Keywords: Endodntic regenerative treatment, revascularization, triple antibiotic mixture

How to cite this article:
Petel R, Noy AF. Regenerative endodontic treatment of an immature permanent canine – A case report of a 13-year follow-up. J Indian Soc Pedod Prev Dent 2021;39:106-9

How to cite this URL:
Petel R, Noy AF. Regenerative endodontic treatment of an immature permanent canine – A case report of a 13-year follow-up. J Indian Soc Pedod Prev Dent [serial online] 2021 [cited 2021 Aug 2];39:106-9. Available from: https://www.jisppd.com/text.asp?2021/39/1/106/314354

   Introduction Top

Since Iwaya et al.[1] first used the term “revascularization” in 2001, regenerative endodontic procedures have become a viable biological therapeutic approach to save or extend the life of necrotic, immature teeth, as well as to preserve the alveolar bone and maintain optimal function in the long term. The term “regenerative endodontics” was adopted by the American Association of Endodontists in 2007.[2]

Regenerative endodontic treatment (RET) is planned to replace damaged tissues, including dentine and root structures, as well as cells of the pulp–dentine complex. In cases of immature teeth with open apices and necrotic pulps, RETs promote root development and apical closure. The treatment does not include a mechanical preparation of the root canal walls but a thorough irrigation and introduction of antimicrobial agents into the canal.[2] The necrotic and infected pulp tissue is removed, leaving residual vital tissue remnants apically to promote revascularization. It is assumed that vital tissue may still be present in the most apical part of the canal when a large apical orifice exists in a very young tooth, even in the presence of necrotic and infected pulp tissue. Successful removal and disinfection of the necrotic and infected coronal pulp tissue still leave vital pulp cells with the potential to proliferate and regenerate tissue in the coronal pulp space.[2]

The use of a triple antibiotic mixture – ciprofloxacin, metronidazole, and minocycline – as a “three-mix” paste was developed by Hoshino et al.[3] The bactericidal efficacy of the drug combination is sufficiently potent to eradicate bacteria from the infected dentin of root canals, setting the conditions for subsequent revascularization. A blood clot derived from the periapical tissues containing stem cells from the apical papilla and growth factors released from platelets is expected to serve as a scaffold, permitting the growth of new tissue into the pulp space.[4],[5]

According to the recommendations of Duggal et al.,[6] published in a systematic review in 2017, clinicians should consider using the RET in cases where the root development is very incomplete with insufficient amount of dentine, and where it is considered that the tooth has a hopeless prognosis even with application of mineral trioxide aggregate (MTA). In these cases, it would be advantageous to gain some deposition of hard tissues through a regenerative approach. However, this is based on weak evidence.

The present report describes the procedures and the outcome of a RET approach of an immature permanent canine and a follow-up of 13 years after treatment.

   Case Report Top

A 12.5-year-old healthy boy of Ethiopian origin had his first ever dental check-up at a public dental clinic (Dental Volunteers for Israel) without any complaint. The patient had no complaint and was asymptomatic. The permanent mandibular left canine exhibited a lingual cavity and hypoplasia of the lingual and buccal surfaces, and the tooth was slightly mobile. Radiographic examination revealed incomplete root development and periradicular radiolucency [Figure 1]. The tooth was diagnosed with pulp necrosis and chronic apical periodontitis, and the root was less than a half of its complete length.
Figure 1: Radiographic image showing an incompletely developed apex of the canine and periapical radiolucency

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At first appointment, after isolation with a rubber dam, an access cavity was prepared. Root canal length was estimated using endodontic K-file. A 20G needle was placed to within 3 mm of the apex, and the canal was slowly and gently irrigated three times: First with 10 ml of 2.5% NaOCl, then with 5 ml of sterile saline, and then with 10 ml of 2% chlorhexidine gluconate. The canal was then dried with paper points, and a mixture of 250 mg ciprofloxacin, 250 mg metronidazole, 250 mg minocycline, and sterile saline, in a creamy consistency (as described by Hoshino et al.[3]), was introduced into the root canal using a spiral lentulo (Lentulo Spiral Fillers, Dentsply Maillefer, Birmingham). The access cavity was sealed using intermediate restorative material (IRM; Caulk Dentsply, Milford, DE).

At second appointment, 3 weeks later, the access was re-opened and the canal was irrigated twice: with 10 ml of 2.5% NaOCl and with 5 ml of sterile saline. The canal was then dried using paper points. An endodontic explorer was introduced into the canal up to the apex, and with a gentle scraping, the apical vital tissue was irritated creating bleeding into the canal. Presence of the blood clot was confirmed visually. Gray MTA (Dentsply Tulsa Dental, Tulsa, OK) was carefully placed over the blood clot, followed by a wet cotton pellet and IRM.

At the third appointment, 2 weeks later, a gray discoloration was demonstrated. MTA was found hard and the IRM and cotton pellet were replaced with a bonded resin restoration.

Follow-up appointments

At a 6-month recall appointment, the patient was asymptomatic, with no tooth mobility and no tenderness to percussion, yet apical radiolucency was still apparent on the radiograph [Figure 2]. 16 months [Figure 3] and then 2 and 4 years of follow-ups confirmed that the patient was clinically asymptomatic and radiographically stable, although without evidence of continued root development. At 13 years of follow-up, the tooth was still sound and stable, without evidence of continued root development [Figure 4]. The patient, for the first time, asked about an esthetic solution due to the gray discoloration [Figure 5]. A veneer composite (Esthet X HD, Dentsply Caulk, Milford, USA) was made after a preparation of the buccal surface of the tooth and application of a dense layer of Vitrebond® (3M™ ESPE™, St. Paul, MN, USA) as an opaquer [Figure 6].
Figure 2: Radiographic image at 6-month recall appointment, apical radiolucency was still apparent

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Figure 3: Radiographic image 16 months after treatment with complete resolution of the apical radiolucency

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Figure 4: Photograph of tooth #33 presenting discoloration after 13 years

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Figure 5: Radiographic image at 13 years of follow-up, no signs of periapical radiolucency but with no continued root development

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Figure 6: Photograph of tooth #33 immediately after the veneer treatment

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   Discussion Top

Several case reports and clinical studies have been published describing regenerative endodontic procedures applied to cases with necrotic immature permanent teeth.[4],[5],[6],[7],[8],[9],[10],[11],[12],[13] The outcomes vary from radiographic resolution of periradicular radiolucencies, narrowing of the wide apical opening, thickening of apical and lateral dentinal walls, and increased root length to complete resolution of clinical signs and symptoms.[4],[5],[6],[7],[8],[9],[10],[11],[12],[13]

The patient in the present case matched Gracia-Godoy and Murray's[14] guidelines of using regenerative endodontic procedures for the treatment of permanent immature traumatized teeth, based on the presence of necrosis or infection, periodontal status, presence of periapical lesions, stage of root development, vitality status, patient age, and patient health status.

The regenerative endodontic procedure proposes the use of MTA to perform a tight seal, but the updated guidelines advise the use of other bioactive endodontic cements that incorporate calcium and silicate in their compositions. They share most of their characteristics with MTA but claim to have fewer drawbacks with regard to manipulation and esthetics.[15]

The main reason for tooth staining has been advocated to minocycline, a tetracycline derivate, present in the conventional triple antibiotic paste (metronidazole, ciprofloxacin, and minocycline).[16] Discoloration induced by minocycline normally occurs in the first 24 h after its use, promoting a bluish-gray staining, clinically perceivable.[17] Usually, this alteration is more evident in tooth crown and in the cervical third of the root.[18] Therefore, modifications to the original paste have been proposed, with the aim at avoiding discoloration, by the use of cefaclor, amoxicillin, and clindamycin instead of minocycline.[17] Nevertheless, some degree of discoloration has been still observed after the use these alternative medications. On the other hand, double antibiotic paste (metronidazole and ciprofloxacin) and Ca (OH)2 did not produce color alterations.[18]

Bakhtiar et al.[19] also sealed coronal dentinal tubules before treat root canal with triple antibiotic paste/cefaclor, however, as cervical sealing material Biodentine™ was used rather MTA. Discoloration occurred in all the four revascularized teeth.

In this case, the gray discoloration was solved by preparing the buccal surface of the tooth, an application of an opaque, and a restoration with a composite veneer.

Even after a follow-up period of 13 years in the present case, radiographs demonstrated complete resolution of the periapical large radiolucency and the tooth remained asymptomatic.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient (s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Iwaya SI, Ikawa M, Kubota M. Revascularization of an immature permanent tooth with apical periodontitis and sinus tract. Dent Traumatol 2001;17:185-7.  Back to cited text no. 1
Murray PE, Garcia-Godoy F, Hargreaves KM. Regenerative endodontics: A review of current status and a call for action. J Endod 2007;33:377-90.  Back to cited text no. 2
Hoshino E, Kurihara-Ando N, Sato I, Uematsu H, Sato M, Kota K, et al. In vitro antibacterial susceptibility of bacteria taken from infected root dentine to a mixture of ciprofloxacin, metronidazole and minocycline. Int Endod J 1996;29:125-30.  Back to cited text no. 3
Jung IY, Lee SJ, Hargreaves KM. Biologically based treatment of immature permanent teeth with pulpal necrosis: A case series. J Endod 2008;34:876-87.  Back to cited text no. 4
Banchs F, Trope M. Revascularization of immature permanent teeth with apical periodontitis: New treatment protocol? J Endod 2004;30:196-200.  Back to cited text no. 5
Duggal M, Tong HJ, Al-Ansary M, Twati W, Day PF, Nazzal H. Interventions for the endodontic management of non-vital traumatised immature permanent anterior teeth in children and adolescents: A systematic review of the evidence and guidelines of the European Academy of Paediatric Dentistry. Eur Arch Paediatr Dent 2017;18:139-51.  Back to cited text no. 6
Thibodeau B, Trope M. Pulp revascularization of a necrotic infected immature permanent tooth: Case report and review of the literature. Pediatr Dent 2007;29:47-50.  Back to cited text no. 7
Ding RY, Cheung GS, Chen J, Yin XZ, Wang QQ, Zhang CF. Pulp revascularization of immature teeth with apical periodontitis: A clinical study. J Endod 2009;35:745-9.  Back to cited text no. 8
Thibodeau B. Case report: Pulp revascularization of a necrotic, infected, immature, permanent tooth. Pediatr Dent 2009;31:145-8.  Back to cited text no. 9
Petrino JA, Boda KK, Shambarger S, Bowles WR, McClanahan SB. Challenges in regenerative endodontics: A case series. J Endod 2010;36:536-41.  Back to cited text no. 10
Nosrat A, Seifi A, Asgary S. Regenerative endodontic treatment (revascularization) for necrotic immature permanent molars: A review and report of two cases with a new biomaterial. J Endod 2011;37:562-7.  Back to cited text no. 11
Noy AF, Nuni E, Moskovitz M. Regenerative endodontic treatment of an immature permanent canine following infant oral mutilation. Pediatr Dent 2013;35:355-9.  Back to cited text no. 12
Lin J, Zeng Q, Wei X, Zhao W, Cui M, Gu J, et al. Regenerative endodontics versus apexification in immature permanent teeth with apical periodontitis: A prospective randomized controlled study. J Endod 2017;43:1821-7.  Back to cited text no. 13
Garcia-Godoy F, Murray PE. Recommendations for using regenerative endodontic procedures in permanent immature traumatized teeth. Dent Traumatol 2012;28:33-41.  Back to cited text no. 14
Staffoli S, Plotino G, Nunez Torrijos BG, Grande NM, Bossù M, Gambarini G, et al. Regenerative endodontic procedures using contemporary endodontic materials. Materials (Basel) 2019;12:908.  Back to cited text no. 15
Santos LG, Chisini LA, Springmann CG, Souza BD, Pappen FG, Demarco FF, et al. Alternative to avoid tooth discoloration after regenerative endodontic procedure: A systematic review. Braz Dent J 2018;29:409-18.  Back to cited text no. 16
Cho WC, Kim MS, Lee HS, Choi SC, Nam OH. Pulp revascularization of a severely malformed immature maxillary canine. J Oral Sci 2016;58:295-8.  Back to cited text no. 17
Akcay M, Arslan H, Yasa B, Kavrık F, Yasa E. Spectrophotometric analysis of crown discoloration induced by various antibiotic pastes used in revascularization. J Endod 2014;40:845-8.  Back to cited text no. 18
Bakhtiar H, Esmaeili S, Fakhr Tabatabayi S, Ellini MR, Nekoofar MH, Dummer PM. Second-generation platelet concentrate (platelet-rich fibrin) as a scaffold in regenerative endodontics: A case series. J Endod 2017;43:401-8.  Back to cited text no. 19


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]


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