Root Growth and Revascularization in an Immature Necrotic Permanent Tooth: A Case Report

Root Growth and Revascularization in an Immature Necrotic Permanent Tooth: A Case Report
Ebtissam M. Ali-Madi*

Assistant Professor, Department of Restorative Dental Sciences, College of Dentistry, King Saud university, Riyadh , Saudi Arabia.
Correspondence: “Dr.Ebtissam M.A-Madi” m

How to CITE:

J Pak Dent Assoc 2010;19(3): 184 – 187


Successful continued growth of infected pulpless immature roots may occur with normal procedure of CaOH placement and minimal disinfection. This case report demonstrates the evidence of continued root growth by the process of revascularization after going through a period of Ca(OH)2 apexification.


Root growth, Revascularization, Necrosed Pulp, Ca(OH)2


When the pulp undergoes necrosis before root growth is complete, dentin formation ceases and root growth is arrested. In most cases, the canal remains wide, the apex open, the root may also be shorter, and the walls of the canal are thinner than those of a mature root 1.

Treatment of necrotic teeth with immature root has traditionally been treated by calcium hydroxide apexification 2. Apexification is a method of inducing apical closure through the formation of mineralized tissue in the apical region of a non-vital tooth with an incompletely formed root and an open apex (3). This technique has been extensively studied and has proven to have a very high success rate (2, 4, 5, 6). Another approach is to use MTA (Mineral trioxide aggregate) to create an immediate hard tissue barrier after disinfection of the root canal (7,8). A newer approach to treatment of non-vital pulps is pulp revascularization, which has traditionally been considered only after avulsion of immature permanent teeth (9). Very few cases have been reported wherein regeneration has occurred in the case of infected non-vital immature teeth (10)

The aim of this case report was to demonstrate that apexification (complete removal of necrotic pulp and placement of CaOH), and revascularization of the root canal is a viable clinical solution

Case Report

A healthy 10-year-old Saudi male was referred by the intern’s clinic of the college of dentistry at King Saud University, Riyadh, Kingdom of Saudi Arabia, to the endodontic specialist clinic.

The patient chief complaint was pain related to the upper left second premolar (#25), with a history of previous dental treatment. Review of the patient’s record revealed that the patient was initially seen 10 months earlier in the general clinics (Fig1), where initial examination and pulp testing was carried out. Caries excavation, access, pulp extirpation, irrigation with saline, drying of the canal, calcium hydroxide placement and temporization with cavit (3M ESPE AG, Seefeld, Germany) was performed. The patient returned seven months later, complaining of a fallen restoration and upon examination there was an exposed canal of #25. The root canal was cleaned and refilled with calcium hydroxide and referred to the endodontic specialist clinic

Fig 1. Initial Radiograph- Preoperatively

The patient appeared at the endodontic clinics 3 months after the refill of the canal with Ca(OH)2. Clinical examination revealed that the tooth was tender to percussion with an intact temporary restoration. Standard procedures dictated that pulpal testing must be done, which revealed no response to cold or electric stimuli. A diagnostic periapical radiograph showed a calcified barrier at mid-root with an underdeveloped root and wide-open apex with no periapical (PA) radiolucency (Fig.2). The diagnosis was determined to be necrotic pulp with normal PA structure. Treatment plan was to evaluate midroot barrier and attempt completion of RCT

Fig 2. Calcific barrier at mid-root with an underdev eloped root and wide-open apex with no PA radio lucency after 10 months of initial CaOH placement

After the administration of buccal infiltration local anesthesia (1 carpule of 2% Lidocaine with 1:80,000 epinephrine), the tooth was isolated with a rubber dam. The temporary restoration was removed with a #3 high speed round carbide bur (Midwest Dental Product Corp., Des Plaines IL, USA under copious irrigation

Fig 3. Obturation

The access cavity was refined and the canal was negotiated. A paper point was used to probe the canal, and once a sturdy barrier was found, verification was followed with a size #25 k-file (L.D. Caulk Division, Dentsply International, Inc., Milford, DE, USA). A definite solid barrier was found at mid-root, and the maximum length that could be reached was 14.5mm. The canal was necrotic with a great amount of debris. The canal was cleaned to the barrier and irrigated with NaOCL (2.5%). The canal was obturated with Obtura system (Obtura, Obtura Co., USA), and the tooth was restored with Ketac-Fil (3M ESPE, Seefeld, Germany) (Fig3). The patient was referred to the restorative specialist clinic for a final restoration.

Fig 4. Continued growth and regeneration of root after 14 months

A clinical and radiographic check up on the same tooth was carried out after 9 months and after 14 months by the same operator (Fig 4). The radiograph showed evidence of healing and closure of the apex. The root walls were thick and the development of the root below the restoration was similar to the adjacent and contra-lateral teeth


Endodontic treatment and management of immature permanent teeth with a blunderbuss apex is often complicated. According to the level of the development of the tooth, the canal walls may be divergent, and the apices immature, making the cleaning, shaping and consequently the obturation of the canals difficult (11). The treatment of necrotic teeth with immature root development has traditionally been by CaOH2 apexification technique. This has been extensively studied and has proven to have a very high success rate (2, 3, 12). A calcific barrier is formed at the apex of the tooth. Cvek (13) reported an average barrier formation time of 18.2 months, however shorter average barrier formation times of <12 months have been reported in more recent reports (14, 15, 16). There was a tendency for earlier detection in cases with more frequent CaOH changes (14). On the other hand it has been postulated that if CaOH is not replaced often enough, its dissolution from the apical area will create a void thus allowing in-growth of tissue and increasing the likelihood that the barrier is formed coronal to the apex (16). Others have found that for at least 6 months after initial root filling with CaOH there is nothing to be gained by repeated root filling either monthly or after 3 months (17). Recently a Mineral Trioxide Aggregate (MTA) apical barrier technique has steadily gained popularity with clinicians, as it allows an immediate hard tissue barrier after disinfection of the root canal, although long-term comparative outcome studies to that of the traditional CaOH2 technique are not available (8,9). Both techniques have many disadvantages; prolonged treatment time for barrier to form in the CaOH technique (6-18 months). In addition, the roots of teeth treated with both apexification methods are thin and have a significant risk of subsequent fracture. This also complicates obturation, as there should be no pressure applied to these thin fragile roots during condensation. In this case; a thermoplastisized obturation method that did not place any pressure on the walls and produced a homogenous mass of gutta percha was used for that reason (Obtura system, Obtura Co., USA). Although arguably a better approach might be to use a material that adhered to the canal walls, rather than adapt to it.

A more contemporary yet conservative approach to treatment of immature roots is pulpal revascularization. Reservation of remaining vital pulp tissue may provide hope for a better outcome, through further root development, thus reinforcing the dentinal walls and strengthening the root against fracture ( 1 , 11 ) . Revascularization of the pulp in necrotic canals has been thought to be impossible (18). Control of root canal infection may be a difficult issue as the duration of the infection, involved microbial species, host immunity, and size of the open apex may theoretically play a role in the outcome of this conservative treatment approach (19). Therefore many cases in which successful regeneration of root could have been possible weren’t attempted, and tooth extraction was deemed necessary. However, as vascular supply is a critical requirement for maintaining vitality of any tissue (20), patient age must play a role in this decision. In our case, the young age of the patient was a positive factor influencing our decision to treat the case. However a new disinfection protocol has been established for revascularization attempts. This is a tri-antibiotic mix of Ciproflaxacin (200mg), metronidaxole (500mg), and minocycine (100mg) in a saline or glycerin vehicle (21, 22, 23). In addition, it is thought that partial resection of the pulp would help build a synthetic scaffold to increase possibility of re-growth (1), while others (24) showed conditions in which it was not necessary to evoke intracanal bleeding to have continued root development. In the present study, successful regeneration of the pulp after pulp removal in an immature tooth was achieved even in the case of repeated pulp infection. The previous attempt at pulpectomy could have been inadvertently incomplete, thereby possibly creating a hemorrhage (that formed a blood clot in the pulp space serving as a scaffold and growth factor source for the generation of new tissue). Minimal mechanical instrumentation was also possible due to the time limitation in the ER clinic- thus performing minimum mechanical instrumentation of the root canal (retaining surviving tissue in the root canal, especially near the apex so that apexogenesis or maturogenesis of the root can occur). In addition, neither a tri-antibiotic paste nor a blood clot provoked to induce scaffold for the new tissue. Rather normal irrigation and disinfection procedures and available material (CaOH2) may be adequate to stimulate revascularization. This is in contrast with the results reported by Nygaard-Østby and Hjortdal (18) who were unsuccessful in the case of infection in the pulp space. However, Andreason (12) suggested that root formation could continue even in the presences of pulpal inflammation and necrosis due to the vascularity and cellularity of the apical region of the tooth.

Whether this is a case of revascularization and the tissue in the pulp space is more similar to periodontal ligament than pulp tissue (25), or whether this is a case of regeneration of pulp tissue is debatable unless histologically proven. The achievement of apical barrier has been established, however a longer follow up needs to be scheduled to show complete apical closure & lateral root growth development. Further investigation and histological studies are needed to evaluate re-growth potential of roots and the level of disinfection needed or required. Revascularization has been deemed a term to describe a new type of treatment process. This case proves the potential of root revascularization and regrowth, thereby drawing the attention to clinicians of this possibility, emphasizing this attempt with more rigorous protocol. The value of this case report is the demonstration of what is possible and to add to the growing number of case reports to provide insights to the roles of different factors that come into play in pulpal revascularization and/or regeneration


Continued growth of root canal sthrough revascularization may be possible in infected immature roots with Ca(OH)2 placement. This growth is evidenced radiographically by continuing thickness of dentinal walls, apical closure and further development of root length


1. Trope M. Treatment of immature teeth with non-vital pulps and apical periodontitis. Endodontic topics 2006:14;51-59

2. Kerekes K, Heide S, Jacobsen I. Follow-up examination of endodontic treatment in traumatized juvenile incisors. J Endod 1980:6;744-748
3. Frank AL. Therapy for the divergent pulpless tooth by continued apical formation. J Am Dent Assoc 1966:72;87-92
4. Sheehy EC, Roberts GJ. Use of Calcium hydroxide for apical barrier formation and healing in non-vital immature permanent teeth: a review. British Dental Journal 1997;183:241-246
5. Reyes DA, Muñoz ML, Martín AT. Study of calcium hydroxide apexification in 26 young permanent incisors. Dent Traumatol 2005;21:141-145
6. Çalişkan MK, Türkün M. Periapical repair and apical closure of a pulpless tooth using calcium hydroxide. Oral Surgery Oral Medicine Oral Pathology 1997; 84:683-687
7. Morse DR, O’Larnie J, Yesilsoy C. Apexification: review of the literature. Quintessence Int 1990;21:589-598
8. Giuliani V, Baccetti T, Pace R, Pagavino G. The use of MTA in teeth with necrotic pulps and open apices. Dent Traumatol 2002; 18:217-221
9. Maroto M, Barberia E, Planells P, Vera V. Treatment of a non-vital immature incisor with mineral trioxide aggregate (MTA). Dent Traumatol 2003:19;165-169
10. Skoglund A, Tronstad L, Wallenius K. A micro-radiographic study of vascular changes in replanted and autotransplanted teeth in young dogs. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1978:45;17-28
11. Banches F, Trope M. Revascularization of immature permanent teeth with apical periodontitis: new treatment protocol? J Endod 2004:30;196-200
12. Andreason JO, Hjorting- Hansen R. Intra-alveolar root fractures: radiographic and histologic study of 50 cases. J Oral Surg 1967;25:414-26
13. Cvek M, Nord CE, Hollender L. Antimicrobial effect of root

canal debridgement in teeth with immature roots. A

clinical and microbiologic study. Odontological review 1976;27:1-10

14. Finucane D, Kinirons MJ. Non-vital immature permanent incisors: factors that may influence treatment outcome. Endod Dent Traumatol 1999;15:273-277
15. Mackie IC, Bentley EM, Worthington HV. The closure of open apices in non-vital immature incisor teeth. British Dental Journal 1988;165:169-173
16. Yates JA. Barrier formation time in non-vital teeth with open apices. International Endodontic Journal 1988; 21:313-319

17. Chosack A, Sela J, Cleaton-Jones P. A histological and quantitative histomorphometric study of apexification of non-vital permanent incisors of vervet monkeys after repeated root filling with a calcium hydroxide paste. Endod & Dent Traumatol 1997; 13: 211-217
18. Nygaaard-Østby B, Hjortdal O. Tissue formation in the root canal following pulp removal. Scand J Dent Res 1971:79;333-348
19. Cheuh LH, Huang GTJ. Immature teeth with periradicular periodontitis or abscess undergoing apexogenesis: A paradigm shift. J Endod 2006;32:1205-1213

20. Huang GTJ, Lin LM. To the editor. J endod 2008; 34: 511

21. Sato T, Hoshino E, Uematsu H, Noda T. In vitro antimicrobial susceptibility to combination of drugs on bacteria from carious and endodontic lesions of human deciduous teeth. Oral Microbiol Immunol 1993; 8: 172-176

22. Hoshino E, Kurihara- Ando N, Sato I, Uematsu H, Sato M, Kota K, Iwaku M. In vitro antimicrobial susceptibility of bacteria taken from infected root dentine to a mixture of ciprofloxacin, metronidazole and minocycline. Int Endod J 1996; 29:125-130

23. Windley W III, Teixeira F, Levin L, Sigurdsson A, Trope M. Disinfection of immature teeth with a triple antibiotic past. J Endod 2005; 31: 439-443
24. Jung IY, Lee SJ, Hargreaves KM. Biologically based treatment of immature permanent teeth with pulpal necrosis: A case series. J Endod 2008;34:876-887
25. Thibodeau B, Teixeria F, Yamauchi M, Caplan DJ, Trope M. Pulp revascularization of immature dog teeth with apical periodontitis. J Endod 2007; 33:680-689