Journal of Indian Society of Pedodontics and Preventive Dentistry
Journal of Indian Society of Pedodontics and Preventive Dentistry
                                                   Official journal of the Indian Society of Pedodontics and Preventive Dentistry                           
Year : 2022  |  Volume : 40  |  Issue : 1  |  Page : 94--97

A segmental root development as an unusual healing response to the revitalization of mandibular second premolar

Sadaf Tamanna, Aaliya Rehman, Rajendra Kumar Tewari, Surendra Kumar Mishra 
 Department of Conservative Dentistry and Endodontics, Dr. Z. A. Dental College, A.M.U., Aligarh, Uttar Pradesh, India

Correspondence Address:
Dr. Aaliya Rehman
Department of Conservative Dentistry and Endodontics, Dr. Z. A. Dental College, A.M.U., Aligarh - 202 002, Uttar Pradesh


A 15-year-old patient reported persistent pain in the left mandibular second premolar (#35) following a traumatic bite 3 months ago. Clinical examination revealed a fractured central cusp suggestive of dens evaginatus. Intraoral periapical radiograph revealed an immature permanent tooth with a periapical radiolucency. A diagnosis of pulp necrosis with symptomatic apical periodontitis was made. The tooth was treated according to the revised guidelines of regenerative endodontic procedure by the American Association of Endodontics. The follow-up evaluation revealed a complete resolution of periapical pathology. A detached radiopaque tissue was appreciated at the 12-month follow-up. It resembled a broken root tip at the 24-month follow-up. Both the main root body and disjointed root tip developed independently. A cone-beam computed tomography evaluation at the 36-month follow-up confirmed the segmented development of the apical root tip.

How to cite this article:
Tamanna S, Rehman A, Tewari RK, Mishra SK. A segmental root development as an unusual healing response to the revitalization of mandibular second premolar.J Indian Soc Pedod Prev Dent 2022;40:94-97

How to cite this URL:
Tamanna S, Rehman A, Tewari RK, Mishra SK. A segmental root development as an unusual healing response to the revitalization of mandibular second premolar. J Indian Soc Pedod Prev Dent [serial online] 2022 [cited 2022 Jun 29 ];40:94-97
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Full Text


Regenerative endodontic procedure (REP) is a promising biologically based technique for managing nonvital immature teeth.[1] It aims to regenerate the pulp-dentin complex and strengthen the immature tooth by allowing continued root maturation.[2],[3] The current clinical practice of cell-free REP relies on the delivery of endogenous stem cells and may not yield consistent predictable outcomes. Chen has reported five types of responses following REP:[4] type-1, increased canal wall thickness with continued maturation of root; Type-2, lack of significant root development with blunt apex; Type-3, root development without apical closure; Type-4, canal obliteration following calcification; Type-5, hard tissue barrier deposited between Mineral Trioxide Aggregate (MTA) plug and the apex. However, response other than the ones mentioned above has also been reported following REP.[5]

The present case describes an unusual development of a detached root tip following REP. Very little data is available on the incidence and etiology of a separate root tip growing independently. The possible etiological factors and preventive measures are discussed.

 Case Report

A 15-year old male patient presented with pain, following a traumatic dental injury, in the lower left back tooth region for 3 months. A fractured central cusp suggestive of dens evaginatus was seen on the left mandibular second premolar (#35). The tooth was tender to percussion. There was no mobility. Electric pulp test (Parkell, NY, U.S.A) and Cold test (Roeko, Coltene Whaledent Pvt. Ltd.) showed that tooth #35 was nonvital. The radiographs revealed an immature tooth #35 associated with periapical pathology (PAI score 4)[6] [Figure 1]. A diagnosis of symptomatic apical periodontitis with pulpal necrosis was made for tooth #35.{Figure 1}

The case presents an immature tooth; therefore, REP or apexification was the most appropriate treatment option. Although apexification facilitates apical closure, it neither promotes root development nor strengthens the tooth. Alternatively, REP enables root maturation and root strengthening but it is an evolving domain with continuous revision in clinical protocols. A randomized clinical trial reported comparable success rates of REP and apexification, but REP showed a statistically significant better outcome in terms of root thickening and root lengthening.[7] The associated benefits and risks of both the modality were explained to the parents. The parents opted for REP, and written informed consent was obtained. All the procedure was performed in accordance with the revised guidelines by AAE.[8]

Treatment procedure

Following administration of local anesthesia, tooth #35 was isolated with a rubber dam, the access cavity prepared, and the working length determined radiographically. The pulp canal space was disinfected by irrigating with 20 ml of 3% NaOCl followed by flushing with 20 ml of normal saline delivered at a rate of 5 ml/min with a 27 gauge single side-vented needle (S. S White Lakewood, New Jersey). The root canal space was then dried with paper points, calcium hydroxide intracanal medicament was placed, and the cavity temporarily sealed with Cavit for 2 weeks.

On the second visit, the patient was completely asymptomatic. The tooth was anesthetized with epinephrine free 2% lidocaine, isolated under rubber dam, and reaccessed. The root canal was copiously irrigated with 17% ethylenediaminetetraacetic acid for 5 min, and then dried with paper points. Bleeding was then initiated within the canal space by rotating a precurved size #25 K-File 2 mm beyond the apical foramen. The canal was filled with blood up to the middle third; 3–4 mm MTA was placed over the formed blood clot, and the cavity was sealed with glass-ionomer cement (3M, ESPE, Germany). The patient was recalled after 24 h and the access cavity was restored with composite (3M Filtek™ Supreme Ultra Universal).


Regular follow-up was conducted at 3, 6, 12, 18, 24, and 36 months. At the 3-month follow-up, tooth #35 was completely asymptomatic and functional. The periapical radiolucency had reduced from an initial PAI score of 4 to a PAI score of 3 [Figure 2]. At 12-month follow-up, the complete resolution of periapical pathology was appreciated (PAI score 1). A radiopaque object was seen on the periapical radiograph just below the root apex.{Figure 2}

At 24-month follow-up, pulp testing remained negative. The radiopaque object grew independently, and resembled a broken root tip, uniform in shape, and located just beneath the main root body. Apical closure of the main root body was appreciated on the periapical radiograph [Figure 3].{Figure 3}

At 36-month follow-up, pulp testing was negative. The patient was advised cone-beam computed tomography. Sections confirmed the presence of the detached root tip. The apex of tooth #35 was completely formed, and root lengthening and thickening were appreciated [Figure 4], [Figure 5], [Figure 6].{Figure 4}{Figure 5}{Figure 6}


Development of a detached root tip seen in the present case is a rarely documented response to REP treatment.[5],[9] The underlying mechanism of separate root formation is not well understood; nevertheless, the probable suggested causes are severe trauma, long-standing periapical pathology, excessive tooth mobility, and iatrogenic factors.

Hertwig's epithelial root sheath (HERS) and apical papilla play a pivotal role in the regulation of root development.[9] Severe trauma to an immature tooth may cause detachment of HERS from the root apex, and its apical displacement may lead to the formation of a separate root segment when a conducive environment prevails following REP.

Segmental root formation has also been reported following the apexification procedure.[8],[9] The external force application during apexification intervention can detach the HERS and apical papilla from the root end and is implicated in the segmented root development in these cases.[10]

The presence of long-standing periapical pathology has also been advocated as a cause for the separation of HERS.[11] Jiang and Liu reported three cases of separate root development in mandibular premolars with extensive periapical lesion and without a history of severe traumatic injury following treatment by REP. The authors postulated that periapical inflammation present for long duration may also cause the HERS and SCAP to separate from the root end and initiate the formation of an independent root segment in amenable conditions.[9]

Last, iatrogenic factors have also been implicated in causing separation of HERS and SCAP during induction of bleeding by rotational file movement beyond the apex.

The abovementioned factors may cause segmental root development when the separated HERS and apical papilla survive the adverse state of severe trauma or long-standing periapical infection and are presented with favorable conditions by REP treatment.[5]


This case report shows an uncommon response of segmented root development as a healing sequel of REP. Traumatic dental injury and induction of bleeding by rotational file movement could be the possible reasons for segmented root development in the present case report. There is a paucity of evidence of long-term follow-up records in the literature after REP. Comprehensive and long-term follow-up records are needed to ascertain the prevalence and cause of this rare healing response after the revitalization procedure.

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 initials 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.


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