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 Table of Contents  
Year : 2020  |  Volume : 15  |  Issue : 1  |  Page : 127-131

Root submergence: An insight for alveolar bone preservation

1 Department of Periodontics, Sharad Pawar Dental College & Hospital, Datta Meghe Institute of Medical Sciences (Deemed to be University), Sawangi (Meghe), Wardha, Maharashtra, India
2 Department of Prosthodontics, Sharad Pawar Dental College & Hospital, Datta Meghe Institute of Medical Sciences (Deemed to be University), Sawangi (Meghe), Wardha, Maharashtra, India
3 Endodontics, Sharad Pawar Dental College & Hospital, Datta Meghe Institute of Medical Sciences (Deemed to be University), Sawangi (Meghe), Wardha, Maharashtra, India

Date of Submission14-Dec-2019
Date of Decision10-Jan-2020
Date of Acceptance30-Jan-2020
Date of Web Publication13-Oct-2020

Correspondence Address:
Dr. Diksha R Agrawal
Department of Periodontics, Sharad Pawar Dental College, Sawangi (M), Wardha, Maharashtra
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jdmimsu.jdmimsu_221_19

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Ridge resorption results in loss of interdental papillae and creation of unesthetic black triangles. Root submergence technique instead maintains the natural attachment apparatus of the tooth in the pontic site, which in turn allows for complete preservation of the alveolar bone frame and assists in the creation of an esthetic result in adjacent multiple tooth replacement cases. This study reports a case of fractured nonvital tooth where root submergence procedure was carried out, which represents intact bone aiding in the esthetics and function of the prosthesis.

Keywords: Alveolar ridge, endodontically treated tooth, ridge resorption, root submergence

How to cite this article:
Agrawal DR, Jaiswal P, Dhadse PV, Chandak A, Gogiya R. Root submergence: An insight for alveolar bone preservation. J Datta Meghe Inst Med Sci Univ 2020;15:127-31

How to cite this URL:
Agrawal DR, Jaiswal P, Dhadse PV, Chandak A, Gogiya R. Root submergence: An insight for alveolar bone preservation. J Datta Meghe Inst Med Sci Univ [serial online] 2020 [cited 2020 Oct 31];15:127-31. Available from: http://www.journaldmims.com/text.asp?2020/15/1/127/297981

  Introduction Top

Alveolar bone resorption considered as a complex oral condition caused by multiple factors related to physical and physiologic laws. Atwood and Coy[1] concluded that the mean reduction of anterior maxillary ridge occurs up to 1 mm/year with regard to anterior mandibular ridge 0.4 mm/year. The fact assured that alveolar bone resorption is not reversible and continually followed by tooth extraction. The only predictable treatment option is preservation of alveolar bone for the maintenance of functionally healthy teeth. In 1961, Bjorn[2] published the first case report of root submergence. In the late 1960s, this technique was introduced for the preservation of residual ridge resorption in cases of complete denture patients. Immediately after extraction of tooth, the alveolar bone housing is completely occupied by the blood clot further followed with formation of granulation tissue in a period of 1 week.[3] In alveolar bone socket healing process, the migration of epithelial cells occurs over the granulation tissue that fills the said healing socket.[4] This occurs due to the presence of inflammatory tissue identified as connective tissue by the cells of epithelium which leads to cell migration above its surface. Some human histological investigations stated the presence of cancellous bone at the apical two-thirds of extraction socket for about 10 weeks and get almost completely filled with bone at around 15 weeks. Pronounced radiopacity seen within 38 days and radiopacity at 105 days near surrounding bone.[4]

Maintenance of edentulous alveolar ridge morphology in complete denture patients has invited a clinical and laboratory research for the utility of retained root fragments to prevent ridge resorption. This aspect of clinical procedure is called root submergence technique or root burial. Preservation of tooth root by Root submergence technique (RST) achieved more volume of adjoining tissue to be preserved as compared to socket preservation technique as it reduces the interdental papillary height and dimensions of the edentulous ridge. RST provides the innate attachment of the tooth at the pontic area that further allows alveolar bone preservation and helps in achieving esthetic outcomes in adjoining multiple tooth replacement scenarios.

The purpose of our article is to illustrate the concept of root submergence and review the available literature on this subject.

  Alveolar Ridge Preservation Methods Top

Augmentation of hard- and soft-tissue prior, during, or after the insertion of implant has found predictable outcomes, but they have certain limitations such as technique sensitivity, increased time duration, sound health of adjacent tissues, and financial constraints.

Immediate placement of implant was found to be an another option for reduction in bone structure loss at the site of extraction, but its success for outcome rate was prevented by the adjoining tissue biotype and thickness of buccal bone plate. Alveolar preservation reduces bone resorption rate but does not aim to preserve dimensions of edentulous ridge and papillary height.[5]

Partial extraction treatment can be considered as a potential therapeutic modality to prevent bone resorption when other treatment options get restrained by the reason of systemic diseases and patient's financial condition.

Howell[6] was the first to report the human clinical study of the endodontically managed submerged roots. The authors stated that this technique should be used for ridge height below the prosthesis. Tooth root should be 1 to2 mm below the bone level, and the root portion or roots are potentially covered completely with a gingival tissue noted as root submergence technique or root burial (Philip Delivanis 1980). The objective of this technique is to stimulate the formation of bone above the sectioned roots. It was then proposed in the late 1950s for maintenance of the alveolar ridge below the complete dentures and to conserve the natural attachment of tooth.

Selection of roots for submergence

  1. If there is presence of wide buccolingual or mesiodistal dimension of teeth, then it is contraindicated because it offers difficulty for complete flap coverage of tooth and also compromised primary intention healing
  2. Adequate thickness of buccal cortical plate should be present on the retained roots – considerable thickness of buccal cortical portion needed for the retention of roots. Mandibular incisor teeth and maxillary lateral incisor teeth are commonly used because of the presence of the lingual inclined roots which allow increased in the thickness of the labial cortical plate
  3. Roots must not have any undercuts because the prosthesis will not sit properly
  4. There should be a wide zone of attached gingiva.

Root submergence for development of pontic site in esthetic zone for fixed prosthesis

In cases of maxillary anterior region, atrophy of the edentulous alveolar ridge after the extraction of a hopeless tooth compromises the final esthetic appearance. The root submergence maintains the vertical scaffold of bone around the submerged root to achieve ideal soft-tissue support and esthetic outcomes. It helps in development of the interdental soft-tissue profile around the pontic.

  Clinical Procedure Top

Nonvital tooth procedure

The tooth is endodontically treated before decoronation. The said technique involves the removal of the crown of a tooth and allowing the root to remain in the alveolar bone. The root should be covered with a soft-tissue flap or left exposed to heal by the secondary intention of the soft tissue that appears to maintain the epithelial and connective tissue attachment and papillary form. The procedure of decoronation should be 2 mm apical to crestal bone with the help of straight fissure carbide bur under copious irrigation. Then, the teeth were horizontally sectioned and gutta-percha was burnished with a ballpoint burnisher, and residues of the tooth and gutta-percha were washed with saline.

Vital tooth procedure

In 1975, Guyer[7] reported two vital roots submerged in a human. After a period of 27 months, these teeth were evaluated to remain normal radiographically and clinically, and they maintained the alveolar ridge contour. A denture was placed over the roots. This case indeed was the first reported vital root submergence in humans. In vital submergence technique, the teeth which were indicated for root submergence are managed as atraumatically as possible. This procedure is performed by reflecting the full-thickness mucoperiosteal flap. The coronal aspect of the teeth selected for vital root submergence is reduced to 2 mm apical to the alveolar crest, and the root stump/s are irrigated using 0.9% saline irrigation. The irregularly/sharped end surface of the sectioned part and adjacent bony irregularities are smoothened and finished using a round bur using a straight handpiece. Using a bone file, the interdental bone is smoothened. The pulpal tissue in the root portion remains vital owing to the blood supply through the apical ramification and collateral occlusal circulation from the adjacent soft tissue. The merging of healthy pulpal tissues takes place with the covered connective tissue, followed by inevitable closure of the root canal by formation of osteodentin.

  Case Report Top

A 38-year-old female patient reported to the Department of Periodontology, SPDC Sawangi, with the chief complaint of poor esthetics due to broken tooth in the upper left front region of the jaw for 4 weeks. She had no significant medical history. Intraoral examination revealed root piece in relation with 21 [Figure 1] and [Figure 2], tenderness on percussion was negative with 21, prosthesis seen with 11 and 22 and along with attrition of lower anteriors. The patient was not willing for extraction with 21, so root submergence technique option was advised to the patient to which the patient agrees. On radiographic examination (intraoral periapical), root canal treatment was seen with 21, and it showed no periapical pathology where the patient was judged that root can be retained with intact crest level of bone to support the ideal contour of pontic [Figure 3]. Therefore, after prosthodontist consultation, the modified ridge lap pontic was planned as it maintains the esthetics and provides better cleansibility.
Figure 1: Preoperative clinical view

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Figure 2: Preoperative clinical view

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Figure 3: Preoperative radiograph

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Based on the patient's chief complaint and desire, a root submergence technique was planned in relation to maxillary left central incisor, followed by fixed prosthesis.


Scaling was done followed by oral hygiene instructions. Following Phase I therapy, the root submergence technique was performed. The patient preparation was done with proper extraoral asepsis with 2% povidone-iodine, followed by intraoral preprocedural 0.2% chlorhexidine rinses. Local anesthesia (2% lignocaine [1: 80000] with adrenaline) was administered. Crevicular incision was given with Bard-Parker blade no. 15. Labial and lingual mucoperiosteal flaps were raised for the advancement and mobility of the flap. The root in relation with 21 was reduced to 2 mm below the level of the alveolar crest using a high-speed handpiece with straight bur [Figure 4]. Free gingival graft (FGG) was harvested from the palatal donor site. A tinfoil template was used on the recipient site to ensure adequate graft size [Figure 5].[8],[9] FGG was used to increase the soft-tissue augmentation and promote primary healing [Figure 6]. After achieving hemostasis, an interrupted suture technique with 3-0 silk was performed for the placement of graft on the recipient site [Figure 7] and [Figure 8]. The patient was prescribed analgesics (Ibugesic [ibuprofen 400 mg] every 8 h) or when needed and instructed to rinse with 0.2% every 12 h for 14 days. Postoperative written instructions were given. Sutures were removed after 7 days. There was uneventful healing seen [Figure 9]. After that, crown preparation of adjacent teeth done for the fabrication of bridge along with modified ridge lap design allows for the contact of the pontic on the buccal aspect of the underlying ridge. The contact position on the ridge allows for better cleansibility with improved esthetic design. The crown in the region of submerged root exhibited a good emergence profile with better esthetic outcome [Figure 10], [Figure 11], [Figure 12], [Figure 13]. Treating a patient by fixed prosthodontics requires a combination of many aspects of dental treatment.[10]
Figure 4: Decoronation

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Figure 5: Tinfoil placement on donor site

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Figure 6: Free gingival graft

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Figure 7: Suture placed on donor site

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Figure 8: Suture placed on recipient site

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Figure 9: Healed site

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Figure 10: Metal try-in

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Figure 11: Definitive Prosthesis

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Figure 12: Prosthesis

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Figure 13: Postoperative radiograph

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  Discussion Top

The buccal plate of maxillary anterior teeth is most often very thin results in significant dimensional changes during the immediate postextraction period. Thus, reduced vertical ridge dimension and interdental bone lead to interdental papillary loss, and creation of black triangles results in unesthetic smile. If there is no periapical pathology seen in hopeless tooth, its root remnant can be submerged for the preservation of surrounding periodontal tissue are to prevent residual ridge resorption, preservation of bone and the connective tissue attachment, maintains height and width of papilla beyond the need for extensive bone and connective tissue grafting surgery.

However, vital root submergence further develop pulpal infection results in failure or can lead to various complications like root caries especially in cases if the roots are not covered completely then root resorption, ankylosis, periapical pathology, and soft-tissue perforations may occur when the technique is performed under overdentures because it may transfer pressure through the denture base to the soft tissues around the roots. Thus, endodontic-treated tooth being submerged is advised. Salama et al.[11],[12],[13] in their study given predictable results for esthetic implant treatment in multiple teeth through RST. Although this case report supports the success of the technique as this procedure has not been indicated routinely due to lack of long-term evidence. Knowledge about RST in detail and case selection properly is the main role for the success of this therapy.

  Conclusion Top

The undisturbed root present with the alveolar bone through periodontal ligament is the “perfect” implant, and also, it preserves the alveolar bone morphology. The RST was introduced for the preservation of the alveolar ridge. It prevents the downgrowth of epithelium during the periodontal regeneration. Recently, the concepts and techniques of osseointegration, periodontal plastic surgery, tissue regeneration, and esthetic restoration advanced our field.

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.

  References Top

Atwood DA, Coy WA. Clinical, cephalometric, and densitometric study of reduction of residual ridges. J Prosthet Dent 1971;26:280-95.  Back to cited text no. 1
Bjorn H. Experimental studies on reattachment. Dent Pract 1961;11:451-4.  Back to cited text no. 2
Amler MH. The time sequence of tissue regeneration in human extraction wounds. Oral Surg Oral Med Oral Pathol 1969;27:309-18.  Back to cited text no. 3
Mangos JG. The healing of extraction wounds: A microscopic and ridographic investigation. N Zeeland Dent J 1941;37:4-23.  Back to cited text no. 4
Nevins M, Camelo M, De Paoli S, Friedland B, Schenk RK, Parma-Benfenati S, et al. A study of the fate of the buccal wall of extraction sockets of teeth with prominent roots. Int J Periodont Restorative Dent 2006;26:19-29.  Back to cited text no. 5
Howell F. Retention of Alveolar Bone by Endodontic Root Treatment. Seminario Anual de1 Grupo de Estudios Dentales U.S.C. de Mexico; 23 May, 1970.  Back to cited text no. 6
Guyer SE. Selectively retained vital roots for partial support of overdentures: A patient report. J Prosthet Dent 1975;33:258-63.  Back to cited text no. 7
Pakhare VV, Bajaj P, Bhongade ML, Shilpa BS. Gingival depigmentation by free gingival autograft: A case series. Dent Update 2017;44:158-62.  Back to cited text no. 8
Suryavanshi PP, Dhadse PV, Bhongade ML. Comparative evaluation of effectiveness of surgical blade, electrosurgery, free gingival graft, and diode laser for the management of gingival hyperpigmentation. J Datta Meghe Instit Med Sci Univer 2017;12:133.  Back to cited text no. 9
Jadhav VD, Motwani BK, Shinde J, Adhapure P. Comparative evaluation of conventional and accelerated castings on marginal fit and surface roughness. Contemp Clin Dent 2017;8:405-10.  Back to cited text no. 10
[PUBMED]  [Full text]  
Salama M, Ishikawa T, Salama H, Funato A, Garber D. Advantages of the root submergence technique for pontic site development in esthetic implant therapy. Int J Periodontics Restorative Dent 2007;27:521-7.  Back to cited text no. 11
Jain A. Accidental Displacement of Mandibular First Molar Root into Buccal Space: A Unique Case. J Stomatol Oral Maxillofac Surg 2018; 119:429-31. Available from: https://doi.org/10.1016/j.jormas.2018.04.004. [Last acessed on 2019 Nov 10].  Back to cited text no. 12
Shilpa B, Vasudevan S, Bhongade M, Baliga V, Pakhare V, Dhadse P. Evaluation of Survival of 8 Mm-Length Implants in Posterior Resorbed Ridges: A Pilot Study. J Indian Soc Periodontol 2018;22:334-39. Available from: https://doi.org/10.4103/jisp.jisp_368_17. [Last acessed on 2019 Nov 10].  Back to cited text no. 13


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8], [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13]


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