Socket-Shield Technique of Mandibular Anterior Teeth: A Case Report.

With the aim of achieving an optimal aesthetic result, implant dentistry has become a prosthetically driven procedure. Special care is being taken to focus on the details that would lead to this objective. These details may include imitating the natural teeth by harmonizing the structures around the placed implant. The prosthetic and/or surgical parts of the procedure should be performed to reach an optimal outcome. In order to minimize the resorption of hard and soft tissue, which exists around the newly extracted tooth-to create a natural emergence profile of implant born prosthesis-socket preservation procedures were introduced; however, in case of ridge deficiencies, hard and soft tissue augmentation procedures are indicated. In this article, we present a case report using a new approach in socket ridge preservation, which is the socket-shield technique (partial root retention).

INTRODUCTION

The socket-shield technique (SST) was first described by Hürzeler et al.[1] The procedure consists of leaving a root fragment when extracting the tooth, specifically the vestibular portion of the most coronal third of the root. It is widely known that following the extraction of a tooth a dimensional modification of the ridge is going to happen. This unavoidable and irreversible shrinkage is very unfavorable from the restorative point of view, especially in the aesthetic area. After 3 months, horizontal and vertical contractions of the alveolar volume occur and these changes affect both the soft and hard tissues.[2] The SST is aimed at making up for this loss of the vestibular volume “misleading” the bundle bone because the periodontal ligament remains attached to the dentine and cement of the root fragment. Various animal studies demonstrated that the loss of volume after extraction could be highly diminished when leaving a tooth fragment attached to the cortical bone in the vestibular part of the alveolus.[3] The SST is yet missing clinical long-term data to be recommended as a standard treatment.

CASE REPORT

A 46-year-old patient came to the Department of Periodontology (SRM Kattankulathur Dental College) complaining of mobility in her lower anterior teeth. On clinical examination, grade 3 mobility in relation to 31 and 42 was revealed [Figure 1].

Figure 1

Pre-op

SST was planned for this case. Under strict aseptic conditions, tooth 31, 42 was decoronated [Figure 2].

Figure 2

31 and 42 after dissection horizontally

The tooth was sectioned vertically using long tapered fissure diamond bur, and conservative extraction of the lingual root fragment was performed with luxators and forceps [Figures 3–5].

Figure 3

Vertically resected

Figure 5

Buccal tooth fragment

Bone graft with guided tissue regeneration (GTR) was placed to fill the bony defect in the debrided site and crisscross sutures placed [Figures 6 and 7].

Figure 6

Bone graft placed

Figure 7

Crisscross suture placed

After 4 months post-op satisfactory healing in that particular site was observed [Figure 8].

Figure 8

Four-month post-op showed satisfactory healing in the surgical site. Tooth fragment seen in relation to 31

DISCUSSION

SST meets the expectations of an ideal method of implant placement as it reduces invasiveness and reduces the requirements for various bone substituting materials. In this case report it was shown that SST preserves the buccal cortical plate, and healthy peri-implant tissue was observed. Though this technique is still in its infancy, but with such promising results, it will soon be incorporated as a routine procedure in ridge preservation.

In order to overcome the negative consequences of tooth extraction (i.e), bone loss associated with thin tissue biotype in which ridge resorption takes an apico-coronal and buuco-lingual direction, and a minimal ridge atrophy which occurs in association with thick biotype,[4] various treatment approaches such as graft materials and/or barrier membranes have been advocated and described in literature. However, a complete preservation and/or entire regeneration of the extraction socket has not been documented yet.[5]

Many studies were performed to evaluate the safety of remaining roots in alveolar bone and concluded that the roots would stay in the socket—unless infected or mobile because it might be felt that the roots may act as a mobile foreign body and become a nidus for infection or migration; furthermore, it could preserve the bone and soft tissue dimensions.[6]

Filippi et al.[7] concluded that decoronation (removal of crown and pulp, but preservation of the root substance) of ankylosed tooth is a simple and safe surgical procedure for preservation of alveolar bone prior to implant placement. It must be considered as a treatment option for teeth affected by replacement resorption if tooth transplantation is not feasible.

Plata et al.[8] performed a 12-week histologic evaluation of 12 vital submerged roots that were cut at 2 mm below the bone edge. They reported that eight of the roots had complete bone coverage on the cut surfaces, and all pulps were vitally retained.

Salama et al.[9] described the root submergence technique, and they concluded that not only it eliminates the risk of caries and periodontitis, but also the retention of a natural tooth root allows for maximum preservation of the surrounding alveolar bone and soft tissues.

However, a study was conducted in a Beagle dog where only the buccal part of the root and its supraperiosteal attachment were preserved and furthermore no primary closure was obtained in combination with immediate implant. Placement following application of enamel matrix derivate showed that retaining the buccal aspect of the root during implant placement does not appear to interfere with osseointegration and may be beneficial in preserving the buccal bone plate.[1] The major findings of the histological analysis in this study were that the internal aspect of the root was covered with new cementum and new periodontal attachment.

CONCLUSION

The SST has currently not enough clinical evidence for being recommended as a routine option. It seems that if the proper clinical requirements are met and the technical handling of the operator is appropriate, the SST could minimize the resorption of the buccal tissues after the tooth extraction. In selected cases, the immediate placement of implants with the SST seems to be a useful tool for the replacement of the teeth lost, especially in the aesthetic area.

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

Nil.

Conflicts of interest

There are no conflicts of interest.