Treatment of a large periradicular defect using guided tissue regeneration: A case report of 2 years follow-up and surgical re-entry.

Periradicular (PR) bone defects are common sequelae of chronic endodontic lesions. Sometimes, conventional root canal therapy is not adequate for complete resolution of the lesion. PR surgeries may be warranted in such selected cases. PR surgery provides a ready access for the removal of pathologic tissue from the periapical region, assisting in healing. Recently, the regeneration of the destroyed PR tissues has gained more attention rather than repair. In order to promote regeneration after apical surgery, the principle of guided tissue regeneration (GTR) has proved to be useful. This case presents the management of a large PR lesion in a 42-year-old male subject. The PR lesion associated with 21, 11 and 12 was treated using GTR membrane, fixated with titanium minipins. The case was followed up for 2 years radiographically, and a surgical re-entry confirmed the re-establishment of the lost labial plate. Thus, the principle of GTR may immensely improve the clinical outcome and prognosis of an endodontically involved tooth with a large PR defect.

INTRODUCTION

Periradicular (PR) surgery is an inevitable option after an unsuccessful conventional endodontic treatment when orthograde retreatment of root canals is not possible. PR surgery is indicated in cases where there is infection persisting on the apical areas of the tooth, radicular cyst, and foreign body reactions.[1] PR surgery involves the surgical debridement of periapical lesion, root end resection, root end cavity preparation to receive a filling material.[2] The practice of conventional PR surgery after surgical debridement of a large cystic lesion often resulted in healing by scar tissue formation. Histologically, this consisted of replacement of the periapical tissue with fibrous connective tissue.[3] The ideal outcome of the surgical procedure should be regeneration of the tissues. This can be achieved with the application of guided tissue regeneration (GTR) technique. GTR works on the concept of cell occlusion, by restriction of rapidly proliferating epithelial and gingival cells. This promotes the re-population of the surgical defect with periodontal ligament cells, which assists in the regeneration of tooth supporting tissues.[4] The principle of GTR can be successfully used, as an adjunctive technique in PR surgery.[567]

CASE REPORT

A 42-year-old male referred to the Faculty of Periodontics, Tatyasaheb Kore Dental College and Research Centre in June 2011. The patient presented with chronic history of gingival swelling in relation to maxillary right central incisor. The patient reported of this complaint since the past 3 years. The swelling subsided intermittently on intake of antibiotics and nonsteroidal anti-inflammatory drugs. On clinical examination, 11 appeared to be discolored, having undergone endodontic treatment, 5 years ago [Figure 1]. The patient reported no contributory medical history. The patient revealed a history of trauma to the maxillary anterior teeth, 5 years back. Further clinical examination revealed endodontic therapy with 21 and 12 also. Periodontal probing depth with 21, 11 and 12 was all within 3 mm. Occlusal radiograph revealed a large periapical radiolucency with relation to 21, 11 and 12 [Figure 2]. No mobility was observed with these teeth. The teeth adjacent to the endodontically treated teeth were responsive to electronic pulp tester. The lesion was diagnosed to be of endodontic origin with absence of periodontal component. Considering the large size of the lesion and evaluating the prognosis, an interdisciplinary approach consisting of endodontic surgery with periodontal regenerative procedure was decided. The patient was explained about the procedure and due consent obtained.

Figure 1

Preoperative view

Figure 2

Occlusal radiograph showing extent of periapical lesion

After securing local anesthesia in the maxillary anterior region, a sulcular incision was made extending from maxillary right premolar to left premolar, with two vertical incisions. A mucoperiosteal flap was elevated and the periapical area of maxillary anteriors was exposed. A fenestration type of defect was noticed in the periapical region of 11. This was further enlarged to gain complete access to the cystic lesion, which was eventually debrided. A large periapical defect (30 mm × 20 mm) with relation to the apices of 12, 11, 21 was noted [Figure 3]. Apicoectomy and the root end preparations of 12, 11, 21 were performed, under magnification. This was followed by retrofilling of mineral trioxide aggregate. The resultant cystic bony defect was decorticated at multiple sites with a sharp curette to stimulate bleeding. A collagen membrane was approximated to cover the large opening of the PR osseous defect. Membrane fixation kit (INTAKT®) was utilized to stabilize and secure the membrane in the desired place [Figure 4]. The collagen membrane was stretched over the defect opening and pinned with titanium tacks. The membrane covered well beyond the defect margins [Figure 5]. The flap was repositioned and sutured with 5-0 resorbable suture material [Figure 6]. The patient was prescribed amoxicillin 500 mg and diclofenac 50 mg thrice daily for 5 days. An intramuscular injection of dexamethasone 8 mg was also administered to control the postoperative edema. The patient was advised to refrain from mechanical plaque control measures for 2 weeks and prescribed 0.2% chlorhexidine digluconate mouthwash, as an aid for chemical plaque control. A histopathologic study of the cystic capsule was performed to confirm the provisional diagnosis of the periapical cyst. The patient was recalled periodically to note the healing. Long-term radiographic examination was also carried out. All the adjacent teeth were vital, and the gingival condition was healthy. The patient desired to have the titanium tacks removed. We considered this as an opportunity for surgical re-entry. The area of interest was exposed, and titanium tacks located. A complete resolution of the surgical defect was noticed, with the complete replacement of the lost labial cortical plate [Figures 7 and 8]. A 24 months postoperative occlusal radiograph prior to the removal of tacks revealed complete fill of the PR defect as indicated by increase in radiodensity [Figure 9].

Figure 3

Per-radicular defect with apicoectomy

Figure 4

Membrane fixation kit with titanium minipins

Figure 5

Collagen membrane fixated with titanium minipins

Figure 6

Sutures placed

Figure 7

Surgical re-entry 24 months postoperative

Figure 8

Surgical re-entry 24 months postoperative (minipins removed)

Figure 9

Occlusal radiograph 24 months postoperative

DISCUSSION

Periapical pathology may persist in spite of an immaculate endodontic treatment. In such cases, PR surgery may render as a vital therapeutic option to salvage the tooth.[8] Conventional endodontic treatment demonstrated a high-risk of failure, particularly in cases of large periapical lesions.[9] Periapical infection also contributes to the progression of marginal bone destruction in periodontitis subjects.[10] GTR technique successfully used in clinical periodontal practice may be applied as an adjunctive therapy in endodontic surgery. The described case report presents with a large PR lesion from endodontic origin, with no periodontal communication. In order to gain surgical access to the large cystic lesion, to facilitate its complete elimination, a loss of buccal cortical plate ensued. This PR lesion can be included in class I as per von Arx classification of membrane application in endodontic surgery.[11] The healing of PR defects with concomitant loss of buccal cortical plate is compromised, involving poor regeneration of periapical tissues.[12]

Decortication of the defect site induced bleeding into the defect. The rationale of bone decortication though controversial, seems to cause some beneficial effects such as stimulation of a “regional acceleratory phenomenon” and advance the process of angiogenesis accompanied by the recruitment of pluripotential cells in the defect site. The blood clot thus formed may provide a hoard of cytokines and growth factors, accelerating the healing process.[13]

A mere curettage of the defect site could have prompted fibrous tissue growth into the defect site. A barrier membrane was utilized to ward off epithelial cells and fibroblasts, facilitating repopulation of periodontal ligament cells.[14]

Considering the large size opening of the cystic defect, titanium minipins were used. Application of titanium minipins prevented the mobility and collapse of the membrane, thus facilitating space maintenance. The membrane may be stretched to cover the osseous defect like a tent. The minipins thus facilitated to achieve a secured seal allowing a crease-free transition to periosteum.[15]

Several authors have reported the successful resolution of periapical defects with a combined application of GTR and bone grafts[1617181920] or with GTR alone.[212223] Some have resorted to combined technique of GTR and Platelet rich plasma.[24]

The present case report describes a successful resolution of a large PR lesion of endodontic origin, accompanied with loss of labial cortical plate. A biopsy of lesion sent for histopathologic study revealed to be periapical cyst. This is particularly important since keratocyst may have chances of recurrence. In the present case, the authors have used only GTR technique without any bone graft material. Postoperatively 2 years radiographic examination of the defect site revealed augmented radiodensity. A surgical re-entry demonstrated complete re-establishment of the labial cortical plate. The outcome success may be attributed to the following factors:

Complete debridement of the PR defect

Decortication of the bony defect at multiple sites

Fixation of the GTR membrane with titanium minipins

Primary wound closure.

It is imperative to reiterate the PASS principle. PASS involves primary closure of surgical site (P), angiogenesis by providing adequate blood supply and the cell type necessary for regeneration (A), space creation and maintenance (S) and finally stability of the blood clot (S).[25]

However, the present case fails to confirm the histology of formed tissue. A histological study (not carried out in this case) of the tissue formed after re-entry may have revealed the histology of tissues formed. The membrane fixation kit system is an additional armamentarium required during the procedure. It may be difficult to engage the titanium tacks on the surface of tough cortical bone. A longer evaluation period in this case is warranted.

CONCLUSION

It can be concluded that efficacy of GTR procedures can be substantially improved by stabilization and fixation of membrane. A successful resolution of a large PR lesion, unresponsive to conventional endodontic therapy can be obtained with application of GTR. GTR accompanied by the accessory procedures may significantly improve the prognosis of teeth with PR lesion.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.