Intentional Replantation: an Approach to Save Hopeless Natural Teeth (A Case Report)

Post-treatment apical periodontitis, which is persistent intraradicular infection, and in some cases a secondary intraradicular infection due to coronal leakage or an extraradicular infection is a challenging issue for endodontists.

Existence of microorganisms in the root canal system or the periradicular tissue is the primary reason of endodontic disease, although other etiologies, such as foreign bodies, cysts and cholesterol crystals, have also been indicated (1). It can be managed by  either nonsurgical endodontic retreatment or apical surgery with varying success rates (2). However, in some cases due to complex anatomy of the canals or presence of post-core and crown restoration, nonsurgical retreatment of the tooth is not possible. Moreover, surgical treatment is also impossible for the following reasons:

• Difficulty with surgical access, due to the position of the teeth and inadequacy of lips and soft tissues retraction.
• A lingually inclination of the tooth  that needs a large amount of bone removal; a median average of bone covering the roots is7.34 – 8.51mm (3).
• Structures Proximity: Mandibular teeth roots may have spatial relationship with mental foramen or impinge the Inferior Alveolar Nerve (IAN) as a microsurgical intervention may induce a partial or permanent paresthesia. The roots of maxillary molars especially second molar are often in the maxillary antrum. Surgical operation can push debris into the sinus and cause post-operative disease (4)
• Patient limitation:  the patient who are physically unable to sit on dental chair; physically handicaps, medically compromised or patient with limited opening of the mouth or trismus muscles or patient with anxiety disorders are not good candidate for endodontic surgery.
• Sometimes defective areas are not accessible through surgical repair (4).

Intentional Replantation (IR) has been considered as a further procedure to eliminate post- endodontic root canal infection in selected cases. It has been proposed as the last resort for the teeth that needs to be extracted. It is one of the oldest methods introduced for the treatment of endodontic infection, and described by Albulcasis  in11th century (5).  The reported success rates has been in a wide range, however  recent studies have shown higher predictable success at a rate of 88% to 95% (6).  According to these findings, intentional replantation should now be considered as a more acceptable treatment option. Intentional replantation is defined as the purposeful extraction of the tooth, root surfaces evaluation, endodontic interventions and correction and place back the tooth to its socket . In more recent years numerous indications as well as, the evolution of the procedure, has introduced including techniques modification around tooth extraction, preparation and root-end resection, manipulation of the tooth during surgical procedure and root-end filling materials. It has been used for many purpose in recent years such as management of endodontic mishaps, correction of anatomical anomalies, treatment of external root resorption and correction of  root perforation(7-12).

This study describes a case with a complaint of pain in an endodontically treated mandibular second molar that seemed hopeless regarding retreatment and apical surgery.

Case report

A 35-year-old female patient was referred to private office with a complaint of pain in her mandibular right molar when chewing. After examination the tooth ≠47 was found tender to percussion. There was no tenderness when touching and no swelling of soft tissue was observed. Examination of the periodontal tissues of the decayed tooth No. 46 did not provoke the patient's chief complaint. Further examination showed no sign or symptoms in adjacent or opposite teeth.  History revealed that the patient has received root canal treatment for this tooth last year and further clinical and radiographic examination showed the tooth underwent root canal therapy with amalgam post and crown restoration.  Distal root showed signs of asymptomatic apical periodontitis. (Figure 1a)

All different treatment options were explained to the patient including endodontic retreatment, implant therapy, periradicular surgery, tooth extraction and intentional replantation. Endodontic retreatment and implant placement were refused by the patient. Surgical endodontics was contraindicated as bone thickness and proximity to the IAN canal.

 The risks and benefits of all alternative options were completely explained to the patient and an informed consent form was taken. The clinical procedure for IR was as follows:  Prior to the procedure 2% Chlorhexidine (CHX) mouth wash was carried out to decrease the oral microflora. After achievement complete local anesthesia, using a suitable forceps the tooth was gently extracted then was carefully inspected extra-orally. Granulation tissues and other irritants were removed from the root surfaces using periodontal curettes. The sample was sent for histopathologic evaluation, which implied the diagnosis of periapical granuloma. The crown of the tooth was held in hand by a wet gauze, The tooth was carefully examined by loupe and light, and no evidence of a furcal perforation, crack or root fracture was observed. Root resection was done using high speed handpiece, and then 2-3 mm of root-end was resected using a diamond bur (size≠2) and coolant spray. Root-end cavities were shaped with a low-speed round  carbide bur (size ≠2) (Dentsply/Maillefer) to 2- 3 mm depth and Biodentine (Septodont, Saint Maur des Faussés, France) retrograde filling was placed in prepared cavities.

The whole process of root-end preparation and filling took about 5 minutes. The socket was carefully checked for the removal of remnant granulation tissues. Then the tooth was gently replanted followed by gentle pressure on the buccal and lingual plates. The patient bit the gauze gently afterwards in order to help stabilizing the tooth. Periapical radiograph showed the accurate repositioning. Stabilization of the tooth with splints did not require because the roots were somewhat parallel. Antibiotics (oral Amoxicillin, 500 mg) and an anti-inflammatory drug (Ibuprofen, 200 mg) were prescribed for 3 days (3 times per day) postoperatively. The patient recommended eating soft food and rinsing her mouth with CHX and doing regular oral hygiene. The patient was asked for a recall after 7 days, 6 months, and thereafter for each year.

After 6 months the replanted tooth was firmed in its socket and the patient was asymptomatic and the tooth was functional. Radiographic examination showed a decrease in apical radiolucency which indicates progressing healing and bone formation and no evidence of resorption was noticed on the periapical radiograph (figure 1 b). After 5 years the tooth was asymptomatic and functional (figure 1c).

Figure 1:  (a) Periapical radiograph revealed apical radiolucency. (b) A 6-month postoperative view and (c)5 years follow-up.