Managing intentional replantation of teeth during the SARS-CoV-2 pandemic

The acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic is an unprecedented global health crisis. Due to the high mutational ability of spike proteins, SARS-CoV-2 can emerge as a novel type resistant to vaccines and a concern for global health. In this regard, using povidone-iodine (PVP-I) has a high potential to reduce the viral load of SARS-CoV-2. For instance, it is recommended to use PVP-I as mouthwash (gargling with 1% PVP-I for 30 s) and nasal spray (0.5% PVP-I of 0.3 ml in each nostril) before dental procedures during the pandemic. In addition, intentional replantation (IR) is a reliable and predictable treatment option to preserve teeth when orthograde or apical microsurgery treatments are unfeasible.^1,2 This brief letter focuses on the IR of teeth in dentistry.

In IR, a tooth is intentionally extracted and replaced in the tooth socket after proper endodontic or apical surgery treatment. In this regard, Wu and Chen evaluated the success rate of 215 teeth (from 199 patients) that received IR. The follow-up time was between 6 and 120 months. The results showed that the success rate of replantation was 82.8%. The success rate in acute or chronic apical abscesses was 2.7 times lower than in other dental diagnoses. To prevent wound infection, amoxicillin 500 mg and diclofenac 25 mg every 8 hours for 5 days were prescribed for patients. Tissue regeneration material (e.g., Emdogain) on the root surface improved the regeneration of periodontal tissues. Also, applying Emdogain is recommended to increase the treatment outcome.³

To assess IR in a variety of teeth, a systematic review evaluated the IR of single and multi-rooted teeth based on 60 studies. A total of 106 replanted teeth, including 56 single- and 50 multi-rooted teeth, were included in the study. The major outcomes of this study were as follows: 1) there was no significant difference in the survival rate of replanted teeth between single- and multi-rooted teeth, 2) the average extra-oral time for replanting teeth was 13.34 min, and 3) the success rate of IR was 86.7% among 92 teeth. Therefore, IR can be considered a safe treatment to preserve teeth, providing that it is executed correctly and in compliance with the basic biological principles, particularly with regard to the time of the extra-oral environment.⁴

Another systematic review based on meta-analysis evaluated the IR of root canal treated teeth with apical periodontitis. To this end, 13 studies were included in the final review. The study reported that the mean long-term success and survival rates of IR teeth were satisfactory. Besides, the study highlighted the following factors to enhance the outcome of IR: 1) atraumatic extraction (e.g., preferably using forceps), 2) <15 min time for tooth replantation to survive periodontal ligament cells, 3) 2–3 mm root resection, 4) preparing 3 mm retrograde root canal (e.g., piezoelectric system), 5) root-end filling material (e.g., MTA), and 6) using appropriate storage media for the survival of periodontal ligament cells. Hence, IR of teeth with periapical pathosis is a viable treatment possibility with an acceptable survival rate.⁵

Consistent with the previous review studies, a systematic review also evaluated the clinical outcome after IR in 896 patients. For this purpose, 905 teeth from 12 studies were included in the review study. Among the 12 studies, 7 showed that reducing the extra-oral time for IR (i.e., <15 min) was an essential indicator of increasing the success rate. This study found that with longer follow-up (more than 3 years), the survival rate of teeth decreased over time and stabilized at about 60%. To enhance the success and survival rates of IR teeth, short extra-oral time, reducing pocket depth, type of root-end filling material, and the prevention of tooth root damage should be considered.⁶

IR, as a unique treatment, is recommended for unsuccessful non-surgical root canal treatment. In this perspective, a case report with a 2-year follow-up reported the IR of tooth 46. The patient was referred for treatment for pain and a fractured instrument in the MB canal. After an unsuccessful bypass of the instrument, the remaining canals were filled to the working length. Only the MB canal was filled to the point where the canal was patent. After that, the tooth was restored with amalgam. The IR of the tooth was performed after 7 days. The following procedures were highlighted as successful outcomes: 1) using tetracycline containing saline solution during root resection and retrograde preparation, 2) 10 min of extra-oral treatment, and 3) MTA as a retrograde filling material. Moreover, amoxicillin (500 mg every 8 hours for 7 days) administration was recommended. Complete regeneration of the periapical tissue was observed after 2 years of follow-up. Thus, proper case selection, minimizing extra-oral time, and aseptic techniques during the IR were reported as the key factors in increasing the success of the treatment.²

Another challenging issue is the success outcome of IR in dental malformations. In this regard, the results of two relevant studies are as follows.

• 1)In a case report, tooth 12 (i.e., type III radicular groove) was replanted after extra-oral treatment where radicular groove caused periodontal-endodontic lesions. After atraumatic extraction, the small root was resected. During the IR, the tooth was held in saline-soaked gauze, and the extra-oral procedure lasted <8 min. Antibiotic therapy (amoxicillin + clavulanic acid 1 g daily for 7 days) was also prescribed for the patient. The 1-year follow-up examinations showed periodontal and periradicular healing.⁷
• 2)In another report, the retrospective study evaluated the IR of 10 teeth (i.e., dens invaginatus type IIIb) with periapical lesions. The follow-up examinations were between 4 and 39 months. Also, 8 teeth were reported without radiographic or clinical symptoms. Finally, 1 tooth showed sinus tract formation, and another tooth showed mucosal fenestration, which was treated with additional procedures, including surgery in both patients.⁸ Therefore, proper treatment planning and execution in collaboration with an endodontist and oral surgeon could increase the success outcome of IR teeth, particularly in the case of dens invaginatus types.

It has also been reported that IR is a reliable treatment for tooth preservation, even in the case of a vertical root fracture, and has shown satisfactory results in this respect.⁹ Based on the information provided in this brief letter, the following procedures should be considered in the case of IR: 1) atraumatic extraction, 2) using tetracycline containing saline solution during root resection and retrograde preparation, 3) appropriate root-end filling material (e.g., MTA), 4) using tissue regeneration material (e.g., Emdogain), 5) short extra-oral procedure (<15 min), and 6) antibiotic therapy. Consequently, clinicians’ ability to analyze periapical and periodontal tissues to prompt diagnosis and appropriate treatment strategies in detail is essential in increasing the success outcome of IR teeth during the pandemic.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.