Healing of external inflammatory root resorption - a case report Mithra N. Hegde * Deepak Pardal ** ABSTRACT Case report describes a radiographic follow-up of healing of external inflammatory root resorption on a permanent maxillary left central incisor following avulsion and replantation using Vitapex. Since more than 20 % of root surface was resorbed the healing occurred in the form of replacement resorption. The most important factor influencing the prognosis of replanted teeth is the status of periodontal ligament cells. Thus the treatment should aim at minimizing the extra-oral dry time, storage of avulsed tooth in a suitable medium, physiologic splinting for a period of 7-10 days and early endodontic therapy. Although there is no treatment for replacement resorption, it is worth an effort to try slow down the resorption process and maintain the tooth as long as possible in the arch for esthetics, functional and psychological reasons. INTRODUCTION Facial trauma often results in the complete avulsion of a maxillary permanent incisor. The reported incidence of tooth avulsion ranges from 1% to 16% of all traumatic injuries to the permanent teeth 12. These teeth may be replanted. It is well known that the fate of a replanted tooth can cover various healing categories such as; normal periodontal healing, surface resorption, inflammatory resorption and replacement resorption 3, 4. When extensive damage occurs to the innermost layer of the periodontal ligament, competitive healing events take place. Healing from the socket wall (creating bone via bone marrowderived cells) and healing from adjacent periodontal ligament (creating cementum and Sharpey s fibers) occurs simultaneously. If less than 20% of the root surface is involved, a transient ankylosis may occur, which can later be resorbed due to functional stimuli, provided the tooth in the healing period is stabilized with a splint which allows a minimum amount of mobility, or is non-splinted 5,6. But if the trauma is extensive involving more than 20% of root surface, an abnormal attachment can occur after healing. After the initial inflammatory response to remove debris resulting from the injury, a root surface devoid of cementum results. Cells in the vicinity of the denuded root now compete to repopulate it. Often cells that are precursors of bone will move across from the socket wall and populate the damaged root rather that slower moving periodontal ligament cells. Bone resorbs and reforms physiologically through out life. The osteoclasts in contact with the root resorb the dentin. In the reforming phase, osteoblasts lay down bone in the area that was previously root, eventually replacing * Professor and Head. ** Postgraduate student Department of Conservative Dentistry and Endodontics, A.B Shetty Memorial Institute of Dental Sciences, Deralakatte, Mangalore 34
HEALING OF EXTERNAL INFLAMMATORY ROOT RESORPTION - A CASE REPORT it. This progressive effect of ankylosis on the avulsed tooth is termed replacement resorption 1. The prolonged non-physiological storage of avulsed teeth before replantation results in total necrosis of the periodontal ligament, and healing by replacement root resorption (i.e., repair) becomes the only option 7. This case report presents a radiographic follow up (12 months) of treatment of external inflammatory root resorption using Vitapex. CASE REPORT A healthy 22-year-old patient visited the Department of Conservative Dentistry and Endodontics, A.B Shetty Memorial Institute of Dental Sciences, Mangalore, with a chief compliant of broken tooth in the right upper front region of the oral cavity. History revealed that the patient had a fall about three months back, following which avulsion of tooth number 21 and fracture (Ellis class II fracture) of 22 occurred. The patient visited a hospital where the avulsed tooth was replanted after an extra-oral time of more than 1 hour. During this period avulsed tooth was not stored in any suitable medium, instead was held in hand. The replanted tooth was then nonphysiologically splinted for a period of 15 days. No root canal therapy was done at this period. Although patient did not complain of any pain but on clinical examination it was found that tooth number 21 was tender on percussion and had grade- I mobility. An intra-oral periapical radiograph (figure1) revealed areas of radiolucency along the apical and lateral surface of root and surrounding bone (moth eaten appearance) with loss of lamina dura suggesting external root resorption in relation to 21. Tooth number 11 and 22 also showed periapical radiolucency. Electric and thermal pulp testing gave a negative response in relation to tooth number 11, 21 and 22. Access opening and a complete canal debridement was undertaken for all the three teeth. Tooth number 11 and 21 were filled with Vitapex and 22 was obturated using guttapercha (figure2). Tooth number 11 was obturated using guttapercha at 6 month recall (figure 4). It was only after a 12 month recall (figure 5) that the intra-oral periapical radiograph showed sufficient healing of external root resorption in relation to 21 with replacement resorption and so a permanent root canal filling in form of guttapercha was placed (figure 6). There was no mobility and tenderness on percussion in relation to tooth number 21 at the 12 month recall. DISCUSSION Unlike bone, which undergoes resorption and apposition as part of a continual remodeling process, the roots of permanent teeth are not normally resorbed. Only the resorption of deciduous teeth before they are shed can be considered physiologic 8. Avulsion injuries pose a greater and serious assault to the gingiva, the periodontal ligament and the pulp 9. In clinical studies, teeth replanted within 5 minutes after avulsion had the best prognosis and the chance of pulpal and periodontal healing was inversely related to the stage of root development and the period of dry storage 10,11. In the optimal scenario, the avulsed tooth should be replanted immediately or should be stored in a suitable physiological medium before replantation 12,13. The replanted tooth should be splinted flexibly to the adjacent teeth for 7 to 10 days to enhance periodontal healing. If the tooth apex is closed or 35
Mithra N. Hegde, Deepak Pardal Figure1. Pre-operative view Figure3. Post-operative View at 3 months recall Figure5. Post-operative view at 12 months recall Figure2. Post-operative view Figure4. Post-operative view at 6 months recall Figure6. Permanent restoration almost closed, prophylactic root canal treatment should be carried out on the day of splint removal to prevent the onset of inflammatory root resorption 13. Andreasen has shown that resorption defects occur on the root surface adjacent to the areas of damage to the periodontal ligament during avulsion or extended drying before replantation. Inflammatory resorption is a mechanism of eliminating infected calcified tissue from the body; osteoclasts acting as specialized macrophages actively participate in the healing process to repair traumatized tooth and bone 14. Dry extra oral time after avulsion in the present case was more than 1 hour and during this period tooth was not stored in any suitable medium instead was kept in hand, which caused the drying of the periodontal ligament cells. Splinting was done using rigid wires that did not allow for the physiologic movement of the tooth for a period of 15 days. Endodontic therapy was not performed until 3 months. It has been emphasized that endodontic therapy should be undertaken within 7-10 days after replantation so as to remove the necrotic pulp tissue which could get infected and initiate inflammatory root resorption. As the patient in the present case presented with extensive external inflammatory root resorption on the first visit, long term calcium hydroxide treatment was planned using Vitapex. Calcium hydroxide is one of the most effective materials for the treatment of external root resorption because of mainly two properties high calcium ion concentration and alkaline ph 15. The specific mechanism of action of calcium hydroxide is still debated. Several theories have been postulated to 36
HEALING OF EXTERNAL INFLAMMATORY ROOT RESORPTION - A CASE REPORT explain its biological activity. One theory discusses its high alkaline ph, which is important in stimulating matrix formation by the formative cells 16. Another theory postulates that a high ph neutralizes the acidic products of the resorptive cells, creating an unfavorable environment for them 17. Furthermore calcium hydroxide may promote healing because of its antibacterial properties 18. Seltzer and Bender stated that the presence of Ca 2+ ions may activate ATPase, which may then enhance dental tissue remineralization 19. A commercial product named Vitapex (J.Morita) containing viscous mix of calcium hydroxide and iodoform in a syringe with disposable tips was used in the present case. The main ingredients of Vitapex are iodoform 40.4%, calcium hydroxide 30.3%, silicone 22.4% and others 6.9%. Calcium hydroxide and iodoform has been thought to have a synergistic antibacterial effect 20. It is radioopaque so could be easily detected on an intra-oral periapical radiograph. However there is a need to replace it every 3 months within the range of 6 to 24 months. Since in the present case more than 20% of root surface was denuded due to external inflammatory resorption, healing took place with replacement resorption. According to Andersen replacement resorption can take place once inflammatory resorption has been arrested by endodontic therapy 1. This is more in case of young patients because of high turn over rate of bone forming cells. Though there is no treatment for replacement resorption, it is worth an effort to try slow down the resorption process and maintain the tooth as long as possible in the arch for esthetics, mastication, and natural space maintenance and above all psychological uplift of the young minds. CONCLUSION The most important step in case of avulsion injuries is the maintenance of viable periodontal ligament cells which could be achieved with an early replantation of the tooth with minimum extra oral dry time. It is equally important to store the tooth in suitable storage medium. Physiologic splinting and early endodontic intervention has also got an effective role to play. Thus as the degree of trauma cannot be controlled it is the preventive measures that enhance the prognosis of a replanted tooth. External inflammatory root resorption involving more that 20% of root structure will usually go for a replacement resorption. However, an effort should always be made to slow down the resorption process because replantation can restore the patient s esthetic appearance and occlusal function and the replanted incisor can remain functional for some years. REFERENCES 1. Andreasen JO, Andreasen FM. Avulsions. In: Andreasen JO, Andreasen FM, editors. Textbook and color atlas of traumatic injuries to the teeth. Copenhagen: Munksgaard; 1994; pp 383-425. 2. Trope M. clinical management of avulsed tooth. In: Traumatic injuries of teeth. Dent Clin North Am 1995; 39: 93-112. 3. Dumsa TC. Management of avulsions. In: Endodontics. Dent Clin North Am 1992; 36: 425-437 4. Pettini F, Pettini P. Root resorption of replanted teeth: an SEM study. Endod Dent Traumatol 1998; 14: 144-149. 5. Troustad L. Root resorption-etiology, terminology and clinical manifestations. Endod Dent Traumatol 1988; 4: 241-252. 6. Ne RF. Tooth resorption. Quintessence Int 1999; 30: 9-25. 7. Andreasen JO, Borum MK, Jacobsen HL, Andreasen FM. Replantation of 400 avulsed permanent incisors. 4. Factors related to periodontal ligament healing. Endod Dent Traumatol 1995; 11: 76-89. 37
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