Australian Dental Journal

Australian Dental Journal The official journal of the Australian Dental Association Australian Dental Journal 2016; 61:(1 Suppl): 120 127 doi: 10.1111/adj.12403 Life cycles of traumatized teeth: long-term observations from a cohort of dental trauma victims GS Heithersay* *Clinical Professor, Discipline of Endodontology, School of Dentistry, The University of Adelaide, South Australia, Australia. ABSTRACT Life cycles of dental trauma victims can provide important clinical information, especially when viewed over many years. In this first series of life cycles, the pulp and periodontal responses to traumatic injuries of four patients are documented over periods varying from 26 to 51 years. The dynamics of pulp survival following an intrusive luxation and two avulsions are followed, with particular reference to pulp canal calcification to which a new term, root canal stenosis, has been proposed. The life cycles include the successful management of inflammatory root resorption in a replanted tooth with an open apex contrasting with the early prophylactic endodontic treatment of two replanted teeth in a patient with mature apices. The long-term development of invasive cervical resorption in one of the patient s life cycle highlights the importance of ongoing follow-up examinations for dental trauma victims. Keywords: Avulsion, dental trauma, endodontic treatment, intrusion, prognosis, resorption. INTRODUCTION The concept of applying the term life cycle to victims of dental trauma seems appropriate when one considers that injuries to teeth and supporting tissues can result in a number of short- and long-term consequences which may prove to be either favourable or unfavourable to the patient. The competing biological processes in the life cycles of traumatized teeth relate to the patterns of healing versus the development of various pathoses in the dental pulp and periradicular tissues. Inherent in most pulp responses following luxation or avulsion injuries is a reduced blood supply which generally leads to root canal calcification, which is identified radiographically as a progressive narrowing of the root canal. With time and further calcification the radiographic image may give the impression of pulp canal obliteration; however, in most instances a fine residual canal containing fibrotic pulp tissue remains. 1 Pulp canal obliteration 2,3 is the widely accepted descriptor of this radiographic appearance but it is suggested that root canal stenosis could be considered as alternative terminology. 2,3 While these calcific responses are generally considered favourable, in the context of life cycles of traumatized teeth they may predispose to adverse reactions should these teeth be subjected to further trauma. This may be acute trauma, e.g. as a result of a further blow, or induced more subtly by orthodontic forces. Tooth resorption can be induced following dental trauma and may be transient or progressive. Invasion of the root canal system with microorganisms adds another dimension to the life cycle, resulting in either periapical pathosis or infection-induced inflammatory tooth resorption which may occur internally, externally or as a communicating internal-external resorption. Furthermore, damage to the cemento-enamel junction as a result of a luxation or avulsion injury may result in the longer term with the development of invasive cervical or radicular resorption, which is an insidious form of external tooth resorption. Additionally, a life cycle of dental trauma may involve fracture of residual tooth structure due to secondary trauma or dentinal fatigue while caries, tooth restoration or periodontal disease can be further complicating factors. Of particular concern to most patients in their life cycles is tooth discolouration which may occur either at the time of injury or over the ensuing years. The life cycles presented in this first series are of patients who had received either an intrusive luxation or an avulsion injury and were managed in the specialist endodontic practice of the author from 1967 to 2002, and most have been reviewed up to 2015. While there have been excellent prognosis studies published for intrusively luxated or avulsed teeth, 4 9 120 2016 Australian Dental Association

Life cycles of traumatized teeth additional and useful clinical information of significance can be obtained from long-term observational studies of patients whose teeth had been previously traumatized. LIFE CYCLE REPORTS Report 1 Intrusive luxation The patient was 12 years old in March 1982 when she fell on a trampoline, intrusively luxating her maxillary right central incisor approximately 4 mm. The tooth was carefully surgically repositioned within 30 minutes and flexibly splinted (Fig. 1a and 1b). Root development of the intruded tooth was incomplete (Fig. 1c) which improved the possibility of pulp survival. The anticipated pulp survival was confirmed radiographically over the next few months, evidenced by the completion of root development and root canal narrowing due to calcification (Fig. 1d). Externally at a 6-month review there was a slight change in contour on the mesial surface (arrow) indicative of a repaired non-infective surface resorption. Pulp sensibility testing was positive. Regular clinical and radiographic monitoring showed no signs of periradicular pathosis but the patient s central incisor showed evidence of continuing root canal narrowing (stenosis) due to calcification. An image taken 16 months after the injury is shown in Fig. 1e, and at 3 years 10 months in Fig. 1f. The colour of the tooth remained within normal limits during the follow-up period (Fig. 1g). In 1991, at age 21, the patient embarked on orthodontic treatment for aesthetic reasons. During this treatment her maxillary right central incisor became sensitive to thermal changes, which resolved over a few weeks. A radiograph and clinical photograph taken during orthodontic treatment are shown in Fig. 1h and 1i. On completion of the orthodontic treatment the patient was free of symptoms and radiographically the tooth appeared within normal limits (Fig. 1j). However in 1995, 13 years post-trauma, a further examination revealed a periapical radiolucency indicative of apical periodontitis due to an infected root canal system (Fig. 1k). Endodontic treatment was then carried out the extremely fine root canal was located, instrumented, irrigated and root filled after an interim dressing of calcium hydroxide (Fig. 1l). Periapical repair was evident radiographically at a 6-month follow-up examination (Fig. 1m). The crown of the tooth was bleached in 1998 as there had been some slight colour deterioration. The patient has been re-examined at longer intervals since then with the most recent being in 2015. A radiograph representing 33 years since the original injury is shown in Fig. 1n. While there was no radiographic evidence of periradicular pathosis, extensive caries was present on the mesial aspect of the tooth which required restoration by her regular interstate dentist (Fig. 1o, 1p and 1q). Thus, the 33-year life cycle of this patient s central incisor has been pulp survival, but with progressive root canal calcification (stenosis) following an intrusive luxation, stability for 11 years until the additional trauma of orthodontic forces led to pulpitis and ultimately pulp necrosis, and subsequent periapical pathosis due to microbial invasion of the root canal system, endodontic treatment, periapical repair, conservative intracoronal tooth bleaching, late development of caries and restoration. The patient is now 45 years old, 33 years posttrauma. Her central incisor shows no radiographic evidence of periradicular pathosis and the prognosis appears to be satisfactory, providing the crown which has been weakened by caries does not fracture and her caries activity is controlled by preventive measures. Report 2 Avulsion following orthodontic treatment In January 1983, a 14-year-old female fell from her bicycle shortly after the completion of orthodontic treatment with the unfortunate avulsion of her two maxillary central incisors. Being the daughter of a dentist she knew the importance of early replantation, which she was able to achieve within 5 minutes of their avulsion. The maxillary left central incisor clicked back into position while the right central incisor could not be perfectly repositioned. She was seen at the Adelaide Dental Hospital within 30 minutes where the right central incisor was repositioned and the teeth were then splinted with wire and composite. As both teeth had open apices as a result of orthodontically-induced apical root resorption, revasularization of the dental pulps was anticipated (Fig. 2a and 2b). Contrasting responses were observed in the early follow-up examinations. The left central incisor showed favourable radiographic signs while there was clear evidence of inflammatory root resorption in the right central incisor. Additionally, the maxillary right lateral incisor showed radiographic evidence of apical periodontitis due to an infected root canal system (Fig. 2c and 2d). Endodontic treatment in the maxillary right central and lateral incisors was promptly initiated and an intracanal dressing of calcium hydroxide placed. A radiograph 6 months later showed evidence of periradicular healing with remodelling of the mesial surface of the right central incisor and the development of hard tissue at the apex (Fig. 2e). In addition, there was evidence of a favourable response following the root filling of the lateral incisor. The maxillary left 2016 Australian Dental Association 121

GS Heithersay (a) (c) (d) (e) (f) (b) (g) (h) (i) (j) (k) (l) (m) (n) (o) (p) (q) Fig. 1 (a) Radiograph showing evidence of intrusion of the maxillary right central incisor of an 8-year-old female. The intruded tooth was surgically repositioned within 30 minutes of the injury. (Reproduced from Heithersay GS. Management of tooth resorption. Aust Dent J 2007;52(1 Suppl):S105-121). (b) Clinical photograph following surgical repositioning of 11, flexible splinting and soft tissue suturing. (c) Radiograph taken 18 days after surgical repositioning of the intruded central incisor. (Reproduced from Heithersay GS. Management of tooth resorption. Aust Dent J 2007;52(1 Suppl):S105-121). (d) Six months later there is radiographic evidence of apical root development and a slight change in root contour is evident on the mesial aspect of the repositioned tooth (arrow) indicative of trauma induced surface resorption. (Reproduced from Heithersay GS. Management of tooth resorption. Aust Dent J 2007;52(1 Suppl):S105-121). (e) A 16-month follow-up radiograph shows evidence of calcification (stenosis) of the root canal. (f) 3 years 10 months post intrusion a radiograph shows evidence of further root canal calcification (stenosis). (g) The clinical appearance of 11 taken 3 years 10 months post intrusion shows the colour of the crown to be within normal limits. (h) Clinical appearance during orthodontic treatment 9 years post intrusion. (i) Radiograph taken during active orthodontic treatment. (j) Radiograph taken after completion of orthodontic treatment 11 years post intrusion. (k) 13 years post intrusion and 2 years after completion of orthodontic treatment a radiograph shows a periapical radiolucency indicative of apical periodontitis due to an infected root canal system. (l) Post root filling radiograph. (m) A 6-month follow-up radiograph shows evidence of excellent periapical repair. (n) A 33- year review shows no radiographic evidence of periradicular pathosis but caries is present on the mesial aspect of the maxillary right central incisor. (o) Extent of caries is shown after cavity preparation. (p) Palatal view after placement of composite resin restoration. (q) Appearance of anterior teeth following restoration 33 years post intrusion. 122 2016 Australian Dental Association

Life cycles of traumatized teeth (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) Fig. 2 (a, b) Radiographs of a 14-year-old female following the replantation of her central incisor teeth within 5 minutes of their avulsion. (c, d) Radiographs of the maxillary central incisors taken 6 weeks later reveal signs of infection induced external inflammatory root resorption in the right central incisor and a periapical radiolucency associated with the right lateral incisor. The left central incisor remains free of radiographic signs of pathosis. (Reproduced from Heithersay GS. Management of tooth resorption. Aust Dent J 2007;52(1 Suppl):S105-121). (e) Radiograph after 6 months dressing with calcium hydroxide, shows evidence of repair of the resorbed root surface and apical dome formation. Good periapical repair is also evident in the root filled lateral incisor. (Reproduced from Heithersay GS. Management of tooth resorption. Aust Dent J 2007;52(1 Suppl):S105-121). (f) Radiograph taken at the time of root filling the maxillary central incisor 12 months after the injury. Note the root canal calcification (stenosis) of the maxillary left central incisor which provides positive evidence of successful revacularization. (Reproduced from Heithersay GS. Management of tooth resorption. Aust Dent J 2007;52(1 Suppl):S105-121). (g) Appearance of the patient 20 years post replantation. (h, i) 32-year follow-up radiographs shows no evidence of any periradicular pathosis. (j) Facial appearance of the patient 32 years post replantation. central incisor showed radiographic evidence of root canal calcification and apical closure (Fig. 2e). A radiograph taken at the time of root filling the central incisor 12 months after the avulsion and replantation is shown in Fig. 2f. A hard tissue barrier at the apex of the central incisor facilitated the root filling with gutta-percha and AH26. There was radiographic evidence of periradicular repair associated with both treated teeth, while the left central incisor showed further root canal narrowing due to root canal calcification (stenosis). The patient has been checked on several occasions since that time and bleaching of both root filled teeth was carried out in 1986. By 1998 there had been some deterioration in the colour of the maxillary left central incisor as a result of the calcification and to a lesser degree in the root filled teeth (Fig. 2f). Subsequently, intracoronal bleaching was carried out in all teeth, the left central incisor following a minimal access cavity into the coronal tooth structure but not involving the dental pulp. A photograph of the patient in 2002 is shown in Fig. 2g. A 32-year follow-up examination in 2015 showed no radiographic signs of pathosis (Figs. 2h and 2i). However, there had been some deterioration in the colour stability of the lateral incisor which necessitated a further bleaching procedure. A facial photograph of the patient post-bleaching is shown in Fig. 2j. Thus, the life cycle for this patient has been: orthodontic treatment with some apical root resorption which rendered the apices of her anterior teeth to be open; avulsion and early replantation of her central incisor teeth; revascularization in the maxillary left central incisor and root canal calcification; pulp necrosis and infection in the maxillary right central and lateral incisors with the development of apical periodontitis and the added complication of inflammatory root resorption in the right central incisor; endodontic treatment; and finally colour deterioration managed by intracoronal bleaching. At 46 years of age and 32-years post replantation, the long-term prognosis of her replanted teeth appears to be favourable. Report 3 Avulsion In 1964, a 20-year-old champion state footballer (Fig. 3a) had his maxillary right central incisor avulsed by a pugalistic opponent in a charity match in 2016 Australian Dental Association 123

GS Heithersay (a) (b) (d) (f) (h) (k) (c) (e) (g) (i) (j) Fig. 3 (a) Peter Darley, a star South Australian footballer, in action against Victoria in 1969. (b) Radiograph taken in 1979, 15 years post replantation by patient. (c) Labial view of the patient s anterior teeth taken in 1986 showing a discoloured maxillary right central incisor. (d) A radiograph of the replanted tooth 22 years after its replantation shows some narrowing of the root canal in the apical third region of the root canal, but no evidence of periradicular pathosis. (e) Labial view of the patient s anterior teeth taken in 1996, 32 years post replantation, showing the discoloured maxillary right central incisor. (f) A radiograph of the replanted tooth 32 years post replantation shows no obvious further change within the root canal in the apical third region of the root canal, and no evidence of periradicular pathosis. (g) A facial view in 2015, 51 years post replantation shows residual discolouration, which the patient considered to be less than in previous years. Attrition has occurred in the anterior teeth with some changes in the occlusion. (h) A radiograph taken 51 years post replantation shows evidence of invasive cervical resorption in the distopalatal aspect of 11 as indicated by arrow. (i) Microscopic view of the resorptive defect after the topical application of 90% trichloracetic acid and curettage using ultrasonics. (Courtesy Dr Daniel Farmer) (j) Palatal view showing the glass-ionomer restoration of the resorptive defect 10 days postoperatively shows a favourable gingival response. (Courtesy Dr Daniel Farmer) (k) Radiograph taken on completion of endodontic treatment. (Courtesy Dr Daniel Farmer) Bunbury, Western Australia. He immediately replanted the tooth and continued playing. He later saw his dentist, also a former champion state footballer, who checked the replanted tooth and presumably placed a splint but this is unclear. No endodontic treatment was carried out. A radiograph taken by another dentist in 1979 did not show any evidence of periapical or periradicular pathosis (Fig. 3b). The patient was examined in 1986 when he presented for the endodontic management of a mandibular right first molar. The discoloured maxillary right central incisor was noted, and a radiograph and clinical photograph were taken (Fig. 3c and 3d). No observable evidence of pathosis was noted. He was reassessed in 1996, and again the tooth remained in a satisfactory state. Other than some residual discolouration of the crown (Fig. 3e), a radiograph did not reveal any signs of pathosis (Fig. 3f). When the patient was re-examined in June 2015 as part of the present life cycle series, he noticed that the colour of the replanted tooth had improved over the ensuing 19 years (Fig. 3g). A radiograph did not show any evidence of periapical pathosis, but of significance was an observable irregular radiolucency on the distocervical aspect of the tooth and there was a probeable defect on the distopalatal surface, which led to a diagnosis of hyperplastic invasive cervical resorption (Fig. 3h). Subsequently, this lesion has been treated under microscopic magnification in accordance with the protocol described in 1999 10,11 which involves the topical application of 90% aqueous solution of trichloracetic acid to the invading resorptive tissue, curettage (in this case using ultrasonics) (Fig. 3i) and finally the restoration of the defect with a glass-ionomer cement (in this case GC Fuji IX Extra; GC Co., Tokyo, Japan) (Fig. 3j). Due to the proximity of the deeper extent of the resorption to the pulp, symptoms developed 1 month later which necessitated pulpectomy and root filling (Fig. 3k). The life cycle of this replanted tooth with a mature apex is unique. Against the odds, the pulp obviously revascularized, and remained free of any pathosis for at least 32 years. At some stage over the ensuing 19 years, invasive cervical resorption developed without any symptoms or external signs. This provides valuable information in respect to the need for regular follow-up examinations of luxated or replanted teeth where slight damage to the cemento-enamel junction may interfere with the integrity of the cementum barrier. This may then create conditions in which precursor cells derived from the periodontal ligament invade tooth structure, resulting in hyperplastic invasive cervical resorption as a late and significant complication. 12 The final stage of this life cycle to date has been the management of the invasive cervical resorption and endodontic treatment. Thus, the 51-year life cycle of this example of the replantation of a mature tooth involved the rare revascularization of the devitalized pulp, progressive but slow recolouration over the period following the 124 2016 Australian Dental Association

Life cycles of traumatized teeth replantation and the development of late invasive cervical resorption which has necessitated treatment. The patient is now 71 and will need ongoing follow-up examinations to check the stability of his central incisor, which will hopefully continue favourably in his fascinating life cycle. Report 4 Avulsion, early replantation and endodontic treatment In 1989, a 10-year-old boy fell from his bicycle when trying to negotiate a steep road in Adelaide, South Australia and avulsed both maxillary central incisors. Fortunately, the accident happened immediately opposite the home of a dentist, Dr Vincent Brazier, who was mowing his front lawn at the time. He immediately came to check the injured boy he retrieved the teeth, one partly concealed in a bush, washed them in milk and replanted them. He then took the boy to his practice and splinted each central incisor to the corresponding lateral incisor with composite resin. Radiographs showing the replanted teeth are shown in Fig. 4a and 4b. He was referred for management and endodontic treatment was instituted 10 days later with removal of the devitalized pulp, minimal root canal instrumentation, irrigation with 1% sodium hypochlorite followed by EDTAC, and finally the placement of Ledermix paste as an intracanal medicament. The Ledermix paste with its proven anticlastic property 13 was replaced after 6 weeks with a 50:50 mix of Ledermix paste and calcium hydroxide for a further 2 months (Fig. 4c and 4d) when the root canals were filled with gutta-percha and AH26 (Fig. 4e). Intracoronal bleaching proved necessary at that time due to slight medicament-related discolouration. The patient has been re-examined at regular intervals since that time a photograph and radiograph taken in 1994 are shown in Fig. 4f and 4g. The most recent recall examination was in 2015, 26 years post replantation. Radiographs of both central incisors, shown in Fig. 4h and 4i, indicate a most satisfactory response to date with no evidence of periradicular pathosis. Clinically the teeth exhibit normal mobility and there has not been any observable colour deterioration since the original bleaching procedure. A photograph of the now 40-year-old patient is shown in Fig. 4j. Thus, the life cycle of this patient over 26 years has been early replantation of his maxillary central incisors, expeditious endodontic treatment to exclude microbial invasion of the root canal system as a preventive measure to counter potential inflammatory root resorption, extended intracanal medication (a) (b) (c) (d) (e) (f) (g) (h) (i) (j) Fig. 4 (a, b) Radiographs of 11 and 21 after replantation and splinting. (c, d) Radiographs 6 weeks after placement of Ledermix paste as an intracanal dressing material. (e) Radiograph after placement of a gutta-percha and AH26 root filling, 4.5 months post replantation. (f) Facial view of the patient 5 years post replantation. (g) Radiograph of the central incisors at 5 years post replantation. (h, i) Radiographs of the replanted central incisors 26 years post replantation. (j) Facial view of the patient in 2015. 2016 Australian Dental Association 125

GS Heithersay to allow stabilization of the healing responses, root filling, bleaching and follow-up examinations. While the prognosis appears most satisfactory, further examinations will be necessary to exclude the possibility of late invasive cervical resorption. DISCUSSION The life cycles presented in this first series of selected patients display a variety of responses following either intrusive luxation or avulsion and replantation viewed over long-term follow-up examinations. Pulp survival was displayed in three patients. In Reports 1 and 2, the injuries involved teeth with apical foramina wider than 2 mm. In those patients root canal calcification or stenosis became apparent in the follow-up periods. While this root canal calcification is a positive sign of pulp survival, the fine residual pulp with a reduced blood supply has less ability to respond to secondary trauma. This in fact occurred in Report 1 when the patient received orthodontic treatment which, with apologies to the orthodontic community, can be considered as a form of subtle trauma. The clinical result was the late development of apical periodontitis due to an infected root canal system. In Report 3 the patient was 20 years of age with a mature apex when his tooth was avulsed and replanted within a short time. Revascularization in a tooth with a mature apex has been reported as being a rare occurrence, providing the replantation is carried out immediately. 14,15 Obviously this patient joined this rare group as evidenced by the development of root canal calcification and the absence of periradicular pathosis, which would have indicated external inflammatory resorption related to an infected root canal system. The fact that the patient ultimately developed symptoms of acute pulpitis, triggered by thermal stimulation, is evidence of the survival of the neural tissue, in addition to the vascular and cellular components of the dental pulp. Report 2 illustrates how apical root resorption due to previous orthodontic treatment favoured successful revascularization of the patient s maxillary right central incisor, which had been immediately and correctly repositioned. By contrast, the contralateral incisor which needed repositioning after the initial attempt at replantation by the patient developed inflammatory root resorption due to the development of pulp necrosis with bacterial invasion. This report shows the long-term favourable response to the management of inflammatory root resorption by endodontic treatment with the placement of calcium hydroxide. Report 4 illustrates an ideal management of the avulsion of two mature central incisors which were professionally replanted within 10 minutes of their avulsion, then endodontically treated in conformity with accepted guidelines. Ledermix paste was used as the initial intracanal medicament based on its proven anticlastic property 13 and 28 years later there were no observable signs of an adverse response in the form of resorption. By comparison, the surprising long-term development of invasive cervical resorption in Report 3 reflects the importance of regular follow-up examinations of all avulsed teeth as early treatment of this resorptive process should result in a favourable outcome. 10,11 The life cycles of traumatized teeth in this first series indicate that following the initial management of the injuries, careful short and longer term follow-up examinations are of great importance. Armed with knowledge of the tissue dynamics following dental trauma and their clinical manifestations, a clinician should be able to assess either favourable healing responses or adverse changes indicating pulp or periradicular pathosis. In the case of the latter, expeditious treatment can generally affect a favourable healing response to ensure the long-term retention of a traumatized tooth. ACKNOWLEDGEMENTS The author wishes to acknowledge Dr Daniel S Farmer, Endodontist, for his professional help in the examination of three of the patients detailed in this report and for his excellent management of the invasive cervical resorption detailed in Report 3. Thanks are also due to the four patients for their cooperation and their ready consent to the publication of their photographic and radiographic material. DISCLOSURE The author has no conflicts of interest to declare. REFERENCES 1. Lundberg M, Cvek M. A light microscopy study of pulps from traumatised permanent incisors with reduced pulpal lumen. Acta Odontol Scand 1980;38:89 94. 2. Andreasen JO. Traumatic Injuries of the Teeth. Copenhagen: Munksgaard International Publishers, 1972:172 174. 3. Andreasen FM, Yu Z, Thomsen BL, Andersen PK. Occurrence of pulp canal obliteration after luxation injuries in the permanent dentition. Endod Dent Traumatol 1987;3:103 115. 4. Andreasen JO, Bakland LK, Andreasen FM. Traumatic intrusion of permanent teeth. Part 2. A clinical study of the effect of pre-injury and injury factors, such as sex, age, stage of root development, tooth location, and extent of injury including number of intruded teeth on 140 intruded permanent teeth. Dent Traumatol 2006;22:90 98. 5. Andreasen JO, Bakland LK, Andreasen FM. Traumatic intrusion of 140 permanent teeth. A clinical study of the effect of treatment variables such as treatment delay, method of repositioning, type of splint, length of splinting and antibiotics. 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Life cycles of traumatized teeth 6. Andreasen JO, Borum MK, Jacobsen HL, Andreasen FM. Replantation of 400 avulsed permanent incisors. 2. Factors related to pulpal healing. Endod Dent Traumatol 1995;11:59 68. 7. Andreasen JO, Borum MK, Andreasen FM. Replantation of 400 avulsed permanent incisors. 3. Factors related to root growth. Endod Dent Traumatol 1995;11:69 75. 8. Andreasen JO, Borum MK, Jacobsen HE, Andreasen FM. Replantation of 400 avulsed permanent incisors. 4. Factors related to periodontal ligament healing. Endod Dent Traumatol 1995;11:76 89. 9. Andreasen JO, Borum MK, Andreasen FM. Progression of root resorption after replantation of 400 avulsed human incisors. In: Davidovitch Z, ed. The biological mechanisms of tooth eruption, resorption and replacement by implants. Boston: Harvard Society for the Advancement of Orthodontics, 1994:577 582. 10. Heithersay GS. Treatment of invasive cervical resorption: an analysis of results using topical application of trichloracetic acid, curettage, and restoration. Quintessence Int 1999;30:96 110. 11. Heithersay GS. Invasive cervical resorption. Endod Topics 2004;7:73 92. 12. Heithersay GS. Invasive cervical resorption: an analysis of potential predisposing factors. Quintessence Int 1999;30:83 95. 13. Pierce A, Lindskog S. The effect of an antibiotic/corticosteroid paste on inflammatory root resorption in vivo. Oral Surg Oral Med Oral Pathol 1987;64:216 220. 14. Ӧhman A. Healing and sensitivity to pain in young replanted teeth. An experimental, clinical and histological study. Odontologisk Tidskrift 1965;73:165 228. 15. Andreasen JO, Hjὂrting-Hansen E. Replantation of teeth. 1. Radiographic and clinical study of 110 human teeth replanted after accidental loss. Acta Odontol Scand 1966;24:263 286. Address for correspondence: Geoffrey S Heithersay AO Clinical Professor Discipline of Endodontology School of Dentistry The University of Adelaide Adelaide SA 5000 Australia Email: geoffrey.heithersay@adelaide.edu.au 2016 Australian Dental Association 127