Reprint of: Relationship Between Surface and Inflammatory Resorption and Changes in the Pulp After Replantation of Permanent Incisors in Monkeys.

The etiology of surface and inflammatory root resorption after the replantation of incisors was examined in green vervet monkeys. The teeth were examined histologically and histobacteriologically for pulpal healing and root resorption 2 and 8 weeks after replantation. In contrast to surface resorption, inflammatory resorption was related to infected necrotic tissue or an infected leukocyte zone in the root canal. The following theory for surface and inflammatory resorption is presented. Damaged periodontal ligament areas and damaged parts of the root surface are attacked by a resorption process whereby resorption of cementum and dentin may occur. Inflammatory resorption or surface resorption will then occur depending on the pulpal status and the depth of the resorption cavity. If the resorption cavity penetrates the intermediate layer of cementum and contacts dentinal tubules that are in communication with infected necrotic pulp tissue or an infected leukocyte zone, then inflammatory resorption will take place as a result of the diffusion of toxic elements from the pulp canal to the resorption cavity. However, if the resorption cavity is shallow and does not penetrate the intermediate layer of cementum, a tooth that displays similar pulpal changes will elicit only surface resorption because the intermediate layer of cementum will tend to arrest the diffusion of toxic elements. Finally, if the pulp contains vital, inflamed, or noninflamed tissue or if root canal treatment has been performed, surface resorption will occur regardless of the depth of the cavity.

Ectopic eruption of the second premolar: an analysis of four different treatment approaches.

PURPOSE: Ectopic second premolars may lead to impaction and loss of space in the jaws, and in rare cases even to resorption of the first permanent molar. The aim of this study was to analyse different treatment strategies of ectopic second premolars and if possible give guidelines on when to favour different treatment approaches. MATERIALS AND METHODS: The study was a retrospective, non-randomised, outcome analysis of treatment on 41 ectopic second premolars in 37 patients (24 females and 13 males). In all cases oral examination, radiographs (pre-, peri-, and post) and full medical history were obtained. The treatment options included: (a) spontaneous eruption, (b) spontaneous eruption + extraction of primary tooth, (c) surgical exposure, (d) surgical uprighting, and (e) surgical uprighting + orthodontic extrusion. For evaluation each tooth was scored according to: (1) stage of root development, (2) distance between edges of the premolar and first permanent molar, (3) depth of impaction, (4) inclination, (5) horizontal position of the tooth. The level of significance was set to 5%. RESULTS: Only mild cases of ectopic second premolars are self-correcting. Based on the position of the tooth in the jaw different treatment options may be chosen, these may include: extraction of primary predecessor (impaction depth < 5 mm, inclination < 55°), surgical exposure of tooth germ (impaction depth < 5.5 mm, inclination < 95°) or surgical uprighting (impaction depth > 5.5 mm with no inclination limit). CONCLUSION: If there is no sign of self-correction after a short observation period, it is important to consider active treatment to help guiding the tooth into the correct eruption pathway.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 1. Fractures and luxations of permanent teeth. Hebrew edition].

Traumatic dental injuries (TDIs) of permanent teeth occur frequently in children and young adults. Crown fractures and luxations are the most commonly occurring of all dental injuries. Proper diagnosis, treatment planning and follow up are important for improving a favorable outcome. Guidelines should assist dentists and patients in decision making and for providing the best care effectively and efficiently. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the best current evidence based on literature search and professional opinion. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of TDIs. In this first article, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented. The Hebrew Edition is part of the IADT global effort to provide accessibility to these guidelines worldwide.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 2. Avulsion of permanent teeth. Hebrew edition].

Avulsion of permanent teeth is one of the most serious dental injuries, and a prompt and correct emergency management is very important for the prognosis. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the task group. The guidelines represent the current best evidence and practice based on literature research and professionals' opinion. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care of avulsed permanent teeth. The Hebrew Edition is part of the IADT global effort to provide a worldwide accessibility to these guidelines. This scond part of the guidelines will focus on avulsion of permanent teeth.

[International Association of Dental Traumatology guidelines for the management of traumatic dental injuries: 3. Injuries in the primary dentition. Hebrew edition].

Traumatic injuries to the primary dentition present special problems and the management is often different as compared with the permanent dentition. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialities were included in the task group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion or majority decision of the task group. Finally, the IADT board members were giving their opinion and approval. The primary goal of these guidelines is to delineate an approach for the immediate or urgent care for management of primary teeth injuries. The IADT cannot and does not guarantee favorable outcomes from strict adherence to the guidelines, but believe that their application can maximize the chances of a positive outcome. The Hebrew Edition is part of the IADT global effort to provide a worldwide accessibility to these guidelines. This third part will discuss injuries in the primary dentition.

Emdogain does not prevent progressive root resorption after replantation of avulsed teeth: a clinical study.

Emdogain has been shown in clinical and experimental studies to promote regeneration of all periodontal tissues: cementum with anchoring fibres, a functional, periodontal ligament and alveolar bone in connection with treatment of marginal periodontitis. The intention of this study was to analyse whether this regenerative capacity upon the periodontal ligament also worked in a trauma situation where a significant number of PDL cells have been eliminated because of unphysiologic storage or actual damage during avulsion or replantation. Furthermore if ankylosis sites already established because of earlier replantation after avulsion could be surgical removed and application of Emdogain could revert the ankylosis stage to a normal PDL situation. The first treatment situation was tested in seven patients with a total of 16 avulsed teeth with varying time of extra oral storage. The teeth were extra-orally endodontically treated and the root and socket covered with Emdogain before replantation. All teeth demonstrated subsequent ankylosis, primarily diagnosed by a percussion test. The second treatment situation where an ankylosis was already established constituted of seven patients with a total of 11 teeth because of previous replantation after avulsion. These teeth were all extracted, the ankylosis sites removed and the root and socket treated with Emdogain. After 6 months all teeth showed recurrence of ankylosis. It is concluded that Emdogain was not able to prevent or cure ankylosis.

Conservative endodontic treatment of teeth fractured in the middle or apical part of the root.

According to treatment type, root-fractured teeth with pulp necrosis or exposed pulps were divided into five groups, group 1: 17 teeth in which the root canal of the coronal fragment only was filled with gutta-percha (GP); group 2: seven teeth in which the root canals of the coronal and apical fragments were both filled with GP; group 3: 19 teeth in which the coronal fragment was filled with GP and the apical fragment was surgically removed; group 4: 68 teeth where the root canal of the coronal fragment was treated with calcium hydroxide and subsequently filled with GP; and group 5: five vital teeth with root and concomitant crown fractures in which the exposed pulps were treated by partial pulpotomy. The frequency of periodontal healing was 76% in group 1, zero in group 2, 68% in group 3 and 86% in group 4. Compared with groups 1 and 2 combined, healing in group 4 was significantly more frequent. In groups 1, 2 and 4, failures occurred significantly more often in teeth showing overfilling, i.e. protrusion of GP into the space between the fragments, compared with teeth without overfilling. All five teeth in group 5 showed healing. It was concluded that root canal filling with GP of the coronal fragment only, with or without surgical removal of the apical fragment, can be successful in selected cases. Treatment of the root canal with calcium hydroxide followed by GP filling appears to be the treatment of choice in root-fractured non-vital teeth. Partial pulpotomy of exposed pulps in five teeth showed results similar to root-unfractured teeth with pulp exposure treated with this technique.

Healing of 400 intra-alveolar root fractures. 1. Effect of pre-injury and injury factors such as sex, age, stage of root development, fracture type, location of fracture and severity of dislocation.

This retrospective study consisted of 400 root-fractured, splinted or non-splinted incisors in young individuals aged 7-17 years (mean = 11.5 +/- 2.7 SD) who were treated in the period 1959-1995 at the Department of Pediatric Dentistry, Eastman Dental Institute, Stockholm. Four hundred of these root fractures were diagnosed at the time of injury; and 344 teeth were splinted with either cap-splints, orthodontic appliances, bonded metal wires, proximal bonding with composite resin or bonding with a Kevlar or glass fiber splint. In 56 teeth, no splinting was carried out for various reasons. In the present study, only pre-injury and injury factors were analyzed. In a second study, treatment variables will be analyzed. The average observation period was 3.1 years +/- 2.6 SD. The clinical and radiographic findings showed that 120 teeth out of 400 teeth (30%) had healed by hard tissue fusion of the fragments. Interposition of periodontal ligament (PDL) and bone between fragments was found in 22 teeth (5%), whereas interposition of PDL alone was found in 170 teeth (43%). Finally, non-healing, with pulp necrosis and inflammatory changes between fragments, was seen in 88 teeth (22%). In a univariate and multivariate stratified analysis, a series of clinical factors were analyzed for their relation to the healing outcome with respect to pulp healing vs. pulp necrosis and type of healing (hard tissue vs. interposition of bone and/or PDL or pulp necrosis). Young age, immature root formation and positive pulp sensibility at the time of injury were found to be significantly and positively related to both pulpal healing and hard tissue repair of the fracture. The same applied to concussion or subluxation (i.e. no displacement) of the coronal fragment compared to extrusion or lateral luxation (i.e. displacement). Furthermore, no mobility vs. mobility of the coronal fragment. Healing was progressively worsened with increased millimeter diastasis between fragments. Sex was a significant factor, as girls showed more frequent hard tissue healing than boys. This relationship could possibly be explained by the fact that girls experienced trauma at an earlier age (i.e. with more immature root formation) and their traumas were of a less severe nature. Thus, the pre-injury or injury factors which had the greatest influence upon healing (i.e. whether hard tissue fusion or pulp necrosis) were: age, stage of root development (i.e. the size of the pulpal lumen at the fracture site) and mobility of the coronal fragment, dislocation of the coronal fragment and diastasis between fragments (i.e. rupture or stretching of the pulp at the fracture site).

Healing of 400 intra-alveolar root fractures. 2. Effect of treatment factors such as treatment delay, repositioning, splinting type and period and antibiotics.

This is the second part of a retrospective study of 400 root-fractured permanent incisors. In this article, the effect of various treatment procedures is analyzed. Treatment delay, i.e. treatment later than 24 h after injury, did not change the root fracture healing pattern, healing with hard tissue between fragments (HH1), interposition of bone and/or periodontal ligament (PDL) or pulp necrosis (NEC). When initial displacement did not exceed 1 mm, optimal repositioning appeared to significantly enhance both the likelihood of pulpal healing and hard tissue repair (HH1). Significant differences in healing were found among the different splinting techniques. The lowest frequency of healing was found with cap splints and the highest with fiberglass or Kevlar splints. The latter splinting procedure showed almost the same healing result as non-splinting. Comparison between non-splinting and splinting for non-displaced teeth was found to reveal no benefit from splinting. With respect to root fractures with displacement, too few cases were available for analysis. No beneficial effect of splinting periods greater than 4 weeks could be demonstrated. The administration of antibiotics had the paradoxical effect of promoting both HH1 and NEC. No explanation could be found. It was concluded that, optimal repositioning seems to favor healing. Furthermore, the chosen splinting method appears to be related to healing of root fractures, with a preference to pulp healing and healing fusion of fragments to a certain flexibility of the splint and possibly also non-traumatogenic splint application. Splinting for more than 4 weeks was not found to influence the healing pattern. A certain treatment delay (a few days) appears not to result in inferior healing. The role of antibiotics upon fracture healing is questionable.

Effects of temperature, storage time and media on periodontal and pulpal healing after replantation of incisors in monkeys.

The effect of temperature of various storage media and at varying storage periods upon periodontal ligament (PDL) and pulpal healing after tooth replantation was examined in green vervet monkeys (Cercopithecus aethiops). Mandibular lateral incisors with mature root formation were extracted and kept in dry storage at 22, 4 and -18 degrees C; in saline at 37, 22, 4 and -18 degrees C; or in saliva (i.e. in the buccal vestibule) at 37 degrees C for either 60 or 120 min prior to replantation. The animals were sacrificed 8 weeks after replantation and the replanted teeth examined histometrically. The following histological parameters were registered for each tooth: normal PDL, surface resorption, inflammatory resorption, replacement resorption (ankylosis), downgrowth of pocket epithelium, periapical inflammatory changes, and the extent of vital pulp. A total of 125 replanted teeth were examined. Storage in saliva at 37 degrees C showed a similar amount of normal PDL compared to saline storage for both 60 and 120 min. Saline storage for 60 or 120 min showed no difference in the extent of normal PDL when storage was compared at 37, 22 and 4 degrees C. However, storage at -18 degrees C resulted in significantly less normal PDL than storage at other temperatures. Dry storage for 60 min showed significantly less root resorption at 4 degrees C compared to 22 degrees C. Furthermore, dry storage at -18 degrees C showed significantly less normal PDL than storage at 4 degrees C. When the dry storage period was extended to 120 min, no difference was found between 22, 4 and -18 degrees C. It is concluded that the temperature (above 0 degrees C) of the storage medium is of importance only for dry storage and in such a situation only for shorter extra-alveolar periods, i.e. for 60-min storage and not for 120 min, where extensive destruction of the PDL always takes place. It is suggested that the temperature effect of 4 degrees C could be related to less evaporation from the PDL and thereby less damage to the PDL cells or a strict temperature effect upon cell metabolism. Pulp healing in all the cases was limited to the entrance of the pulp canal, and no significant pattern was found between storage media, time and temperature.

Allo- and autotransplantation of mature teeth in monkeys: a sequential time-related histoquantitative study of periodontal and pulpal healing.

Root resorption is known to be the most relevant complication determining the long-term prognosis of allotransplanted teeth, and it is initiated during the first few postoperative months. The aim of the present study was to quantitatively assess the dynamics of the periodontal ligament (PDL) and pulpal healing reactions during the first 8 weeks after allotransplantation of mature teeth. The material comprised 112 maxillary central and mandibular lateral incisors of 28 mature green Vervet monkeys, immunogenetically untested, and only matched according to the size of the grafts. Donors and recipients exchanged simultaneously both maxillary incisors and one mandibular incisor, whereas the contralateral mandibular incisors were autotransplanted as controls. At random, every second maxillary allograft was endodontically treated preoperatively. Histoquantitative analysis of the PDL and pulpal healing reactions was carried out after 1, 2, 4 and 8 weeks on serial cross-sections of the grafts in 6, 6, 6 and 8 monkeys, respectively. Necrosis zones in the PDL were prominent in both auto- and allografts after 1 week. Inflammation in the PDL dominated healing in all types of grafts 1 week after transplantation, whereas it subsided significantly after 2 weeks in autografts compared to allografts (P = 0.005). Inflammatory resorption (IR) became prominent after 4 weeks in autografts and this remained stationary. In contrast, IR initiated significantly earlier in allografts compared to autografts after 2 weeks (P = 0.007), and this type of resorption was further increasing in allografts after 4 and 8 weeks. Endodontic treatment, however, reduced IR nearly totally in the allografts with time. Replacement resorption (RR) was nearly absent in autografts. In contrast, allografts showed increasing appearance of RR with time, initiating at 4 weeks. By removing IR from the allografts by endodontic treatment, RR was unmasked significantly at 4 weeks (P = 0.02) and dominated most of the periodontal ligament (70%) after 8 weeks (P = 0.0004). Within the 8 postoperative weeks autografts showed healing with increasing amount of normal PDL reaching significantly higher levels compared to allografts already after 2 weeks (P = 0.02), with increasing differences thereafter. In most allografts, the normal PDL occupied less than 10% of the entire root surface and was located in the supra-alveolar cervical region. Downgrowth of periodontal pocket epithelium was absent or found very infrequently in all groups irrespective of type, time and treatment. In conclusion, the healing of allo- and autotransplanted mature teeth differed significantly on several aspects during the first 8 postoperative weeks. The recorded differences included a higher amount of inflammation in the PDL of allografts after 2 weeks, inflammatory resorption from the second week, and replacement resorption dominating in the eighth week, indicated that an immunologic stimulus for root resorption existed in the allogenic PDL apart from the pulp. Furthermore, specific healing reactions was found in the cervical region with almost identical gingival healing in auto- and allografts.

Effect of treatment delay upon pulp and periodontal healing of traumatic dental injuries -- a review article.

Based on an analysis of the literature concerning parameters influencing the prognosis of traumatic dental injuries, few studies were found to have examined possible relationships between treatment delay and pulpal and periodontal ligament healing complications. It has been commonly accepted that all injuries should be treated on an emergency basis, for the comfort of the patient and also to reduce wound healing complications. For practical and especially economic reasons, various approaches can be selected to fulfill such a demand, such as acute treatment (i.e. within a few hours), subacute (i.e. within the first 24 h), and delayed (i.e. after the first 24 h). In this survey the consequences of treatment delay on pulpal and periodontal healing have been analyzed for the various dental trauma groups. Applying such a treatment approach to the various types of injuries, the following treatment guidelines can be recommended, based on our present rather limited knowledge of the effect of treatment delay upon wound healing. Crown and crown/root fractures: Subacute or delayed approach. Root fractures: Acute or subacute approach. Alveolar fractures: Acute approach (evidence however questionable). Concussion and subluxation: Subacute approach. Extrusion and lateral luxation: Acute or subacute approach (evidence however questionable). Intrusion: Subacute approach (evidence however questionable). Avulsion: If the tooth is not replanted at the time of injury, acute approach; otherwise subacute. Primary tooth injury: Subacute approach, unless the primary tooth is displaced into the follicle of the permanent tooth or occlusal problems are present; in the latter instances, an acute approach should be chosen. These treatment guidelines are based on very limited evidence from the literature and should be revised as soon as more evidence about the effect of treatment delay becomes available.

Therapeutic and economic implications of traumatic dental injuries in Denmark: an estimate based on 7549 patients treated at a major trauma centre.

AIM: To analyse the type and extent of injuries presented by patients seeking treatment for traumatic dental injuries at a major trauma centre. Furthermore, to analyse acute and subsequent treatment demands and treatment costs. METHODS: A therapeutic and economic analysis was performed of 7549 patients treated for traumatic dental injuries in a major trauma centre located at the University Hospital in Copenhagen, Denmark. Cases were divided into uncomplicated (concussion, subluxation, enamel and enamel-dentine fractures) and complicated cases (crown fractures with exposed pulps and crown-root fractures, luxation injuries with displacement of the tooth and bone fractures). RESULTS: Primary tooth injuries were found in 2874 patients, involving 5443 teeth, among which 62.8% had complicated injuries. Permanent tooth injuries were found in 4525 patients, involving 10,673 teeth, among which 40.4% had complicated injuries. The cost of treatment (including acute trauma service, follow-up and subsequent restoration) was estimated to be 0.6-1 mill USD a year for the patients treated in this trauma centre. If this figure is transferred to the estimated trauma population in Denmark, a yearly cost of traumatic dental injuries appears to range from 2 to 5 mill USD per 1 mill inhabitants per year according to the treatment scenario. CONCLUSION: Thus, treatment of traumatic dental injuries comprises an expensive part of the health services in Denmark.

Buonocore memorial lecture. Adhesive dentistry applied to the treatment of traumatic dental injuries.

Dental adhesive techniques have led to a significant simplification of the immediate and definitive treatment of traumatic dental injuries. Composite restoration of fractured teeth, bonding of tooth fragments, the use of laminate veneers or porcelain onlays and resin retained bridges are some of the ways adhesive techniques are used to treat fractured teeth. Furthermore, splinting of luxated teeth almost entirely relies on the combination of adhesion and a flexible resin which simulates the mobility of a normal periodontal ligament during the healing period. The internal strengthening of immature root-filled teeth with composite using an adhesive technique may possibly prevent late root fractures caused by weakening of the tooth structure resulting from endodontic procedures. Finally, the adhesive principle using a retro-seal with composite after apicoectomy significantly increases the healing rate and healing mode.

Healing of 208 intra-alveolar root fractures in patients aged 7-17 years.

This retrospective study consisted of 208 root-fractured, 168 splinted and 40 not splinted incisors in young individuals (aged 7-17 years) treated in the period 1959-1973 at the Pedodontic Department, Eastman Institute, Stockholm. Clinical and radiographic analyses showed that 69 teeth (33%) had developed hard tissue (fusion) healing of fragments. Interposition of periodontal ligament (PDL) and bone between the fragments was found in 17 teeth (8%). Interposition of PDL alone was found in 74 teeth (36%). Finally, non-healing with pulp necrosis and inflammatory changes between fragments was seen in 48 teeth (23%). Various clinical factors were analyzed for their relationship to the healing outcome with respect to healing/no healing and type of healing (hard tissue versus interposition of bone and/or PDL). Immature root and positive pulp sensitivity at time of injury was found to be significantly related to both pulp healing and hard tissue repair of the fracture. The same applied to concussion or subluxation of the coronal fragment compared to luxation with displacement (extrusive or lateral luxation). This relation was also represented by the variable millimeter diastasis between fragments before and after repositioning. Repositioning appeared to enhance the likelihood of both pulp healing and hard tissue repair. A positive effect of splinting, splinting methods (cap splints or orthodontic bands with an arch wire) or splinting periods could not be demonstrated on either pulp healing or type of healing (hard tissue versus interposition of bone and/or PDL). In conclusion, the findings from this retrospective study have cast doubts on the efficacy of long-term splinting and the types of splint used for root fracture healing. It is suggested that the role of splinting and splinting methods be examined in further studies.