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Aim: The aim of this retrospective analysis was to evaluate the survival, success and possible complications of transplanted premolars in the posterior region subdivided by developmental stage and patient age. Materials and Methods: This study included patients who underwent tooth transplantation between April 2004 and December 2021. A total of 1654 premolars were transplanted into 1243 patients. Tooth mobility, oral hygiene and periodontal parameters were clinically evaluated. Intraoral radiographs were used to evaluate pulpal and periodontal healing, and root formation. The cumulative survival rate was calculated using the Kaplan–Meier method. Results: Data were subdivided into three groups based on the stage of root development and patient age. The mean age at surgery was 14.5 years. The main indication for transplantation was agenesis, followed by trauma and other indications, such as impacted or malformed teeth. A total of 11 premolars were lost during the study period. The overall survival and success rates in the immature premolar group after an observation period of 10 years were 99.7% and 99.4%, respectively. High survival and success rates (95.7% and 95.5%, respectively) were also observed when fully developed premolars were transplanted into the posterior region of adolescents. In adults, the success rate after 10-year follow-up is 83.3%. Conclusions: Transplantation of premolars with developing and fully developed roots is a predictable treatment modality.

BACKGROUND/AIMS Pre-transplant blood transfusions have previously shown a positive effect on organ allograft survival in humans and various animal species. The aims of this study were, first, to evaluate the effect of pre-transplant donor-specific blood transfusions on periodontal healing of fully developed allotransplanted teeth in monkeys; and second, to investigate the immune response against donor antigens and to determine a possible correlation between alloimmune reactions and histopathological signs of rejection. MATERIAL AND METHODS Twenty monkeys (Cercopithecus aethiops) were divided into ten pairs with similar sizes of incisors. One monkey in each pair gave three transfusions to the other monkey with 1-week intervals. One week after the last transfusion, each pair exchanged simultaneously a central maxillary incisor and a lateral mandibular incisor. The corresponding central maxillary and mandibular lateral incisors were autotransplanted to the contralateral sockets. All teeth were treated endodontically per-operatively. Histocompatibility was evaluated by mixed lymphocyte culture before the first transfusion, while alloantibodies and cell-mediated alloresponses were measured before transfusions and at 2 and 8 weeks after transplantation. All animals were sacrificed 8 weeks after tooth transplantation. Serial sections of the transplanted teeth were quantified histologically. RESULTS Mixed lymphocyte cultures showed positive reactions in 19 of 20 cases, indicating incompatibility. The majority of the monkeys developed antibodies towards the tooth donor. Cell-mediated cytotoxicity was negative in all monkeys. Histoquantification revealed a mean score of 70% normal periodontal ligament (PDL) in autotransplanted teeth, with 5% ankylosis. The allografts had a mean score of 17% normal PDL and 63% ankylosis, with no significant influence of transfusion. However, in the mandibular grafts, a tendency towards a positive transfusion effect was seen. CONCLUSIONS Donor-specific blood transfusion did not reduce ankylosis in tooth allografts. The healing of mandibular incisor tooth allografts was improved, but not that of maxillary incisors. Donor-specific antibodies showed no effect on the survival of allograft PDL.

Background/Aims Autotransplantation of developing premolars is an established treatment to replace missing teeth in the anterior maxilla in growing patients with a reported success rate of over 90%. The normal shape of the alveolus is observed after transplantation, but data on the presence and amount of alveolar bone after healing has not been previously reported. The aim of this study was to look for potential differences in alveolar bone dimensions between sites where autotransplanted premolars replaced missing incisors and control sites of contralateral incisors. Material/Methods There were 11 patients aged between 10 and 12 years five months (mean age: 10 years and 7 months) who underwent autotransplantation of a premolar to replace a central incisor. Cone Beam Computed Tomography (CBCT) performed at least 1 year after transplantation served to evaluate bone at sites of autotransplanted premolars and controls (contralateral maxillary central incisor). The thickness of the labial bone, plus the height and width of the alveolar process were measured on scans and compared at transplant and control sites. Results Mean thicknesses of the labial bone at the transplant and control sites were 0.78 mm and 0.82 mm respectively. Mean alveolar bone height was 15.15 mm at the transplant sites and 15.12 mm at the control sites. The mean marginal thickness of the alveolus was 7.75 mm at the transplant sites and 7.98 mm at the control sites. Mean thicknesses of the alveolus for half of its vertical dimension at the transplant and control sites were 7.54 mm and 8.03 mm, respectively. Conclusion The mean values of bone thickness, width and height of the alveolar process at sites of transplanted premolars were comparable to the mean values for the control incisors. Successful autotransplantation of developing premolars to replace missing central incisors allowed preservation of alveolar bone in the anterior maxilla. Plakwicz, P (corresponding author), Med Univ Warsaw, Dept Periodontol, Fac Dent, Ul Binieckiego 6, PL-02097 Warsaw, Poland. info@plakwicz.com

Traumatic injuries to the primary dentition present special problems that often require far different management when compared to that used for the permanent dentition. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on the consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The primary goal of these Guidelines is to provide clinicians with an approach for the immediate or urgent care of primary teeth injuries based on the best evidence provided by the literature and expert opinions. The IADT cannot, and does not, guarantee favorable outcomes from strict adherence to the Guidelines; however, the IADT believes their application can maximize the probability of favorable outcomes.

An accurate, clear, and easy-to-use traumatic dental injury (TDI) classification and definition system is a prerequisite for proper diagnosis, study, and treatment. However, more than 50 classifications have been used in the past. The ideal solution would be that TDIs are adequately classified within the International Classification of Diseases (ICD), endorsed by the World Health Organization (WHO). TDI classification provided by the 11th Revision of the ICD (ICD-11), released in 2018, and previous Revisions, failed to classify TDIs satisfactorily. Therefore, in December 2018, a proposal was submitted by Dr's Stefano Petti, Jens Ove Andreasen, Ulf Glendor, and Lars Andersson, to the ICD-11, asking for a change of the existing TDI classification. Proposal #2130 highlighted the TDI paradox, the fifth most frequent disease/condition neglected by most public health agencies in the world, and the limits of ICD-11 classification. Namely, injuries of teeth and periodontal tissues were located in two separate blocks that did not mention dental/periodontal tissues; infraction, concussion, and subluxation were not coded; most TDIs lacked description; and tooth fractures were described through bone fracture descriptions (e.g., comminuted, compression, and fissured fractures). These limitations led to TDI mis-reporting, under-reporting, and non-specific reporting by untrained non-dental healthcare providers. In addition, no scientific articles on TDIs, present in PubMed, Scopus, and Web-of-Science, used the ICD classification. Proposal #2130 suggested to adopt the Andreasen classification, the most widely acknowledged classification used in dental traumatology. The Proposal was reviewed by two WHO teams, two scientific Committees, one WHO Collaborating Center, and the Department of Non-Communicable Disease Prevention at WHO headquarters, and it underwent two voting sessions. In March 2022, the Andreasen classification was accepted integrally. A new entity was generated, called NA0D, "Injury of teeth or supporting structures" (https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f1413338122). Hopefully, this will contribute to increasing the public awareness, and the dental profession's management, of TDIs.

Ankylosis and subsequent tooth loss is a serious complication following tooth avulsion and replantation. The aim of the study was to evaluate the risk of ankylosis of human teeth replanted after various periods of dry storage prior to replantation. The material originates from a previously reported clinical study of 400 replanted teeth.Initial treatment, clinical and radiological examination and follow-up were conducted according to a standardized protocol. PDL was not removed. Follow-up periods ranged from 0.2 to 20 years (mean 5.1 years). The risk of ankylosis was analysed using the Cox regression model including stage of root development, length of dry time and age 20 years.The risk of ankylosis significantly increased with increasing length of dry time (hazard ratio: 1.22, P = .002) and was significantly higher for teeth with mature root development than for teeth with immature root development (hazard ratio: 2.1 P .0001). The estimated risks of ankylosis after 900 days for teeth with immature root development were: dry time 20 minutes: 33.9% (95% confidence interval (CI): 25.4-42.7), dry time 20-40 minutes: 49.6% (95% CI: 37.5-64.8), dry time 40-60 minutes: 54.4% (95% CI: 37.1-71.3) and dry time 60 minutes: 60.0% (95% CI: 45.0-75.8). The risks for teeth with mature root development were: dry time 20 minutes: 59.4% (95% CI: 51.6-66.5), dry time 20-40 minutes: 78.3% (95% CI: 69.5-86.2), dry time 40-60 minutes: 81.9% (95% CI: 67.2-92.4) and dry time 60 minutes: 86.4% (95% CI: 79.7; 92.9).The risk of ankylosis rose with increasing length of dry time. However, some teeth may heal without ankylosis even after 60 minutes of dry time. Immature teeth have a lower risk of developing ankylosis. Replantation should therefore always be considered for avulsed teeth.

OBJECTIVES The purpose of this retrospective cohort study was to investigate the occurrence of sequelae in the permanent teeth after avulsion of their primary antecessors and to evaluate the factors associated with this occurrence. METHODS We screened 2922 records of patients with photographic and radiographic images who attended a reference centre for dental trauma in the primary teeth from 1998 to 2019. Among them, 240 were eligible records of children who had suffered avulsion of the primary incisors and were followed up until complete eruption of the permanent successors. Multilevel Poisson regression analyses were conducted between the explanatory variables related to children and avulsed teeth; outcome variables were occurrences of any type of sequelae in the permanent teeth, opacities, hypoplasia and malformation. Relative risks (RRs) and respective 95% confidence intervals (95% CIs) were calculated. RESULTS Among the 240 children's records, 194 fulfilled the inclusion criteria. Finally, we found 266 primary avulsed teeth and 115 (43.2%) permanent teeth presenting with sequelae. Avulsion occurring when children were older than 4 years (RR = 0.48; 95% CI = 0.24-0.95) had lower risks for developing sequelae than children aged 0-2 years of age. Additionally, when avulsion occurred in the lower dental arch (RR = 1.45; 95% CI = 1.06-1.99) and when three or more teeth were affected (RR = 1.57; 95% CI = 1.02-2.41), the occurrence of sequelae in the permanent teeth was more probable than if avulsion occurred in the upper arch and affected only a single tooth. Age older than 3 years was a protective factor for the occurrence of hypoplasia and age older than 4 years protective for the occurrence of opacities. CONCLUSIONS The risk of sequelae in the permanent teeth after avulsion of their antecessor is higher when the trauma occurs in young children (

Background/aim Long-term splinting of teeth with intra-alveolar root fractures has been considered important for the deposition of hard tissue between the root fragments. The aim of this study was to compare the healing outcomes in teeth with intra-alveolar root fractures relative to splinting times in three dental centers in Scandinavia, using historical data. Materials and methods A total of 512 maxillary and mandibular incisors from three dental trauma centers were included in the study. Two of the centers used long-term splinting protocols of two to three months while the other center used a short-term splinting protocol of one month or less. Three outcomes were evaluated: (1) Healing with hard tissue (dentin and/or cementum). (2) Healing with connective tissue (periodontal ligament) interposition with or without bone between the fragments. (3) Non-healing due to the coronal pulp being necrotic and infected with granulation tissue interposed between the fragments. Results The mean splinting times were 18, 81, and 110 days in the three centers. Long-term splinting resulted in hard tissue healing more frequently than short-term splinting. Short-term splinting resulted in more connective tissue/bony healing than long-term splinting, while there was no difference in the frequency of non-healing between long-term and short-term splinting protocols. Conclusions While the results suggest that long-term splinting favors hard tissue deposition, one cannot, however, conclude that long-term splinting definitely favors hard tissue healing since the treatment protocols were not randomized among the three centers. More clinical studies on the role of splinting time need to be done.

Background/Aim: The survival of an avulsed tooth highly depends on the emergency management. The aim of this study was to evaluate the risk of ankylosis for avulsed human teeth stored in saliva preceded by various dry storage conditions prior to replantation. Material and methods: Data include 74 patients (54 male and 20 female) with 89 avulsed and replanted teeth (16 immature teeth, 73 mature teeth). Patient ages ranged from 6 to 36 years (median: 13.0 years). All teeth were stored in saliva before replantation. Treatment and follow-up were performed according to a standardized procedure. Follow-up periods ranged from 7 months to 20 years (mean 5.3 years). The risk of ankylosis over time was estimated by the Aalen–Johansen method in relation to the length of dry storage and the stage of root development. The effect of risk factors (root development and length of dry time) on the risk of ankylosis was analysed by Cox regression analysis. Results: For mature teeth, dry storage for 5 min or less before saliva storage resulted in a 47.4% (95% confidence interval (CI): 32.8–60.7) ankylosis rate. When dry storage was >5 min and

Avulsion of permanent teeth is one of the most serious dental injuries. Prompt and correct emergency management is essential for attaining the best outcome after this injury. The International Association of Dental Traumatology (IADT) has developed these Guidelines as a consensus statement after a comprehensive review of the dental literature and working group discussions. It represents the current best evidence and practice based on that literature search and expert opinions. Experienced researchers and clinicians from various specialties and the general dentistry community were included in the working group. In cases where the published data did not appear conclusive, recommendations were based on consensus opinions or majority decisions of the working group. They were then reviewed and approved by the members of the IADT Board of Directors. The purpose of these Guidelines is to provide clinicians with the most widely accepted and scientifically plausible approaches for the immediate or urgent care of avulsed permanent teeth. The IADT does not, and cannot, guarantee favorable outcomes from adherence to the Guidelines. However, the IADT believes that their application can maximize the probability of favorable outcomes.

Background/Aims Intrusive luxation is a frequent injury in the primary dentition. Complications such as ankylosis or pulp necrosis (PN) and infection with periapical inflammation may affect the developing permanent tooth if not diagnosed and treated in time. The aim of this study was to report the risk of PN, pulp canal obliteration (PCO), infection-related resorption (IRR), ankylosis-related resorption (ARR) and premature tooth loss (PTL) in primary teeth following intrusive luxation, and to identify possible risk factors for PN and PTL. Materials and method A retrospective analysis of a cohort comprising 149 patients 194 intruded primary incisors. No treatment was performed. The follow-up programme included examination after 4 weeks, 8 weeks, 6 months, 1 year, and at 6 years of age. The minimum follow-up period was 1 year or until time of tooth loss. Statistics: The Kaplan-Meier and Aalen-Johansen methods were employed along with Cox regression analysis. The level of significance was 5%. Results Risks estimated after 3 years: PCO 38.9% (95% CI: 31.8-46.0), PN 24.2% (95% CI: 17.7-30.6), IRR 8.8% (95% CI: 4.5-13.1), ARR 3.6% (95% CI: 1.0-6.2) and PTL 39.4% (95% CI: 31.2-47.5). Most teeth (83.7%) spontaneously re-erupted within the first year. Most complications were diagnosed within the first year. The risk of PN was lowest in patients less than 2 years of age. The degree of intrusion or a concomitant crown fracture did not affect the risk of PN or PTL. Conclusions Over 80% of the intruded primary teeth re-erupted spontaneously. However, nearly one-third of the teeth showed complications such as pulp infection/periapical inflammation or ankylosis, which could potentially affect the development of the permanent incisor. Therefore, patients should be monitored regularly, especially during the first year after injury, to diagnose and treat complications in time.

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.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%.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).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.

Aim To describe the etiology and clinical characteristics of alveolar process fractures treated in a regional trauma clinic. Material and method The study is a retrospective descriptive analysis of 299 patients (180 males, 119 females; 815 permanent teeth) diagnosed with fractures of the alveolar process. Results Violence was the overall most frequent cause of injury in men (44%), whereas the three most common causes of this type of injury in women were violence (33%), falls (32%), or traffic injuries (26%). Fracture of the alveolar process occurred most frequently in the maxilla (74%) and less frequently in the mandible (26%). The majority of the fractures involved only two teeth (57%) but occasionally involved up to seven teeth. The age at fracture ranged from 5 to 90 years; alveolar process fractures occurred most frequently between 15 and 25 years of age (43%). Concomitant soft tissue injuries were present in 73%. The most frequent location of the mandibular fracture line was along the periodontal ligament of the canine and in the sagittal suture between the two central maxillary incisors. This pattern appears to correlate with weak zones in the jaws. Conclusion In conclusion, alveolar process fractures are rare. They occur most frequently in young males and are often associated with violence. Concomitant soft tissue injuries are frequent. This type of injury accordingly appears to result from a frontal impact transmitted through a soft tissue shield (the lips) where the zone of least resistance gives in, namely the periodontal ligament and areas where the alveolar bone is thin.

Autotransplantation of teeth to the anterior maxilla may be indicated after trauma or in patients with congenitally missing teeth. The aim of this systematic review was to report the current evidence concerning survival and success rate, aesthetic outcome, and patient-reported outcome of autotransplanted teeth to the anterior maxilla.A MEDLINE search followed by an additional hand search was performed to identify relevant literature. All levels of evidence except case reports were considered. Any publication reporting on 10 or more autotransplanted teeth to the anterior maxilla, and written in English were eligible for this systematic review.The systematic search identified 95 abstracts. Thirty-seven full-text articles were evaluated of which 17 could finally be included. Data on survival and success rate of the transplants could be extracted from 11 studies. Survival rates ranged between 93% and 100% (weighted mean: 96.7%, median: 100%) after 9 months to 22 years of observation (median: 8.75 years). No consensus regarding definition of success criteria of the transplants could be found in the literature. Two and four studies contained data on aesthetic and patient-reported outcomes, respectively. In general, they reported favourable aesthetic results and high patient satisfaction.The current available evidence suggests a high survival rate after autotransplantation of teeth to the anterior maxilla. However, the level of evidence is low. Limited data on aesthetic and patient-reported outcomes warrant additional research in this field.

Background/Aim Traumatic dental injuries in the primary dentition occur frequently. Long-term complications may potentially cause damage to the permanent successor. The aim of this study was to report the risk of pulp necrosis (PN), pulp canal obliteration (PCO), repair-related resorption (RRR), infection-related resorption (IRR), ankylosis-related resorption (ARR), and premature tooth loss (PTL) in primary teeth following concussion and subluxation injuries, and to identify possible risk factors for PN, PCO, and PTL following subluxation. Material and methods The study was a retrospective analysis of a cohort comprising 31 patients (36 teeth) with concussion injury and 174 patients (241 teeth) with subluxation injury. No treatment was performed. The follow-up program included examination after 4 weeks, 8 weeks, 6 months, 1 year, and when the patients were 6 years of age. Minimum follow up was 1 year or until the time of tooth loss. Statistics: Kaplan-Meier and Aalen-Johansen methods and Cox regression analysis. Level of significance was set at 5%. Results Risk estimated after one year. Concussion: PCO 8.6% (95% CI: 0-17.9), PN 5.7% (95% CI: 0-13.4), PTL 5.6% (95% CI: 0-13.4). Subluxation: PCO 23.2% (95% CI: 17.8-28.6), PN 8.3% (95% CI: 4.8-11.8), IRR 2.6% (95% CI: 0.5-4.6), PTL 9.5% (95% CI: 5.0-14.1). Most complications (95%) were diagnosed within the first year. Most cases of PN (65%) and PTL (85%) were seen in patients aged 4 years or more. Conclusion Primary teeth with concussion or subluxation injury carry a low risk of PN and infection with periapical inflammation, root resorption, and PTL. Nearly all complications were diagnosed within the first year after the injury. The risk of PTL was highest in patients more than 4 years of age at the time of injury.

Diagnosis and treatment for traumatic dental injuries are very complex owing to the multiple trauma entities represented by six luxation types and nine fracture types affecting both the primary and the permanent dentition. When it is further considered that fracture and luxation injuries are often combined, the result is that more than 100 trauma scenarios exist, when the two dentitions are combined. Each of these trauma scenarios has a specific treatment demand and prospect for healing. With such a complexity in diagnosis and treatment, it is obvious that even experienced practitioners may have problems in selecting proper treatment for some of these trauma types. To remedy this situation, an Internet-based knowledge base consisting of 4000 dental trauma cases with long-term follow up is now available to the public and the professions on the Internet using the address http://www.DentalTraumaGuide.org. It is the aspiration that the use of this Guide may lead the practitioner to offer an evidence-based diagnosis and treatment.

– The history of the Dental Trauma Guide dates back to 1965, where guidelines were developed for trauma records and treatment of various trauma entities at the Department of Oral and Maxillofacial Surgery at the University Hospital in Copenhagen. In 1972, a unique possibility came up at the Serum Institute in Copenhagen to test various dental trauma procedures in monkeys, which served as kidney donors in the polio vaccine production. Over the years, 40 000 dental trauma patients were treated at the Trauma Centre according to established guidelines, and 4000 of these have been enrolled in long-term follow-up of various trauma entities. This has resulted in 79 clinical studies, and 64 studies in monkeys have examined the effect of various treatment procedures and the aetiology of most healing complications.

– Background: Traumatic dental injuries (TDI) comprise six types of luxation and seven types of tooth fractures. The risk of pulp necrosis is increased in teeth with combination injuries where fractures and luxations occur concomitantly. Aim: To report and compare the distributions of luxations and fracture types among children, adolescents, and adults, and to analyze the distribution and prevalence of combination injuries. Material and method: The study group included 4754 patients (3186 men and 1568 women) with 10 166 traumatized permanent incisors treated at Copenhagen University Hospital, Rigshospitalet. Differences in the distributions of trauma types among age groups (children 20 years) and distributions of concomitant crown fractures for each luxation type were analyzed with the Chi-square test. Results: A total of 7464 teeth (73.4%) had suffered a luxation injury and 5914 teeth (58.2%) a fracture. The overall most frequent injuries were crown fractures without pulp exposure (34.9%), concussions (24.2%), and subluxations (22.2%). The relative frequency of crown fractures without pulp exposure decreased across age groups (children 45.2%, adolescents 36.5%, adults 26.3%, P

BACKGROUND/AIM: Prediction tools are increasingly used to inform patients about the future dental health outcome. Advanced statistical methods are required to arrive at unbiased predictions based on follow-up studies. MATERIALS AND METHODS: The Internet risk calculator at the Dental Trauma Guide provides prognoses for teeth with traumatic injuries based on the Copenhagen trauma database: http://www.dentaltraumaguide.org The database includes 2191 traumatized permanent teeth from 1282 patients that were treated at the dental trauma unit at the University Hospital in Copenhagen (Denmark) in the period between 1972 and 1991. Subgroup analyses and estimates of event probabilities were based on the Kaplan-Meier and the Aalen-Johansen method. RESULTS: The Internet risk calculator shows individualized prognoses for the short- and long-term healing outcome of traumatized teeth with the following injuries: concussion, subluxation, extrusion, lateral luxation, intrusion, avulsion, crown fractures without luxation, root fractures and alveolar fractures. The prognoses for pulp necrosis, pulp canal obliteration, infection-related root resorption, ankylosis, surface resorption, marginal bone loss, and tooth loss were based on the tooth's root development stage and other risk factors at the time of the injury. CONCLUSIONS: This article explains the database, the functionality and the statistical approach of the Internet risk calculator. Language: en

– Aim: The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed. Material and methods: Long-term survival rates were calculated using data from 492 root-fractured teeth in 432 patients. The cause of tooth loss was assessed as being the result of either pulp necrosis (including endodontic failures), new traumas or excessive mobility. The statistics used were Kaplan–Meier and the log rank method. Results and Conclusions: The location of the root fracture had a strong significant effect on tooth survival (P = 0.0001). The 10-year tooth survival of apical root fractures was 89% [95% confidence interval (CI), 78–99%], of mid-root fractures 78% (CI, 64–92%), of cervical-mid-root fractures 67% (CI, 50–85%), and of cervical fractures 33% (CI, 17–49%). The fracture-healing type offered further prognostic information. No tooth loss was observed in teeth with hard tissue fracture healing regardless of the position of the fracture. For teeth with interposition of connective tissue, the location of the fracture had a significant influence on tooth loss (P = 0.0001). For teeth with connective tissue healing, the estimated 8-year survival of apical, mid-root, and cervical-mid-root fractures were all more than 80%, whereas the estimated 8-year survival of cervical fractures was 25% (CI, 7–43%). For teeth with non-healing with interposition of granulation tissue, the location of the fracture showed a significant influence on tooth loss (P = 0.0001). The cause of tooth loss was found to be very dependent upon the location of the fracture. In conclusion, the long-term tooth survival of root fractures was strongly influenced by the type of healing and the location of the fracture.

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 purpose of this study was to analyze tooth mobility changes in root-fractured permanent teeth and relate this to type of interfragment healing (hard tissue healing (HT), interfragment healing with periodontal ligament (PDL) and nonhealing with interposition of granulation tissue (GT) because of pulp necrosis in the coronal fragment. Furthermore, the effect of age, location of the fracture on the root, and observation period on mobility values was analyzed. Mobility values were measured for 44 of 95 previous reported root-fractured permanent incisors. Mobility changes were measured with a Muhlemanns periodontometer and noninjured incisors served as controls. The mobility values represented the labial-lingual excursion of the root measured in μm when the tooth received a frontal and a palatal impact of 100 g force. In 18 cases of hard tissue healing (HT), a slightly increased mobility was seen after 3 months and 1 year, and a normalization of mobility value was usually found after 5 and 10 years. In 17 cases of PDL healing, generally a higher mobility was found in comparison with root fractures healing with hard tissue, and a consistent decrease in mobility value was found in the course of the 10 year observation period. A tendency for reduced mobility over time was found, a relation that could possibly be explained by the known general decrease in tooth mobility with increasing age. Finally, nine cases of nonhealing with initial interposition of granulation tissue (GT) because of pulp necrosis in the coronal fragment resulted in increasing mobility values possibly related to a lateral breakdown of the PDL in relation to the fracture line. In control teeth, a lowering of mobility was found over the course of a 10-year observation period. In conclusion, mobility changes appeared to reflect the radiographic healing stages and known age effects upon tooth mobility.

– Aim: To analyze the influence of a crown fracture without pulp exposure on the risk of pulp necrosis (PN) in teeth with extrusion or lateral luxation. Material and methods: The study included 82 permanent incisors with extrusion from 78 patients (57 male, 21 female) and 179 permanent incisors with lateral luxation from 149 patients (87 male, 62 female). A total of 25 teeth with extrusion and 33 teeth with lateral luxation had suffered a concomitant crown fracture (infraction, enamel fracture or enamel-dentin-fracture). All the teeth were examined and treated according to a standardized protocol. Statistics: The risk of PN was analyzed separately for teeth with immature and mature root development by the Kaplan–Meier method, the log-rank test and Cox regression (lateral luxation only). The level of significance was set at 5%. Risk factors included in the analysis were gender, age, crown fracture, and response to electric pulp test at the initial examination. Results: A concomitant crown fracture significantly increased the risk of PN in teeth with lateral luxation. For teeth with immature root development (hazard ratio: 10 [95% confidence interval (CI): 1.1–100] P = 0.04), the overall risk increased from 4.7% (95% CI: 0–10.8) to 40% (95% CI: 2.8–77.2). For teeth with mature root development [hazard ratio: 2.4 (95% CI: 1.4–4.2) P 0.05). Conclusion: A concomitant crown fracture without pulp exposure significantly increased the risk of PN in teeth with lateral luxation. This risk factor may be used to identify teeth at increased risk of PN following lateral luxation injury.

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 followup 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.

– Background: The reported risk of pulp necrosis (PN) is generally low in teeth with subluxation injuries. A concomitant crown fracture may increase the risk of PN in such teeth. Aim: To analyse the influence of a concomitant trauma-related infraction, enamel-, enamel–dentin- or enamel–dentin–pulp fracture on the risk of PN in permanent teeth with subluxation injury. Material and Methods: The study included 404 permanent incisors with subluxation injury from 289 patients (188 male, 101 female). Of these teeth, 137 had also suffered a concomitant crown fracture. All the teeth were examined and treated according to a standardized protocol. Statistical Analysis: The risk of PN was analysed separately for teeth with immature and mature root development by the Kaplan–Meier method, the log-rank test and Cox regression analysis. The level of significance was set at 5%. Risk factors included in the analysis were gender, patient age, crown fracture type, mobility and response to an electric pulp test (EPT) at the initial examination. Results: Teeth with immature root development: The risk of PN was increased in teeth with a concomitant enamel fracture (log-rank test: P = 0.002), enamel–dentin fracture (log-rank test: P

Background/Aim: Intrusive luxation in the permanent dentition is an uncommon injury but it is considered one of the most severe types of dental trauma because of the risk for damage to the periodontal ligament, pulp and alveolar bone. Management of intrusive luxation in the permanent dentition is controversial. The purpose of this study was to evaluate pulp survival and periodontal healing in intrusive luxated permanent teeth in relation to treatment alternatives, degree of intrusion and root development. Material and Method: The material consisted of 60 intruded permanent teeth in 48 patients (32 boys and 16 girls) aged 6-16 years (mean 9.4, median 9.0). The observation time was 6-130 months (mean 47.8, median 40.0). The analysed treatments were spontaneous re-eruption (17 teeth), orthodontic extrusion (12 teeth) and surgical reposition (31 teeth). The degree of intrusion was registered as mild (0-3 mm), moderate (4-6 mm) and severe (‡7 mm). Root development was categorized with respect to root formation and development of the apex into four stages; one-quarter to three-quarters root formation, full root formation with open apex, full root formation with half-closed apex and full root formation with apex closed. Ankylosis-related resorption with pulp necrosis was diagnosed in 20 teeth, ingrowth of bone apically in two teeth, pulp necrosis without ankylosis- related resorption in 23 teeth and pulp revitalization occurred in 15 teeth. Results: Significant correlations to the treatment outcome were root development (P = 0.03) and degree of intrusion (P = 0.03). Conclusions :N o firm conclusion could be drawn for the difference in outcome between orthodontic extrusion and surgical reposition. To conclude, evaluation of the prognosis for intruded teeth should be based on the stage of root development and degree of intrusion. In teeth with immature root development, no active treatment appears to result in fewer healing complications.

Regeneration (revitalization) of infected necrotic pulp tissue has been an important issue in endodontics for more than a decade. Based on a series of case reports, there appears to be evidence that new soft tissue can enter the root canal with a potential for subsequent hard tissue deposition resulting in a narrowing of the root canal. Very little is presently known about the exact nature of this tissue growing into the canal and how it may behave in the long term. In the case of regeneration of necrotic non-infected pulp tissue, a series of clinical and histological studies have shown that such events may take place in four variants: (i) Revascularization of the pulp with accelerated dentin formation leading to pulp canal obliteration. This event has a good long-term prognosis. (ii) Ingrowth of cementum and periodontal ligament (PDL). The long-term prognosis for this event is not known. (iii) Ingrowth of cementum, PDL, and bone. The long-term prognosis is only partly known, but cases developing an internal ankylosis have been described. (iv) Ingrowth of bone and bone marrow is a rare phenomenon and the long-term prognosis does not appear to be good. Based on current knowledge, expectations with respect to pulp regeneration (revitalization) of infected necrotic dental pulps are difficult to predict; more information than now available is needed before procedures for pulpal regeneration can be routinely recommended with a predictable long-term prognosis.

Healing subsequent to dental trauma is known to be very complex, a result explained by the variability of the types of dental trauma (six luxations, nine fracture types, and their combinations). On top of that, at least 16 different cellular systems get involved in more severe trauma types each of them with a different potential for healing with repair, i.e. (re-establishment of tissue continuity without functional restitution) and regeneration (where the injured or lost tissue is replaced with new tissue with identical tissue anatomy and function) and finally metaplasia (where a new type of tissue replaces the injured). In this study, a review is given of the impact of trauma to various dental tissues such as alveolar bone, periodontal ligament, cementum, Hertvigs epithelial root sheath, and the pulp.

– The aim of this article is to give an overview of the art of writing a good manuscript for original articles specifically for the scientific journal Dental Traumatology. Selection of journal, style and language, structure of the original article and important aspects of content and online submission are presented. The authors share their experience in this field from the perspectives of the researcher, editor and publisher.

In vivo studies are sometimes needed to understand healing processes after trauma. For several reasons, not the least ethical, such studies have to be carefully planned and important considerations have to be taken into account about suitability of the experimental model, sample size and optimizing the accuracy of the analysis. Several manuscripts of in vivo studies are submitted for publication to Dental Traumatology and rejected because of inadequate design, methodology or insufficient documentation of the results. The authors have substantial experience in experimental in vivo studies of tissue healing in dental traumatology and share their knowledge regarding critical considerations when planning experimental in vivo studies.

The purpose of this article is to suggest important considerations for epidemiologic and clinical studies in the field of dental traumatology. The article is based on the authors' experiences from research in this field and editorial board work for the scientific journal Dental Traumatology. Examples are given of issues where development is important. The importance of planning ahead of the study and consulting with experts in other fields is emphasized.

International Journal of Paediatric Dentistry 2011 Aim. To assess the relation between type of traumatic injury and use of pacifier at the time of a fall accident in 0- to 2-year olds. Material and methods. The study draws on data from the database on traumatic dental injuries at the Department of Oral and Maxillofacial Surgery, Copenhagen University Hospital. Results. The study includes 1125 patients ≤2 years of age, representing a total of 1886 injuries. A total of 176 patients had fallen while using a pacifier, whereas 949 children suffered a fall without using a pacifier. In the pacifier group, 11.9% had crown fractures compared with 20.0% of children who had fallen without a pacifier (P = 0.012). Tooth displacement (lateral luxation, extrusion or avulsion) was relatively more frequent in children falling with a pacifier compared to children falling without a pacifier (64.8%vs 54.8%; P = 0.014). Furthermore, soft tissue injury was less frequent among the former (28.4%vs 38.3%; P = 0.013). Conclusions. Injuries occurring while using a pacifier tend to be tooth displacement rather than fractures. This is in accordance with the theoretical consideration that a blunt impact tends to favour displacement, whereas a sharp impact tends to favour fractures of the hard dental tissues. Language: en

The purpose of the present retrospective study was to analyze treatment choice and outcome in patients with retention/impaction of the mandibular second molar. Radiographic material, from three large clinics, from 106 patients (60 males and 46 females) with 126 retained/impacted permanent mandibular second molars treated during the years 1985-2005 was evaluated for treatment choice and treatment outcome. Follow-up questionnaires were sent to dentists in cases where treatment outcome could not be determined from the radiographic material. Clinical evaluation was not possible as the patients were no longer associated with the clinic where they were treated. The cases were categorized into six groups: (A) no treatment; (B) orthodontic treatment; (C) surgical exposure of the second molar; (D) removal of the third molar; (E) removal of the second molar; and (F) other treatments. The various treatment choices performed during 1985-2005 showed acceptable results in 66 of the cases. In 23 cases, the results were unacceptable. In 37 cases, the radiographic material could not document the outcome nor was evaluation of the final outcome possible due to the patient's young age. Remarkable are the high percentages of unacceptable treatment outcome, 25.9% in group D (removal of third molar) and 23% in group E (removal of second molar). As the material was collected before new advanced methods of surgical uprighting and new methods of orthodontic uprighting had been introduced, these percentages are expectedly lower today. Even so, it is highly recommended to focus especially on these two groups in future studies on treatment outcome.

The purpose of the study was to evaluate and assess the survival rate of 534 root fractured teeth, including factors that may affect the survival rate but were not included in previous long-term studies. Location of fracture was registered as in the cervical, cervical/middle, middle and apical one-third of the root, and root development was categorized into five stages. Altogether, 383 (78%) showed healing of the fracture, with either formation of hard tissue or interposition of soft tissue between the fragments. In these teeth, no significant difference was found between positions in the root or types of healing. In 325 teeth, the healing remained unchanged throughout the control period, while 58 teeth showed a posthealing complication. A new injury occurred in 47 teeth; in 21 of these, the injury healed spontaneously, in four after endodontic treatment. Increased mobility of the coronal fragment was recorded for 32 teeth, and in 11 of these, the looseness of the fragment was so pronounced that the teeth had to be extracted. No healing, i.e. radiolucency in the alveolar bone, adjacent to fracture, took place in 109 teeth (22%). Of these teeth, 34 were extracted during the observation time while 75 (69%) showed healing after endodontic therapy. At the final assessment of survival (including all parameters) of 534 root fractured teeth, 425 (80%) showed survival and 109 (20%) were extracted during the observation period. It was concluded that the survival of root-fractured teeth was high for up to 10 years of observation (mean = 63 months). The highest frequency of tooth loss (70%) was found in 77 teeth with horizontal fractures restricted to the cervical part of the root. When these teeth were excluded, the frequency of survival in remaining teeth rose to 88%.

The objective of the present study was to test the hypothesis that the fracture strength of calcium hydroxide and mineral trioxide aggregate (MTA)-filled immature teeth decreased over time. Immature mandibular incisors from sheep were extracted and the pulps were extirpated using an apical approach with a barbed broach, and the teeth were divided into three experimental groups. Group 1: untreated teeth. Group 2: the root canals were filled with calcium hydroxide paste. Group 3: the root canals were filled with MTA. All specimens were kept in saline with 1% antibiotics at 4 degrees C for certain periods of time: 2 weeks, 2 months, and 1 year. Then they were tested for fracture strength in an Instron testing machine. The results were subjected to statistical analysis by the Tukey-Kramer tests. A P-value (0.05) was considered statistically significant. One tooth from each group was selected randomly for a histological study, examining matrix metalloproteinases (MMP2 and MMP14) and tissue inhibitor of metalloproteinase (TIMP). The results showed the mean fracture strengths decreased over time for all the three groups. Although the untreated teeth showed the highest value (45.5 MPa) at 2 weeks, the fracture strengths decreased significantly after 2 months (P0.05). On the other hand, the teeth treated with calcium hydroxide or MTA decreased, but not significantly over time (P0.05). For the MTA-treated teeth, the fracture strengths were not found significantly different from the untreated or calcium hydroxide-treated teeth at 2 weeks or 2 months (P0.05). However, the strength was significantly higher in the MTA group compared with the other two groups after 1 year (P0.05). Immunofluorescence images revealed expression of collagen type 1, MMP-2 and MMP-14 in both untreated and endodontically treated teeth. However, TIMP-2 was only observed in the MTA-treated teeth. In conclusion, the teeth with root treatment with MTA showed the highest fracture resistance at 1 year (P0.05). An explanation could be that MTA induced the expression of TIMP-2 in the dentin matrix and thereby possibly prevented destruction of the collagen matrix.

The clinical outcome of closed vs open reduction and rigid fixation was compared based on a systematic review of the literature. Ten non-randomized retrospective studies were found. In six of these ten studies, the complication rate was significantly increased when open reduction and plating was performed. In the remaining studies, a slightly elevated (but not significant) infection rate was found when compared with closed reduction. Altogether, an infection rate of 5.0% was found in the closed reduction group whereas 10.6% and 14.6% were found when open reduction was performed using either plates or wires. Nerve injuries were slightly increased when open reduction was found (although not significant). With regard to occlusal disturbances, no difference was found in the open and closed reduction group. Concerning overall complication problems, six of seven studies showed more problems after open than closed reduction. In conclusion, this literature review using retrospective studies has raised doubts regarding the superiority of open reduction and rigid splinting, compared to closed reduction and intermaxillary splinting. However, a bias concerning the preferential use of open reduction in case of more complicated fractures cannot be excluded, which might explain the differences found between the two procedures. Prospective, randomized clinical trials are needed to illuminate this problem.

Background/Aim The aim of the study was to evaluate the survival of intruded permanent teeth related to treatment in a large number of patients, with special focus on development of pulp necrosis and replacement resorption (ankylosis-related resorption). Materials and Methods The material consisted of 168 patients (mean age 9.6 years) with 230 intruded permanent teeth from dental trauma clinics in Copenhagen, Denmark, Stockholm, Sweden, and Oslo, Norway. The degree of intrusion was classified as mild (1– 7 mm). Root development was categorized with respect to root formation and development of the apex into three groups of increasing tooth maturity: very immature, immature, and mature. Results Awaiting re-eruption was the treatment of choice in 107 teeth (47%), orthodontic repositioning in 28 (12%) and surgical repositioning in 95 (41%) teeth. Pulp necrosis was diagnosed in 173 teeth (75%), infection-related root resorption in 57 (25%) and replacement resorption in 50 teeth (22%). Very immature teeth, teeth diagnosed with mild intrusion, and teeth awaiting re-eruption had significantly (P < 0.05) fewer complications. In a stepwise discriminant function analysis, choice of treatment, root development, and degree of intrusion were significantly (P < 0.05) associated with the development of replacement resorption. Root development and degree of intrusion were significantly (P < 0.05) associated with the development of pulp necrosis. Conclusion This study indicates that root development and degree of intrusion may be important for the development of pulp necrosis as well as replacement resorption, whereas choice of treatment only seems to influence the development of replacement resorption in intruded permanent teeth. Awaiting re-eruption resulted in the lowest risk for developing replacement resorption.

Aim. The aim of this study was to classify early arrested eruption of primary molars and to analyse and explain the sequelae for the surrounding alveolar bone and the succeeding premolar. Design. The position of the arrested primary molars in the mandible, the height of the local alveolar bone, and the morphology and location of the succeeding premolar were evaluated on radiographs from 29 children. Results. Four groups of arrest from mild to severe with regards to infra-position were categorized (Groups I–IV). Mean ages at the time of referral decreased from Groups I (8 years, 10 months) to Group IV (5 years, 9 months). Sequelae. (i) Reduction of alveolar bone height (Groups I–III); (ii) delayed maturity of the succeeding premolar (two-thirds of the cases); (iii) malformation of the succeeding premolar (mainly Groups III and IV); and (iv) ectopically located premolar occlusal to the retained molar (Group IV). Conclusions. The deeper in the alveolar process a primary molar is retained, the earlier the disturbance in the eruption has occurred, and the greater is the risk of the permanent tooth germ being malformed and malpositioned. It is estimated that the earliest occurrences of arrested eruption of primary molars supposedly occur before the age of 3.

Trauma to the primary dentition present special problems and the management is often different as compared with permanent teeth. An appropriate emergency treatment plan is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. 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 in which the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence based on literature research and professional opinion. In this third article out of three, the IADT Guidelines for the management of traumatic injuries in the primary dentition, are presented.

Avulsion of permanent teeth is the most serious of all dental injuries. The prognosis depends on the measures taken at the place of accident or the time immediately after the avulsion. Replantation is the treatment of choice, but cannot always be carried out immediately. An appropriate emergency management and treatment plan is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. 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 in which the data did not appear conclusive, recom- mendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence based on literature research and professional opinion. In this second article of three, the IADT Guidelines for management of avulsed permanent teeth are presented.

Aim To analyze the risk of pulp canal obliteration (PCO), pulp necrosis (PN), repair-related resorption (RRR), infection-related resorption (IRR), ankylosis-related resorption (ARR), marginal bone loss (MBL), and tooth loss (TL) for teeth involved in an alveolar process fracture and to identify possible risk factors. Material and method A total of 91 patients with 223 traumatized teeth. Statistics The risks of PCO, PN, RRR, IRR, ARR, MBL, and TL were analyzed separately for teeth with immature and mature root development using Kaplan–Meier and Aalen–Johansen methods. Possible risk factors for PN (age, fracture in relation to apex, displacement, gingival injury, degree of repositioning, type of splint, duration of splinting, treatment delay, and antibiotics) were analyzed for mature teeth using Cox regression. The level of significance was 5%. Results Immature: No severe complications (PN, IRR, ARR, MBL, or TL) were diagnosed during follow up. Mature: Estimated risk after a 10-year follow up: PN: 56% (95% confidence interval (CI): 48.1–63.9), IRR: 2.5% (95% CI: 0–5.1), ARR: 2.1% (95% CI: 0.1–4.1), MBL: 2.4% (95% CI: 0.3–4.4), and TL: 7.8% (95% CI: 0–15.7). The following factors significantly increased the risk of PN in teeth with mature root development: fracture in relation to apex (hazard ratio (HR): 2.6 (95% CI: 0.2 – 5.7), P = 0.01), displacement in the horizontal part of the fracture >2 mm (HR: 1.8; 95% CI: 1.1–3.2, P = 0.03), incomplete repositioning (HR: 2.1 (95% CI: 1.3–3.5), P = 0.003), and age >30 years (HR: 2.3 (95% CI: 1.1–4.6), P = 0.02). The type of splint (rigid or flexible), the duration of splinting (more or less than 4 weeks), and the administration of antibiotics did not affect the risk of PN. Conclusion Teeth involved in alveolar process fractures appear, apart from PN, to have a good prognosis. A conservative treatment approach is recommended.

Purpose A systematic review was performed to find evidence for prophylactic administration of antibiotics in relation to treatment of maxillofacial fractures. Methods Four studies were retrieved that fulfilled most of the requirements of being randomized controlled clinical trials. Results An analysis of these studies showed a 3-fold decrease in the infection rate of mandibular fractures in the antibiotic treated groups compared with the control groups. A variety of antibiotics had been used with an apparently uniform effect. A “1-shot” regimen or a 1-day treatment course had a similar or perhaps even better effect than 7 days of treatment. No infections were related to condylar, maxillary, or zygoma fractures. Conclusion A 1-shot or 1-day administration of prophylactic antibiotics seem to be the best documented to reduce infections in the management of mandibular fractures not involving the condylar region.

Calcium hydroxide [Ca(OH)2], when used as a root canal dressing, has been shown to promote periapical healing, induce formation of an apical hard tissue barrier (apexification), and arrest infection-related root resorption. The main mechanism of action is thought to be the high alkalinity of Ca(OH)2 ensuring a bactericidal or bacteriostatic effect upon microorganisms in the root canal and dentinal tubules. Several anatomical factors related to the root canal, such as the coronal access cavity, the apical foramen, the dentinal tubules, and existing resorption cavities on the root surface, all allow leakage of hydroxide ions from the root canal. The purpose of the present clinical study was to analyze pH changes in 63 permanent anterior teeth in which Ca(OH)2 (Calasept®) was used as an initial canal dressing after replantation and subsequent pulp necrosis had developed. The pH changes in the pulp canal were studied with relation to observation period, stage of root formation, healing of any periapical radiolucency, infection-related root resorption, formation of an apical hard tissue barrier, and finally the radiographic appearance of Ca(OH)2 in the canal (i.e. present or not). The study showed that several factors determined the pH level: the observation period (i.e. observation periods exceeding 6 months showed a significant drop in pH level below a pH of 10), an initial active inflammatory root resorption (tendency to be related to a drop in pH), and a subsequent progression of infection-related resorption (the same tendency to be related to a drop in pH to below 10). The size of the apical foramen and the length of the pulp had no relation to pH change. The radiographic disappearance of Ca(OH)2 in the root canal (loss of radiopacity of the canal dressing) was found to be significantly associated with a drop in pH (P=0.001). It was concluded that radiographic monitoring of the Ca(OH)2 presence in the root canal is essential for endodontic treatment planning (i.e. when to replace Ca(OH)2 or perform a permanent root filling). Furthermore, continuous activity of inflammatory root resorption may indicate a drop in pH and should result in replacement of new Ca(OH)2. It should be noted that these findings apply to a Ca(OH)2 product (Calasept®) with no added radiopaque material.

Replanting avulsed teeth with a doubtful long-term prognosis due to unfavorable extra-alveolar conditions has recently been questioned by Kenny and Barrett (1). Many factors, however, still favor replanting such teeth. First of all, reliability of failure predictors has not yet been tested in prospective studies. Secondly, preservation of even resorbing replanted teeth may offer significant long-term advantages in preparation for definitive treatment. Also, for psychological reasons, replantation can significantly reduce the anxiety and despair of both the injured child and the parents. Furthermore, decoronation of a resorbing anterior tooth will allow it to serve as a matrix for alveolar bone formation and preserve an otherwise resorbing alveolar process, thereby leaving an environment of bone and soft tissue that is optimal for both single implant insertion or fixed prosthesis. Finally, replantation and subsequent decoronation, if indicated, appears to be cost-effective in comparison with non-replantation combined with subsequent repeated prosthetic tooth replacements owing to vertical alveolar growth of adjacent ridge areas, with eventual definitive implant placement or a fixed prosthesis.

Decoronation of ankylosed teeth in infraposition was introduced in 1984 by Malmgren and co-workers (1). This method is used all over the world today. It has been clinically shown that the procedure preserves the alveolar width and rebuilds lost vertical bone of the alveolar ridge in growing individuals. The biological explanation is that the decoronated root serves as a matrix for new bone development during resorption of the root and that the lost vertical alveolar bone is rebuilt during eruption of adjacent teeth. First a new periosteum is formed over the decoronated root, allowing vertical alveolar growth. Then the interdental fibers that have been severed by the decoronation procedure are reorganized between adjacent teeth. The continued eruption of these teeth mediates marginal bone apposition via the dental-periosteal fiber complex. The erupting teeth are linked with the periosteum covering the top of the alveolar socket and indirectly via the alveolar gingival fibers, which are inserted in the alveolar crest and in the lamina propria of the interdental papilla. Both structures can generate a traction force resulting in bone apposition on top of the alveolar crest. This theoretical biological explanation is based on known anatomical features, known eruption processes and clinical observations.

A prospective study of 140 intruded permanent teeth was examined for the following healing complications: pulp necrosis (PN), root resorption (RR; surface, inflammatory and replacement resorption), and defects in marginal periodontal bone healing (MA). The occurrence of these healing complications was related to various treatment factors such as treatment delay, method of repositioning (i.e. expecting re-eruption, orthodontic reposition and surgical reposition), type of splint (rigid, semirigid and flexible), length of splinting (days) and the use of antibiotics. Treatment delay, i.e. before and after 24 h, had no effect upon healing. Active repositioning in individuals with incomplete root formation (surgical or orthodontic) had a negative effect upon the three healing parameters compared with spontaneous eruption. In teeth with complete root formation and an age of 12-17 no repositioning was still the best treatment in regard to MA. In individuals older than 17 years of age, cases were not anticipated to spontaneously erupt and in these cases, the general choice of treatment was either active orthodontic or surgical repositioning. The former procedure appeared in this treatment scenario to slightly reduce the risk of MA complications. However, this treatment procedure was also found to be more time demanding (an average of 22 consultations for orthodontic repositioning compared with 17 consultations for surgical repositioning). If a surgical repositioning was performed, the type of splint (i.e. flexible, semirigid or rigid) appeared to have no significant effect on the type of healing. The same applied to the length of splinting time (shorter or longer than 6 weeks). No effect of dentin covering procedures for associated crown fractures (enamel-dentin fractures) could be demonstrated. Likewise, antibiotics had no apparent effect upon healing. In conclusion, in patients with intruded teeth with incomplete root formation, spontaneous eruption should be expected. In patients with completed root formation and with an age of 12-17 spontaneous eruption can still occur, but must be monitored very carefully. In older patients (i.e. >17 years) with completed root formation, either surgical or orthodontic extrusion should be attempted. The latter procedure appeared to lead to a slight reduction (not significant) in the risk of MA complications. The extent and direction of the intrusion may however favour surgical repositioning.