The status of the periodontal ligament (PDL) and of the pulp are decisive for the healing of avulsed and replanted teeth. A tooth rescue box was developed and distributed to offer optimal storage conditions for avulsed teeth. The therapy comprised extraoral endodontic treatment and applications of medicaments to enhance periodontal healing. In this long-term clinical study the healing results following avulsion and replantation were investigated. Twenty-eight permanent teeth in 24 patients were evaluated. The extraoral storage media and periods varied considerably. Soon after avulsion six teeth were stored in a cell culture medium (tooth rescue box Dentosafe) for 1-53 h; the PDL was defined as not compromised. Sixteen teeth were stored in a non-physiologic situation temporarily, the PDL was considered as compromised. Six teeth were stored in non-physiologic conditions for longer periods; the condition of the PDL was defined as hopeless. On 14 teeth antiresorptive-regenerative therapy (ART) with the local application of glucocorticoids and enamel matrix derivative and the systemic administration of doxycyclin was used. In all teeth extraoral endodontic treatment by retrograde insertion of posts was performed. The mean observation period was 31.2 months (+/-24.1; 5.1-100.2; median: 23.8). All six teeth rescued physiologically healed with a functional PDL (functional healing, FH) irrespective of the storage period. Of eight teeth with a compromised PDL on which ART was used, three teeth healed with a functional PDL. All other teeth showed replacement resorption, in three teeth additionally infection-related resorption was recorded. The predominant influence on the healing results was the immediate physiologic rescue of avulsed teeth (chi-square, P = 0.0001). The use of ART seemed to support FH (chi-square, P = 0.0547) in teeth with a compromised PDL. No other factors (maturity of roots, crown fractures, gender, age, antibiotics) were related to healing. In a linear regression analysis physiologic storage (P = 0.0013) and ART (P = 0.0421) were related to FH. For a good prognosis avulsed teeth should be stored immediately in a cell-compatible medium. Therefore the tooth rescue box should be distributed at places with higher risks of accidents, in families with children and in emergency facilities. The use of ART might have potential for enhancing the prognosis of teeth with a PDL that is compromised but not in a hopeless condition. Extraoral endodontic treatment reduces infection-related complications; this item was discussed in the first part of the publication.

Following avulsion and replantation, teeth are at risk for infection and infection related resorption (IRR). Severe discolorations of tooth crowns and cervical root fractures are common. This study presents data on endodontic related complications of avulsed teeth replanted following an extraoral endodontic treatment. Periodontal aspects will be discussed in the second part of the present publication. Twenty-eight permanent teeth in 24 patients aged seven to 17 years were replanted after avulsion. All teeth could be evaluated. In all teeth extraoral endodontic treatment by retrograde insertion of ceramic or titanium posts was performed. Mean observation period was 31.2 months (median: 24.1 months). Nine teeth healed with a functional periodontal ligament (PDL) (functional healing, FH), 19 teeth exhibited replacement resorption (RR), which was succeeded by IRR in three teeth after observation periods of more than 14 months. Diagnosis was set to tunneling resorption (one case) and to cervical resorption preceded by complete RR (two cases). No early IRR was observed. All six teeth rescued in physiologic conditions (cell culture medium of tooth rescue box) exhibited FH. Discolorations of tooth crowns or other complications (cervical root fractures, fractures of posts) were not observed. No differences in the healing results of immature and mature teeth were observed which is in contrast to previous studies. This finding is explained with the different endodontic treatment protocols. Extraoral endodontic treatment by retrograde insertion of posts prevents early IRR and minimizes the overall incidence of IRR. The method does not negatively influence periodontal healing. As there are further advantages (no discoloration, no root fractures, patient not involved, less radiographs, less time consumption, less costs) the method is recommended in isolated teeth before replantation. Especially immature teeth profit from the prevention of complications.

Avulsed permanent teeth were replanted following immediate extraoral endodontic treatment by insertion of posts from a retrograde direction. Some teeth were rescued in a physiologic environment (tissue culture medium contained in a tooth rescue box), and in some cases antiresorptive-regenerative therapy (ART) was used. The aim of the study was to identify variables that influence the incidence of tooth loss and the survival of avulsed and replanted permanent incisors. Twenty-eight permanent teeth in 24 patients aged 7-17 years were investigated. In all teeth extraoral endodontic treatment by retrograde insertion of posts was performed. All nine teeth with functional healing (FH) were in situ. Of the 19 teeth with non-FH, seven were removed to allow transplantations. Two teeth were removed due to severe infrapositions. One tooth was lost following a new trauma. No tooth was lost due to acute infections. In descriptive statistics the incidence of tooth loss was significantly related to healing (P = 0.0098, Fisher's exact test), to treatment planning, i.e. consecutive replantation of premolars and primary canines (P = 0.0001, Fisher's exact test) and to immediate physiologic rescue (P = 0.0394). ART was related to tooth loss when tested in teeth with a compromised periodontal ligament (P = 0.0389). No influence could be found for the parameters maturity, age and all other factors. In a regression analysis treatment planning was the only factor left which had a significant influence (P = 0.0002). The estimated mean survival time (Kaplan-Meier analysis) for all teeth was 57.3 months. The survival was significantly reduced (P = 0.0002, log rank test) when consecutive transplantations were intended and performed. No influence could be found for maturity, age and all other factors. The different findings to previous studies can be explained by the prevention of complications related to conventional endodontic treatment approaches. Statistics have to be carefully interpreted due to case preselection which is determined by the treatment guidelines and actual treatment options of the individual treating dentist.