Autotransplante dentário como ferramenta de tratamento para perdas precoces de molares / Dental self transplantation as a treatment tool for early molar loss / Auto trasplante dental como herramienta de tratamiento para la pérdida molar temprana

O transplante dentário autógeno é um procedimento cirúrgico que consiste na transposição de um elemento dentário do seu alvéolo para um outro, em um mesmo indivíduo. Esta abordagem é indicada para substituir elementos com prognóstico desfavorável ou reabilitar áreas edêntulas. O objetivo deste trabalho é apresentar as vantagens do transplante dentário autógeno frente a perdas dentárias precoces e os critérios necessários para indicação do mesmo, por meio de um relato de caso clínico no qual, uma paciente do gênero feminino, 16 anos foi submetida ao transplante do elemento 48 para o alvéolo do 47 por motivos de lesão cariosa com extensa destruição coronária com impossibilidade de tratamento clínico restaurador. Em acompanhamento pós-operatório de 01 ano os resultados demostraram continuidade do desenvolvimento radicular do elemento transplantado em seu novo alvéolo, estando este, sem mobilidade, livre de lesões periodontais e/ou endodônticas. Desta forma, conclui-se que as vantagens do transplante dentário autógeno incluem a possibilidade de reabilitação dentária de forma natural, imediata e de baixo custo comparado a tratamentos como implantes e próteses. E este método quando indicado corretamente e realizado sob os devidos cuidados pode alcançar excelentes resultados funcionais e estéticos, sendo uma opção viável para reabilitação de perdas dentárias precoces... (AU)

The Autogenous dental transplantation is a surgical procedure that consists of the transposition of a dental element from its socket to another, in the same individual. This approach is indicated to replace elements with an unfavorable prognosis or to rehabilitate edentulous areas. The objective of this paper is to present the advantages of autogenous dental transplantation against early tooth loss and the necessary criteria for its indication, through a clinical case report in which a 16-year-old female patient underwent transplantation element 48 for the alveolus of the 47 due to carious lesions with extensive coronary destruction with impossibility of restorative clinical treatment. In a 01-year postoperative follow-up, the results showed continuity of root development of the transplanted element in its new alveolus, which is without mobility, free from periodontal and/or endodontic lesions. Thus, it is concluded that the advantages of autogenous dental transplantation include the possibility of natural, immediate and low-cost dental rehabilitation compared to treatments such as implants and prostheses. And this method, when correctly indicated and performed with due care, can achieve excellent functional and esthetic results, being a viable option for the rehabilitation of early tooth loss... (AU)

El trasplante dentario autógeno es un procedimiento quirúrgico que consiste en la transposición de un elemento dentario de su alvéolo a otro, en el mismo individuo. Este abordaje está indicado para reemplazar elementos con pronóstico desfavorable o para rehabilitar áreas edéntulas. El objetivo de este trabajo es presentar las ventajas del trasplante dentario autógeno frente a la pérdida dentaria precoz y los criterios necesarios para su indicación, mediante el reporte de un caso clínico en el que se trasplantó a una paciente de sexo femenino de 16 años. 47 por lesiones cariosas con extensa destrucción coronaria con imposibilidad de tratamiento clínico restaurador. En un seguimiento postoperatorio de 01 año, los resultados mostraron continuidad del desarrollo radicular del elemento trasplantado en su nuevo alvéolo, que se encuentra sin movilidad, libre de lesiones periodontales y/o endodónticas. Así, se concluye que las ventajas del trasplante dental autógeno incluyen la posibilidad de una rehabilitación dental natural, inmediata y de bajo costo frente a tratamientos como implantes y prótesis. Y este método, correctamente indicado y realizado con el debido cuidado, puede lograr excelentes resultados funcionales y estéticos, siendo una opción viable para la rehabilitación de la pérdida dentaria temprana... (AU)

Analysis of the cells isolated from epithelial cell rests of Malassez through single-cell limiting dilution.

The epithelial cell rests of Malassez (ERM) are essential in preventing ankylosis between the alveolar bone and the tooth (dentoalveolar ankylosis). Despite extensive research, the mechanism by which ERM cells suppress ankylosis remains uncertain; perhaps its varied population is to reason. Therefore, in this study, eighteen unique clones of ERM (CRUDE) were isolated using the single-cell limiting dilution and designated as ERM 1-18. qRT-PCR, ELISA, and western blot analyses revealed that ERM-2 and -3 had the highest and lowest amelogenin expression, respectively. Mineralization of human periodontal ligament fibroblasts (HPDLF) was reduced in vitro co-culture with CRUDE ERM, ERM-2, and -3 cells, but recovered when an anti-amelogenin antibody was introduced. Transplanted rat molars grown in ERM-2 cell supernatants produced substantially less bone than those cultured in other cell supernatants; inhibition was rescued when an anti-amelogenin antibody was added to the supernatants. Anti-Osterix antibody staining was used to confirm the development of new bones. In addition, next-generation sequencing (NGS) data were analysed to discover genes related to the distinct roles of CRUDE ERM, ERM-2, and ERM-3. According to this study, amelogenin produced by ERM cells helps to prevent dentoalveolar ankylosis and maintain periodontal ligament (PDL) space, depending on their clonal diversity.

Long-term outcomes 1-20 years after autotransplantation of teeth: clinical and radiographic evaluation of 66 premolars and 8 molars.

In this retrospective study we investigated the long-term survival of autotransplanted premolars and molars with incompletely developed roots. The presence of the transplanted teeth and their outcome after autotransplantation was ascertained from clinical and radiographic evaluation by a maxillofacial surgeon or dentist. Kaplan Meier survival curves were estimated for the total population and for the two groups (premolars and molars). Fifty-one patients with 74 transplanted teeth were included, and the median duration of follow-up was 10 (range 1-20) years. Four of 66 premolars and one of 8 molars were removed and the cumulative survival was 95.4% (95% CI 90.3 to 100). The difference in survival between the premolars and molars was not significant. These results show that the long-term survival of autotransplanted teeth is good. Replacement of a single tooth by autotransplantation should therefore always be considered and is preferred when a suitable donor tooth is available.

A new procedure for processing extracted teeth for immediate grafting in post-extraction sockets. An experimental study in American Fox Hound dogs.

OBJECTIVES: To investigate freshly extracted dental particulate used to graft post-extraction sockets in dogs, comparing new bone formation at experimental and control sites. MATERIALS AND METHODS: Bilateral premolars P2, P3, P4 and first mandibular molars were extracted atraumatically from six American Fox Hound dogs. The teeth were ground immediately using a 'Smart Dentin Grinder'. The dentin particulate was sieved to ensure a grain size of 300-1200µm and immersed in an alcohol cleanser to dissolve organic debris and bacteria, followed by washing in sterile saline buffer solution. The animals were divided into two groups randomly: group 'A' (control) samples were left to heal without any extraction socket grafting procedure; group 'B' (experimental) sockets were filled with the autogenous dentin particulate graft. The rate of tissue healing and the quantity of bone formation were evaluated using histological and histomorphometric analyses at 60 and 90 days post-grafting. The type of bone generated was categorized as woven (immature bone) or lamellar bone (mature bone). RESULTS: Substantially more bone formation was found in Group B (experimental) than Group A (control) at 60 and 90 days (p<0.05). Less immature bone was identified in the dentin grafted group (25.7%) than the control group (55.9%) [corrected]. Similar differences were also observed at 90 days post grafting. CONCLUSION: Autogenous dentin particulate grafted immediately after extractions may be considered a useful biomaterial for socket preservation, protecting both buccal and lingual plates, generating large amounts of new woven bone formation after 60 days, and small amounts of lamellar bone after 90 days healing.

Success and survival of autotransplanted premolars and molars during short-term clinical follow-up.

AIM: Autotransplantation is an elegant therapy for single tooth replacement that is too often overlooked in patients with missing teeth. Especially, autotransplantation of third molars to replace heavily damaged or missing molars is often not considered. This study investigated the success and survival of autotransplanted premolars and molars during clinical follow-up. MATERIALS AND METHODS: The medical files and radiographs of 97 consecutive patients were retrospectively investigated. Seventy-nine patients could be included in this study. Autotransplantation of 97 premolars and 14 molars (111 procedures) was performed. The median follow-up time was equal to 13.4 months. RESULTS: In this study group, 82.0% of transplanted teeth were classified as successful and 98.2% were present at the end of follow-up. No transplants were extracted during standard follow-up of 1 year. The 5-year tooth survival probability was 87.5% (95%CI 64.5-100). One premolar and one molar were extracted, respectively, 4 and 9 years after autotransplantation. CONCLUSIONS: These results show that autotransplantation is associated with high success and survival rates and can provide a reliable treatment option for tooth replacement in young patients. Further research regarding long-term outcome is necessary to assess if the transplanted teeth function as normal teeth after clinical follow-up.

A retrospective analysis of factors influencing the success of autotransplanted posterior teeth.

BACKGROUND: Survival and success rates of tooth transplantations even after long follow-up periods have been shown to be very high. Nevertheless, it is important to analyse factors potentially influencing these rates. The aim of this study was to assess the influence on success of potential factors. METHODS: The research was based on a retrospective analysis of clinical and radiological data from a sample of 59 subjects (75 transplanted teeth). The follow-up period varied from 0.44 to 12.28 years (mean 3.95 years). Success rates were calculated and depicted with Kaplan-Meier plots. Log-rank tests were used to analyse the effect of root development stage, apex width, the use of enamel matrix proteins or the surgeon on success of transplantations. RESULTS: Results for success of premolar transplantations were comparable with already published data, while molars performed worse than shown in other studies. The surgeon performing the transplantation (p = 0.001) and tooth type (p ≤ 0.001) were significantly associated with transplantation success. Use of enamel matrix proteins (p = 0.10), root development stage (p = 0.13), the recipient area (p = 0.48) and apex width (p = 0.59) were not significantly associated with success. CONCLUSIONS: Molar transplantations were not as successful as premolar transplantations; however, success rates varied greatly depending on the surgeon's experience. The use of enamel matrix proteins as well as root development stage, the recipient area and apex width did not show significant associations with success of tooth transplantations.

Eight-year follow-up of autogenous tooth transplantation involving multidisciplinary treatment.

Although autogenous tooth transplantation is a widely reported procedure, its success is dependent on a number of factors. Here we describe the surgical technique, endodontic treatment and rehabilitation employed for a patient in whom a lower right third molar was transplanted to substitute an adjacent second molar with extensive caries. During an 8-year follow-up period, normal periodontal healing was observed and no infection, ankylosis or progressive resorption occurred. It may be concluded that transplantation of a third molar is a practicable approach for replacement of a lost permanent tooth, with restoration of esthetics and function.

Biological restorations as an alternative to reconstructing posterior teeth: a case report.

This article reports on a three-year follow-up of two biological restorations performed on a 15-year-old female patient. After clinical evaluation, tooth fragments from extracted permanent molars were obtained from a Human Teeth Bank and were autoclaved, adjusted to the prepared cavity, and bonded to the remaining tooth structure with dual resin cement. The technical aspects are described and the benefits and disadvantages of biological restorations as an alternative treatment for rehabilitation of severely destroyed permanent molars are discussed.

Contribution of donor and host mesenchyme to the transplanted tooth germs.

Autologous tooth germ transplantation of immature teeth is an alternative method of tooth replacement that could be used instead of dental implants in younger patients. However, it is paramount that the dental pulp remain vital and that root formation continue in the transplanted location. The goal of this study is to characterize the healing of allogenic tooth grafts in an animal model using GFP-labeled donor or host postnatal mice. In addition, the putative stem cells were labeled before transplantation with a pulse-chase paradigm. Transplanted molars formed cusps and roots and erupted into occlusion by 2 wk postoperatively. Host label-retaining cells (LRCs) were maintained in the center of pulp tissue associating with blood vessels. Dual labeling showed that a proportion of LRCs were incorporated into the odontoblast layer. Host cells, including putative dendritic cells and the endothelium, also immigrated into the pulp tissue but did not contribute to the odontoblast layer. Therefore, LRCs or putative mesenchymal stem cells are retained in the transplanted pulps. Hertwig's epithelial root sheath remains vital, and epithelial LRCs are present in the donor cervical loops. Thus, the dynamic donor-host interaction occurred in the developing transplant, suggesting that these changes affect the characteristics of the dental pulp.

Similar in vitro effects and pulp regeneration in ectopic tooth transplantation by basic fibroblast growth factor and granulocyte-colony stimulating factor.

OBJECTIVES: Granulocyte-colony stimulating factor (G-CSF) has been shown to have combinatorial trophic effects with dental pulp stem cells for pulp regeneration. The aim of this investigation is to examine the effects of basic fibroblast growth factor (bFGF) in vitro and in vivo compared with those of G-CSF and to assess the potential utility of bFGF as an alternative to G-CSF for pulp regeneration. MATERIALS AND METHODS: Five different types of cells were examined in the in vitro effects of bFGF on cell migration, proliferation, anti-apoptosis, neurite outgrowth, angiogenesis, and odontogenesis compared with those of G-CSF. The in vivo regenerative potential of pulp tissue including vasculogenesis and odontoblastic differentiation was also compared using an ectopic tooth transplantation model. RESULTS: Basic fibroblast growth factor was similar to G-CSF in high migration, proliferation and anti-apoptotic effects and angiogenic and neurite outgrowth stimulatory activities in vitro. There was no significant difference between bFGF and G-CSF in the regenerative potential in vivo. CONCLUSIONS: The potential utility of bFGF for pulp regeneration is demonstrated as a homing/migration factor similar to the influence of G-CSF.

Importancia del primer molar permanente y consecuencias clínicas de su pérdida en edades tempranas del desarrollo / Importance of the first permanent molar and clinical consequences of its loss at early developmental stages

El primer molar permanente es la undiad más importante de la masticación y es esencial en el desarrollo de una oclusión funcionalmente deseable. La pérdida de este molar en un niño puede conducir a cambios en las arcadas dentarias que se perpetúan a lo largo del tiempo. Si no se toman medidas preventivas o correctivas apropiadas, podrán encontrarse: disminución en la función local, desviaciones de las piezas dentarias, extrusión de la pieza antagonista y trastornos de las articulaciones temporomandibulares, entre otras alteraciones. El presente artículo pretende evidenciar el protagonismo del primer molar permanente en la cavidad bucal y las consecuencias negativas que derivan de su ausencia. Además, deja entrever las necesidades de conocimiento por parte del odontólogo en los cuidados preventivos de dichas piezas dentarias y sobre la existencia de posibles tratamientos al momento de una pérdida inminente.

Allogenic tooth transplantation inhibits the maintenance of dental pulp stem/progenitor cells in mice.

Our recent study suggested that allogenic tooth transplantation may affect the maintenance of dental pulp stem/progenitor cells. This study aims to elucidate the influence of allograft on the maintenance of dental pulp stem/progenitor cells following tooth replantation and allo- or auto-genic tooth transplantation in mice using BrdU chasing, immunohistochemistry for BrdU, nestin and Ki67, in situ hybridization for Dspp, transmission electron microscopy and TUNEL assay. Following extraction of the maxillary first molar in BrdU-labeled animals, the tooth was immediately repositioned in the original socket, or the roots were resected and immediately allo- or auto-grafted into the sublingual region in non-labeled or the same animals. In the control group, two types of BrdU label-retaining cells (LRCs) were distributed throughout the dental pulp: those with dense or those with granular reaction for BrdU. In the replants and autogenic transplants, dense LRCs remained in the center of dental pulp associating with the perivascular environment throughout the experimental period and possessed a proliferative capacity and maintained the differentiation capacity into the odontoblast-like cells or fibroblasts. In contrast, LRCs disappeared in the center of the pulp tissue by postoperative week 4 in the allografts. The disappearance of LRCs was attributed to the extensive apoptosis occurring significantly in LRCs except for the newly-differentiated odontoblast-like cells even in cases without immunological rejection. The results suggest that the host and recipient interaction in the allografts disturbs the maintenance of dense LRCs, presumably stem/progenitor cells, resulting in the disappearance of these cell types.

Validation of the cone beam computed tomography-based stereolithographic surgical guide aiding autotransplantation of teeth: clinical case-control study.

OBJECTIVE: To compare the outcome of cone beam computed tomography (CBCT)-based surgical planning and transfer technique for tooth autotransplantation versus conventional autotransplantation. STUDY DESIGN: The study material comprised 40 pediatric subjects in whom 48 teeth were transplanted following a case-control design. While the study group (mean age 11 years) underwent CBCT imaging for surgical planning and transfer via stereolithographic tooth replica fabrication, the historical control group (mean age 12 years) was subjected to conventional autotransplantation. RESULTS: The CBCT-based preoperative planning and the use of a tooth replica decreased the extra-alveolar time and reduced the number of positioning trials with the donor tooth. In the control group, 6 patients showed 1 or more complications, while this was noticed for only 2 study patients. CONCLUSION: CBCT-based surgical planning of tooth autotransplantation may benefit from a shorter surgical time, while being a less invasive technique, causing fewer failures than a conventional approach.

An experimental study on periodontal regeneration after subcutaneous transplantation of rat molar with and without cryopreservation: an in vivo study.

This study analysed the effects of cryopreservation on periodontal regeneration of autotransplanted rat molars. First and second maxillary molars (n=92) of 24 four-week-old Wistar rats were gently extracted and autotransplanted into the abdominal tissue immediately (control group n=44) or after cryopreservation in liquid nitrogen for 7 days (experimental group n=48). At 1, 2, 4 and 10 weeks after transplantation, the transplanted molars were excised and regeneration of the periodontal tissues was analysed on histological sections stained with routine H&E and Goldner method. Different tissue responses were scored on a tooth basis: inflammation, regeneration of the periodontal ligament, resorption/apposition of cementum, and alveolar bone formation. Sixty-two teeth were available for histological evaluation, including 30 experimental and 32 control samples. One week after transplantation, both control and test teeth were surrounded by granulation tissue and some areas of root resorption could be seen. After 2 weeks, signs of regeneration of the periodontal ligament, cementum apposition, and new bone formation roughly coincided in both groups, however markedly retarded in the experimental group. After 4 weeks, regeneration progressed equally in both groups, presenting fewer areas of cementum apposition in experimental samples. Finally, 10 weeks after baseline transplantation, no significant differences between both groups could be observed. Cryopreservation followed by autotransplantation of extracted teeth in rats appears to have minimal detrimental effects on regeneration of periodontal tissues after integration periods of 1-10 weeks. However, the present findings indicated that the regeneration process in general is retarded for cryopreserved teeth, as compared to their immediately transplanted homologues.

Importance of root development in autotransplantations: a retrospective study of 137 teeth with a follow-up period varying from 1 week to 14 years.

The aim of the present study was to perform a retrospective study of autotransplanted teeth with a variable but individually maximized follow-up period in order to provide information on the long-term clinical outcome. The sample was obtained from patients who were treated at the University Hospitals KU-Leuven, Belgium, during the period 1996-2010. Of the total of 109 subjects (137 teeth), 98 patients were invited for recall, of whom 68 patients (87 teeth) responded positively. Eleven out of the 109 patients were excluded due to loss of the transplanted tooth. Although 41 patients had no re-examination visit, clinical and radiological data from all 109 subjects were included in the sample. The follow-up period varied from 1 week of 14.8 years, with a mean of 4.9 years. Transplanted teeth receiving orthodontic treatment had a lower risk of ankylosis and were less likely to fail. The risk of root resorption was lower for teeth with stages one-half to three-quarters of root length at the time of transplantation. Molars were more susceptible to ankylosis. Almost all teeth showed partial or full obliteration of the pulp. Absence of further root development was higher in donor teeth with root length stage less than one-half. Trans-alveolar transplantation was less successful. Autotransplantation can be a valid alternative method in young adolescents for replacing missing teeth because of agenesis or trauma. The optimal time to transplant is when the root has reached two-thirds to three-quarters of the final root length.

Gender difference in tooth autotransplantation with complete root formation: a retrospective survey.

Gender-related risk factors in the survival of transplanted teeth with complete root formation have not yet been identified. The purpose of this study was to investigate gender differences in tooth autotransplantation at dental clinics. We asked participating dentists to provide information on transplantations they had undertaken from 1 January 1990 to 1931 December 2010. The data were screened to exclude patients who underwent more than one transplantation, smokers or those whose smoking habits were unknown, patients under 30 or who were 70 years old and over, cases where the transplanted teeth had incomplete root formation or multiple roots and those with fewer than 20 present teeth post-operation. We analysed 73 teeth of 73 males (mean age, 47.2 years) and 106 teeth of 106 females (mean age, 45.3 years) in this study. The cumulative survival rate and mean survival time were calculated using the Kaplan-Meier method. The cumulative survival rate for males was 88.3% at the 5-year mark, 64.8% at 10 years and 48.6% at 15 years; for females, it was 97.2% at the 5-year mark, 85.9% at 10 years and 85.9% at 15 years. A log-rank test indicated the difference between males and females to be significant (P = 0.011). There was also a significant difference in the main causes for the loss of transplanted teeth: males lost more transplanted teeth due to attachment loss than females (P < 0.05). These results indicate that males require more attention during the autotransplantation process, particularly at the stage of pre-operation evaluation and that of follow-up maintenance.

Esthetic and functional recovery of extensively decayed posterior teeth through conservative treatment.

The case exemplifies the combination of two important principles in dentistry: 1) the maintenance of pulp vitality by the partial excavation of the contaminated dentin followed by the application of a biomaterial; and 2) esthetic and functional recovery based on biological restoration. Tooth vitality was confirmed two months after pulp treatment and restoration was accomplished with a fragment of a tooth extracted from another individual. This method is easy to perform and offers esthetic, functional, emotional and social benefits to the patient.

Comparison of prognosis of separated and non-separated tooth autotransplantation.

The aim of this study was to compare the prognosis of separated and non-separated tooth autotransplantation of the upper first and second molars with complete root formation undertaken at dental clinics. The participating dentists were requested to provide information on transplantations they had undertaken from 1 January 1990 to 31 December 2010. Data on a total of 708 teeth from 637 patients were collected. This study analysed 35 separated teeth and 22 non-separated teeth of 47 participants ranging from 27 to 76 years of age (mean age: 55·0 years) after data screening and elimination. The cumulative post-transplantation survival rate at 10 years was 77·1% for separated teeth and 63·6% for non-separated teeth as calculated with the Kaplan-Meier method. There were no significant differences between separated teeth and non-separated teeth in a log rank test (P = 0·687). Separated-tooth autotransplantation can help fill narrow recipient sites and increase occlusal supporting zones, but the clinical success rate was only 48·6%. Although transplantation of teeth with complete root formation has limited prognosis, transplantation of upper first and second molars, whether separated or non-separated, is a viable option to replace missing teeth.

Application of orthodontic forces prior to autotransplantation - case reports.

AIM: This case report describes the successful autotransplantation of mandibular molars after application of orthodontic forces and discusses the advantages of this technique, that is, pre-application of an orthodontic force for autotransplantation. SUMMARY: After clinical and radiographic examination, autotransplantation was planned with the patient's written informed consent. An orthodontic force was applied, and the surgical procedure was performed after tooth mobility had increased. Root canal treatment was performed within 2 weeks of autotransplantation. At the 1-year follow-up, the transplanted teeth revealed asymptomatic and healthy periodontal conditions. KEY LEARNING POINTS: Autotransplantation is the surgical movement of a tooth from its original location to another site. The pre-application of orthodontic force technique was recently introduced for autogenous tooth transplantation. Pre-application of an orthodontic force may be a useful treatment option for autotransplantation.

Two distinct processes of bone-like tissue formation by dental pulp cells after tooth transplantation.

Dental pulp is involved in the formation of bone-like tissue in response to external stimuli. However, the origin of osteoblast-like cells constructing this tissue and the mechanism of their induction remain unknown. We therefore evaluated pulp mineralization induced by transplantation of a green fluorescent protein (GFP)-labeled tooth into a GFP-negative hypodermis of host rats. Five days after the transplantation, the upper pulp cavity became necrotic; however, cell-rich hard tissue was observed adjacent to dentin at the root apex. At 10 days, woven bone-like tissue was formed apart from the dentin in the upper pulp. After 20 days, these hard tissues expanded and became histologically similar to bone. GFP immunoreactivity was detected in the hard tissue-forming cells within the root apex as well as in the upper pulp. Furthermore, immunohistochemical observation of α-smooth muscle actin, a marker for undifferentiated cells, showed a positive reaction in cells surrounding this bone-like tissue within the upper pulp but not in those within the root apex. Immunoreactivities of Smad4, Runx2, and Osterix were detected in the hard tissue-forming cells within both areas. These results collectively suggest that the dental pulp contains various types of osteoblast progenitors and that these cells might thus induce bone-like tissue in severely injured pulp.