Transmission electron microscopy of supraalveolar periodontal healing of auto- and allotransplanted teeth in monkeys (original) (raw)
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Supra-alveolar periodontal healing of auto- and allotransplanted teeth in monkeys
Dental Traumatology, 1989
Abstraet-Although intra-alveolar healing of allotransplanted teeth often shows pathological changes due to rejection of the tooth graft, previous clinical findings seem to indicate that the supra-alveolar part of the allografts heals differently, whieh is of significant prognostic value. The aim of the present study was to determine the healing of the cervical part of the periodontium of auto-and allotransplanted mature teeth in monkeys. In 4 adult, immunologieally unmatched, green vervet monkeys 16 mature permanent maxillary and mandibular incisors were extracted, endodontieally treated and either auto-or allotransplanted; 8 untreated neighbouring ineisors served as controls. Block biopsies including part of the tooth and the adjacent vestibular tissues were obtained after a healing period of 8 weeks. The biopsies were deealeified in EDTA and embedded in Epon. In semi-thin sections (1.5 |im) the morphology of the supra-alveolar periodontal tissues was analysed in the light microscope. The orientation of the conneetive tissue fibres elose lo the root surfaee was found to be more parallel to the root surfaee of allotransplants compared with autografts, while in the control teeth the fibres were generally oriented perpendicular to the root surface. Resorption of the root was seldom found in the supra-alveolar portions of any of the transplanted teelh. The junetional epithelium had migrated slightly apically onto the root surfaees of allotransplanted teeth. The gingival eonneetive tissue adjaeent to allotransplanted teeth showed a signifieantly inereased number oflymphoeytes compared with autografts and controls. Gingival healing of allotransplanted teeth only differed slightly concerning the orientation of inserting fibres, the number oflymphoeytes surrounding the graft and the position of the junelional epithelium, compared with autografts and control teeth.
Introduction: Recently, regenerative endodontic procedures (REPs) have been used to treat mature permanent teeth with apical periodontitis. Although animal studies with regard to histopathological findings after REPs exist, there is a paucity of studies on mature human teeth. As yet, the nature of tissues formed in the root canal of such teeth has not been established. This report presents histologic findings with regard to regenerative tissues in the pulp spaces exposed after dental trauma in human mature maxillary incisor teeth successfully treated with REPs. Methods: A 20-year-old girl was referred to our clinic for the treatment of her central incisors (#8 and #9). The incisors had apical periodontitis. REPs were performed on both maxillary central incisors. Three years 5 months after the initial treatment, the teeth had a horizontal crown fracture and needed a fiber post as well as root canal treatment. Mineral trioxide aggregate was carefully removed, and the tissue that had formed in the canal space was processed for routine histologic and immunohistochemical examination. Results: Histologic findings of the present case showed that the vital tissue formed in the canal space was fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings obtained from mature teeth were similar to the findings of previous reports relating to immature teeth. Conclusions: Based on the present case, the vital tissue formed in the canal space is fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings with regard to mature teeth were similar to the findings of previous reports relating to immature teeth. (J Endod 2019;-:1-6.)
Cell and Tissue Research, 2006
Dental pulp is assumed to possess the capacity to elaborate both bone and dentin matrix under the pathological conditions following tooth injury. This study was undertaken to clarify the mechanism inducing bone formation in the dental pulp by investigating the pulpal healing process, after tooth replantation, by micro-computed tomography (mu-CT), immunocytochemistry for heat-shock protein (HSP)-25 and cathepsin K (CK), and histochemistry for both alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). Under deep anesthesia, the upper right first molar of 4-week-old Wistar rats was extracted and immediately repositioned in the original socket. In control teeth at this age, the periphery of the coronal dental pulp showed intense ALP-positive and HSP-25-positive reactions, whereas there were no TRAP-positive or CK-positive cells. Tooth replantation weakened or terminated ALP-positive and HSP-25-positive reactions in the pulp tissue at the initial stages. At 3-7 days after operation, the ALP-positive region recovered from the root apex to the coronal pulp followed by HSP-25-positive reactions in successful cases showing tertiary dentin formation. In other cases, TRAP-positive and CK-positive cells appeared in the pulp tissue of the replanted tooth at postoperative days 5-10 and remained associated with the bone tissue after 12-60 days. Immunoelectron microscopy clearly demonstrated that CK-positive osteoclast-lineage cells made contact with mesenchymal cells with prominent nucleoli and well-developed cell organelles. These data suggest that the appearance of TRAP-positive and CK-positive cells is involved in the induction of bone tissue formation in dental pulp.
Repair of periodontal tissues In vivo and in vitro
Journal of Clinical Periodontology, 1983
Repair of experimental cavities in dental roots and of periodoniai wounds was studied in vivo and/« vhro. Incisors from monkeys were extracted and experimenlal cavities were made in the roots. The teeth were either replanted immediately or cu!lured for 1-12 weeks in tissue culture medium. After 8 weeks the tissue reaction around the replanted, teeth was evaluated on demineralized hi;;tol()gical sections and undecalcified freeze-sections incubated for histochemical demonstration of certain enzymes. Tbe cultured teeth were evaluated on decalcified histological sections.
Journal of Endodontics, 2013
Introduction: The aim of this study was to investigate the capacity of endodontic regenerative procedures combining an induced blood clot, platelet-rich plasma (PRP), and bone marrow aspirate (BMA) to regenerate dental pulp in canine closed-apex necrotic teeth. Methods: Apical periodontitis was induced in 20 upper and lower premolars of 2 dogs. After biomechanical preparation, enlargement to a #60 file, and disinfection with a triantibiotic paste for 28 days, the roots were randomly assigned to 4 treatment groups: blood clot (BC), BC + PRP gel, BC + BMA gel, and BC + BMA/ PRP gel. Negative controls were also included. After a 3-month follow-up period, the animals were killed. Results: Histologic analysis showed the presence of newly formed vital tissues (connective, cement-like, and bone-like tissue) in 23 of the 32 treated roots (71.87%). There was no statistically significant difference between the treatment groups. Conclusions: New vital tissues were formed and characterized as connective, cementum-like, or bone-like, but not as pulp-like tissue; PRP and/or BMA did not improve the tissue ingrowth. (J Endod 2013;39:1549-1556
International Journal of Oral Surgery, 1980
Two types of dental isografts were implanted into the femoral bone" of inbred mice: type A, encompassing mature maxillary molars including supporting structure and type B, consisting of the tooth alone. The isografts, together with their host tissues, were examined histologically beginning at day 1 and continuing until day 42 posttransplantation, In both types, the cellular components underwent necrosis with subsequent repopulation of the pulp and periodontal ligament of the graft. A new bony socket formed and partial resorption and ankylosis started on day 10 of transplantation. It is suggested that the host cells present in the periodontal ligament are responsible for the ankylosis and resorption of the tooth root surface.
Journal of …, 2002
Background: The purpose of this report was to evaluate the histological characteristics of 4 clinically successful root coverage procedures performed with a combination of a connective tissue (CT) graft and an enamel matrix derivative (EMD) preparation. Methods: Four maxillary teeth (3 canines and 1 first premolar) that presented with mucogingival problems and Miller's Class II and III gingival recession were evaluated in the study. Surgical therapy for root coverage consisted of autogenous CT grafts combined with the topical application of EMD. Following healing, treated teeth were extracted with a portion of their buccal attachment apparatus. Two teeth were extracted at 6 months and 2 teeth at 1 year postoperatively. Specimens were prepared for histology and analyzed by light microscopy. Results: All treated teeth presented with clinical signs of successful root coverage. Histological observations of the 4 specimens revealed similar findings. The junctional epithelium was ≤2 mm long. Apical to the junctional epithelium, dense CT fibers were found in close proximity to the root surface, but in general, no insertion of these fibers into the root was observed. In one 6-month specimen, formation of new cementum and new bone was observed in the most apical end of the grafted area. Conclusions: The results of this study suggest that a combination of CT grafts and EMD results mainly in an adhesion between the CT and root surface. Some periodontal regeneration may occur in some regions. The development of a long junctional epithelium was not observed with this combined therapy for the treatment of gingival recession.
Autogenous tooth transplantation: Evaluation of pulp tissue regeneration
Medicina Oral Patología Oral y Cirugia Bucal, 2011
Objective: The aim of this study was to assess the pulp survival that occur in transplants of autologous teeth, by comparing two surgical techniques: the conventional technique (autotransplantation for newly formed alveoli), and an alternative technique, (autotransplants for alveoli in the initial phase of healing). In each surgical techniques were applied, randomly, either saline solution or Emdogain ®. Study Design:The study group comprised 26 patents, in which 28 teeth were transplanted to recipient sockets prepared mechanically. Of the 28 teeth transplanted, 4 were intentional replants, and of the remainer, 11 had the apex closed and 13 open. The mean age at the time of transplantation was 22.34±8.14 years (mean ± SD). The transplantation were performed by the same operator, with the informed consent of the patient and authorized by the ethical committee of the hospital. Clinical and radiological examinations were performed during 24 to 65 months (48±12.96; MED±SD), from 10 days, 1 month, 3 months, 6 months and annually to 5.6 years. Results: Only two transplanted teeth were lost, due persistent apical periodontitis, and one transplanted patient with open apex missed the treatment. In the teeth with pulp, we needed to perform root canal therapy in 9. In the 73% of the teeth with closed apex, we needed to perform root canal treatment, with no statistically significant difference found among closed apex and root canal therapy (p=0.083). In only 8% of the teeth with open apex did we need to perform root canal treatment, with an association between open apex and root canal therapy (p=0.0002). The overall success rate was 98% with significant difference for losses (p=0.0001). Conclusions: Although not a frequent procedure, it was concluded that autotransplanted teeth, performed with appropriate surgical care had a good prognosis, and can render a very useful service to the patients.