Autogenous tooth transplantation : evaluation of pulp tissue regeneration

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. © Medicina Oral S. L

The effect of Emdogain gel on periodontal regeneration in autogenous transplanted dog′s teeth

Aim: The aim of this study was to assess the enamel matrix derivative (EMD) as biomaterial used in autogenous tooth transplantation. Material and Methods: The study consisted of 3 beagle dogs, 5 months old, in which six incisors and six premolars were transplanted to mechanically prepared recipient alveolar sockets. One group of teeth was transplanted to a recipient bed, with EMD in the root surface. The second groups of teeth were transplanted using saline solution in the root surface. Every week, clinical examinations were done. Nine weeks later, the animals were killed and the specimens decalcified and prepared for histological and imunohistochemical analysis. Periodontal healing was evaluated by undertaking histomorphometric investigation and analyzed using the Mann- Whitney test (P = 0.05). Results: In both groups, all the transplanted teeth survived. Between the experimental groups, there was statistically significant difference in the complete healing (P = 0.004). There was statistically significant difference between the treatment group in the occurrence of inflammatory root resorption (P = 0.015) and the occurrence of replacement root resorption (P = 0.041). Conclusions: Emdogain gel used on the surface of transplanted teeth improves the occurrence of complete healing and reduces root resorption

BDNF increases synaptic NMDA receptor abundance by enhancing the local translation of Pyk2 in cultured hippocampal neurons

The effects of brain-derived neurotrophic factor (BDNF) in long-term synaptic potentiation (LTP) are thought to underlie learning and memory formation and are partly mediated by local protein synthesis. Here, we investigated the mechanisms that mediate BDNF-induced alterations in the synaptic proteome that are coupled to synaptic strengthening. BDNF induced the synaptic accumulation of GluN2B-containing NMDA receptors (NMDARs) and increased the amplitude of NMDAR-mediated miniature excitatory postsynaptic currents (mEPSCs) in cultured rat hippocampal neurons by a mechanism requiring activation of the protein tyrosine kinase Pyk2 and dependent on cellular protein synthesis. Single-particle tracking using quantum dot imaging revealed that the increase in the abundance of synaptic NMDAR currents correlated with their enhanced stability in the synaptic compartment. Furthermore, BDNF increased the local synthesis of Pyk2 at the synapse, and the observed increase in Pyk2 protein abundance along dendrites of cultured hippocampal neurons was mediated by a mechanism dependent on the ribonucleoprotein hnRNP K, which bound to mRNA and dissociated from it upon BDNF application. Knocking down hnRNP K reduced the BDNF-induced synaptic synthesis of Pyk2 protein, whereas its overexpression enhanced it. Together, these findings indicate that hnRNP K mediates the synaptic distribution of Pyk2 synthesis, and hence the synaptic incorporation of GluN2B-containing NMDARs, induced by BDNF, which may affect LTP and synaptic plasticity