SHEDs which had been isolated and characterized 5 years ago and stored with cryopreservation banking were capable of proliferation and osteogenesis after 5 years, and no immune response was observed after three months of seeded SHEDs.

No abstract

The purpose of this study was to characterize the impact of tooth injury on the distribution of tyrosine receptor kinase B (TrkB) among trigeminal ganglion neurons and assess the time course for tooth injury-induced TrkB distribution changes. In addition, we sought to further characterize the subpopulation of the afferents expressing TrkB receptors. Fifteen adult male Sprague-Dawley rats were studied. Pulpal inflammation was induced and ganglia were subsequently harvested and processed at different time points. Standard immunohistochemical fluorescence techniques were used to visualize TrkB-like immunoreactivity and isolectin B4 binding. Results indicate that full-length TrkB receptors are present in 36.6% of trigeminal ganglion neurons. This percentage decreases for the first 48 h and then increases to 41% by 7 days after tooth injury. Finally, TrkB appears to be present in a large percentage (54%) of isolectin B4+ neurons, suggesting that it is present in nociceptive afferents. These data highlight the fact that even mild injury results in sustained changes in nociceptive circuitry and raise the possibility that the brain-derived neurotrophic factor/TrkB system may contribute to persistent pain after tooth repair.

No abstract

The purpose of this in vitro study was to investigate root surface temperatures generated by the Thermafil Plus system using infrared thermography. A total of 60 extracted human maxillary central incisors and maxillary first molars were biomechanically instrumented using ProFile 0.04 Taper Series 29 rotary instruments. The root canals were obturated using the Thermafil Plus system. An infrared thermography camera was used to measure the external root surface temperatures during and after the completion of obturation. The mean temperature rise of the external root surface from the ambient temperature was 4.26 degrees C for the mesial buccal roots, 4.58 degrees C for the distobuccal roots, 4.76 degrees C for the palatal roots, and 4.87 degrees C for the anterior roots. These temperatures were well below the critical level of 10 degrees C needed to cause damage to the attachment apparatus. From this in vitro experiment, no evidence was discovered which would indicate that the Thermafil Plus obturation system would result in damage to the periodontal ligament and the surrounding attachment apparatus as a consequence of temperature rise on the external root surface.