The overall study of the pulp and periodontal ligament of replanted tooth - The change of sensory nerve and the development of root end filling material -

点击翻译按钮获取中文摘要

The nociceptive neurons responding to noxious stimuli of the tooth, oral mucous or facial skin were recorded in the ventral posteromedial nucleus (VPM), and the posterior thalamic group (PO) and the zona incerta (ZI) in the diencephalon. These neurons were classified into the low threshold mechanoreceptive neurons, wide dynamic range neurons and nociceptive-specific neurons. Functional segregation of these nociceptive neurons was not apparent within the nucleus or between nuclei.The nociceptive neurons are also recorded at the trigeminal caudal nucleus and the reticular subnuclei in the medulla oblongata. These nurons were divided into three groups depending their response pattern, (1) neurons with a latency of less than 30 msec, (2) those with a latency of more than 30 msec and (3) those with both latency. The nociceptive neurones showed all these response pattern, but the low threshold mechanoreceptive (LTM) neurons responded with the pattern of (1) suggesting the input from A-fiber.The composition and properties of experimental and commercial bone grafting gypsum was evaluated. The experimental bone grafting gypsum was revealed that was calcium phosphate hemihydrate. The arsenic concentration of experimental bone grafting gypsum was under the detection limit (0.2 ppm) and lower level than the other materials.The biocompatibility of the experimental bone grafting gypsum was tested at the periapical portion of the replanted rat incisor. In the control group, the reinforced eugenol cement was filled as root end filling material. The cement was not absorbed until four weeks after operation and the inflammation was still observed until four weeks after operation. In the experimental group, the experimental bone grafting gypsum was filled as root end filling material. The experimental bone grafting gypsum was absorbed until two weeks after operation and the inflammation went out until four weeks after operation.