| Toothache is a common symptom in oral disease and constitutes two thirds of patients' chief complaints, and 60% among toothache cases attributes to pulp pathological changes. Furthermore, the treatment itself(including local anesthetic injection) could revoke ache, so many patients feel anxious and dreadful to teeth treatments. Therefore, the problem of analgesia in tooth and pulp treatments is one of attention focuses and main research title for all dentists all over the world, which is badly needed to solve.The main anaesthesia methods for tooth and pulp operations in clinical practices consists of local anesthetic injection, electronic anaesthesia, acupuncture anaesthesia, laser anaesthesia, devitalization of dental pulp(including arseniious oxide, citromint and traditional Chinese medicine devitalizer). It was reported that toad venom agents has been used for fast indolent pulpotomy and pulp devitalization for more than 30 years with good curative effects, while few reports were found to assess the possibility for pulpectomy. SP(p substance) and CGRP(calcitonin gene related peptide) are neurotransmitters which are widespread in nerve systems and play an important role in perception messages transmition. It was demonstrated in previous research worksthat the concentration of these peptides substances could be changed by many factors, such as inflammation, drugs and outside stimulations, which suggested that SP and CGRP were very important substances in perception and adjustment of pulp ache. However, the curative effects for pulpectomy, anaethesia mechanism, cytotoxicity for pulp cells, positive nerve fibers in SP and CGRP immunologic reaction, changes of SP and CGRP concentration in correlated position of trigeminal ganglion and feasibility to be a clinical anaesthesia method of toad venom are still unclear.Mechanism of toad venom for fast indolent pulpectomy and pulp anaesthesia, feasibility and influence factors were assessed by methods of tissue pathology, immunohistochemistry, cytotoxicity tests and clinical observations. The results are as below:1. SP and CGRP positive fibers in root pulp gradually decrease after toad venom agents was administrated in rat pulp and the fiber number was significantly less than control side in 1 hour with shallow dyeing. The positive fibers gradually increase with time went by and showed no difference with control side in 2 hours and 4 hours. In 6 hours, the number of positive fibers was apparently less than control side and destructive morphological changes appeared, no positive fibers could be found in root pulp in 24 hours. Meanwhile, the number of SP and CGRP positive fibers in root pulp accorded with each other, which suggested the pulp anaesthesia effect of toad venom was strong and fast and lead to anaesthesia function in early stage, while resulted in destructive damages to root pulp nerve fibers after 6 hours.2. The number of SP and CGRP positive nerve cells in the maxillofacial region of trigeminal ganglion started to decrease after toad venom agents were administrated. In 1 hour, the number of positive fibers was less than control side and significantly less in 2 hours, while the number of positive fibers gradually increase in 4hours and approach normal level and accord with the control side in 6 hours. The concentration of SP and CGRP positive nerve fibers in the spinal trigeminal caudal subnucleus in 1 hour was less than the control side and a little higher than the control side in 2 hours, significantly higher than the control side in 4 hours, then gradually decrease and accord with the control side till 24 hours.3 The number of live cells showed no difference among lh, 2h, 4h group after the pulp cells were stimulated by three kinds of immersion fluids, while apparent difference could be found between 6h, 24h and other groups. The number of live cells in 24 hours increased in order from citromint group (0.132), toad venom agent (0.218) to arseniious oxide (0.393), which suggested that cytotoxicity of the above-mentioned drugs decreased one by o...
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