| Traumatic occlusion refers to pathological damages or adaptive changes in certain parts of chewing system, because of an abnormal occlusive contact between the occlusive and/or abnormal function of chewing system. Due to abnormal occlusion relationship or uncoordinated occlusion force, the periodontal tissue suffers an occlusive force more than its tolerance brought about by a single or a group of teeth, which results in periodontal tissue injury. Furthermore, severe cases can result in alveolar bone absorption. The change of capillaries has a key role to play in the process of traumatic occlusion development. The capillaries casting can show absolute changes of capillaries structure after traumatic occlusion occurred and provide straight-forward evidence of microcirculation changes in periodontal tissue under abnormal external force.In order to reveal the relationship between the morphological changes of microcirculation and traumatic occlusion, the study established models of Wistar rats with the first molar of mandibular suffering, which was designed to simulate human traumatic occlusion. These models were subjected to some methods such as capillary casting technology, SEM, pathological biopsy and so on. The study of alternations in capillary casting models of periodontal tissue and temporomandibular joint can show the morphology of capillary in the process of traumatic occlusion which provide experimental evidence and theoretical basis of the mechanism of traumatic occlusion associated symptoms in somatogenetic system as well as its treatment and prevention.1. Capillary molding material researchAt room temperature and45℃constant temperature water baths, respectively, the polymerization of low and high viscosity resin was observed and the viscosity, the volume change, whether the pipes below and bubbles were analyzed.At room temperature, the low viscosity of the resin solution is split into0.1%,0.3%,0.5%,1.0%,1.5%.1.5%groups.1hour later, in the1.5%group, large bubbles were found in all five tubes. In the1.0%group, relatively large bubbles were noted in two tubes among the five, and small bubbles were found in the rest three.3hours later, squib phenomenon occurred in the0.5%group and no bubbles were noted in the0.1%and0.3%groups.It took48hours for the0.1%group to polymerize whereas36hours for the0.3%,36hours for the0.5%,30hours for the1.0%and12hours for the1.5%. Volume after polymerization of the resin with low viscosity is4.32±0.05ml (0.3%group),4.30±0.08ml (0.5%group),4.30±0.11ml(1.0%group), and4.35±0.12ml(1.5%group). The volume of0.1%group was not measured, because it was unable to polymerize within48hours. Statistical analysis of the volume of the4groups after polymerization reaction showed no significant difference.Under45℃constant temperature water baths, large bubbles were found in all tubes in the groups of1.0%and1.5%after1hour, and0.5%group is squib, and0.3%and0.1%group are a few tiny bubbles. The polymerization of0.1%group was18hours,12hours (0.3%and0.5%groups),6hours (1.0%and1.5%groups). The volume of polymerization are4.31±0.06ml (0.1%group),4.27±0.06ml(0.3%group),4.28±0.12ml (0.5%group),4.30±0.17ml (1.0%group), and4.27±0.13ml (1.5%group). Statistical analysis saw no meaningful difference in polymerization reaction volume among5groups.At room temperature, the extreme viscosity of the resin solution was divided into0.1%,0.3%,0.5%,1.0%,1.5%.4tubes had large bubbles and the rest had moderate amount of bubbles at1hour for1.5%group.1.0%and0.5%groups had small bubbles.0.3%and0.1%groups had very limited groups of microscopic bubbles. No pipe blowed. The time of polymerization was24hours (0.1%group),18hours (0.3%and0.5%groups),12hours (1.0%and1.5%groups). The volume of polymerization were4.52±0.05ml (0.1%group),4.47±0.06ml (0.3%group),4.39±0.13ml (0.5%group),4.33±0.16ml (1.0%group), and4.38±0.18ml (1.5%group). Statistical analysis saw no noteworthy difference in polymerization reaction volume among5groups.Under45℃constant temperature water baths, the groups of0.5%,1.0%and1.5%had larger bubbles at1hour. No pipes bursted. The time of polymerization was6hour for0.1%,0.3%and0.5%groups, and1hour for1.0%and1.5%groups. The volume of polymerization are4.46±0.08ml (0.1%group),4.55±0.09ml(0.3%group),4.54±0.16ml (0.5%group),4.46±0.21ml (1.0%group), and4.46±0.25ml (1.5%group). Statistical analysis saw no meaningful difference among5groups polymerization reaction volumes.For capillary casting material, we need the resin solution of high viscosity and low viscosity, and0.3%of initiator, so that we have enough time to perfuse capillary system of specimens at room temperature and the resin can polymerize perfectly in the capillaries at45℃water bath.2. Wistar rats stomatognathic system capillary corrosion castingEight eight-week-old healthy Wistar rats were chosen, with no trauma to the head and face, complete dentition, normal occlusive relationship and no caries and periodontal disease. Wister rats were anesthetized with2%pentobarbital sodium. Their chest and abdomen were opened and the trocar were integrated into the aorta from the left ventricle. Abdomen and lower limbs were stopped off and the livers were stored. After Wistar rats were washed to remove the blood,50ml low viscosity resin solution was injected with the KDS200pump system at the rate of5ml/min. When forelimbs were tough and straight,5ml high viscosity resin solution was injected at the rate of1ml/min. The needle was composed of and the aorta was fastened. The specimens were dipped in45℃constant temperature water baths for24hours to ensure the polymerization was a good thing.Their specimens were dissected into some parts, such as the sample of tongue, the maxillofacial skin and subcutaneous tissue, the mandible and maxilla, and the temporomandibular joint specimen. Wister rat specimens were corrosive. Specimens containing bone and soft tissues, were plunged into sodium hypochlorite solution and other specimens of skin and tongue were immersed in10%NaOH solution. Then the specimens were taken from the oil, washed by running water and ultrasonically cleaned. After they were dried, specimens of capillary corrosion casting were properly can directly be observed and applied with SEM.Tongue capillary casting showed the surface maintains morphologically integrity and clears anatomical capillary network. The depression in the middle of the anterior tongue was caused by the capillary networks on each side were separated apart from the median lingual fiber. The branch of arteriae profound linguae gave rise to submucosa capillary network of the tongue back. No obvious vascular anastomosis was observed and position and morphology of the hiatus vascular in the middle part were expected to be released.Under the SEM, abundant capillary plexus around filiform papillae and mushroom papillae were found in the back, with numerous and varied forms. From 300to1000times magnified under SEM, filiform papillae vascular plexus present cone or basket shape with varied size. Top of mushroom papillae was flat and present disc looks. Moving closer to3000and4500times. Capillary surfaces were still pleasant and smooth. In the field of4500times magnified vision, the capillaries cast diameters were less than10M which verified that resin material could be completely fulfilled the capillaries.From jaw root vascular corrosion casting specimen, the capillary system was very clear and showed the relationship among jaw bone, teeth, and the capillary. Arterioles from alveolar bones and gingival mainly distributed along the alveolar bone and gradually gave rise to smaller branches which intertwined to form network closely attached to and surrounded the root. Condylar artery networks mainly came from the joint capsule and pterygoid arteries. Anastomosis branches of condylar neck were paralleled to the transverse vascular arch of the long axis of the condylar, of which branch distributed to the surface of condyle to form cooperative surface vascular network.The specimen of maxillofacial skin and subcutaneous tissue structure was subtle, and all levels of vascular network were shown in three-dimensional vascular structure, ranging from a larger branch to the capillary network. Under SEM, the spatial structure of the minute arteries, precapillary arterioles, capillaries and venules were observed and thicker vascular interwoven with capillaries to from ample vascular network.3. Making of traumatic occultation model of Wistar ratTwelve eight-week-old healthy Wistar rats were chosen and were anesthetized with2%pentobarbital sodium first and the inlays of1.0mm high were formed in the right first and second mandibular molar with light cure resin material to construct right molars early traumatic occlusion with the left side out of contact. Inlay was competent for occlusive trauma group after1month. Local periodontal tissue was slightly rubor and tumor. The right side of the maxillary teeth significantly wears, and the correct mandibular does not afford to lose. The weight gain of Wistar rats is less on average30g the treatment group than the control group. The hair of the treatment group was messy and Matt, and Wistar rats were docile, with smooth and luster hair in control group.Wister rats were used as a model animal of traumatic occlusion in this study. Because the Wistar rats are in the habit of teeth wear, which resulted in quick development of traumatic occlusion so that the animal model could be established in a short period of time. Wister rats were plentiful in source, inexpensive, easy breeding, and had strong disease resistance which helped to the progress of the bulk of the study.4. Periodontal capillary corrosion casting of Wistar rats traumatic occlusion model48male healthy Wistar rats were randomly divided into eight groups, each group of six. For the treatment group, the time of making models is respectively3days,1week,2weeks,3weeks,6weeks,4weeks,8weeks.6were positioned in the control group. The8th week was meant for the observation.For the3day group and1week group, the alveolar bones did not absorb, and the capillaries of gums and mucoperiosteal structure were dilated. For2,3, and4weeks groups, the jaws were susceptible to accelerated alveolar bone resorption, and the density of capillary became smaller and the structure turned thinner. The4weeks group was most understandable, but the6weeks group was in the quiescent stage. Alveolar bone reconstruction was strengthening, and periodontal capillary density was increased in8weeks.Traumatic occlusion can lead to the pathological changes of rat alveolar and periodontal tissue. Along with the reconstruction of dental occlusion, the destruction of alveolar bone and periodontal tissue has been repaired. Capillary corrosion casting of Wistar rats traumatic occlusion model reveals the relationship between the traumatic occlusion and microcirculation which provided a morphological basis for the research of the pathological and physiological changes in periodontal tissue.5. TMJ capillary corrosion casting of Wistar rats traumatic occlusion model48male healthy Wistar rats were randomly divided into eight groups, each group of six. For the treatment group, the time of making models is respectively3days,1week,2weeks,3weeks,6weeks,4weeks,8weeks.6were positioned in the control group. The8th week was meant for the observation. The capillary system of the temporomandibular joint was researched by capillary corrosion casting technology. For the traumatic occlusion model of Wistar rats, under SEM, the capillary density of the mandibular condyle and articular disc gradually decreased gradually from the3days group to4weeks group and the4weeks group was minimal, but the6weeks is static, and the capillary has been reconstructed in8weeks group.The capillary corrosion casting technique can truly reveal the anatomy structure and spatial distribution of the capillary network. The characteristic change of TMJ capillary has been cast for Wistar rats traumatic occlusion model. It can be utilized to explore the pathophysiology of TMD in its clinical application and basic research.The main innovation and conclusions of the studyWith the capillary corrosion casting technique, the capillary morphology changes of periodontal and temporomandibular joint have been investigated for the traumatic occlusion model of Wistar rats, which create a new method for the study of microcirculation.①The capillary corrosion casting technique was improved by the design of the Wistar rat models which provides a morphological basis for the research of physiology and pathology of microcirculation.②The periodontal capillary casting of Wistar rats traumatic occlusion models revealed the morphological changes of alveolar bone reabsorption, and periodontal membrane capillaries.③The temporomandibular joint capillary casting of Wistar rats traumatic occlusion models reveals that the capillary morphological changes that are expected to result in pathologic changes in the joint.④With the macroscopic and the microscopic corroborated, the morphological study of microcirculation can be involved in the molecular biological technique for Wistar rats traumatic occlusion model which provides a reliable basis of the mechanism and the treatment of the disease. |
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