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Odontology - Recently, sealers based on calcium silicates were developed as a new class of endodontic sealers. Inspired by the excellent sealing ability and biocompatibility of calcium...  相似文献   
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Brain Imaging and Behavior - Motor learning is a multi-stage process, in which the involvement of different brain regions is related to the specific stage. We aimed at characterising short...  相似文献   
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Journal of Neurology - Volume loss in the deep gray matter (DGM) has been reported in patients with multiple sclerosis (MS) already at early stages of the disease and is thought to progress...  相似文献   
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SmartPrep is a rotating instrument for dentin caries excavation made from a special polymer. The manufacturer's product information stated that SmartPrep removes carious dentin selectively. This in vitro study compared the efficiency of SmartPrep with conventional tungsten carbide bud burs. Fifty extracted teeth were split in the center of a carious lesion. The 100 specimens were randomly divided into five groups. Five dentists were asked to excavate 10 teeth each: one half with SmartPrep and the corresponding half with conventional bud burs. The time needed for the caries excavation was measured. Subsequently, histological specimens were produced from all cavities and analyzed by light-microscope after Mallory-Azan-staining. The thickness of the remaining caries was measured (< 1 mm or > 1 mm). The time expended was analyzed using the paired t-test. The results were analyzed for the remaining caries and thickness of the carious layer for every tooth, using the non-parametric Wilcoxon test for combined random samples. A binary logistical regression was performed to determine the influence of the three variables (tooth, sections or bur) on the criteria "caries" or "carious layer thickness (> 1 mm)." The average time to excavate a cavity with SmartPrep was 208.1 seconds, and it was 228.32 seconds with conventional bud burs. The difference between the recorded times was not statistically significant (p > 0.05). In 37 of 50 teeth, the number of carious sections was higher in the SmartPrep group than in the bud bur group. In nine teeth, the quantity of carious sections was higher in the bud bur group than in the SmartPrep group. Four teeth showed no difference in the number of carious sections. The results were statistically significantly different (p < 0.001). In 30 teeth, the number of carious sections with a carious layer thicker than 1 mm was higher in the SmartPrep group compared with the bud bur group. In nine teeth, the number of carious sections was higher in the bud bur group than in the SmartPrep group. Eleven teeth showed no difference in thickness of the carious dentin layer. These results were statistically significantly different (p = 0.003). Binary logistical regression showed that only the variable "bur" (bud bur or SmartPrep) influenced the results concerning the criterion "caries" (p < 0.001).  相似文献   
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OBJECTIVES: The aim of the present study was to assess the structural reaction of intact dentine to Carisolv in vivo and in vitro. METHODS: For the in vivo study occlusal cavities were prepared in 48 caries-free molars in Wistar rats (age: three months) and Carisolv-solution was placed into the cavities of 24 M for 1, 10 and 20 min. Twenty four contralateral molars served as controls and were treated with an inert liquid containing purified water, carmellose and erythrosin for corresponding periods. For the in vitro study 24 rat molars were resected en bloc and fractured to expose an area of crown dentine area. Molars were demineralised with EDTA for eight weeks to expose the collagenous dentinal matrix. One half of the specimens was then coated with Carisolv-solution for 20 min. The other half served as a control and was coated with an inert solution for 20 min. RESULTS: In the in vivo specimens no signs of pulp cell damage were observed in the experimental group. The odontoblastic processes were destroyed in proximity to the floor of the cavity but were intact in the inner portion of dentinal tubules in experimental molars and a mechanical damage was noted in the control molars. In the in vitro specimens no structural discrepancy was detected between the experimental molars and the control molars in collagen fibrils of demineralised dentine. CONCLUSIONS: Carisolv causes destruction of cellular components of odontoblastic processes but does not attack healthy collagen fibrils.  相似文献   
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