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The National Collegiate Athletic Association (NCAA) mandates the use of brightly colored, intraoral mouth- guards by football players to reduce the frequency and severity of craniofacial and intraoral morbidity and mortality, and to enhance the ability of officials to observe player compliance. The purpose of this 12-question mail survey was to determine the attitudes of on-Held game officials regarding current NCAA mouthguard regulations and patterns of utilization by college football players. The sample consisted of all 50 Big East Football Conference officials; a response rate of 100 percent was achieved. Only 42 percent of the officials reported observing all players in compliance, and quarterbacks were identified by others as the least compliant group (52%). The majority (88%) indicated that the 1990 rule for brightly colored mouthguards had been beneficial to them in determining player compliance, and 52 percent reported that this rule had resulted in more frequent use by these athletes. Nearly all officials (96%) indicated that they would issue a warning for noncompliance to the player or coach, rather than charging a timeout for a violation as prescribed by NCAA regulations. The majority (70%) believe current enforcement is appropriate, but expressed the opinion that coaches should be held more accountable for player compliance.  相似文献   
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In Vitro Wear of Nano-Composite Denture Teeth   总被引:2,自引:0,他引:2  
PURPOSE: Few laboratory tests have been able to substantiate and quantify the wear resistances of polymeric denture teeth. This study evaluated the relative wear resistance of several types of denture teeth using an in vitro wear testing device. MATERIAL AND METHODS: Four different types of denture teeth [nano-filled (Veracia) and micro-filled composites (SR-Orthosit, Endura, Duradent, Surpass), cross-linked acrylic (SR-Postaris, Genios-P, Creapearl, Vitapan Physiodens, Premium 8, Integral), and a conventional acrylic (Biotone)] were used. The flattened buccal surface of each denture tooth was subjected to the evaluation of Knoop hardness (n=5) and localized wear for 100,000 cycles (n=10). Wear values were determined in micrometers using a profilometer. The data for the hardness, wear depth, and worn surface areas were individually analyzed by one-way ANOVA. RESULTS: Knoop hardness values (KHN) ranged from 28.2 to 29.8 for micro-filled composite, 18.9 to 21.6 for cross-linked acrylic, 22.7 for nano-composite, and 18.6 for conventional acrylic teeth. All micro-filled composite teeth were significantly harder than other teeth (p <0.0001). The wear depth values were 90.5 microm for the nano-composite, 69.8 to 93.0 microm for the micro-filled composite, 80.8 to 104.0 microm for the cross-linked acrylic, and 162.5 microm for conventional acrylic teeth. The worn surface areas were 5.1 mm2 for the nano-composite, 2.6 to 3.6 mm2 for the micro-filled composite, 4.4 to 5.7 mm2 for the cross-linked acrylic, and 10.1 mm2 for conventional acrylic teeth. The wear values of the acrylic control were significantly different from all other denture teeth (p <0.001). CONCLUSION: The nano-composite tooth was harder and more wear resistant than the acrylic teeth but not significantly different from most of the cross-linked and micro-filled composite teeth tested.  相似文献   
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Foods have always been considered by man as a means of ensuring his physiological needs, allowing the growth, development and preservation of the body and its tissues (nutritional value of food). To this can be added the feelings of satisfaction and well-being that food gives to its consumer, thus constituting an element that is fundamental for our physiological and mental balance (the sensorial value of food).Nevertheless, recent scientific studies have shown that over and above the ensuring of nutritional needs, eating habits can also adjust certain functions of the human organism and thus play a beneficial or harmful role on one's health (the functional value of food).The whole concept of nutrition has been enriched by the notion that eating is not only a survival reflex (satisfaction derived through eating and the avoidance of harmful effects due to eating deficiencies or excesses): eating aims to improve one's health and well-being and to reduce the risk of developing various pathologies. These new data open interesting new horizons in today's context where health is increasingly expensive and people are increasingly concerned to improve their quality of live.  相似文献   
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