Tooth agenesis constitutes one of the most common developmental anomalies in man. Oligodontia is defined as congenital absence of six or more teeth. Based on the studies of our team in cooperation with Peking Universi...
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Tooth agenesis constitutes one of the most common developmental anomalies in man. Oligodontia is defined as congenital absence of six or more teeth. Based on the studies of our team in cooperation with Peking University Center for Human Disease Genomics in the past five years, this article reviews the current research progress in clinical phenotypes and case collection, epidemiological investigation and etiological genetic studies of oligodontia. The symptoms of oligodontia were classified into syndromic and non-syndromic according to the occurrence of tooth agenesis with or without systemic developmental defects. As for the advancement of theories and techniques of molecular genetics, a number of gene mutations have been identified to be the direct etiological factors causing some specified diseases, especially those with developmental defects. Here, this article summarized the outcomes of molecular genetic study of some cases we collected. Of the systemic oligondontia patients, a new four-base-deletion mutation in PITX2 was identified in a large kindred with typical symptoms of Rieger Syndrome; four different gene mutations in ED1 casing X-linked hypohidrotic ectodermal displasia were found in five nucleus families. Compared with the former, non-syndromic oligodontia has more genetic heterogeneity rather than some specific virulence gene. PAX9 and MSX1 are the identified genes associated with family tooth agenesis without systemic syndrome. Also, in our research, three gene mutations in CBFA1 were detected in four cleidocranial dysplasia families, which is a systemic developmental disease including the symptoms of tooth eruption abnormality and accessory teeth.
目的:为了提高氧化锆修复体的粘接强度,使用热酸蚀法处理氧化锆的粘接表面,并比较处理后用两种常用树脂粘接剂粘接到牙釉质表面的剪切粘接强度。方法:分别制作光滑的牙釉质粘接面和氧化锆粘接面,氧化锆表面分别接受空白处理、喷砂处理、热酸蚀表面处理。电子显微镜观察处理后的氧化锆表面形态,使用Super Bond C&B和Panavia F 2.0树脂粘接剂进行粘接。使用万能力学试验机进行剪切实验,十字头加载速度为1 mm/s,并使用单因素方差分析对数据进行统计学分析以比较热酸蚀处理对氧化锆和树脂粘接强度的影响。结果:Super Bond组氧化锆剪切粘接强度分别为:空白处理(23.37±3.94)MPa、喷砂处理(25.95±3.05)MPa、热酸蚀处理(34.52±1.8)MPa;Panavia组氧化锆剪切粘接强度分别为:空白处理(12.91±3.33)MPa、喷砂处理(14.00±3.28)MPa、热酸蚀处理(18.47±4.16)MPa。两种粘接剂组中热酸蚀处理后的氧化锆试件剪切粘接强度明显高于空白处理和喷砂处理,差异具有统计学意义(P<0.01)。结论:热酸蚀处理可以有效提升氧化锆表面和树脂的粘接强度。
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