阳极氧化处理后的新型钛合金表面成骨细胞OPG、RANKL基因表达研究

目的:新型钛合金Ti-24Nb-4Zr-7.9Sn(TNZS)经过阳极氧化(anodic oxidation,AD)技术处理后,分析其表面的人成骨样MG63细胞骨保护素(osteoprotegerin,OPG)、细胞核因子-κB受体活化因子配体(RANKL)基因表达水平.方法:将人成骨样MG63细胞接种于Ti-6Al-4V、TNZS、AD-TNZS表面,采用半定量RT-PCR法检测OPG、RANKL mRNA的表达量.结果:人成骨样MG63细胞在AD-TNZS表面的OPGm RNA表达量有所提高,而RANKL mRNA的表达量3组材料间无明显差异.结论:阳极氧化处理的TNZS钛合金可能通过影响骨保护素、细胞核因子-κB受体活化因子配体调节成骨细胞、破骨细胞的平衡,从而促进种植体植入后的骨重建.     

拔牙诱发唇血管神经性水肿1例

血管神经性水肿为一种过敏性疾病。其发病机制属I型变态反应。过敏原可能为特定的食物、药物、肠道寄生虫、感染因子等。此外，外伤、情绪激动、寒冷等可能诱发本病^[1]。我科收治1例患儿乳牙拔除后出现唇血管神经性水肿，现报告如下。     

全国第七次牙体牙髓病学学术会议纪要

由中华口腔医学会牙体牙髓病学专业委员会主办，上海交通大学医学院附属第九人民医院·口腔医学院承办的全国第七次牙体牙髓病学学术会议于2007年3月10至11日在上海召开。本次大会同时还召开了中华口腔医学会牙体牙髓病学专业委员会全体会议，进行了新一届专业委员会的换届。本次会议共收到来自全国各地28个省、市、自治区的论文共338篇，参会代表347名。[第一段]     

p53基因抑制涎腺腺样囊性癌细胞端粒酶及增殖活性

目的研究外源性野生型p53基因对涎腺腺样囊性癌细胞的抑制作用。方法构建携带野生型p53基因的腺病毒表达载体，以脂质体法转染涎腺腺样囊性癌SACC-83细胞，RT-PCR检测p53基因表达；采用TRAP—PCR—ELISA法检测转染细胞端粒酶活性，荧光素酶分析法检测人端粒酶逆转录酶基因（hTERT）肩动子的转录；流式细胞术、软琼脂集落实验及裸鼠成瘤实验观察细胞生物特性的变化。结果外源性野生型p53基因导入使p53基因在涎腺腺样囊性癌细胞SACC-83中表达增强，其端粒酶活性降低、hTERT启动子转录抑制；转染细胞出现G1期阻滞，软琼脂集落形成率减少，裸鼠成瘤能力降低。结论腺病毒载体介导的外源性野生型p53基因可以抑制涎腺腺样囊性癌细胞端粒酶活性及细胞恶性表型。     

An In Vitro Investigation of a Comparison of Bond Strengths of Composite to Etched and Air-Abraded Human Enamel Surfaces

PURPOSE: The purposes of the study were to measure the tensile bond strength of composite resin to human enamel specimens that had been either etched or air-abraded, and to compare the quality of the marginal seal, through the assessment of microleakage, of composite resin to human enamel specimens that had been either etched or air-abraded. MATERIALS AND METHODS: Thirty mandibular molar teeth were decoronated and sectioned mesio-distally to produce six groups, each containing ten specimens that were embedded in acrylic resin using a jig. In each of the four treatment groups, the specimen surfaces were treated by either abrasion with 27 or 50 microm alumina at 4 mm or 20 mm distance, and a composite resin was bonded to the treated surfaces in a standardized manner. In the two control groups the specimens were treated with 15 seconds exposure to 36% phosphoric acid gel and then similarly treated before being stored in sterile water for 1 week. All specimens were then subjected to tensile bond strength testing at either 1 or 5 mm/min crosshead speed. For the microleakage study, the degree of dye penetration was measured 32 times for each treatment group, using a neutral methylene blue dye at the interface between composite and either 27 or 50 microm air-abraded tooth structure or etched enamel surfaces. RESULTS: The mean bond strength values recorded for Group 1 (phosphoric acid etch, 5 mm/min crosshead speed) was 25.4 MPa; Group 2 (phosphoric acid etch, 1 mm/min), 22.2 MPa; Group 3 (27 microm alumina at 4 mm distance), 16.8 MPa; Group 4 (50 microm alumina at 4 mm distance), 16.9 MPa; Group 5 (27 microm alumina at 20 mm distance), 4.2 MPa; and for Group 6 (50 microm alumina at 20 mm distance) 3.4 MPa. An analysis of variance (ANOVA) demonstrated significant differences among the groups, and a multiple comparison test (Tukey) demonstrated that conventionally etched specimens had a greater bond strength than air-abraded specimen groups. No significant difference in dye penetration could be demonstrated among the groups (p= 0.58). CONCLUSIONS: Composite resin applied to enamel surfaces prepared using an acid etch procedure exhibited higher bond strengths than those prepared with air abrasion technology. The abrasion particle size did not affect the bond strength produced, but the latter was adversely affected by the distance of the air abrasion nozzle from the enamel surface. The crosshead speed of the bond testing apparatus had no effect on the bond strengths recorded. The marginal seal of composite to prepared enamel was unaffected by the method of enamel preparation.     

30%双氧水浸泡后对牙本质中钙/磷含量的影响

目的针对临床型漂白剂在使用中直接接触牙颈部暴露的牙本质和通过牙釉质渗透到牙本质的特点,观察30%双氧水对牙本质中的Ca/P的影响.方法实验组7颗离体牙浸泡在30%双氧水24小时后,对照组5颗离体牙浸泡在生理盐水中24小时后,两组使用OCPC法对浸泡液中的Ca离子含量进行测定,同时运用Fiske-Subbarow法对浸泡液中的磷酸根含量进行测定.然后两组进行统计学比较分析.结果实验组30%双氧水浸泡液中Ca/P含量明显高于对照组(P<0.01).说明在30%双氧水浸泡过程中发生了明显脱矿现象.结论 30%双氧水对牙本质有脱矿作用,建议在使用临床型漂白治疗后应加以再矿化和防龋措施.     

Antibiotic prophylaxis for dentoalveolar surgery: is it indicated?

Usually dentists in Australia give patients oral antibiotics after dentoalveolar surgery as a prophylaxis against wound infection. When this practice is compared to the principle of antibiotic prophylaxis in major surgery it is found to be at variance in a number of ways. In major surgery, the risk of infection should be high, and the consequences of infection severe or catastrophic, before antibiotic prophylaxis is ordered. If it is provided then a high dose of an appropriate spectrum antibiotic must be present in the blood prior to the first incision. Other factors which need to be considered are the degree of tissue trauma, the extent of host compromise, other medical comorbidities and length of hospitalization. Standardized protocols of administration have been determined and evaluated for most major surgical procedures. Dentoalveolar surgery is undoubtedly a skilled and technically challenging procedure. However, in contrast to major surgical procedures, it has a less than five per cent infection rate and rarely has severe adverse consequences. Dentoalveolar surgery should be of short duration with minimal tissue damage and performed in the dental chair under local anaesthesia. Controlled studies for both mandibular third molar surgery and placement of dental implants show little or no evidence of benefit from antibiotic prophylaxis and there is an adverse risk from the antibiotic. This review concludes that there is no case for antibiotic prophylaxis for most dentoalveolar surgery in fit patients. In the few cases where it can be considered, a single high pre-operative dose should be given.     

Localization of Lower Right Molars in a Panoramic Radiograph, Lateral Cephalogram and Dental CT

In this investigation, the radiological status of angular measurements in the wisdom tooth area was examined. The angles of the tooth center lines of the second and third lower molars (48,47) to the occlusal plane and to one another in 25 orthodontically untreated patients (average age: 16.3 years) were measured and compared with angular values of the patients concerned measured in a dental CT. The assessment of these 3 radiological documents in an absolute comparison revealed closely corresponding angular values. However, the dental CT provided a considerably more accurate and, in addition, a three-dimensional topographical localization of lower wisdom teeth. Zusammenfassung: In der vorliegenden Untersuchung wurde der radiologische Stellenwert von Winkelmessungen im Weisheitszahnbereich überprüft. Im Fernröntgenseitenbild und Orthopantomogramm wurden die zur Okklusionsebene und zueinander gemessenen Zahnachsenwinkel des dritten und zweiten unteren Molaren (48, 47) von 25 kieferorthopädisch unbehandelten Patienten (Durchschnittsalter: 16,3 Jahre) vermessen und mit im Dental-CT gemessenen Winkelwerten des jeweiligen Patienten verglichen. Die Beurteilung dieser drei radiologischen Unterlagen ergab im absoluten Vergleich annährend sich entsprechende Winkelwerte. Das Dental-CT gestattete jedoch eine wesentlich genauere und zudem dreidimensionale topographische Lagebestimmung unterer Weisheitszähne.     

苯丙芘诱导口腔上皮细胞癌变过程的差异基因表达谱分析

目的：检测并分析苯丙芘诱导的口腔上皮细胞癌变过程中基因表达的变化，寻找在口腔上皮细胞癌变过程中起重要作用的基因。方法：使用课题组前期建立的一株永生化细胞系，以及经过苯丙芘诱导而逐步产生的具有成瘤性的肿瘤细胞系【首代成瘤细胞（HB-56P）及典型鳞状细胞癌细胞（HB-94P）】，通过Affymetrix U133 plus 2．0基因芯片。检测在永生化细胞（HIOEC）向成瘤细胞转化过程中的基因表达变化。使用GenSpring7．0进行标准化及单因素方差分析，通过Venn图分析差异基因在癌变不同阶段的变化，并进一步通过GO术语进行注释。对部分基因使用实时定量PCR在细胞系中进行了验证。结果：在HIOEC向HB-94P转化过程中，共有883条差异基因，大部分集中于肿瘤发生的早期阶段。差异基因主要涉及大分子代谢、信号传导等生物学过程。具有过渡金属离子结合能力、腺核苷酸结合能力及激酶活性。其蛋白产物主要是膜结合蛋白，位于核内或细胞骨架。IGFBP3、S100A8、MAP2K、KRT6B、GDF15和MET的表达基本符合芯片结果。结论：本研究检测了苯丙芘相关口腔上皮细胞癌变过程中基因表达的变化，为苯丙芘相关的口腔癌分子发病机制研究提供了基础。