Expression of two drug-metabolizing cytochrome P450-enzymes in human salivary glands

Objective:  The oral cavity is constantly lubricated by saliva and even small amounts of xenobiotics and / or their metabolites in the saliva may affect the oral mucosa. Our aim was therefore to clarify if xenobiotic metabolizing enzymes CYP1A2 and CYP3A4 are expressed in salivary glands.
Methods:  Formalin-fixed paraffin-embedded specimens from parotid (10), submandibular (7) and labial (10) salivary glands were examined immunohistochemically and by in situ hybridization for expression of CYP1A2 and CYP3A4 protein and mRNA.
Results:  CYP1A2 and CYP3A4 protein and mRNA were detected in ductal and seromucous / serous acinar cells in all gland types although to a varying degree and intensity. Mucous acinar cells were positive to a lesser extent.
Conclusion:  The results indicate a xenobiotic metabolizing capability of salivary glands. This may have implications for development of oral mucosal disease as a result of mucosal exposure to metabolites originating from internal sources (blood) as well as from saliva.     

牙本质牙髓复合体的形成研究(二)牙本质牙髓复合体的在体形成研究

牙本质牙髓复合体在体形成研究包括牙齿发育完成后在各种因素下形成的第三期牙本质和成牙组织、细胞在口腔以外部位形成牙齿样结构两方面。一些细胞外基质分子和生长因子形成的网络调控在其形成中发挥关键性作用。对这些分子机理的研究将为临床牙髓病的生物保髓治疗和牙髓、牙齿再生替代治疗奠定了基础。     

不同浓度复方奥硝唑甲磺酸培氟沙星牙栓的体外抑菌作用的实验研究

目的：观察5种不同浓度（10g／L、20g／L、50g／L、100g／L、200g／L）的复方奥硝唑甲磺酸培氟沙星牙栓的体外抑菌作用。方法：采用Kirby—Bauer纸片扩散法测定5种不同浓度的复方牙栓对牙周主要可疑致病菌的抑菌作用。结果：不同浓度的复方牙栓对牙龈卟啉单胞菌、具核梭杆菌、中间普氏菌、消化链球菌、变形链球菌、金黄色葡萄球菌、表皮葡萄球菌均有一定的抑菌作用。7种菌株间的抑菌圈直径不同、5种不同药物浓度之间的抑菌圈直径也不同，并且菌株和药物浓度两个因素之间存在交互作用（P〈0．001）。上述7种菌株间的F值分别为：91．391、170．431、255．187、143．636、211．839、347．639、580．238（P〈0．001），具有显著性差异。结论：5种不同浓度的复方奥硝唑甲磺酸培氟沙星牙栓在体外均有明显的抑菌作用，以200g／L的给药浓度的抑菌效果最强。     

A simple model to demonstrate the electronic apex locator

AIM: To describe and evaluate a newly developed model for demonstrating and teaching the use of electronic apex locators. SUMMARY: A phantom model, master jaw model and extracted human teeth were used to construct the demonstration model with alginate impression material as the periapical conductive medium. The model was validated in a series of length determinations with apical foramina enlarged to 0.20, 0.30 and 0.45 mm diameter, and the stability of the model was evaluated up to 45 h after construction. All evaluations were conducted with the Root ZX apex locator with 2.65 and 5.25% NaOCl in the canals. Most length measurements were within 1 mm of actual root length (range: -2.2 to +0.21 mm) and did not change significantly over 45 h for teeth with foramina of 0.3 mm or less. Measurements for teeth with wide (0.45 mm) apices were stable up to 28 h. NaOCl concentration did not significantly affect the readings. KEY LEARNING POINTS: A simple, inexpensive model can be manufactured from plastic dental jaws, natural teeth and alginate impression material to demonstrate electronic working length measurement. The model is stable for many hours and provides consistent results with different concentrations of NaOCl in the canal and various apical diameters. The model is a useful teaching aid but needs further evaluation and refinement before use in research applications.     

体内诱导法建立的Tca8113细胞耐卡铂细胞株的耐药性表达研究

目的探讨通过体内诱导法得到的耐药细胞株的耐药性表达情况。方法以人舌癌Tca8113细胞系为研究对象,实验组采用荷瘤耐药动物的肿瘤细胞培养获得,对照组为体外连续培养诱导其产生耐药性。用四唑蓝法检测细胞耐药指数,标记生物素链亲和素法免疫细胞化学检测耐药相关蛋白P糖蛋白、谷胱甘肽S转移酶π、多药耐药蛋白和拓扑异构酶Ⅱ的表达,逆转录PCR检测多药耐药基因、多药耐药蛋白、拓扑异构酶Ⅱ和谷胱甘肽S转移酶π的表达。结果免疫细胞化学和逆转录PCR显示2组细胞多药耐药蛋白、谷胱甘肽S转移酶π、拓扑异构酶Ⅱ等表达均升高,但体内诱导较体外诱导可以获得更高、更稳定的耐药性。诱导后的Tca8113细胞对氨甲喋呤、卡铂、平阳霉素、长春新碱耐药性明显升高,而对5-氟尿嘧啶耐药性增加不明显。结论体内诱导得到的细胞株耐药性明显高于体外诱导株,肿瘤细胞的耐药现象受多种基因的调节。体内诱导Tca8113卡铂耐药细胞株Tca8113/CBP-vo可以作为肿瘤耐药研究的平台。     

螺旋型牙种植体下颌磨牙区种植的尝试

磨牙区种植对种植义齿修复，特别是下颌总义齿的稳固和Ｈｅ力均匀分布非常重要。但是，由于下颌管走行于下颌骨体中间，盲目种植会损伤下齿槽神经和血管。作者采取Ｘ线测量，根据所测下颌管上壁至牙槽嵴顶的距离，选用一定长度的固位钉作种植；和对骨吸收严重者由下颌管上方去除舌侧骨板，解剖游离该神经血管束将其避开，选长钉植入，可抵达下颌下缘皮质骨，解决了此类病人磨牙种植的难题。作者对磨牙区种植的适应证、手术方法及可能     

口腔生物膜体外模型的建立和应用评估

目的：通过建立体外生物膜模型，模拟口腔内生态环境以探索生物膜在龋病发生发展中的作用。方法：利用发酵罐与恒流培养室的组合构建简易的体外生物膜模型，通过恒流培养室内液体培养基连续的流动循环，模拟出口腔内液体持续冲刷的生态环境。在羟磷灰石片上定植4种口腔常驻菌，以形成实验性生物膜，并通过每12h定时给以蔗糖底物，模拟致龋环境，观察系统中实验菌CFU计数、pH动态变化等各项反应及不同环境下所形成生物膜的微结构变化。结果：本研究建立的系统能较好的控制各项实验参数，加入蔗糖底物后表现出明显的致龋反应。结论：本组建立的体外模型有着良好的可靠性与可重复性，可用于对口腔生物膜的各项体外研究。     

Fracture characteristics of carbon fibre, ceramic and non-palladium endodontic post systems at monotonously increasing loads

A carbon fibre post system, three non-palladium and one palladium metal post systems, two ceramic post systems, and a metal post system with a ceramic core were studied in vitro. The control group consisted of root-filled test teeth without posts. The test teeth were identical artificial roots of an upper central incisor made from a posterior composite whose module of elasticity was similar to that of natural dentine. All posts were cemented in the roots using Panavia 21 TC. Subsequently, standardized full crowns were cemented onto all roots. On a universal testing machine, the test teeth were loaded palatally at monotonously increasing loads until root fracture. The highest mean fracture loads were found for the carbon fibre post system (312.5 +/- 58.8 N). The fracture load of non-palladium metal posts (242.3-300.4 N) did not differ significantly from that of the Perma-dor post (265.9 N), which does contain palladium. Values of 300.3 +/- 89.3 N (aluminium oxide ceramics) and 193.5 +/-57.0 N (zirconia ceramics) were found for the ceramic posts. The control group exhibited a fracture load of 228.8 +/- 35.7 N. The mean distance between the vestibular end of the fracture gap and the point of force application was between 10.1 +/- 2.3 and 14.7 +/- 1.2 mm.     

Teeth in a day for the maxilla and mandible: case report

Background: A growing body of evidence indicates that successful osseointegration of dental implants can take place in the wake of immediate loading, providing that bone quality and quantity are adequate, and patients follow postsurgical instructions carefully. Purpose: The goal of this report is to demonstrate the efficient treatment protocol based on immediate loading for both the maxilla and mandible, including extraction site locations. Materials and Methods: Following extraction of the remaining anterior mandibular teeth, 18 Brånemark implants (Nobel Biocare AB, Gothenburg, Sweden), including two zygoma and two pterygoid implants, were installed in both arches in accordance with the Teeth in a Day protocol developed by the authors 9 years ago. This protocol uses an acrylic screw‐retained prosthesis, with steel prosthetic copings embedded, supported by full‐size Brånemark implants to prevent micromotion at the bone‐to‐implant interface. Results: Only 1 of the 18 immediately loaded implants failed to osseointegrate. Three years after completion of treatment, the patient reported functioning well with no complications. Conclusions: When appropriate subjects are selected, the Teeth in a Day protocol offers patients a number of significant advantages, including condensed treatment time, reduced postsurgical discomfort, and almost instantaneous improvement in speech and masticatory function, esthetics, and patient self‐image.     

Histological evaluation of oral implants inserted with different surgical techniques into the trabecular bone of goats

OBJECTIVE: The aim of this study was to investigate the influence of implant surface topography and surgical technique on bone response. MATERIAL AND METHODS: For the experiment, 48 screw-designed implants were used with two different surface finishes, i.e. machined and 'blasted, etched'. The implants were inserted into the left and right medial femoral condyle of eight goats using three different surgical approaches: press-fit (implant diameter=implant bed diamete(r), undersized (implant bed diameter相似文献