选择性微电极测定唾液中氟离子的初步探讨

目的 :研制氟离子选择性微电极 (F -ISME)并探讨其在口腔领域应用的可行性。方法 :采用氟化镧电极晶体 (LaF3:EU :Ca)为敏感膜制备F -ISME ,并进行各项性能测试 ,结合氟离子选择性电极 (F -ISE)对成人唾液样本的氟离子进行检测和对比分析。结果 :F -ISME的检测下限为 2 .5× 10 -6 mol/L ,试样的加标回收率平均为 95 .5 % ,线性范围、重现性、稳定性、响应时间、pH范围等各项性能良好 ,对唾液中氟离子的测定与F -ISE基本一致。结论 :F -ISME具有简便、快速、敏感、准确的性能 ,在口腔研究领域有较好的应用前景     

钙离子选择性微电极对唾液中游离钙的检测与评价

作者采用中性载体Ca2 －ISME对唾液中的生理性游离钙浓度进行测定和分析，对比结果显示：儿童与成人之间、男女儿童之间、无龋组与龋活跃组之间以及间隔两周时间之间的唾液Ca2 浓度均无显著性差异（P均＞0．05），提示龋病与儿童的生理性唾液中的钙含量无直接关系。Ca2 -ISME适用于对口腔微量液体中Ca2 的检测分析．     

离子选择性微电极在龋病研究中的应用

龋病的整个发生，发展过程都与无机离子在牙齿硬组织中和菌斑中的交换密切相关，但对许多离子确切的作用机理尚有待深入探讨。离子选择性微电极对探讨各种离子的代谢规律以及影响因素具有很多的优越性。本文就其应用现状及其发展前景作了介绍。     

选择性激光加工技术在口腔医学领域的应用进展

选择性激光加工技术是近几年来研究的热点,在机械制造领域已被广泛应用。由于口腔医学材料使用的局限性及特殊性,该技术尚未能广泛使用,基于该技术的多种优点,很多学者做了大量的研究及尝试。本文对近年来选择性激光加工技术在口腔医学领域的应用进展作一综述。     

选择性激光熔化技术在口腔医学中的应用

选择性激光熔化（Selective laser melting,SLM）技术是一种快速成型技术,它以其制作方便、快捷、产品组织结构密度高、精度高、避免传统加工方式原材料浪费等优点,被逐渐运用于各个行业。然而,在口腔医学中的应用还报道较少,主要集中在冠桥修复、可摘局部义齿支架、骨替代物及生物植片等方面。本文介绍了SLM技术的原理,分类以及在口腔医学中的应用特点和前景。     

异搏定对Ca^2＋增加牙髓神经纤维诱发放电的抑制作用

目的：了解钙离子及钙通道在牙齿激发痛传导中的作用。方法：应用牙齿激发痛动物模型观察低浓度ＣａＣｌ２及钙通道阻滞剂异搏定对牙髓神经诱发放电的影响。结果：０．８５％ＣａＣｌ２溶液可增加气流刺激诱发牙髓神经放电数目。异搏定可抑制气流刺激诱发的牙髓神经放电，并抑制ＣａＣｌ２增加牙髓神经诱发放电的作用，两种抑制作用与异搏定的浓度有关。结论：０．８５％ＣａＣｌ２增加诱发放电的作用与Ｃａ２＋通道有关     

四种浓度氢氧化钙药物在模拟根尖周组织内扩散效果的观察

目的观察不同浓度Ca(OH)2糊剂在模拟根尖周模型内的扩散效果。方法用吸液管尖、琼脂及5ml塑料注射器制备成药物扩散的模拟根尖周模型。选取根尖孔径40#的吸液管120支。分为4组,每组30支,置入模拟根尖周组织内形成模型。第一组:封入10?(OH)2100μl;第二组:封入30?(OH)2100μl;第三组:封入60?(OH)2100μl;第四组:封入90?(OH)2100μl;对照组:封入蒸馏水100μl。在封药后2d、5d、10d、15d、20d后提取模拟根尖周组织测定pH及钙离子浓度。结果根管内封入Ca(OH)2糊剂各组琼脂内Ca2 浓度和pH改变显著高于对照组(P<0.05),Ca2 浓度逐渐升高,但15天后呈稳定趋势,琼脂中的pH则呈持续上升趋势。不同浓度Ca(OH)2糊剂对尖周区域的钙离子浓度和pH的影响有显著性差异。结论根管内封入Ca(OH)2对模拟根尖周Ca2 浓度和pH值有显著影响,不同浓度的Ca(OH)2糊剂对根尖周Ca2 浓度和pH改变的影响有显著性差异,30%和60%的Ca(OH)2糊剂的扩散效果较好,而90?(OH)2糊剂的扩散效果最差。     

抗菌钛合金在口腔医学中应用研究进展

广泛应用于口腔医学领域的钛合金,由于长期处于复杂微生物环境中,材料表面易形成细菌生物膜,影响其使用效率和寿命.抗菌钛合金是一种通过表面改性或整体改性的方法添加了抗菌剂的新型钛合金.根据抗菌剂在钛合金材料中分布的位置,抗菌钛合金分为涂层型和合金型.涂层型抗菌钛合金的抗菌效果良好,但缺点是涂层大多不耐磨;合金型抗菌钛合金的...     

定量温度觉检测在口腔医学领域的应用

定量温度觉检测(quantitative thermal perception testing,QTT)是一种能对温度觉进行定量评估的神经物理学技术,其操作简便、无创,且结果具备敏感性、特异性、可靠性及重复性。近年来,在口腔医学领域的应用日渐增多,并在慢性疼痛机制研究、疾病诊断和预后评估等方面做出了卓越的贡献。本文将就定量温度觉检测在口腔医学领域的应用作一综述。     

Sjogren综合征的白细胞介素2及其受体系统的初步研究

目的探讨白细胞介素2(IL-2)及其受体系统检测在S(o)jgren综合征发生发展中的作用.方法采用放射免疫法(RIA)检测S(o)jgren综合征患者外周血的IL-2含量,双抗体夹心法测定可溶性白细胞介素2受体(sIL-2R)表达水平.结果患者的IL-2含量明显低下,血清sIL-2R表达水平显著增高,与对照组相比有非常显著性差异;治疗后IL-2的水平有明显的上升,sIL-2R的表达水平有显著的下降,但与正常人相比还是有统计学上的差异;停药后症状复又加重者,其血清IL-2含量再趋下降,而sIL-2R水平又见回升,说明S(o)jgren综合征患者存在着明显的IL-2/sIL-2R系统紊乱,治疗后得以部分或完全纠正,患者的自觉症状明显好转.结论对患者外周血IL-2及sIL-2R水平的研究有助于进一步探索S(o)jgren综合征免疫调节紊乱的发生机制,两者的检测有助于评价其免疫功能状态,动态观察对监察病情的发展及评价治疗效果有重要的临床意义.     

微型pH电极直接测试人牙菌斑pH的应用研究

目的：进一步探讨微型ｐＨ电极在原位检测人牙菌斑ｐＨ的可行性，了解漱糖后对菌斑ｐＨ的影响。方法：采用微型蜂式ｐＨ指示电极直接测试人牙邻面菌斑ｐＨ变化。结果：微型ｐＨ电极与玻璃ｐＨ大电极所测结果基本一致；漱糖后菌斑ｐＨ呈下降趋势，２０ｍｉｎ时达到最低点；无龋组与龋敏感组之间的ｐＨ改变无显著性差异。结论：微型ｐＨ电极适用于在原位直接测试菌斑ｐＨ；漱糖后菌斑ｐＨ发生改变，但龋坏与否的个体之间未见明显不同     

酪蛋白磷酸多肽-无定形磷酸钙在口腔治疗中的研究应用

随着人们对口腔健康重视程度的提高,人们逐渐意识到对于口腔健康而言,预防保健的作用及意义远远甚于后期的治疗。酪蛋白磷酸多肽-无定形磷酸钙作为一种新型口腔用品,因其较好的再矿化作用,良好的安全性和方便的操作性,得到越来越广泛的应用。该文就酪蛋白磷酸多肽-无定形磷酸钙的基本结构、作用原理、研究现状作一综述。     

Mechanical properties of calcium phosphate based dental filling and regeneration materials

The objective of this study was to compare the mechanical properties of calcium phosphate cements (CPC) for possible dental applications with varied liquid and powder compositions under the same testing condition. Cements studied in this experiment were divided into two groups of CPC not containing polymer and polymeric CPC (PCPC). Cement powder was formed by combining equimolar amounts of dicalcium phosphate anhydrous and tetracalcium phosphate, or acrylic resin polymer powder mixture. The CPC specimens for the compressive strength (CS) and diametral tensile strength (DTS) measurements were prepared by mixing powder and liquid for 30 s with a powder/liquid ratio of 3:1, and subsequently packing the paste into a brass mould. The specimens were kept at 37 degrees C and 100% relative humidity for 24 h before measurements were conducted on a Universal Testing Machine with a cross-head speed of 1 mm min-1. The CS of CPC was 0.14-10.29 MPa and that of PCPC was 0.26-117.58 MPa. The DTS of CPC was 0.10-4.56 MPa and that of PCPC was 0.07-22.54 MPa. The CS and DTS were very diverse depending on the composition of powder and liquid. Some compositions showed higher values than commercial liners. Thus compositions of 2% carboxymethyl cellulose + 35% citric acid in phosphate buffered saline (PBS), 20% gelatin in PBS, 2% sodium alginate in PBS, 20-40% aqueous acrylic-maleic copolymer solution, and some of the HPMC and PMVE-Ma solutions exhibited promising formulae for dentine regenerating materials. Acrylic resin-PCPC group showed generally higher CS and DTS values. Based on this study, further studies on the reaction with odontoblast and resultant dentine regeneration should be performed using promising compositions.     

前列腺素E2对鼠头盖骨钙代谢的作用

目的：观察前列腺素E2（PGE2）对骨细胞钙代谢的作用。方法：原子吸收分光光度计检测骨器官培养上清中Ca^2 浓度。结果：0．01－0．1ng/ml浓度PGE2促进Ca^2 吸收,10－100ng/ml浓度PGE2促进Ca^2 释放。结论：PGE2在骨钙代谢中的作用与其局部浓度有关。     

酪蛋白磷酸肽钙磷复合体在牙菌斑中的作用

酪蛋白磷酸肽钙磷复合体是由一种含成簇磷酸丝氨酸的生物活性肽———酪蛋白磷酸肽与无定形磷酸钙经生物结合而形成,具有重要的生物活性,是一种新型的生物防龋制剂。本文就其结构特征、在牙菌斑中对主要致龋菌的影响、抑制脱矿及促进早期龋再矿化作用,以及研究展望等方面作一综述。     

含钙、氟的漱口液对唾液和菌斑中氟浓度的影响

目的:测定正常人应用加入钙离子的含氟漱口液漱口后菌斑和唾液中的氟离子浓度,并探讨其防龋作用。方法:成人自愿者15名,使用0.2%NaF 2?Cl2漱口液漱口1min,分别收集漱口后1h和2h的唾液和菌斑,用氟离子选择性电极测定氟离子浓度,并与基线水平以及0.2%NaF漱口液相比较。结果:两种漱口液漱口后1h和2h,牙菌斑及唾液中氟浓度较基线水平有显著性增高(P<0.05),尤其是0.2%NaF 2?Cl2漱口液差异较明显。结论:在相同的氟离子浓度条件下,加入钙离子的含氟漱口液可以增加菌斑和唾液中的氟离子释放,延长了氟作用时间,提高防龋效果。     

Study on the dissolution behaviour of calcium fluoride

Abstract – The dissolution of two analytical calcium fluoride preparations was studied in aqueous solution. Dissolved calcium fluoride was determined from analysis Ca and F in solution. Original samples of the two preparations and the residue after partial dissolution were studied by X-ray diffractometry in comparison with natural fluorite. The dissolution of calcium fluoride was found to be extremely slow. After a period of 1–15 weeks, depending on the experimental conditions, a state was reached where apparently no further dissolution occurred, although the solution was far from saturation. The dissolution rate was obviously closely related to the crystal size. On partial dissolution the mean crystal size increased, probably due to the disappearance of the finest fractions. Placing the salt in a dialysis bag before immersion in the water lowered the dissolution rate and increased the undissolved fraction considerably. The results seem to support the assertion that calcium fluoride accumulated in early carious lesions after topical applications of fluoride may persist for considerable periods of time.     

An enzyme histochemical study of the influence of formocresol and calcium hydroxide on the dental pulp

Abstract Sections of goat incisor pulps were studied after a 5-min application of formocresol (FC) or after calcium hydroxide or saline/ZnOE treatment followed by freeze-sectioning. After 3–7 days the incisal part of the pulp was necrotic, as shown by absence of lactate dehydrogenase (LDH) activity. The necrotic zone was much larger after FC than after saline/ZnOE or calcium hydroxide. The LDH negative area after application of FC appeared to consist of a layer showing nuclei that were well-preserved by the formaldehyde from the FC, and an area of tissue breakdown, which showed no or a reduced structure according to hematoxylin and eosin. Well-preserved nuclei were not found in the 2 other groups. After 14 days all necrotic tissue, except that subjacent to calcium hydroxide, had been replaced by vital (LDH-positive) tissue. After saline/ZnOE or calcium hydroxide treatment, hard-tissue formation was found in all teeth, and after FC treatment in the majority of teeth.