非血管化游离骨移植中细胞活力的实验研究

目的 :探讨非血管化游离骨块中细胞存活能力及数量与离体时间的关系。方法 :取狗非血管化游离髂骨块 ,在离体 2 5～ 15 0min的不同时间点 ,消化骨块获得细胞 ,进行活细胞计数。对消化获得细胞体外培养2 4h后 ,再进行活细胞计数 ,分析细胞存活与离体时间的关系。结果 :在离体 2 5～ 15 0min时间内 ,骨块细胞的存活率从 91.96%降至 9.5 2 %。统计学检验 ,2 5min组与 70min以前组之间没有统计上的差别 ,P >0 .0 5 ;2 5min组与 70min及其以后组之间有明显差别 ,P <0 .0 1。培养 2 4h后 ,以上各时间点的细胞存活率则从88.73 %到 3 .88% ,组间差别与刚离体时相同 ,但 70min后的各组活细胞率明显下降。结论 :非血管化狗游离髂骨块的离体时间对其中的细胞存活有明显影响 ,离体 70min可能是其关键点 ;在非血管化游离骨移植中 ,尽量缩短骨块的离体时间 ,有利于保存更多的活细胞     

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目的探讨螺旋CT三维重建技术在埋伏尖牙正畸牵引中的应用价值。方法2006年3月至2007年12月,南京大学医学院附属口腔医院正畸科对12例颌骨内尖牙埋伏阻生患者进行螺旋CT检查、颌面骨三维重建,并与曲面断层X线片进行对比观察。结果CT三维重建能对颌骨内埋伏阻生尖牙准确定位,与颌骨内的实际情况所见完全一致,极大的提高了埋伏尖牙正畸牵引的成功率,有效地缩短了患者的治疗时间,减少了患者的痛苦。结论螺旋CT三维重建影像可以直观地显示埋伏阻生尖牙在颌骨内的生长情况,对上颌骨埋伏阻生尖牙的定位、治疗方案的制定具有重要指导作用。     

女性生长发育高峰期后安氏Ⅱ1类错(牙合)后部牙弓与颌骨宽度的分析

目的分析生长发育高峰期后女性安氏Ⅱ1类患者存在的后部牙弓及颌骨宽度不调,为安氏Ⅱ1类患者的早期治疗提供临床依据.方法选取30例生长发育高峰期后的女性安氏Ⅱ1类及35例安氏Ⅰ类患者,在模型上测量上下牙弓的宽度并计算宽度差值(PTID),在头颅后前位X线片上测量上颌宽度、鼻宽度及下颌角间宽度,用独立样本的t检验进行统计学分析.结果生长发育高峰期后的安氏Ⅱ1类患者均存在着上牙弓及上颌骨的狭窄,其PTID与安氏Ⅰ类患者相比具有显著性差异(P<0.05).结论生长发育没有改善安氏Ⅱ1类患者上颌后部牙弓及基骨的狭窄;对于安氏Ⅱ1类患者,早期通过扩大上牙弓的宽度,使下颌自由前伸,有利于Ⅱ类关系的纠正.     

Tissue oxygen tension and blood-flow changes in rat incisor pulp with graded systemic hyperoxia

The role of oxygen in the regulation of the pulpal microcirculation is unknown. This investigation is aimed to measure tissue oxygen tension and blood-flow changes in the pulp of rat lower incisors during graded systemic hyperoxia, and to determine the response of the pulpal vasculature to various oxygen tensions. Twenty-four Sprague-Dawley rats were anaesthetized and artificially ventilated with the appropriate gas mixture. Recessed oxygen-sensitive microelectrodes were used to measure pulpal tissue oxygen tension via a small access cavity filled with saline on the labial surface of the incisor. A laser Doppler flowmeter was used to record pulpal blood-flow. Inspired oxygen was increased stepwise from 20 to 100% in 20% steps. Systemic blood-gas concentrations were measured at each step. Systemic arterial oxygen tension at 100% oxygen ventilation reached 481.2 +/- 30.7% of the baseline at 20% oxygen breathing (n=21). Pulpal tissue oxygen tension did not change significantly whereas pulpal blood-flow fell dose-dependently to 74.6 +/- 5.0% at 100% oxygen ventilation (n=21). Systemic hyperoxia, therefore, induces a significant reduction in pulpal blood-flow whereas pulpal tissue oxygen tension remains relatively stable, indicating an oxygen-dependent local regulatory mechanism.     

Er, Cr: YSGG激光与氟化物联合应用对牙体硬组织脱矿的影响

目的：体外研究Er，Cr：YSGG激光与氟化物联合应用对牙体硬组织抗酸性的影响。方法：标本随机分成4组，分别为对照组，激光组，氟处理组，激光＋氟组，进行不同处理后，0．1mol／L乳酸（pH4．8）脱矿24h，原子吸收分光光度计检测脱矿液中溶解的钙离子浓度，能谱分析仪进行氟原子含量分析，扫描电镜观察牙釉质和牙本质表面超微结构的变化。结果：激光组、氟处理组、激光＋氟组溶解的钙离子浓度都明显降低，与对照组有显著性差异（P〈0．05），但是激光＋氟组钙离子浓度仅略低于激光组、氟处理组，与其无显著性差异（P〉0．05）；氟含量的测定仅在氟处理组牙釉质和牙本质标本有氟峰出现；扫描电镜观察见，激光组：表面不平呈鳞片状、峭壁状，无玷污层，釉质结构清晰可见，牙本质小管开放，无熔融、炭化等热损伤的表现；氟化钠组：表面有大量玷污层和碎屑，并可见到许多小颗粒沉积在牙釉质和牙本质表面；激光＋氟组：表面结构与激光组相似，未见颗粒沉积。结论：Er，Cr：YSGG激光与氟化物无联合效应，其机制仍需进一步的研究与探讨。     

创伤性面瘫物理疗法的临床研究

目的 比较超短波加离子导入疗法（A组）与电刺激加离子导入疗法（B组）治疗创伤性面瘫的效果。方法 对39例创伤性面神经损伤患者进行临床对照研究，通过量化面神经功能评价、神经电图检查及面神经功能的主观评价比较面神经损伤的治疗效果。结果 创伤性面瘫以青年男性多见，损伤程度以中、重度为主；对于神经损伤轻、中度患者,A组与B组均能促进神经恢复，B组神经功能开始恢复时间早于A组。对于神经损伤重度患者，A组与B组神经恢复率高于对照组，两组均不能减少并发症出现率。结论 超短波加离子导入疗法与电刺激加离子导入疗法均能促进面神经损伤的恢复，但对于减少并发症发生率并无帮助。     

涎腺肌上皮癌的生物学行为及治疗

为了总结涎腺肌上皮癌的生物学行为及有效治疗，作者对１９例涎腺肌上皮癌患者进行临床分析，其临床特点为：发病部位以腮腺为最常见，其次为腭部；部分肿瘤生长迅速，广泛侵犯周围组织；颈部淋巴结转移率不很高，但血行性转移率高；治疗后极易复发；患者预后差。其生物学行为属高度恶性肿瘤。治疗以根治性切除为主，原则上不作选择性颈淋巴清扫术；放射治疗不敏感。对于局限性肿瘤复发灶及时手术可获得较好的效果。     

Effect of Dynamic Loading Methods on Cement Film Thickness In Vitro

Purpose Reduced cement film thicknesses can improve crown seating and decrease marginal discrepancies. Improved marginal adaptation has the potential to reduce plaque accumulation, periodontal disease, and cement dissolution. Studies have indicated that dynamic seating methods can reduce seating discrepancies associated with zinc phosphate and resin cements. However, other types of cements and other dynamic techniques have not yet been studied or compared, nor has the mechanism for improved seating been fully explained. Therefore, the purpose of this study was to investigate the effect of a variety of loading methods on the film thicknesses of current types of crown and fixed partial denture cements compressed between glass plates. Materials and Methods This study investigated the effect of three dynamic loading methods on film thickness of six representative fixed prosthodontic cements. These included zinc phosphate, resin-modified glass ionomer, encapsulated glass ionomer, adhesive composite resin, composite resin, and polycarboxylate. The method was derived from American Dental Association specifications for cement film thickness. In control groups, the cements were placed between two glass plates and statically loaded with a 15-kg weight. The test groups were initially similarly loaded, and then for 30 seconds further subjected to simulated repeated patient opening and closing, vibrations from an electromallet, or an ultrasonic device. Results Mean film thicknesses ranged from 7.4 μm for polycarboxylate/ultrasound up to 40.3 μm for composite resin/static. Two-way analysis of variance revealed that the effects of material type and cementation method and their interaction all significantly affected film thickness (P < .0001). Multiple range analysis showed that dynamic methods were generally superior to static loading and that the ultrasonic method was the best overall. Conclusions The different dynamic loading methods all significantly decreased cement film thicknesses between glass plates. The ultrasonic method was the most effective. The type of cement used also influenced film thickness. Composite resins were more affected than other materials.     

纳米根管充填材料根尖封闭能力的实验研究

目的 观察纳米材料根充后根尖微渗漏请况，评价其根尖封闭能力。方法 30颗离体单根管牙牙根，随机分为三组，每组10个，预备完成的根管用牙胶尖和一种根管糊荆、采用侧方加压法进行充填。根据染料在牙根中的渗入深度，评价根尖微渗漏情况。结果 三种材料的根尖微渗漏有显著差异（P〈0．01）；n-ZO组的根尖微渗漏最小，n-HA组次之，ZOE组最大。结论 纳米氧化锌糊剂和纳米羟磷灰石糊剂具有良好的根尖封闭性，可以作为根管封闭剞用于根管充填。     

CT辅助咽后壁瓣手术设计

目的 建立CT辅助设计咽后壁瓣的方法,以提高治疗效果。方法 应用CT测量26例腭咽闭合不全者在静止和发“i”时腭咽腔的宽度和长度,观察分析咽后壁瓣成形术所需的宽度、长度和咽后壁瓣蒂的位置和与软腭的附着位置。结果 静止时腭咽腔的宽度15.10-37.25mm,平均27.01mm,长度12.54-30.39mm,平均22.10mm;发“i”时腭咽腔的宽度为9.11-34.06mm,平均17.69mm;咽后壁瓣蒂的位置都在第一颈椎平面或以上;与软腭的附着位置大部分在软腭的中后1/3处。结论 CT作为一种定量评价腭咽闭合功能的方法,能够辅助设计咽后壁瓣手术方法。