单氟磷酸钠加入可摘局部义齿热凝基托树脂后氟离子的体外释放实验

目的:通过观测加单氟磷酸钠热凝基托树脂的氟释放率,寻找一种较为理想的给氟剂量预防义齿基牙龋.方法:将含单氟磷酸钠0、10%、15%、20%、25%(单氟磷酸钠占牙托粉的重量比)5 种不同浓度的热凝树脂各3 块,每块重1 g,分别随机放入装有100、200、500 ml蒸馏水的聚乙烯盒中浸泡,前2 种溶液定期完全更换浸泡用的蒸馏水(第1、2、3、6、9、16天换水,以后为每7 d换水,共2 个月),每次留取2 ml浸泡液待测.500 ml溶液定期取浸泡液2 ml,取液期间不换水,第3、6、9 天取液1 次,以后每7 d取液1 次,待测,共2 个月.用氟离子选择电极法测量待测溶液中氟离子浓度,观察和对比树脂中氟的释放速率及释放规律.结果:各浓度含氟树脂块在观察期间于浸泡液中均能释放不同浓度氟离子.结论:将单氟磷酸钠加入热凝基托树脂中,具有良好的缓释氟的作用;15%的单氟磷酸钠是较好的加氟比例.     

不同含氟试剂的热凝树脂释氟率的比较研究

目的比较不同含氟试剂的热凝树脂释氟率,为寻找适宜的预防义齿基牙龋的氟试剂和氟含量提供理论依据。方法将NaF、Na2PO3F、CaF23种试剂分别制成含氟5%、10%、15%、20%的热凝树脂块(聚甲基丙烯酸甲酯),于100ml去离子水中浸泡。选择电极法测定各浸泡液中氟释放量。结果同浓度下各含氟试剂块氟释放量为NaF>Na2PO3F>CaF2,且含氟浓度越高氟释放量也越大。结论各含氟树脂块均能释放氟离子。     

含氟热凝树脂预防可摘局部义齿基牙龋的体外研究

目的:研究基托局部含氟对基牙的防龋作用.方法:将10颗健康离体牙制成20块2～3mm厚的釉质块,采用配对设计的实验方法,利用简易人工口腔装置,分别随机地紧邻于含氟及无氟热凝树脂块,流动人工唾液冲洗.每周测定人工唾液的氟浓度,四周后测定各釉质块的表面显微硬度及抗酸性.结果:两组中人工唾液氟浓度无显著性差异,表面显微硬度及酸蚀后的龋损深度有显著性差异.结论:含氟树脂有利于预防可摘局部义齿基牙龋.     

单氟磷酸钠对口腔义齿基托树脂材料力学性能的影响

目的：将单氟磷酸钠按一定比例添加到聚甲基丙烯酸甲酯义齿基托材料中,探讨不同用量的单氟磷酸钠加入可摘局部义齿的基托树脂后,对其力学性能的影响。方法：将单氟磷酸钠0、10％、15％、20％、25％5种不同质量分数的热凝和自凝树脂制备成大小为60mm×8mm×4mm的含氟树脂块共180个并按各种质量分数随机分为3组,分别进行冲击强度、抗弯曲强度、50牛顿力作用下横向弯曲值3项指标测试。记录结果后进行计算和统计分析。结果：单氟磷酸钠质量分数为20％以下各组抗弯曲强度、冲击强度与对照组无显著差异（P〉0．05）,50牛顿力作用下平均横向弯曲值在国家标准内;单氟磷酸钠质量分数为25％时抗弯曲强度、冲击强度与对照组有显著差异（P〈0．05）,50牛顿力作用下平均横向弯曲值超出国家标准外。结论：将质量分数0-20％的单氟磷酸钠添加到聚甲基丙烯酸甲酯义齿基托材料中不会影响其力学性能,当单氟磷酸钠质量分数超过25％时将明显影响基托材料的力学性能。     

含氟树脂氟释放率的体外试验

目的 通过观察几种不同浓度含氟树脂氟的释放率，试图寻找一种较为理想的给氟剂量，以达到预防义齿基牙龋的目的。方法 将含ＣａＦ２５％、１０％、１５％、２０％、２５％的树脂块分别放入１００ｍｌ、２００ｍｌ、５００ｍｌ蒸馏水中浸泡。用电位法测量水中氟离子浓度，观察树脂氟的释放速率及释放规律。结果 ２０％的含氟树脂其氟释放速率优于其它浓度的含氟树脂。结论 ＣａＦ２微溶于水，混入固化的树脂中，具有良好缓释氟的     

离子色谱法测定含氟牙膏氟含量研究

目的:探讨离子色谱法测定含氟牙膏中氟化物的可行性和准确度。方法:比较离子色谱法与国家牙膏标准(GB8372-2001)氟离子电极法对含氟化钠、单氟磷酸钠和双氟3类牙膏氟含量测定的精密度和回收率,分析离子色谱法测定9支市售含氟牙膏的回收率情况以了解其抗干扰能力。结果:2种方法精密度之间经方差齐性检验没有统计学差异(P>0.05)。离子色谱法和氟离子电极法测定F-回收率的均值分别为1.00和0.99,差异无显著性(P>0.05);2种方法测定MFP2-回收率的均值分别为1.00和1.08,差异有显著性(P<0.05)。离子色谱法干扰实验结果显示个别数据偏差较大。结论:离子色谱法可用于含氟牙膏氟浓度测定,其在测定单氟磷酸钠牙膏的总氟含量准确度方面有一定优势,但实测中实验条件需进一步研究以提高抗干扰能力。     

冷酸解离-氟离子电极法测定牙膏中总氟含量的评价

目的 探讨冷酸解离-氟离子电极法测定含氟牙膏中总氟含量的可行性和可靠性。方法 选择市售无氟牙膏和含氟牙膏各4个品种,采用2 mol/L高氯酸、室温、过夜的解离 条件,对无氟牙膏加入标准氟后测定总氟量,对市售含氟牙膏进行总氟测定,以确定此方法的可行性和可靠性。结果 牙膏中使用的氟化物与摩擦剂配伍不同对氟测定结果有影响。冷酸解离-氟离子电极法对于含钙类摩擦剂的无氟牙膏加入标准氟（单氟磷酸钠）后总氟的回收率为99.5%～100.5%,对于市售单氟磷酸钠与钙类摩擦剂配伍的含氟牙膏总氟的测得率在94%以上,此方法的相对标准偏差均小于1.54%。对于摩擦剂为二氧化硅的无氟牙膏加入标准氟（氟化钠）后总氟的回收率为83.4%,对于市售氟化钠与二氧化硅配伍的含氟牙膏中总氟的测得率为89.7%。结论 采用冷酸解离-氟离子电极法测定单氟磷酸钠与钙类摩擦剂配伍的含氟牙膏中的总氟含量,具有准确可靠、简便易行的优点。     

两种含氟流动树脂释氟能力的体外研究

目的：体外比较2种含氟流动树脂Beautifil Flow Plus F00和Dyad Flow的短期释氟量,以探讨2种材料释氟能力的差异。方法选取含氟流动树脂F00、DF和不含氟树脂Valux,制备直径10mm,厚1mm的样本,每组10个。将样本分别浸泡于5ml去离子水,第1、2、3、7、14、21、28d使用氟离子选择电极测量去离子水中的氟离子浓度,Va组为对照,比较F00和DF组前3d的单日氟释放及28d内各时间点的累积氟释放情况。结果 F00和Dyad Flow的释氟浓度均第1d最高;前3d单日释氟浓度呈下降趋势,差异有统计学意义(P<0．01);28d内2实验组均有缓慢持续的氟释放,随着时间延长累积释氟量增加;各个时间点,Dyad Flow组累积释氟量高于F00组,差异有统计学意义(P<0．01)。结论2种含氟流动树脂F00和Dyad Flow第1d氟释放最多,在测试时间内均有低量但持续的释氟能力,Dyad Flow释氟量略高于F00。     

2种含氟窝沟封闭剂氟释放的体外研究

目的:观察和比较2种含氟窝沟封闭剂在人工唾液中的释氟情况.方法:将2种含氟窝沟封闭剂各制备5个6 mm×1.5 mm的盘状标本,浸入12 mL人工唾液中,恒温37℃.采用氟离子选择性电极法,分别于第1、2、3、7、14、21、28、35天测定2种窝沟封闭剂氟离子的释放量.结果:2种含氟窝沟封闭剂均在第1天的氟释放量最高,然后1周内急剧降低,在14～35 d内维持于稳定水平.在各时间点,玻璃离子封闭剂氟释放量均高于含氟树脂封闭剂,差异有统计学意义(P＜0.01).结论:新型含氟树脂窝沟封闭剂与玻璃离子封闭剂均能够作为氟库在一定时间内持续缓慢地向周围液体环境释放氟离子,对于窝沟封闭剂的防龋性能可能具有潜在的增强作用.     

用于正畸托槽的氟化钠微胶囊释氟性能研究

目的比较改良型含氟正畸托槽中氟化钠微胶囊的长期氟释放情况。方法将氟化钠微胶囊及普通氟化钠分别按15％比例与树脂改良型玻璃离子水门汀（GC）混合,填充在改良型正畸托槽内,测定在50d内氟的释放量。结果氟化钠微胶囊组氟释放速度缓慢持续,曲线较平缓,氟化钠组在2d后释氟浓度大幅度下降,30d后低于氟化钠微胶囊组,差异有统计学意义（P〈0．05）。结论氟化钠微胶囊较普通氟化钠更适合用作缓释型含氟改良托槽。     

Evidence of the validity of a model of determinants of quality of restorative dental care

A model describing the relationship between self-reported quality of restorative dentistry and dentist characteristics for 119 Montana general dentists is presented. The best predictors formed a significant model explaining 22% of the variance of the quality measure. Results are contrasted with a previous estimation of the model for 102 Washington general practitioners. Evidence for the external validity of the model is presented.     

Experimental evidence of formation of imines in the course of reduction of hydrazones

The reduction of hydrazones is generally suggested to proceed through a reductive cleavage of the nitrogen–nitrogen bond followed by a reduction of the carbon–nitrogen bond. This sequence of reduction processes is here supported for fluorenone (V) and benzophenone (VI) hydrazones as well as by a comparison of the reduction of fluorenone and benzophenone hydrazonium ions (I,III) with corresponding imines (II,IV). Another proof of the presence of imines as intermediates is the splitting of four-electron waves of hydrazones V and VI and hydrazonium ions I and VIII into two waves at pH < 2. This has been interpreted as due to differences in slopes dE_1/2/dpH and pK_a-values of protonated hydrazine derivatives on one side and corresponding imines on the other. In this pH-range imines formed in reductions of VI and VIII are reduced in a single two-electron wave, those of I and V in two one-electron steps. Fluorenone imine (II) is sufficiently stable to allow recording of time-independent current–voltage curves between pH 6 and 11. In this pH-range the imine (II) is reduced in two one-electron steps. Benzophenone imine (IV) has been found stable between pH 4.6 and 12. At pH 4.6–8 the reduction of the imine IV takes place in a single two-electron step, at pH 8–12 in two one-electron steps. Final proof of the initial cleavage of the N–N bond is presented by comparison with the reduction of nitrones.     

不同剂型玻璃离子水门汀溶解性比较研究

目的:研究、比较不同剂型玻璃离子水门汀的溶解性和表面微观形态改变,为临床使用提供依据.方法:将3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)及GC玻璃离子水门汀(双糊剂型)分别在人工唾液中浸泡30 d,冷热循环15000次,烘干测重,比较前后质量变化,计算溶解率,并用扫描电镜观察表面微观改变.结果:不同剂型的玻璃离子水门汀溶解率由高到低分别为3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(双糊剂型).3种玻璃离子水门汀经浸泡溶解后,SEM扫描表面微观形态可观察到GE玻璃离子水门汀(双糊剂型)表面形态改变较少,其他2组玻璃离子水门汀表面微观改变较多.结论:双糊剂型玻璃离子水门汀理化性能及溶解率均低于传统水粉剂型,是未来临床修复治疗的的良好选择.     

Evaluation of efficacy of chemiluminescence for diagnosis of leukoplakia

ObjectiveLeukoplakia is the most common potentially malignant disorder preceding oral cancer. Chemiluminescence has been developed as an adjunct to conventional examination for the diagnosis of these potentially malignant disorders. This study was conducted to assess the efficacy of chemiluminescence in the diagnosis of leukoplakia and to compare the results with histopathological examination.Study designA total of 50 patients with leukoplakia were included from the outpatients attending the Department of Oral Medicine and Radiology, Dental Hospital, Bengaluru, Karnataka, India. These patients were subjected to conventional oral examination followed by chemiluminescent examination with Vizilite (Zila, Fort Collins, CO, USA) and biopsy for histopathological confirmation.ResultsThe sensitivity, specificity, positive predictive value, and negative predictive value of chemiluminescence were 93.75%, 55.56%, 78.95%, and 83.3%, respectively. The overall accuracy of chemiluminescence was 80%. A statistically significant association was observed between histopathology results and chemiluminescence results.ConclusionAlthough it is an easy, safe, minimal time consuming, and noninvasive technique, it has only adjunctive utility and it does not replace biopsy for the diagnosis of leukoplakia.     

颌骨动静脉畸形的栓塞治疗

目的：总结直接穿刺结合经血管内介入栓塞治疗颌骨动静脉静脉畸形的经验。方法：收治凳骨动静脉畸形患者6例,均进行了介入栓塞治疗。采用的栓塞材料为附凝血棉纤毛的螺圈,聚乙烯醇泡沫微粒和二氰基丙烯酸对丁酯。数字减影颈动脉造影在PHILIPSV300下完成。结果6例颌骨动静脉畸形患者中4,例急性出血得到了快速、有效控制,1例慢性渗血的右下 骨动静脉畸形患者,介入栓塞治疗,拔除松动的右下凳第一磨牙,有效地控制了出血,另1例伴局部软组织搏动性膨隆的上凳骨动静脉畸形患者,介入治疗后膨隆的搏动性得到明显改善,栓塞治疗后分别随访3－24个月,均未发现有口腔内渗血或出血。随访的X线片上,病灶区可见新骨形成。结论：局部穿刺结合经血管内介入栓塞治疗颌骨动静畸形是一种安全、有效的治疗方法。     

Design of clinical trials of traditional therapies of periodontitis

The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the "experimental unit". For a number of years, the "experimental unit" in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site-to-site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites. Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely: to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium; to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re-establishment of the subgingival infection; to gain attachment as a result of treatment; to assess the effect of a certain chemotherapeutic agent on periodontal disease.     

正畸患者切牙影像失真发生情况分析

目的研究正畸患者曲面体层片上的切牙影像失真发生情况，并分析其原因。 方法从中山大学附属口腔医院放射科影像数据库中选取500例正畸患者的曲面体层片和头影测量侧位片，所有曲面体层片均采用咬合杆投照，分别从切牙牙体影像放大、缩小、牙根变短、根尖模糊等评价指标分析上下颌切牙影像失真的发生情况，在头影测量侧位片上测量中切牙根尖-对颌切牙切缘的距离，探讨切牙影像失真发生的原因。采用SPSS 19.0统计软件对所得数据进行统计学检验。 结果500例患者中，切牙牙体影像正常者共417例，切牙牙体影像失真者共83例，影像失真发生率16.6%，其中切牙牙体影像放大17例、牙体影像缩小0例、牙根变短30例，牙根影像变短伴模糊36例。影像失真患者的根尖-切缘距离大于影像正常的患者，差异有统计学意义（F = 5 187.18，P = 0）；影像失真患者的覆盖值大于影像正常的患者，差异有统计学意义（F>477，P = 0）。 结论严重牙颌面畸形如反 、深覆盖是导致曲面体层片的切牙影像失真的主要原因之一。     

正常青年Monson球面半径的测量研究

目的测量正常青年Monson球面半径。方法选择60名(男30名,女30名)正常青年制取全口印模,应用立体摄影成像的原理与方法对Monson球面半径进行测量和统计学处理。结果Monson球面的半径平均为10.173 cm,大于理论值10.160 cm,差异有显著性(P<0.01);男、女性球面半径差异无显著性。结论本实验所得到的数据可作为全口义齿修复中记录颌位关系的一个参量。     

鼻测量法的进展

唇裂术后继发畸形是指唇裂修复术后,仍遗留或继发于手术操作和生长发育变化而表现出来的一类畸形[1]。包括唇畸形、鼻畸形和颌骨畸形。其修复较原发性唇裂修复更复杂,更灵活多变。而导致其修复复杂性的一个重要原因即是局部组织结构复杂变异和缺乏可靠的三维测量手段[2],鼻畸形     

口底癌34例临床分析

目的探讨口底癌的临床特性、治疗方法及预后。方法对我院自1992—2002年住院治疗的34例口底癌患者进行回顾性分析。结果34例口底癌患者中,男28例(82.4%),女6例(17.6%),男女比为4.7∶1,平均发病年龄58岁。发病部位:前口底22例(64.7%),后口底12例(35.3%)。淋巴结转移率41.2%。单纯手术组、化疗加手术组、放疗加手术组、化疗加手术加放疗组的5年生存率分别为45.5%、60.0%、50.0%、62.5%。结论口底癌以中老年患者好发,男性居多。易发生淋巴结转移,综合疗法疗效较好。