不同采样方法对龈下牙周致病菌检出的比较研究

目的:比较4-site法和full-mouth法对慢性牙周炎病人龈下菌斑中牙龈卟啉单胞菌、福赛斯坦纳菌、伴放线菌嗜血菌、具核梭杆菌检出的影响.方法:对30例慢性牙周炎病人用纸尖收集4个区牙周袋探诊最深位点龈下菌斑(4-site法)和收集全口龈下菌斑(full-mouth法),采用16S rRNA PCR方法检测两种方法收集到的龈下菌斑样本中的牙龈卟啉单胞菌、福赛斯坦纳菌、伴放线菌嗜血菌、具核梭杆菌.结果:两种方法一致性较好,4-site法与full-mouth法无显著差异(P>0.05).结论:4-site法采集到的龈下菌斑具有良好的代表性.     

慢性牙周炎龈下菌斑中五种牙周可疑致病微生物的分布

目的研究五种牙周可疑致病微生物在慢性牙周炎患者龈下菌斑的分布。方法选择27例慢性牙周炎患者,每位患者选取牙周袋最深的两个位点作为观察位点,采集龈下微生物样本,采用多重聚合酶链反应和反杂交的方法对伴放线菌嗜血菌、牙龈卟啉单胞菌、福赛斯坦纳菌、中间普雷沃菌和齿垢密螺旋体五种微生物进行半定量检测。结果在所检测的54个位点中,牙龈卟啉单胞菌、中间普雷沃菌、福赛斯坦纳菌和齿垢密螺旋体均有较高的检出率,分别为98.15%、92.59%、100%和98.15%;伴放线菌嗜血菌检出率较低,为20.37%。牙龈卟啉单胞菌和福赛斯坦纳菌的检出量明显高于其他三种微生物,其差异有统计学意义（P<0.05）。结论慢性牙周炎患者多存在牙龈卟啉单胞菌、福赛斯坦纳菌、中间普雷沃菌和齿垢密螺旋体的同时感染,且牙龈卟啉单胞菌和福赛斯坦纳菌的感染量较高。     

不同牙周状况龈下菌斑中牙龈卟啉单胞菌和福赛斯坦纳菌的分布

目的 分析中国牙周健康者和慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌和福赛斯坦纳菌的分布情况,探讨两种细菌在中国慢性牙周炎患者中的分布及其致病机理.方法 收集65例牙周健康者、62例慢性牙周炎患者的龈下菌斑,采用16S rRNA PCR方法检测牙龈卟啉单胞菌和福赛斯坦纳菌的分布.结果 牙周健康者牙龈卟啉单胞菌和福赛斯坦纳菌的检出率分别是21.6%、12.3%,慢性牙周炎患者病变位点两菌检出率分别为74.2%、58.1%,牙周炎健康位点两菌的检出率分别是22.6%、4.8%.牙周炎病变位点两种细菌的检出率均明显高于牙周健康者和牙周炎健康位点(P＜0.001);福赛斯坦纳菌在牙周健康者中的检出率高于牙周炎健康位点(P＜0.05);牙周健康者和牙周炎健康位点牙龈卟啉单胞菌的检出率没有差异.慢性牙周炎患者两菌联合检出率为51.6%.结论 牙龈卟啉单胞菌、福赛斯坦纳菌以及两种细菌联合感染与牙周炎密切相关.     

5种牙周龈下可疑致病微生物与慢性牙周炎局部不同牙周状态间的关系

目的 观察5种龈下微生物检出水平与慢性牙周炎局部牙周状态的关系。方法 选择20例慢性牙周炎患者的80个位点及10例牙周健康者的20个位点为观察位点,采集龈下微生物样本,记录牙周探诊深度（PD）,根据所测位点的PD进行分组。PD≤4 mm为A组,4 mm＜PD≤6 mm为B组,PD>6 mm为C组,健康对照组为H组。通过聚合酶链反应（PCR）和DNA探针反杂交技术半定量检测各组伴放线菌嗜血菌、牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体和中间普氏菌的检出率和检出水平。结果 B、C组牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体和中间普氏菌的检出率和检出水平均高于H组,A组牙龈卟啉单胞菌的检出率和检出水平也高于H组,C组福赛斯坦纳菌和齿垢密螺旋体检出水平高于B组,以上差异均有统计学意义（P<0.05）;伴放线菌嗜血菌在各组间的检出率及检出水平都无明显差异。结论 随着牙周袋的加深,牙龈卟啉单胞菌、福赛斯坦纳菌、齿垢密螺旋体和中间普氏菌体的阳性检出率和检出水平都有随之增加的趋势;牙龈卟啉单胞菌与慢性牙周炎的早期炎症关系较为密切,而福赛斯坦纳菌和齿垢密螺旋体与中重度慢性牙周炎炎症位点的严重程度有关。     

牙周致病菌的共聚及其对人工牙根面黏附力的影响

目的比较具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌等牙周病致病菌彼此之间的共聚力大小,观察四者在具核梭杆菌介导下对人工牙根面黏附力的影响,了解牙周生物膜结构中细菌间可能存在的相互作用。方法目测具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间的共聚力,以放射性核素闪烁计数四者在具核梭杆菌黏附和未黏附状况下对胶原包被羟磷灰石(c-HA)的黏附间是否存在着差异。结果具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间存在着共聚作用,其中,具核梭杆菌与牙龈卟啉单胞菌、牙龈卟啉单胞菌与中间普雷沃菌间的共聚度均可达4度,具核梭杆菌与其他三菌间的共聚度均大于3度。牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌在具核梭杆菌黏附的状况下对c-HA的黏附率高于其在具核梭杆菌未黏附时的黏附率,具核梭杆菌在未黏附的状况下对c-HA的黏附率高于其在黏附后的黏附率。结论具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间均存在共聚关系,具核梭杆菌可能对其他牙周病致病菌定植于牙菌斑起到了桥梁作用。     

牙周致病菌的共聚及其对人工牙根面黏附力的影响

目的比较具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌等牙周病致病菌彼此之间的共聚力大小,观察四者在具核梭杆菌介导下对人工牙根面黏附力的影响,了解牙周生物膜结构中细菌间可能存在的相互作用。方法目测具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间的共聚力,以放射性核素闪烁计数四者在具核梭杆菌黏附和未黏附状况下对胶原包被羟磷灰石（c—HA）的黏附间是否存在着差异。结果具核梭杆菌、牙龈啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间存在着共聚作用,其中,具核梭杆菌与牙龈卟啉单胞菌、牙龈卟啉单胞菌与中间普雷沃菌间的共聚度均可达4度,具核梭杆菌与其他三菌间的共聚度均大于3度。牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌在具核梭杆菌黏附的状况下对c—HA的黏附率高于其在具核梭杆菌未黏附时的黏附率,具核梭杆菌在未黏附的状况下对c—HA的黏附率高于其在黏附后的黏附率。结论具核梭杆菌、牙龈卟啉单胞菌、中间普雷沃菌和伴放线嗜血菌彼此间均存在共聚关系,具核梭杆菌可能对其他牙周病致病菌定植于牙菌斑起到了桥梁作用。     

牙周可疑致病菌对胶原包被羟磷灰石黏附的体外实验研究

目的比较对牙根面具有黏附能力的具核梭杆菌、牙龈卟啉单胞菌、中间普氏菌和伴放线菌嗜血菌对胶原包被的羟磷灰石实验膜（C- HA）的黏附能力,初步探讨以上牙周可疑致病菌在牙根表面形成菌斑生物膜的能力。方法采用同位素闪烁计数法测定上述4种细菌黏附至C- HA表面的黏附量及黏附率,比较其黏附能力。结果培养相同时间,不论是培养24 h还是培养48 h,4种不同细菌两两比较,具核梭杆菌ATCC 10953和牙龈卟啉单胞菌ATCC 33277对C- HA表面黏附率的差异无统计学意义;中间普氏菌ATCC 25611和伴放线菌嗜血菌ATCC 29523的黏附率之间差异也无统计学意义,但是具核梭杆菌ATCC 10953和牙龈卟啉单胞菌ATCC 33277对C- HA表面的黏附率显著高于中间普氏菌ATCC 25611和伴放线菌嗜血菌ATCC 29523（P<0.001）。同一种细菌,在培养不同时间即培养24 h和48 h,对C- HA表面黏附率的差异均无统计学意义。结论不同的牙周可疑致病菌对胶原包被的羟磷灰石的选择性黏附作用不同,具核梭杆菌和牙龈卟啉单胞菌对胶原有较强的亲和作用,在细菌的局部定植过程和牙周炎的进展和复发中可能发挥重要作用。     

牙周炎的厌氧菌群的分离及对抗生素的敏感性研究

目的：调查牙周炎思考口腔厌氧菌群的分布并研究其对β内酰胺药物的敏感性。方法：选择44例牙周炎患者，对其龈下菌斑中的厌氧菌进行分离培养，用7种β内酰胺药物对分离到的厌氧菌进行敏感性试验。结果：与牙周病有关的厌氧菌分离率为100％，产黑色素普雷沃菌86．4％，中间普雷沃菌56．8％，具核梭杆菌63．6％，放线菌38．6％，微小消化链球菌52．3％，牙龈卟啉单胞菌65．9％，二氧化碳嗜纤维菌9．1％。厌氧菌对各类β内酰胺药物保持敏感。结论：产黑色素普雷沃菌、中间普雷沃菌、具核梭杆菌、微小消化链球菌、牙龈卟啉单胞菌和放线菌，是牙周炎思考牙龈沟中的优势菌；β内酰胺药物可作为厌氧菌牙周炎的治疗药物。     

慢性牙周炎致病菌与冠状动脉粥样硬化相关性研究

目的 探讨慢性牙周炎与冠状动脉粥样硬化性心脏病(简称冠心病)发病的相关性机制。方法 收集36例行冠状动脉搭桥手术并伴有慢性牙周炎患者的冠状动脉粥样硬化斑块和龈下菌斑,50例慢性牙周炎患者的龈下菌斑,采用Chelex-100法提取细菌DNA,以聚合酶链反应(PCR)法检测冠状动脉粥样硬化斑块和龈下菌斑中牙龈卟啉单胞菌(Porphyromonasgingivalis,Pg)、伴放线放线杆菌(Actinobacillus actinomycetemcomitans,Aa)、具核梭杆菌(Fusobacterium nucleatum,Fn)、中间普氏菌(Preuotella intermedia,Pi)、福赛斯坦纳菌(Tannerella forsythensis,Tf)5种慢性牙周炎相关致病菌。结果 36例患者冠状动脉粥样硬化斑块中,各种牙周炎相关致病菌的检出率分别为:Pg 36%,Aa 3%,Pi 14%,Fn 25%,Tf 47%;同一患者冠状动脉粥样硬化斑块及龈下菌斑中同时检出5种牙周炎相关致病菌的一致的例数:Tf 15例,Pg 13例,Fn 5例,Pi 3例,Aa 0例;冠心病组的Pi检出率高于对照组,二者差异具有统计学意义(P<0.05)。结论 在冠状动脉粥样硬化斑块中慢性牙周炎相关致病菌DNA的检出,提示慢性牙周炎相关致病菌在冠心病的发生、发展中可能起着重要的作用;中间普氏菌可能是冠心病的危险因素。     

牙周基础治疗对慢性牙周炎患者临床指标及5种牙周可疑致病微生物的影响

目的:观察牙周基础治疗对临床指标及5种牙周可疑致病微生物的影响。方法:选取20例慢性牙周炎患者(40个位点),在治疗前和基础治疗后3个月时检测观测位点的临床指标牙周探诊深度(PPD),临床附着丧失(CAL)和探诊出血(BOP),同时采集龈下微生物样本。采用PCR和反杂交的方法对所采集微生物样本中的牙龈卟啉单胞菌、福赛斯坦纳菌,中间普氏菌、伴放线放线杆菌和齿垢密螺旋体进行半定量检测。结果:通过牙周基础治疗后临床指标PPD及BOP的改善具有统计学意义(P<0.001),而CAL的改善不具有统计学意义。治疗后牙龈卟啉单胞菌、福赛斯坦纳菌和齿垢密螺旋体的检出量显著减少(P<0.05或P<0.001)。治疗前PPD>6mm的位点只有福赛斯坦纳菌在治疗后比治疗前有显著减少(P<0.05),而牙龈卟啉单胞菌和齿垢密螺旋体的变化不具有统计学意义。结论:基础治疗是治疗慢性牙周炎的有效方法,可改善临床指标,减少龈下牙龈卟啉单胞菌、福赛斯坦纳菌和齿垢密螺旋体的数量。但在PPD>6mm的位点基础治疗对于这五微生物的影响作用是有限的。     

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.     

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.     

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.     

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.     

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。     

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。     

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。     

Electrodeposition of bilayers of dithiols

We report an electrochemical method to form a bilayer of dithiol. The cyclic voltammogram of the oxidative deposition of an aromatic dithiol on gold from an alkaline aqueous solution reveals two current peaks separated by more than 400 mV. The integrated charge of the oxidative current peak (B) at the most positive potential is twice that of the other oxidative current peak (A). These two oxidative current peaks were characterized by differential capacitance and electrochemical quartz crystal microbalance (EQCM) measurements. A decrease of the capacity by a factor of two, and an increase of the EQCM frequency change by a factor of two were observed when the potential was scanned from a value where only the first oxidative peak (A) is obtained, to a potential where both oxidative current peaks (A and B) are obtained. Infrared spectra show that the aromatic dithiols adsorb vertically at potentials corresponding to the current peak A and they become tilted for potentials corresponding to the current peak B. The simple relationships between the properties of the two oxidative current peaks are found to be compatible with a step-wise oxidative deposition of a bilayer of dithiol.