微型种植体在安氏Ⅱ^1类错[牙合]矫治中的应用研究

目的：评价微型种植体在安氏Ⅱ^1类错[牙合]矫治中的应用和疗效。方法：安氏Ⅱ^1类错[牙合]患者19例,上颌拔除双侧第一前磨牙,矫治设计上颌强支抗,在矫治器粘结之后植入微型种植体。应用上颌后牙区微型种植体作为支抗内收前牙,治疗前后拍摄头颅定位侧位片并进行头影测量分析。结果：19例中16例应用微种植体支抗顺利完成正畸治疗,均建立了正常的前牙覆[牙合]覆盖关系,切牙内收（5．29±0．52）mm,磨牙近中移动（0．89±0．33）mm,患者上颌凸度明显改善。结论：安氏Ⅱ^1类错[牙合]矫治要求最大支抗时,微型种植体的应用能达到良好的效果。     

自攻型微螺钉种植体支抗稳定性的临床研究

目的:研究自攻型微螺钉种植体加载正畸负荷后的稳定性。方法:本研究包括了15例成年患者,以植入上颌颧突的自攻型微螺钉作为前牙内收的颌内支抗。微螺钉植入2周后施力。加力前及加力后9个月分别拍摄X线头颅定位片,将头影测量片进行重叠,测量微螺钉的移位变化。结果:15例中6例患者的微螺钉伸出并向前移位(-0.5～1.5mm)。微螺钉头部平均向前移位0.4mm,有统计学意义(P<0.05)。结论:自攻型微螺钉种植体是一种稳定的支抗装置,但是在承载正畸负荷的过程中,并不保持绝对的稳定,部分微螺钉在正畸力作用下有移位。为了防止因种植体移位伤及临近的重要组织结构,建议自攻型微螺钉应植入在没有主要神经、血管通过的非齿槽骨区,或植入在齿槽间隔区,但种植体与牙根之间应留出2mm的安全距离。     

微型种植体支抗压低上前牙的临床应用

目的观察微型种植体支抗压低上前牙的临床疗效,评价其压低上前牙的有效性。方法选择6例高角或高角倾向伴前牙Ⅲ°深覆,上颌前部牙槽发育过度,上唇与上前牙关系严重不调的患者,平均年龄24.4±1.4岁,采用微型种植体作支抗,在两侧上侧切牙牙根和尖牙牙根间牙槽骨唇侧植入,每侧以50克的牵引力压低上前牙。测量治疗前后X线头颅定位侧位片,包括6-PP距的改变量、上中切牙压低量和转矩改变量。结果6-PP距的变化均值为0.27±0.05mm,无统计学意义(P>0.05),上中切牙平均压低6.12±0.16mm,临床牙冠平均缩短0.66±0.05mm。治疗过程中微型种植体无松动和脱落。结论用微型种植体作支抗压低上前牙,操作简单,异物感不明显,上前牙明显压低,效果良好。     

自攻型微螺钉种植体支抗的临床应用研究

目的 研究自攻型微螺钉种植体作为磨牙强支抗的临床应用效果.方法 在30例采用自攻型微螺钉种植体作为磨牙支抗的临床病例中,选择6例已经结束治疗的患者进行分析.6例患者均为骨性Ⅱ类上颌前突患者,拔除上颌双侧第一前磨牙后采用上颌强支抗进行矫治.选择自攻型微螺钉种植体作为上颌支抗,以内收上颌前牙、关闭拔牙间隙.种植体植入部位为上颌第二前磨牙与第一磨牙牙根间的颊侧牙槽间隔,加力值为每侧1.47～1.96 N.对患者拔牙间隙关闭前后的头颅定位侧位片进行分析,测量前牙内收情况和磨牙支抗的变化.结果 6例患者共植入12枚微螺钉种植体,矫治后其上颌前突症状均得到明显改善,上颌切牙切缘平均内收6.06 mm,支抗磨牙平均前移0.44 mm,均获得了磨牙强支抗效果.治疗中,种植体保持稳定,种植体周围的软组织健康.结论 自攻型微螺钉种植体支抗是一种简便、有效的支抗形式,可以满足正畸临床治疗的需要.     

安氏Ⅰ类拔牙病例关闭间隙时切牙移动方式分析

目的：探讨安氏Ⅰ类错[牙合]拔牙病例关闭间隙时切牙的移动方式。方法：安氏Ⅰ类错[牙合]牙列拥挤病例20例，均拔除4个第一前磨牙，采用方丝弓细丝弓技术矫治，牙性支抗（弱支抗）。矫治前后摄X线头颅定位侧位片，对切牙位置及硬、软组织进行测量分析。结果：上颌切牙牙冠平均后移2．55mm；牙根平均后移0．20mm，下颌切牙牙冠平均后移1．78mm、牙根平均后移0．28mm。结论：牙性支抗控制下，安氏Ⅰ类错[牙合]拔牙病例关闭间隙时切牙移动是有控制的倾斜移动。     

应用微型种植体作支抗压低磨牙

目的：探讨微型种植体作为正畸支抗在压低磨牙中的应用。方法：选择5例需要压低磨牙的患者（包括3例开殆患者和两例因对殆牙缺失而致磨牙伸长的修复前正畸患者），使用微型种植体作支抗压低磨牙，治疗前后拍摄头颅侧位定位片，测量比较磨牙在矫治前后的压低量。结果：矫治结束后开殆患者前牙达到正常的覆殆覆盖，修复前正畸患者矫治至缺牙区能进行常规修复。磨牙平均压低3．1mm。结论：应用种植体作支抗能有效地压低磨牙，为某些错合畸形的矫治提供了新思路。     

微型支抗种植体稳定性的动物实验研究

目的　探讨微型支抗种植体即刻加力的稳定性。方法　 2 0 0g力值作用下 ,以微型种植体为支抗 ,牵拉犬上下颌第二前磨牙 ,以及种植体间交互牵引 ,观察 2个月后牵引侧和对照侧牙齿及微型支抗种植体位移情况。结果　被牵引牙齿均较对照侧发生明显位移 ,实验结束时微型种植体无松动 ,大多微型种植体位移不显著。结论　微型种植体植入后可即刻施加 2 0 0g水平力 ,用作移动牙齿的支抗     

比较2种部位种植钉支抗推上颌磨牙向远中移动的效果

目的：比较2种位置的微种植钉支抗推磨牙向远中的临床效果。方法：选择安氏Ⅱ类错25例,男7例,女18例,年龄15～29岁,平均22．58岁,牙列轻中度拥挤,面型较好,无明显前突。实验组（n ＝12）于颊侧第一磨牙近中颊根上方颧牙槽嵴处植入微螺钉种植体;对照组（n ＝13）于上颌第一磨牙与第二前磨牙牙根之间植入微螺钉种植体。推磨牙向远中,推力2．5 N。通过临床评价和对比2组矫治前后的头颅侧位定位片评价其治疗效果差异。结果：实验组和对照组微种植体首次植入成功率分别为100％（26/26）和87．5％（21/24）。治疗后上颌磨牙分别后移（2．91±0．96）mm 和（2．29±0．66）mm（P ＞0．05）。实验组磨牙压低的作用优于对照组,切牙唇倾的副作用小于对照组,切牙压入的作用优于对照组。结论：颧牙槽嵴处的微种植钉支抗推磨牙向远中移动较传统颊侧种植钉支抗对磨牙的垂直向压入及对抗切牙唇倾的效果好。     

微型自攻钛钉种植体支抗压低切牙的初步应用研究

目的介绍微型自攻钛钉种植体用于正畸支抗的临床经验,评价自攻型微型钛钉种植体作为垂直向支抗压低前牙的有效性.材料方法在26例采用微型自攻钛钉种植体作为支抗手段的临床病例中,选择3名患者(年龄20-25岁),均表现为上颌或下颌前部牙齿槽发育过度,采用微型种植体支抗压低前牙.种植体植入上颌中切牙和侧切牙之间的牙槽间隔或下颌侧切牙和尖牙之间的牙槽间隔,每侧以50克力压低前牙.比较压低治疗前后的X线头颅侧位片,测量前牙切缘的压低量和转矩的改变量.结果所有病例治疗后前牙覆(牙合)达到正常,切缘平均压低4.3毫米,转矩平均增加9.8度.治疗过程中所有微型种植体均保持了稳定,种植体周围软组织健康.结论微型自攻钛钉种植体能够作为稳定的骨性正畸支抗,压低前牙,改善覆(牙合)和龈笑.并且具有操作简单灵活,可即刻加力,不依赖患者合作的优势.     

微种植体或Nance弓支抗矫治上颌前突的临床对比研究

目的：对比研究以微种植体作支抗及以Nanee弓作支抗矫治上颌前突的临床效果。方法：选取80例安氏Ⅱ1错（牙合）畸形病例,随机分为两组,均采用滑动直丝弓矫治技术,实验组40例使用微种植体支抗;对照组40例采用Nance弓支抗。通过对两组治疗前后的头颅侧位X线片进行头影测量分析,评价两组病例在上颌前突矫治中软硬组织的变化。结果：实验组上前牙后移4．93mm,磨牙近中移动0．48mm,上前牙后移的平均速度1．38mm／月,矫治疗程平均16．6个月,对照组上前牙后移3．69mm,磨牙近中移动1．02mm,上前牙后移速度平均1．05mm／月,矫治疗程平均20．5个月。结论：微种植体和Nance弓支抗均可取得显著临床疗效,但微种植体支抗可使上前牙更多内收,且可有效地缩短矫治时间。     

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.     

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.     

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.     

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.