牙冠延长术治疗龈染色的临床效果观察

目的:观察牙冠延长术联合金沉积烤瓷冠修复治疗前牙龈染色的临床效果。方法:对12例共46颗经镍铬合金烤瓷冠修复后出现龈染色的前牙采用牙冠延长术联合金沉积烤瓷冠修复,追踪观察1年。结果:46颗龈染色牙,治疗后未出现牙周组织病变及再次龈染色,美观恢复良好。结论:牙冠延长术联合金沉积烤瓷冠修复是治疗龈染色的有效方法。     

牙冠延长术在外伤前牙修复中的临床应用

目的：探讨牙冠延长术在外伤前牙牙冠过短或缺损至龈下的患牙进行修复的临床疗效。方法：选择外伤后松动度≤Ⅰ度,牙冠折断至龈下≥3 mm的前牙52颗,对患牙完成根管治疗及牙周基础治疗后,采用翻瓣联合骨切除的方法及根向复位瓣手术行牙冠延长术,术后4～6周根据患者的口腔情况进行常规桩核冠修复。结果：所有患牙术后获得足够的临床冠长度,残根断端产生有效的箍效应。术后对患牙进行跟踪随访,患牙龈缘色泽正常、高度与邻牙相协调、全冠边缘密合。患者对患牙的功能、美观满意。结论：牙冠延长术对于外伤前牙的成功修复有重要意义,治疗过程中应注重手术的细节及修复时机的选择。     

冠延长术保存前牙龈下残冠的美学修复效果观察

目的: 观察冠延长术结合桩核冠修复治疗前牙龈下残冠的临床效果。方法: 选择前牙缺损患者25例（共28颗患牙）,缺损断面最低点均在龈缘下3 mm以内,经完善根管治疗后行冠延长术;术后8周开始桩核冠修复,随访观察修复后1、6、12个月的牙根松动度、牙周组织情况、修复体边缘和稳定性。结果: 随访1年,患者牙龈健康优于术前,术后修复成功率为89.28%。失败3颗,其中牙根松动1颗,牙龈退缩、冠边缘暴露2颗。结论: 牙冠延长术对前牙龈下残冠保存修复效果满意,牙周组织健康、修复美观稳定,但需严格掌握适应证。     

玻璃纤维桩修复前牙牙体缺损的临床效果比较

目的 探讨不同程度前牙牙体缺损玻璃纤维桩核修复的临床疗效。比较前牙重度牙体缺损运用冠延长术和未运用冠延长术后玻璃纤维桩修复的临床效果。方法 临床选择182例前牙缺损患者的共295颗患牙,按牙体缺损程度分3类:Ⅰ类、Ⅱ类和Ⅲ类,按缺损程度所有患牙分为A、B、C、D、E五组,A组为Ⅰ类牙体缺损62颗,B组为Ⅱ类牙体缺损77颗,C组为Ⅲ类牙体缺损并保留2 mm以上牙本质肩领的患牙59颗,D组为Ⅲ类牙体缺损48颗,E组为Ⅲ类牙体缺损49颗,A、B、C、D四组均采用玻璃纤维桩核修复,E组采用牙冠延长术牙体颈部获得至少2 mm大小的牙本质肩领后采用玻璃纤维桩核修复。结果 A、B、C、D、E各组治疗成功率分别为100%、100%、96.6%、85.4%、97.9%,其中A、B、C、E四组之间两两比较无显著性差异(P>0.05),D、E两组之间比较有显著性差异(P<0.05)。结论 前牙牙体缺损颈部留有至少2 mm大小的牙本质肩领,玻璃纤维桩核修复能达到较好的效果,牙冠延长术后玻璃纤维桩核能有效修复重度前牙缺损。     

前牙不良冠修复所致牙周病的临床治疗评价

目的：评价牙周基础治疗及牙冠延长术治疗前牙不良冠修复所致牙周病的临床疗效。方法：选取21例前牙冠修复所致牙周病患者共208颗患牙,均采用牙周基础治疗及牙冠延长术后再行全瓷冠修复,分别于基线点、术后8周、修复后3个月分别记录探针出血（BOP）、探诊深度（PD）、患者满意度,观察临床疗效。结果：术后8周BOP、PD较基线点时有统计学差异（P〈0.05）,修复后3个月BOP、PD与冠延长术后8周相比较无统计学差异。修复后患者的满意度为91.7%。结论：牙周基础治疗及牙冠延长术有利于不良冠修复所致牙周病的治疗,且冠延长术解决了生物学宽度的问题,确保了牙周健康的长期稳定。     

前牙残根牙冠延长术后冠修复的临床效果评价

目的：评价前牙区残根行牙冠延长术后全冠修复的临床效果,并分析主要的影响因素。方法：对21例患者共72颗前牙残根行牙冠延长术,术后12周行桩冠修复,并记录术前、术后6周、术后12周、冠修复后1月、6月、12月的相关评价指数,包括龈沟出血指数（sulcus bleeding index,SBI）、菌斑指数（plaque index,PLI）、松动度（tooth mobility,TM）、延长出的冠高度及黑三角（black triangle,BT）发生率,进行统计学分析。结果：与术前相比,术后6周、12周患牙SBI,PLI均有显著改善（P〈0.05）;与术前相比,术后6周、12周患牙TM有显著增加（P〈0.05）;与术后2周比较,术后6周及术后12周时新延长出的冠高度均有显著差异（P〈0.05）;修复后患牙SBI、PLI有增高趋势,对比修复即刻,术后12个月时有显著差异（P〈0.05）;修复后患牙TM趋于稳定。修复后黑三角发生率逐渐下降,对比修复即刻,修复后6个月及修复后12个月时有显著差异（P〈0.05）。结论：对于前牙残根采用牙冠延长术,能够获得足够的临床高度以满足修复体固位需求,结合桩冠修复是保留残根的有效方法。     

前牙牙冠延长术后冠修复材料对牙周状况影响研究

目的 探讨前牙牙冠延长术后采用氧化锆全瓷和金属烤瓷（porcelain fused to metal, PFM）冠修复对牙周的影响。方法 选择2009—2011年惠州市口腔医院修复科收治的拟行牙冠延长术+冠修复患者18例（共108颗上颌前牙）,分成两组（全瓷组和PFM组）,每组54颗,均行牙冠延长术;术后6个月,全瓷组行氧化锆全瓷冠修复,PFM组行钴铬合金烤瓷冠修复。随访8 ~ 32个月,评价两组冠修复后的牙周状况。结果 PFM组有34颗（62.96%）修复后出现牙周病损,其中轻度病损25颗,中度病损5颗,重度病损4颗;而全瓷组仅2颗（3.70%）发生轻度牙周病损。经Ridit分析,两组间差异有统计学意义（P < 0.05）。结论 前牙牙冠延长术后采用氧化锆全瓷冠修复的牙周状况明显优于PFM冠修复。     

分根术联合牙冠延长术保存治疗下颌磨牙残冠残根的临床观察

目的 观察采用分根术联合牙冠延长术保存治疗下颌磨牙残冠残根的临床效果.方法 对36例共42颗已行完善根管治疗及牙周基础治疗、冠部缺损至龈缘或龈下的下颌磨牙残冠残根,联合应用分根术和牙冠延长术进行保存治疗并用钛合金桩核-联冠修复,随访2年.结果 完成随访的39颗牙中有32颗牙咬合、咀嚼功能良好.结论 联合应用分根术和牙冠延长术并行钛合金桩核-联冠修复,可有效地保存治疗下颌磨牙残冠残根并恢复其咀嚼功能.     

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目的探讨前牙牙冠延长术后采用氧化锆全瓷和金属烤瓷（porcelainfusedtometal,PFM）冠修复对牙周的影响。方法选择2009--2011年惠州市口腔医院修复科收治的拟行牙冠延长术＋冠修复患者18例（共108颗上颌前牙）,分成两组（全瓷组和PFM组）,每组54颗,均行牙冠延长术;术后6个月,全瓷组行氧化锆全瓷冠修复,PFM组行钴铬合金烤瓷冠修复。随访8～32个月,评价两组冠修复后的牙周状况。结果PFM组有34颗（62．96％）修复后出现牙周病损,其中轻度病损25颗,中度病损5颗,重度病损4颗;而全瓷组仅2颗（3．70％）发生轻度牙周病损。经Ridit分析,两组间差异有统计学意义（P〈0．05）。结论前牙牙冠延长术后采用氧化锆全瓷冠修复的牙周状况明显优于PFM冠修复。     

牙冠延长术用于上前牙残根固定修复11例临床观察

目的 观察牙冠延长术应用于上前牙残根固定修复的临床疗效。方法 选取2010—2011年安徽医科大学附属口腔医院牙周黏膜科门诊收治的上前牙残根患者11例（共15颗患牙）,行牙冠延长术并于术后6周进行桩核冠修复,修复后随访1年观察疗效。结果 牙冠延长术后1～2周,11例患者术区牙龈均无出血、溢脓,部分患牙牙龈组织稍红肿;术后6周,所有患牙牙龈组织基本不红肿,患牙无松动。龈缘至断端的距离测量结果显示,术后各时间点与术前比较,差异均有统计学意义（P < 0.05）。在冠修复后1个月,有1颗上侧切牙邻面有黏结剂,牙龈红肿,探诊出血,经过处理去除黏结剂,教会患者正确使用牙线,1个月后炎症消退;其余l4颗患牙经1年观察,龈缘位置正常,修复体与软组织协调,冠边缘密合,稳固无松动,患者对修复效果满意。结论 牙冠延长术是保留上前牙残根的一种有效方法,扩大了桩冠修复的适应证。     

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.