氧化锆全瓷修复体崩瓷原因分析

氧化锆全瓷修复体具有良好的生物相容性和物理性能,在临床上广泛应用于牙体缺损和牙列缺损的修复治疗,而崩瓷是影响氧化锆全瓷修复体临床成功率的重要因素。本文从临床因素、制作工艺及材料性能等多方面对氧化锆全瓷修复体崩瓷原因的相关研究进展进行综合分析。     

瓷肩台在烤瓷修复中的临床应用效果分析

普通镍铬金属烤瓷存在着龈缘染色的问题,尤其影响前牙美观,我们对2003-2006年876例患者1363个单位的镍铬合金烤瓷修复体进行了加瓷肩台与不加瓷肩台的分析、比较。1资料与方法1.1一般资料2003-2006年来我科就诊的876例患者,其中男524例,女352例。年龄18-72岁,前牙842颗,后牙521     

钛网结合Masquelet技术治疗创伤后干骺端大段骨缺损临床效果分析

目的 探讨钛网结合Masquelet技术治疗创伤后干骺端大段骨缺损的临床效果。方法 选取北部战区总医院自2018年4月至2021年12月收治的7例创伤后干骺端大段骨缺损患者为研究对象。所有患者均采用Masquelet技术分为2个阶段治疗。第1阶段清创后采用抗生素骨水泥棒及骨水泥分别占位缺损髓腔及骨缺损诱导局部诱导膜形成,第2阶段采用钛网结合自体颗粒骨填充骨缺损。记录所有患者患肢术后并发症、骨愈合时间及功能情况。采用膝关节功能评分评估患者骨折愈合情况。结果 7例患者术后均获得12个月随访。1例患者术后出现皮瓣边缘部分坏死,2例患者出现髂骨切口浅表感染,加强换药后好转,其余患者无明显围术期并发症发生。7例患者均获得骨折愈合,愈合时间3～7个月,平均愈合时间4.5个月。完全负重时间4～8个月,平均完全负重时间5.2个月。末次随访时膝关节功能评分为(86.49±6.21)分。7例患者中,优5例,良1例,可1例,优良率为85.7%(6/7)。结论 钛网结合Masquelet技术可以有效解决高能量损伤所致大段骨缺损,术后并发症较少,患肢功能恢复良好,临床疗效满意。     

钛-6铝-4钒颗粒对破骨细胞形态和功能的影响

目的在体外条件下观察钛-6铝-4钒（Ti-6AL-4V）颗粒对破骨细胞形态和功能的影响。方法取新西兰大耳兔破骨细胞培养在玻璃盖玻片和牛皮质骨片上，实验组用0．1mg／ml颗粒刺激，经不同时段培养后行抗酒石酸酸性磷酸酶（TRAP）染色，观察颗粒对破骨细胞形态的影响。对骨片上形成的骨吸收陷窝进行甲苯胺蓝染色观察，并用计算机图像分析软件评估吸收面积的大小。结果破骨细胞可以吞噬颗粒，形态变得不规则，特征性TRAP染色加深，较早出现凋亡征象。经颗粒刺激后在骨片上形成的骨吸收陷窝面积较大、数量较多。结论破骨细胞有吞噬功能，吞噬Ti-6AL-4V颗粒后发生形态和功能的变化，骨吸收功能增强。     

钢制和钛制扩髓带锁髓内针治疗股骨干骨折临床分析

目的比较钢制和钛制扩髓带锁髓内针治疗股骨干骨折的临床效果。方法股骨干新鲜骨折108例,应用钢制扩髓带锁髓内针治疗52例,与钛制扩髓带锁髓内针治疗56例进行对照研究。手术方式及围手术期处理相同。结果钢制扩髓带锁髓内针治疗的52例均在术后4~6个月临床愈合,无延迟愈合或不愈合,6例出现锁定失败,其中2例发生远端锁钉松动;钛制髓内针组延迟愈合12例,不愈合4例,锁定失败10例,其中锁钉松动6例。两组相比具有统计学差异(P0.05)。结论正确合理地使用钢制扩髓带锁髓内针治疗新鲜股骨干骨折,可以明显减少锁定失败、骨折延迟愈合、不愈合的发生。     

颅骨缺损钛网修补63例临床分析

<正>颅骨缺损成形术是神经外科较为常见的手术,但其并发症发生率较高,常见的有皮下积液、感染、修补材料外露、修补材料松动、癫痫、颅内血肿等[1],2009年1月—2011年1月我院行颅骨缺损修补术63例均取得了满意的疗效,现报告如下。1资料与方法1.1一般资料2009年1月—2011年1月我院行颅骨缺损修补术63例,其中男48例,女15例;年龄18～56岁,平     

不同海拔地区烤瓷修复体选色差异原因分析

目的：探讨海拔高度不同引起烤瓷修复体选色差异的原因.方法：对不同海拔地区各600例烤瓷修复体选色进行调查统计分析.结果：西宁地区人群牙冠颜色主要为A2-A3色,南京地区人群牙冠颜色主要为D2-D3色.地区差异与选色差异关系经行×列2检验,P〈0.001,有非常显著性差异.结论：海拔高度,特殊的地理环境及气候,种族及饮食习惯不同,可引起牙齿钙化,发育颜色差异.     

咽鼓管钛镍支架置入治疗和预防中耳炎粘连

目的　探讨咽鼓管软骨段钛镍合金支架置入治疗和预防粘连性中耳炎的可行性。方法　5 6例粘连性中耳炎 ,2 7例渗出性中耳炎 ,5 2例无耳疾的鼻病患者 (为对照 )作了咽鼓管咽口检查 ;2例尸头的咽鼓管解剖 ;8例 (侧 )粘连性中耳炎和顽固性渗出性中耳炎作了软骨段钛镍合金支架 (国产材料自制 )置入。设计制作了安装器。结果　咽口形态被分类为宽敞、狭小、缝隙 3种类型 ,粘连性中耳炎组分别有 2 0 ,31,5例 ;渗出性中耳炎组有 9,13,5例 ;鼻病对照组有 4 5 ,7,0例。支架置入后 :4例粘连性中耳炎患者都取得了 (乏氏法 )通畅 ,鼓室充气良好 ,听力增进 (语言频率气骨差分别比术前缩小 15和 30dB)。 4例顽固性渗出性中耳炎中 2例鼓室充气 ,气骨差闭合 ,随访 12～ 2 8个月仍保持良好。另 2例捏鼻鼓气已经通畅 ,取出了鼓膜置管。 8例支架置入者均没有任何异常不适 ,1个月内都呈现咽鼓管内黏膜反应性肿胀伴黏液渗出 ,1～ 2个月后肿胀消失 ,捏鼻鼓气通畅。结论　咽鼓管软骨段置入钛镍合金支架治疗和预防粘连性中耳炎具有良好效果 ,没有发生咽鼓管异常开放的不良反应。     

纯钛烤瓷冠和镍铬烤瓷冠的临床效果分析比较

目的：评价完成修复1～6年的240个纯钛烤瓷冠和260个镍铬烤瓷冠的远期临床效果,为临床制作提供参考依据。方法对完成修复1～6年的240个纯钛烤瓷冠和260个镍铬烤瓷冠进行复查,按照修复体完整度、边缘染色、边缘适合性、继发龋及牙龈指数5项指标进行评估。结果纯钛烤瓷冠1～6年成功率分别为99.17％、97.9％、96.14％、95.54％、94.39％、92.08％。镍铬烤瓷冠的1～6年成功率分别为98.85％、96.89％、95.98％、93.72％、91.62％、84.24％。结论纯钛烤瓷修复技术的远期临床效果良好。     

两种不同口径的钛轮钉对尿毒症患者行动静脉内瘘术的临床研究

目的：探讨两种不同口径的钛轮钉吻合血管对透析治疗影响的观察。方法：将本组84例慢性肾功能不全尿毒症患者手腕行动静脉内瘘吻合手术，一组采用直径2．0mm的钛轮钉行动静脉吻合术42例；另一组采用直径为2．5mm的钛轮钉行动静脉吻合术42例。结果：在84例内瘘手术中有3例第一次手术失败，经再次手术获成功，其中使用2．0mm钛轮钉组2例，使用2．5mm钛轮钉组1例，其主要原因为钛轮钉吻合口处血栓形成所致。结论：采用2．0mm钛轮钉组较2．5mm钛轮钉组在2、4、6周的透析血流量低，但经统计学处理，两组无统计学差异。     

骨内牙种植体在牙缺失修复中的应用

目的回顾分析骨内牙种植体的适应证及临床应用效果。方法对94例患者的157个骨内牙种植体进行4个月～8年的临床观察,根据种植体的分布情况了解种植牙适应证的变化。通过对种植体周软组织状况、种植体动度、种植体周骨吸收情况及抗旋转扭力的检查,评价其骨整合成功率和修复成功率。结果有7.6%和25.5%的骨内牙种植体分别用于修复全颌缺失和游离端缺失,66.9%用于修复非游离端缺失。种植后初期骨整合成功率达98.1%,修复后5年种植成功率为93.8%。种植体初期稳定性<10N.cm者与≥10N.cm者相比种植成功率明显降低(P<0.05)。结论骨内牙种植体是临床上修复各种类型缺牙的理想手段之一,成功率高,初期稳定性对于提高种植成功率有重要意义。     

Three-dimensional visualization of composite fillings for dental identification using CT images

Objectives

This study aimed to discriminate between enamel and composite resins by differences in Hounsfield units shown on 16 section multidetector CT (MDCT) images taken of unidentified bodies.

Methods

First, we determined the Hounsfield units of composite resins in 15 extracted human teeth. We then filled a single cavity prepared in each of the teeth with one of five different types of composite resins, and scanned the teeth using our routine post-mortem CT protocol for the head and neck. Obtained data were transferred to a radiological workstation and reconstructed. Furthermore, post-mortem CT images of the head of three unidentified bodies were reconstructed in the same manner.

Results

Four types of composite resins containing radio-opaque fillers showed a constant value of 4000 HU, and one radiolucent composite resin showed values in the range of 660–800 HU in the extracted teeth. Pixels at 4000 HU indicated that the composite resins were selected and visualized as three-dimensional colour images. Composite resins could be visualized on reconstructed images of the three unidentified bodies, and the sites visualized matched those noted on the forensic dental charts.

Conclusions

Discriminating enamel and composite resins containing radio-opaque materials was difficult because of their similar Hounsfield unit values. However, we did succeed in visualizing the composite resins despite limitations of the CT scale. CT reconstructed images can contribute to dental identification, particularly in cases where it is difficult to detect composite resins on external investigation, and these images can be prepared during routine dental identification work.     

Comparison of digital systems and conventional dental film for the detection of approximal enamel caries

Objectives

The aims of this study were (1) to compare the accuracy of the detection of approximal enamel caries lesions using three intraoral storage phosphor plate digital systems and one conventional film-based radiographic system; and (2) to determine whether there is a correlation between the histological and radiographic measurements of enamel caries.

Methods

160 approximal surfaces were radiographed under standardized conditions using three storage phosphor stimulable systems (DenOptix and Digora FMX with white and blue plates), and one film system (Insight film). 17 observers scored the images for the presence and depth of caries using a 4-point scale. The presence of caries was validated histologically (gold standard). Two-way analysis of variance was used to test the differences in sensitivity, specificity and overall accuracy (TP + TN). The data from the radiographic and histological measurements were statistically analysed by Spearman’s rank correlation coefficient.

Results

Two-way analysis of variance and the post hoc t-test demonstrated that Digora (white plate) had higher specificity and overall accuracy values than DenOptix (P = 0.021); there was no statistically significant difference among the other imaging modalities (P > 0.05). There was no significant correlation between the histological depth measurements and the radiographic measurements from Digora (blue plate) (P = 0.43), Digora (white plate) (P = 0.15), DenOptix (P = 0.17) and Insight film (P = 0.06).

Conclusions

The results suggest that (1) the performance of the three storage phosphor image plate systems was similar to that of the Insight film for detection of approximal enamel caries, and (2) the increase in histological depth of enamel caries was not significantly correlated with radiographic measurements.     

Magnification rate of digital panoramic radiographs and its effectiveness for pre-operative assessment of dental implants

Objectives

The purpose of this study was to determine the accuracy and effectiveness of digital panoramic radiographs for pre-operative assessment of dental implants.

Methods

We selected 86 patients (221 implants) and calculated the length of the planned implant based on the distance between a selection of critical anatomical structures and the alveolar crest using the scaling tools provided in the digital panoramic system. We analysed the magnification rate and the difference between the actual inserted implant length and planned implant length according to the location of the implant placement and the clarity of anatomical structures seen in the panoramic radiographs.

Results

There was no significant difference between the planned implant length and actual inserted implant length (P > 0.05). The magnification rate of the width and length of the inserted implants, seen in the digital panoramic radiographs, was 127.28 ± 13.47% and 128.22 ± 4.17%, respectively. The magnification rate of the implant width was largest in the mandibular anterior part and there was a significant difference in the magnification rate of the length of implants between the maxilla and the mandible (P < 0.05). When the clarity of anatomical structures seen in the panoramic radiographs is low, the magnification rate of the width of the inserted implants is significantly higher (P < 0.05), but there is no significant difference between the planned implant length and actual inserted implant length according to the clarity of anatomical structures (P < 0.05).

Conclusions

Digital panoramic radiography can be considered a simple, readily available and considerably accurate pre-operative assessment tool in the vertical dimension for dental implant therapy.     

Application of 3D imaging and selfies in forensic dental identification

With increased access to smartphones, the selfie has gained immense popularity in the past decade. Selfie images could be a significant source of ante-mortem (AM) image data in cases where dental records are unavailable or considered insufficient. The application of 3D imaging and selfies has not been explored to its full potential in human dental identification. The present study aimed to evaluate the feasibility of using selfies as AM data and comparing with 3D post-mortem (PM) scans as an alternative to multiple 2D PM photographs in forensic dental identification. The study sample consisted of 18 selfies (12 matching and 6 non-matching) and 15 3D dental scans obtained from the study participants. The study sample was assessed by 6 experienced forensic odontologists (Raters) in two phases; Phase I-Visual comparison of 2D selfies to 3D scans and Phase II-2D selfies superimposed upon 3D scans. Each rater looked at 15 cases, and a total of 1620 comparisons were made by 6 raters (72 for the 12 matching cases and 1548 were for non-matching) and the opinions for each of the comparisons were analyzed. The results of the study show that use of the 3D superimposition method increased the certainty of the conclusions reached by the raters for the cases with correct matches. Furthermore, 94.2% of the 1548 non-matching comparisons were correctly excluded, compared with 77% for the 2D visual comparison method. The study demonstrated the applicability of this 3D method as a valuable tool in assisting the forensic odontologist with dental identification using selfies.     

Contrast-enhanced dental MRI for visualization of the teeth and jaw.

A technique for contrast-enhanced dental MRI is described that enables 3D visualization of the oral cavity, including the jaw and teeth. Since teeth are MR-invisible, the basic principle of this technique is that the teeth and jaw can be observed indirectly through contrast with a surrounding MR-visible medium. For this purpose, the oral cavity is filled with a nontoxic substance, such as water or MR contrast media, that gives a high MR signal. A 3D data set covering the entire buccal space is acquired, and the image intensities are inverted. Since isosurface reconstructions of the teeth and jaw, as well as panoramic views analogous to orthopantomography, can be extracted from these data, contrast-enhanced dental MRI may be useful as a flexible tool for dentistry and orthodontics. Moreover, contrast-enhanced dental MRI works without radiation exposure, and therefore it is an interesting alternative to X-ray-based imaging modalities such as conventional radiography and dental CT. In this article, some preliminary results obtained with contrast-enhanced dental MRI are shown in order to demonstrate the feasibility and performance of this new approach.     

Effects of developer exhaustion on DFL Contrast FV-58 and Kodak Insight dental films

Objectives

The aim of this study was to compare the properties of the DFL Contrast FV-58 F-speed film (DFL Co., Rio de Janerio, Brazil) with the Kodak Insight E/F speed film (Eastman Kodak, Rochester, NY) in fresh and exhausted processing solutions. The parameters studied were the speed, average gradient and latitude.

Methods

Five samples of each type of film were exposed under standardized conditions over 5 weeks. The films were developed in fresh and progressively exhausted processing solutions. Characteristic curves were constructed from values of optical density and radiation dose and were used to calculate the parameters. An analysis of variance was performed separately for film type and time.

Results

DFL Contrast FV-58 film has a speed and average gradient that is significantly higher than Insight film, whereas the values of latitude are lower. Exhausted processing solutions were not significant in the parameters studied.

Conclusion

DFL Contrast FV-58 film has stable properties when exhausted manual processing solutions are used and can be recommended for use in dental practice, contributing to dose reduction.     

Colonic Anastomotic Stenoses and Memotherm Stent Fracture: A Report of Three Cases

Deployment of a Memotherm colonic stent (Bard, Angiomed, Karlsruhe, Germany) across anastomotic strictures, following anterior resection, is described in three patients. Two patients presented with symptoms of colonic obstruction. Two of the patients had previously undergone unsucessful balloon dilation of the stricture. In the third, in addition to the anastomotic stricture, there was local tumor recurrance. Initially, stenting provided effective relief of symptoms. However, in all three patients, fracture of the stents occurred at intervals of 3-7 months after insertion. This use and complication of colonic stenting has not been reported previously.