Investigation of Peri-implant Status and Risk Variables for Implant Failure in Body of Maxilla after Oral Tumor Surgery

The aim of this study was to assess the peri-implant parameters and evaluate the clinical status with the survival of dental implants in body of maxilla after treatments of oral tumor. A follow-up examination included 27 patients who underwent the ablative tumor and （or） reconstructive surgery during a 5-year period. The follow-up protocol included clinical examination, radiological evaluation, and an interview using a standardized questionnaire. The reasons related to implant failure were studied by comparing the amount of failure with the value of marginal bone resorption, probing pocket depth, and plaque index using statistical t-test. The relationship between smoking and implant failure was analyzed statistically by chi-square test. The results showed among the 112 implants observed after implant loading, 29 have failed with the failure rate being 22.14 %. There was no significant correlation between the peri-implant status and the implant failure （P〉0.05）, however, the association of smoking and implant failure was statistically tested （P〈0.05）. It was suggested that the association of peri-implant status and implant failure in the maxilla after tumor surgery can＇t be statistically tested, however smoking was still a mainly significant factor.

Comparative Cytological and Histopathological Study of Peri-Implantitis and Periodontitis

Peri-implant diseases, such as peri-implant mucositis and peri-implantitis, pose significant challenges to the long-term prognosis of dental implants. This study aimed to comprehensively compare peri-implantitis with periodontitis from cytological and histopathological perspectives, shedding light on the morphological characteristics associated with peri-implantitis. Thirteen patients, including six with peri-implantitis and seven with periodontitis, were included in the study. Cytological examination of affected gingival mucosa revealed distinct differences between the two conditions. Peri-implantitis exhibited an inflammatory background predominantly composed of neutrophils with lobulated nuclei, accompanied by stratified squamous epithelial cells showing signs of keratinization. In contrast, periodontitis showed a similar neutrophilic inflammatory background but with non-keratinized epithelial cells. Histopathological examination further confirmed these differences, with peri-implantitis showing keratinized epithelium in the inner epithelial layer. This histological finding aligns with the notion that peri-implantitis has a distinct mucosal profile compared to periodontitis. Additionally, cytological analysis revealed that peri-implantitis had a lower occurrence rate of Light green-positive cells, indicating a tendency toward keratinization. This finding suggests that the presence of keratinized mucosa might be associated with peri-implant health, although further research is needed to clarify this relationship. Overall, this study demonstrates the potential of cytological examination and Papanicolaou staining for assessing mucosal inflammatory conditions and distinguishing between keratinized and non-keratinized cells. These findings underscore the utility of oral mucosal smears as a valuable tool for diagnosing peri-implantitis and enhancing our understanding of its pathogenesis.

Investigation of Bacteria Species Most Involved in Peri-Implantitis

Purpose: Currently, bacteriological examinations of implant treatments target periodontopathic bacteria such as red complex bacteria, including Porphyromonas gingivalis, and detect them qualitatively or quantitatively. However, it seems that those examinations do not reflect the peri-implant tissue conditions precisely, because periodontopathic bacteria are also frequently detected from healthy peri-implant sites. The purpose of the present study was to investigate bacteria species most involved in peri-implantitis using a PCR method. Methods: Polymerase chain reaction (PCR) primers in this study were designed based on partial sequences of 16S rDNA of bacteria species involved in peri-implantitis that were described in numerous previous studies. Peri-implant sulcus fluid (PISF) samples were collected from thirty periodontally healthy patients with implants (HI) and thirty patients with peri-implantitis (PI). Each detection frequency of bacteria species in PISFs of both groups was investigated using a PCR method, and was compared using Fisher’s exact test. Results: In PI group, detection frequencies of Corynebacterium durum, Fretibacterium fastidiosum and Slackia exigua were significantly higher than those of HI group (p P. gingivalis and Tannerella forsythia belonging to red complex were frequently detected in the PISF samples of HI group (p > 0.05). Conclusion: It was suggested that monitoring C. durum and F. fastidiosum levels in PISF samples was useful as a clinical indicator for the evaluation of peri-implant tissue conditions.

Study on matrix metalloproteinase-2, 9 in peri-implant sulcular fluid

Objective: To study the expression of matrix metalloproteinases-2, 9 (MMP-2, MMP-9) of healthy implant and peri-implant sulcular fluid (PISF) by enzyme-linked immunosorbent assay (ELISA) method, and evaluate the level of MMP-2 and MMP-9 in sulcular fluid as an objective indicator of tissue inflammation around implants. Methods: A total of 40 implants were selected from 30 patients who were treated with dental implants and were divided into two groups: the inflammatory group and the healthy control group with 20 pieces respectively. ELISA double antibody sandwich method was used to detect the levels of MMP-2 and MMP-9 in PISF. Results: The MMP-2 and MMP-9 expressions were significantly different between the healthy implant group and the peri-implant group (p < .05). The concentration of MMP-2, MMP-9, and the amount of sulcular fluid in the inflammatory implant group were positively correlated with the clinical parameters (probing depth [PD], modified sulcus bleeding index [mSBI]). Conclusions: Under physiological conditions, the levels of MMP-2 and MMP-9 were low. When the periodontal tissue was stimulated by inflammation, the expression levels of MMP-2 and MMP-9 were increased, which could reflect the severity of inflammation. The increase levels of MMP-2 and MMP-9 in PISF could better reflect the health status of peri-implant tissues, which could be used as an objective indicator to assist in the diagnosis of peri-implant inflammation.

盐酸纳布啡用于小儿尺桡骨骨折闭合复位克氏针内固定术后镇痛的临床观察

目的比较盐酸纳布啡和舒芬太尼对小儿尺桡骨骨折闭合复位克氏针内固定术后的镇痛效果及不良反应,探讨盐酸纳布啡用于术后镇痛的安全性和有效性。方法选取湖南省儿童医院于2017年9月至2018年8月收治的60例尺桡骨骨折需行尺桡骨闭合复位克氏针内固定的患儿为研究对象,依据术后镇痛药物的不同分为盐酸纳布啡组( n =30)和舒芬太尼组( n =30)。比较两组镇痛镇静效果及术后呼吸抑制、恶心呕吐、皮肤瘙痒等不良反应发生率。结果手术前两组患儿的FLACC评分分别为(1.56±0.32)分和(1.54±0.41 )分,差异无统计学意义( t =1.12, P =0.41);手术后0.5 h、6 h、12 h、24 h两组患儿FLACC评分差异均无统计学意义( P >0.05)。手术后0.5 h、6 h、12 h、24 h两组患儿Ramsay评分差异均无统计学意义( P >0.05)。盐酸纳布啡组的术后呼吸抑制、恶心呕吐、皮肤瘙痒等不良反应发生率低于舒芬太尼组,差异均有统计学意义( P <0.05)。结论相比于舒芬太尼,盐酸纳布啡更适用于中等疼痛强度手术的术后镇痛。

MB_2镁等四种金属材料的本构关系和动态断裂研究

采用炸药爆轰－分离飞片加载装置与电容传感技术相结合，由高速示波器连续记录靶板自由面速度剖面，通过波剖面的时间分辨测量，研究了ＭＢ＿２镁、ＬＹ－１２铝、钨合金、２１６９钢四种金属材料的动力学响应特性，给出了这几种材料在弹性－理想塑性模型假设下的本构关系，还给出了它们的动态断裂强度，并对标准化层裂强度与破坏比功、屈服强度之间的相关性进行了分析和讨论。

自制节段记忆合金固定器治疗腰椎峡部裂(附10例报告)

目的观察自行研制的腰椎峡部单节段固定器械──节段记忆合金固定器（ＩＭＡＦ）临床疗效。方法 峡部原位植骨 后应用ＩＭＡＦ固定有峡部裂的腰椎，术后软腰围固定３个月。结果１０例病人均获随访，随访时间３个月～２年，病人临 床症状全部消失，Ｘ线片示峡部完全融合。结论ＩＭＡＦ是一种简便易行、固定可靠的治疗腰椎峡部裂的新方法。

上颈椎骨折的非手术治疗:5年经验总结

目的探讨采用非手术治疗上颈椎骨折的适应证并观察其疗效。方法检索我科近5年收治的44例上颈椎创伤患者病例资料,其中29例接受了非手术治疗,包括寰椎骨折6例,Hangman骨折7例(Ⅰ型4例,Ⅱ型3例),齿状突骨折14例(Ⅱ型4例,Ⅲ型10例),枢椎侧块骨折1例,枢椎体粉碎性骨折1例。采用的非手术治疗方法如下:Halo-vest支架固定14例,颈托固定4例,头颈胸支具固定11例。结果27例患者获得完整随访资料,2例失访,随访时间4～45个月。末次随访均可见骨折处愈合,未见寰枢关节不稳表现。结论采取适宜的非手术方法治疗上颈椎稳定性骨折,可取得较好的临床疗效。手术仅在寰枢关节稳定性遭到破坏且无法通过非手术治疗恢复时才必须实施。

多重分形在测井资料裂缝研究中的应用

在测井资料的解释中，通常是利用双侧向曲线的数值大小来研究裂缝的发育情况，由于地区、岩性、深度等因素的不同，仅根据双侧向曲线数值大小确定裂缝发育的边界具有很大的人为因素和随机性。本文利用多重分形对其进行研究，由于多重分形谱包含非常丰富的信息，可以大大提高裂缝发育研究的可靠性，并可较准确地确定裂缝发育的边界。

BMP促进去神经后废用性骨质疏松骨折愈合的实验研究

为了观察ＢＭＰ对去神经后废用性骨质疏松性骨折愈合的作用，作考选用６月龄健康标准大鼠，严格配对分组，切除双侧坐骨神经后３周证实有明显骨质疏松。然后在腔骨人工骨折骨缺损处分别植入酸解胶状鼠尾胶原（对照）及ＢＭＰ与胶原混和物（实验组）。通过血清钙浓度、碱性磷酸酶活性及骨组织形态计量学多项参数的观察，显示ＢＭＰ对去神经后废用性骨质疏松骨折愈合有明显促进作用（Ｐ＜０．０５～０．０１）

Rosenblueth方法在软破围岩锚喷支护系统评价中的应用

软破岩的特点是成分复杂 ,裂隙发育 ,含有膨胀性矿物。在软破岩中的巷道围岩的地压是变形压力 ,它首先表现为侧壁岩体鼓胀成楔形被挤出。这种现象与Rabcewicz提出的软岩剪切滑移理论基本吻合。对这类围岩最为有效的支护形式是锚喷支护 ,由于软破岩的特点和复杂性 ,其本身和锚喷支护结构的力学参数和失效机理存在不确定性。对这类地下结构的稳定性分析时最为合适的是采用能考虑不确定性的可靠度方法。在建立可靠度方程时 ,按照该类岩体的地压特点 ,将承载结构分成两个子结构 ,根据子结构变形特点和受力条件建立结构总体极限状态方程。由于总体极限状态方程是在圆形巷道的基础上建立的 ,因此在文中还给出了一般形状巷道转化为等代圆形巷道时其半径的四种计算方法。最后给出了一个工程算例。

四种髓内针固定股骨中下段骨折的生物力学比较

目的研制一种新型的髓内内固定器械一带内锁髓内针，对其生物力学性能进行测试，为临床安全应用提供依据。 方法采用 ６副新鲜人股骨标本，人为造成股骨中下 １／３骨折并 ２ ｃｍ的骨缺损，分别用自带内锁髓内针、国产的交锁髓 内针、Ｅｎｄｅｒ氏针和梅花针内固定，对内固定后的标本进行生物力学测试，用ＳＰＳＳ统计软件对实验数据进行分析。结 果自带内锁髓内针的抗短缩刚度、抗旋转刚度接近于交锁髓内针，抗弯曲刚度优于交锁髓内针。梅花外、Ｅｎｄｅｒ氏针的 抗短缩、抗旋转、抗三点弯曲刚度明显较自锁针和交锁针差。结论自带内锁髓内针内固定在治疗长骨骨折中固定可 靠，符合生物学固定的要求。该器械结构合理、安全、简单、实用，有一定的临床应用价值。

喷射沉积IC6合金的拉伸性能及断裂特征

拉伸性能测试表明 ,喷射沉积 IC6合金的屈服及抗拉强度具有明显的“R”特性 ;断裂特征分析表明 ,合金沿八面体滑移系的 { 111}面开裂。

坪北油田长6储层裂缝特征

坪北油田长6储层属于湖相三角洲前缘砂体,是坪北油田的主力产层。通过用倾角测井及微地震波裂缝监测、几何变形分析和相对地压力分析等方法点、面结合分析了坪北长6储层裂缝特征,按成因总结了三种类型,即剪切构造裂缝、层间缝和压裂缝。构造裂缝、层间裂缝不发育,作为渗流通道对坪北长6储层意义不大。压裂缝中的粒间缝与一般的孔喉所起作用相当,而超微压裂缝在原始状态下对渗流没有意义。

陶瓷修复体缺损的修补

陶瓷修复体临床应用日趋广泛 ,瓷裂是这类修复体应用过程中经常出现的问题。本文介绍了近年来有关瓷修复体折裂修补技术及应用材料的研究进展情况 ,从修复体断面机械粗化 ,表面调节剂、粘结剂的应用 。

混气压裂施工的一些经验

对混气压裂典型施工曲线进行分析 ,总结出液氮泵车在施工各阶段注气压力变化的规律 ;推荐了一种从设备能力出发进行注气设计的气相设计方法 ,现场应用情况表明这一方法有着较强的实用性和可操作性 ;同时 。

肌骨瓣移植治疗高危股骨颈骨折66例临床分析

目的 :分析高危股骨颈骨折的临床特点 ,探讨肌骨瓣移植治疗高危股骨颈骨折的治疗原理和与手术有关的问题。 方法 :分别采用股方肌骨瓣移植和缝匠肌骨瓣移植方法治疗 66例高危股骨颈骨折。 结果 :随访 5 4例病人 ,平均随访5 2年 ,优 2 8例 ,良 2 2例 ,优良率 92 5 %。 结论 :肌骨瓣移植治疗高危股骨颈骨折技术成熟 ,简便易行 ,疗效满意 ,并发症少 ,适于基层医院推广应用。

导航引导椎弓根钉内固定系统治疗胸腰段椎体爆裂骨折

目的评价计算机导航引导椎弓根内固定系统治疗胸腰椎爆裂性骨折的安全性与准确性。方法回顾性分析2009年1月至2011年1月汕头大学医学院第二附属医院收治的56例胸腰椎爆裂性骨折患者的临床资料,其中导航组26例、常规手术组30例。对比分析两组的置钉安全性、准确性,手术时间,术中出血量及手术疗效等指标。结果 56例患者共置钉268枚,准确置钉248枚(92.5%)。导航组和常规手术组置钉成功率分别为93.6%和91.7%、手术时间分别为(2.4±0.4)h和(2.2±0.7)h,两组比较,差异无统计学意义(P>0.05)。导航组和常规手术组术中出血量分别为(184±49)mL和(276±81)mL,两组比较,差异有统计学意义(P<0.05)。过伸过屈动力摄片显示固定段无异常活动,未发现椎弓根钉松动、断裂。结论计算机导航辅助椎弓根内固定术治疗胸腰椎爆裂性骨折安全性和准确性较好,可减少术中出血量,疗效满意。

裂缝控制油藏非牛顿流试井分析

采用组合系统方法提出裂缝控制油藏非牛顿幂律流体不稳定流动数学模型，并求出Ｌａｐｌａｃｅ空间分析解，对于组合参数不同值给出该类油藏模型典型曲线，分析了早后期井底压力动态特征。从而可用于分析稠油或聚合物驱油藏流体流动参数及井周裂缝参数。

91例第一、二肋骨骨折与闭合性胸部损伤临床分析

目的：探讨第一、二肋骨骨折与闭合性胸部损伤的关系。方法：对我院自1985年8月至1997年8月收治的91例合并第一、二肋骨骨折的闭合性胸外伤病人进行分析。结果；胸廓出口部位大血管神经损伤者6例（6．60％），肺挫伤53例（58．24％），合并多系统损伤者44例（48．35％）。结论：第一、二肋骨骨折为严重闭合性胸部损伤的标志之一，应受到临床高度重视。