冠和固定义齿对牙周组织的影响

不良固定修复体可引起局限性牙周炎。文章从牙龈指数、探诊深度及X射线检查等来探讨冠和固定义齿对牙周组织的影响,除修复体边缘密合性欠佳、龈边缘在龈沟内过深、轴面凸度不良等常见原因外,与固定修复后牙周炎相关的其它因素,也是进一步研究中应控制的变量。     

全冠的牙体预备

全冠的牙体预备是修复体能否成功的前提。本文从(牙合)面聚合度,(牙合)龈/切龈距离与颊舌径的比值,轴面、(牙合)面、切缘的切削量,预备体外形和表面质地、冠的边缘方面探讨全冠牙体预备时应遵循的原则,有助于临床提高冠、桥的修复质量。     

冠和固定义齿对牙周组织的影响

不良固定修复体可引起局限性牙周炎，文章从牙龈指数，探诊深度及X射线检查等来探讨冠和固定义齿对牙周组织的影响。除修复体边缘密合性欠佳。龈边缘在龈沟内过深，轴面凸度不良等常见原因外，与固定修复后牙周炎相关的其它因素，也是进一步研究中应控制的变量。     

全冠的牙体预备

全冠的牙体预备是修复体能否成功的前提。本文从He面聚合度，He龈／切龈距离与颊舌径的比值，轴面，He面，切缘的切削量，预备体外形和表面质地，冠的边缘方面探讨全冠牙体预备时应遵循的原则，有助于临床提高冠，桥的修复质量。     

双线排龈技术在固定修复中的应用

目的：通过双线排龈获取精细印模，减轻牙龈损伤，保护牙周组织健康，提高固定修复体的质量。方法：62例冠桥修复病例168个牙随机分成两组，31例按常规单线排龈，另31例牙体预备时，取模前使用双线压排龈法排龈。结果：97．7％双线排龈的印模非常清晰，边缘线均匀连续，模型肩台与游离龈之间出现肉眼可见间隙。修复体戴入后边缘适合性及美观效果均较单线组好。观察6—10个月后软组织健康状况良好。结论：应用双线排龈法，可取得清晰的印模，减少牙龈出血，可提高修复体质量。     

基于逆向工程技术的烤瓷固定义齿基底支架计算机辅助设计

目的 探讨烤瓷固定义齿基底支架的计算机辅助设计（CAD）路线，确定合适的三维CAD方法。方法 选取1例上颌第二前磨牙缺失患者，获取其工作模型的三维数据。基于临床设计原则，在逆向工程软件Surfacer10．5平台中调用标准桥体数据，利用三维曲线、点云和曲面编辑工具，提取预备体边缘线和桥体龈面边界线，创建基底桥体空间形态和位置定位参考线，分别创建固位体基底冠轴面部分、肩台部分、桥体龈面和轴面，创建连接区、连接体轴线及连接体曲面。结果完成1例后牙3单位烤瓷固定义齿基底支架的CAD，设计出的修复体形态合理、表面光滑、边缘密合。结论 本项研究的设计路线可行，结果 具有一定的理论和实践意义，为国产口腔修复体计算机辅助设计与计算机辅助制作（CAD-CAM）系统的完善，提供了技术方法的参考。     

296件树脂暂时冠导致牙龈炎的原因分析及应对措施

目的：分析树脂暂时冠戴冠后并发牙龈炎的原因,探讨减少牙龈炎、保护牙周组织的措施。方法：选择患者183例,共296件树脂暂时冠,戴冠1周后。对患者进行牙周状况和修复体的检查。结果：有68件树脂暂时冠发生牙龈炎症,其中修复体边缘不合要求者24件,占35．2％;粘接材料龈沟内残留者15件,占22．1％;邻接关系不良者15件,占22．1％;修复体外形不合要求者11件,占16．2％;差异均具有统计学意义（P〈0．01）;另有暂时冠局部无明显异常者3件,占4．4％。结论：暂时冠边缘不合要求、粘接材料龈沟内残留、邻接关系不良、修复体外形不合要求是导致牙龈炎症的主要原因,对暂时冠材料过敏也可能是原因之一。预防牙龈炎症,暂时冠制作时应注意修复体边缘及外形、修复体与邻牙的邻接关系,粘接完成后应尽量去除残留于龈沟内的粘接材料。     

固定修复的生理设计原则

本文的目的是探索牙的轴面外形和周围组织之间的关系,使之发挥生理功能作用。生理性外形的设计: (牙合)面外形设计的作用是使其对支持组织产生最小的压力,而轴面外形设计的作用是为了对周围组织,主要是对龈缘起保护作用和刺激作用,形成不利于牙菌斑生长的环境。一般在固定修复的轴面产生牙菌斑时就会导致细菌分泌毒素,从而形成明显的龈炎,比咬(牙合)创伤形成的损害更为复杂。因此固定修复轴而外形的设计与(牙合)面外形的设计同样重要。而轴面外形的设计着重在便于清洁,使之有效地防止牙菌斑的形成,对龈组织既有刺激作用又有保护作用。     

310件金属烤瓷修复体并发牙龈炎的原因及预防措施

目的：研究金属烤瓷修复体修复后并发牙龈炎的原因,探讨减少牙龈炎,保护牙周组织的措施。方法：选择280例患者,共310件金属烤瓷修复体,经3—5年的临床观察。对患者进行牙周状况和修复体的检查。结果：有37件金属烤瓷修复体发生牙龈炎,其中修复体边缘不合要求占56.76%,修复体外形不合要求占18.92%,邻接关系不良占24.32%。结论：修复体边缘不合要求、修复体外形不合要求、邻接关系不良是并发牙龈炎的原因。预防牙龈炎,金属烤瓷修复体修复前需保持牙周组织的健康状态;修复过程中注意对牙周组织的保护;修复后注意对牙周组织的保健。     

三种排龈方法对固定修复效果影响的比较

目的比较3种排龈方法对固定修复效果的影响。方法金属烤瓷单冠修复患者79例203颗牙,随机分为3组,分别采用机械法、化学法和机械化学法压排牙龈,制取印模,完成修复体。对排龈止血效果、牙预备体肩台、印模、模型清晰程度及修复体边缘密合程度进行评价。结果采用机械化学法排龈的患者,在模型清晰程度及修复体边缘密合程度方面均优于其他两组。结论机械化学排龈法操作简便,易于暴露清晰的牙体边缘线,是一种较好的排龈方法。     

The effect of removable partial dentures on periodontal health of abutment and non-abutment teeth

BACKGROUND: A removable partial denture (RPD) is a common treatment available for restoration of partially edentulous ridges. Longitudinal studies indicate that RPDs have been associated with increased gingivitis, periodontitis, and abutment mobility. METHODS: A total of 205 patients with RPDs participated in this study. There were 80 males and 125 females aged 38 to 89, with 123 maxillary and 138 mandibular RPDs. Patients were wearing existing RPDs for different periods ranging from 1 to 10 years. A two-part questionnaire was devised for this study. In the first part, patients answered questions on gender; age; smoking habits; denture age; denture wearing habits; mouth odor; and problems with food accumulating under the denture base, on the outside surface of the denture, and on the outside surface of remaining teeth after eating. The Kennedy classification, material, denture support, denture base shape, and number of teeth in contact, number of existing clasps, and occlusal rests were categorized. The quality of denture construction was also evaluated. In the second part of the questionnaire, baseline recordings of plaque (PI), gingival (GI), and calculus (CI) indexes were made, and Tarbet index (TI), as well as probing depth (PD), gingival recession (GR), and tooth mobility (TM) were measured, both on abutment and non-abutment teeth. RESULTS: Significant differences (P <0.01) were noted for PI, Cl, GI, PD, TM, and GR between abutment and non-abutment teeth, with abutment teeth showing more disease. CONCLUSIONS: RPD design plays an important role in the state of the periodontium. Appropriate design and good oral hygiene may decrease the appearance of periodontal disease.     

远航舰艇官兵牙周病发病状况调查分析

目的调查分析长时间远航舰艇官兵牙周病的发病状况。方法对比分析参与长时间远航的186名舰艇官兵远航前、后的简化牙石指数（CI-S）、菌斑指数（PLI）、牙龈指数（GI）、社区牙周指数（CPI）、附着丧失(AL)、缺失牙数（NMT）和牙周病患病率的差异。采用SPSS14.0软件包对数据进行统计学分析。结果远航后各项牙周检测指标值均较远航前显著增高（P<0.01）。186名研究对象在远航前牙周病总患病率为59.7%,远航后患病率增加到83.3%。其中,牙龈炎和轻、中度牙周炎患者增加较多,远航后牙周病患病率和患病程度与远航前相比差异显著（P<0.01）。结论远航环境、饮食约束和口腔卫生不良可显著影响舰艇官兵的牙周状况,及时有效地加强口腔卫生宣教、养成良好正确的刷牙习惯、均衡合理膳食及适当的牙周基础和药物治疗,对远航舰艇官兵的牙周健康十分重要。     

套筒冠固位式固定桥基牙牙周状况的评定分析

目的:观察套筒冠固位式固定桥基牙的牙周变化情况,探索该修复方法对于牙周维护的作用。方法:选择符合入选标准的患者22例,随机分为两组,即拆卸组和对照组,所选患者均为下颌第一磨牙缺失,每位患者均以下颌第二双尖牙和下颌第二磨牙为基牙,在修复后即刻以及修复后3、6、9个月,对基牙四个面——近中面、远中面、颊面、舌面进行牙龈指数和龈沟出血指数的检测,利用SPSS12.0统计软件对检测数据进行分析,评定基牙不同时间段及不同部位的牙周状况。结果:全部入选患者按照要求完成了基牙制作和戴用,并完成了相关的检测。统计分析显示拆卸组近远中面牙周指数与对照组相比,有显著差异,有统计学意义(P<0.05)。而拆卸组颊舌面牙周指数与对照组相比,无显著差异,无统计学意义(P>0.05)。结论:套筒冠固位式固定桥便于拆卸,有利于基牙牙周的定期卫生维护。     

Periodontal diseases in the child and adolescent

BACKGROUND: Periodontal diseases are among the most frequent diseases affecting children and adolescents. These include gingivitis, localized or generalized aggressive periodontitis (a.k.a., early onset periodontitis which includes generalized or localized prepubertal periodontitis and juvenile periodontitis) and periodontal diseases associated with systemic disorders. The best approach to managing periodontal diseases is prevention, followed by early detection and treatment. METHODS: This paper reviews the current literature concerning the most common periodontal diseases affecting children: chronic gingivitis (or dental plaque-induced gingival diseases) and early onset periodontitis (or aggressive periodontitis), including prepubertal and juvenile periodontitis. In addition, systemic diseases that affect the periodontium and oral lesions commonly found in young children are addressed. The prevalence, diagnostic characteristics, microbiology, host-related factors, and therapeutic management of each of these disease entities are thoroughly discussed.     

Photoelastic stress analysis of mandibular posterior cantilevered pontic

The quasi-3D technique of photoelastic stress analysis was used to evaluate the stresses of mandibular posterior cantilevers for distal terminal abutments at various levels of periodontal support. The stress concentration index was selected to compare each model. The periodontal support of terminal abutment and the length of pontic must be considered, when a cantilever fixed partial denture is anticipated.     

Biomechanics of Cantilever Fixed Partial Dentures in Shortened Dental Arch Therapy

PURPOSE: The purpose of the present study was to investigate, by means of 3-dimensional finite element analysis, aspects of the biomechanics of cantilever fixed partial dentures replacing the maxillary canine in shortened dental arch therapy. The null hypothesis was that no differences would be identified by finite element analysis in the mechanical behavior of the 2 designs of cantilever fixed partial denture under different scenarios of occlusal loading. MATERIALS AND METHODS: Single- and double-abutted cantilever fixed partial dentures were modeled and analyzed using the finite element packages PATRAN and ABAQUS. Displacement and maximum principal stresses (magnitude and location) within the fixed partial dentures, supporting structures, and the periodontal ligament/bone and abutment/retainer interfaces were examined under 20 different scenarios of axial and lateral occlusal loading. RESULTS: The results indicate that more displacement occurred in the 2 rather than the 3-unit cantilever fixed partial denture, with the greatest displacement having occurred under lateral loading. The maximum principal stresses observed in the periodontal ligament/bone interfaces were greatest buccocervically, with the highest value being observed in the 2-unit fixed partial denture under lateral loading. The highest maximum principal stresses observed in the retainer/abutment interfaces were located cervically in relation to the distal margin of the retainer of the 2-unit fixed partial denture under axial loading. CONCLUSIONS: It was concluded that in adopting a cantilever fixed partial denture approach for the replacement of a missing maxillary canine in shortened dental arch therapy, there may be merits, in terms of mechanical behavior, in selecting a double-rather than a single-abutment design. Furthermore, prostheses' displacement and functional stresses may be minimized by reducing lateral loading and avoiding pontic only loading.     

套筒冠式牙周夹板固定在重度牙周病治疗中的应用观察

目的临床观察重度牙周病患者经套筒冠式牙周夹板固定后临床治疗效果的影响。方法选择13例重度牙周炎患者,制作套筒冠式牙周夹板修复体19件,分别记录治疗前、治疗后3个月、6个月和12个月4个时段基牙的菌斑指数(PLI)、牙龈指数(GI)、牙龈出血指数(BOP)、探诊深度(PD)、牙齿松动度,并进行对照比较。结果经套筒冠式牙周夹板固定治疗后,牙齿松动度及牙周袋深度逐步变小,与治疗前相比有明显改善,差异有统计学意义(P<0.05),其他指标无明显差异(P>0.05)。结论牙周病患者经套筒冠式牙周夹板固定修复并结合牙周序列治疗,可提高牙周病治疗的成功率。     

Tetracycline inhibition identifies the cellular origin of interstitial collagenases in human periodontal diseases in vivo

Mammalian interstitial collagenases (E.C.3.4.24.7) are considered as key initiators of collagen degradation in periodontal diseases. However, the cellular sources of collagenases present in gingival crevicular fluid have not been completely clarified. Resident fibroblasts and epithelial cells as well as infiltrating neutrophils and monocyte/macrophages are potential sources of the enzymes. We have recently found significant differences in tetracycline inhibition between human neutrophil and fibroblast interstitial collagenases. To address the cellular source of collagenase present in gingival crevicular fluid in 2 distinct periodontal diseases, we studied the tetracycline inhibition of collagenase in gingival crevicular fluid of patients with localized juvenile periodontitis and adult periodontitis. Gingival crevicular fluid samples were collected from deep (greater than 5 mm) periodontal pockets and assayed for collagenase in the presence of 0-1000 microM doxycycline as well as a chemically modified tetracycline devoid of antimicrobial activity (4-de-dimethylaminotetracycline). The drug concentration required to inhibit 50% of collagenase activity (IC50) in localized juvenile periodontitis gingival crevicular fluid was 280 microM for doxycycline and 470 microM for 4-de-dimethylaminotetracycline. Significantly lower values, 10-20 microM, were obtained for collagenase in gingival crevicular fluid of patients with adult periodontitis. We propose that systemic tetracycline levels are efficient inhibitors of collagenase in gingival crevicular fluid in affected sites of patients with adult periodontitis but not of patients with localized juvenile periodontitis and that the fibroblast type interstitial collagenase is the predominant collagenase type in gingival crevicular fluid in affected sites of patients with localized juvenile periodontitis and the neutrophil collagenase in adult periodontitis gingival crevicular fluid.(ABSTRACT TRUNCATED AT 250 WORDS)     

暂时固定桥对双端固定桥桥体龈端密合度的影响

目的:探讨暂时固定桥对双端固定桥桥体龈端密合度的影响。方法:选择37例拟行后牙三单位双端固定桥修复的患者,按常规步骤制作修复体,选用Luxatemp材料制作暂时固定桥,复诊时检查双端固定桥桥体龈端密合情况,同时针刺法检测并记录缺牙区黏膜厚度。结果:初次复诊时13例双端固定桥桥体龈端不密合,缺牙区黏膜厚度2.215±0.410mm;24例密合,缺牙区黏膜厚度1.918±0.128mm,二者有显著性差异。13例不密合者磨去暂时固定桥桥体部分,观察1周,再次复诊时12例恢复密合。结论:暂时固定桥在牙合力作用下使桥体覆盖区的黏膜发生弹性形变,导致双端固定桥桥体龈端出现间隙。黏膜的变形与黏膜厚度有关,且具有可复性。