Complement fixing activity in diseased human gingival tissues

Human gingival tissue biopsies were classified as "initial or early" or "established or advanced" periodontal lesions on the basis of the histopathological criteria of Page and Schroeder (1976). They were then examined for the ability to fix complement by the anticomplement immunofluorescence technique which detects fixation of exogenously applied guinea pig complement. Complement fixation was found in association with IgG deposits (detected by immunohistochemical staining) in 80 % of the established and advanced lesion, thus suggesting that it was fixed by immune complexes or aggregated IgG. The complement fixing activity was not associated with IgA or IgM deposits. In contrast, less than 13 % of the initial and early lesions were found to contain such activity. The presence of complement fixing activity was thus found to be significantly correlated with the more advanced as opposed to the earlier stages of periodontal inflammation (p = 0.02 by Chisquare analysis).     

CS3600■口扫数字化印模技术与传统硅橡胶印模技术在磨牙全瓷冠修复中的比较

目的:比较数字化口内直接印模技术与传统精细硅橡胶印模技术在磨牙全瓷冠修复中的效果。方法:研究选取2019年10月~2020年1月于华中科技大学同济医学院附属同济医院口腔修复科行磨牙全瓷单冠修复治疗的患者32例,共计36颗患牙。实验组18颗患牙采用CS3600^■口内扫描仪制取数字化印模,对照组18颗患牙采用传统硅橡胶印模技术制取印模。记录两组取模时间、戴牙时间及患者舒适度,修复完成2个月参照改良美国公共卫生署(USPHS)标准对修复体进行评价。结果:实验组取模时间更短、取模更舒适;制作的修复体戴牙时间更短、修复体边缘适合性更好(P<0.05)。结论:在磨牙全瓷冠的修复治疗中,CS3600^■口内扫描技术在取模时间、取模舒适度、戴牙时间和修复体边缘适合性等方面都优于传统硅橡胶印模技术。     

Sagittal ramus osteotomy with tandem screw fixation. Technique and results

Spiessl's traction screw osteosynthesis with compression of the cut surfaces can lead to dislocation of the condyles and crushing of the mandibular nerve in cases of sagittal ramus osteotomy. Such disadvantages can be minimized by joining the bony segments with tandem screws with threads in both parts of the bone. This technique avoids compression at the cut surfaces and permits contact and distance fixing by screws which are adapted to the course of the split. Since 1981, 132 mandibular osteotomies have been performed; they have proved to be adequately stable. The operative technique, the instruments used and the results of the follow-up are described. In order to evaluate the results, an index, namely the joint, relapse and sensation index is proposed for classification. This index can readily be used in practice.     

In vitro testing of a measuring system for in vivo recording of orthodontically applied forces and moments in the multiband technique

Summary The aim of this study was to measure in vivo the forces and moments acting therapeutically on the individual tooth in connection with the multiband technique. Securing and evaluating the planned in vivo measurements involves analysing the measuring accuracy of the system as a whole by means of corresponding in vitro investigations. Errors in determining the therapeutically effective force system may result from the electrical measurement of the mechanical quantities by the sensor system and from the fixing of the archwire in therapeutic position. The precision of this fixing is influenced by displacements induced by elasticities and mechanical tensions in the measuring system. Calibration test series have shown the sensor system to have a margin of error of less than 2%. The displacements influencing precision fixing of the archwire were determined by means of a laser position measuring system. For a maximum orthodontic force of 1.5N, they are 0.06 mm in the least favourable case. The resulting measuring accuracy was determined analytically or graphically, depending on the key parameters. Successful in vivo studies of the therapeutically applied force systems are to be expected on the basis of these results.Part I of this article is published in J Orofac Orthop/Fortschr Kieferorthop 1996; 57:298–305.     

侧向拉力螺钉技术治疗髁突囊内矢状骨折

目的　探讨应用侧向拉力螺钉技术治疗髁突囊内矢状骨折的方法与疗效。方法　对11例患者 ( 13侧 )髁突囊内矢状骨折经耳前途径行髁突游离复位 ,用 2颗钛螺钉依照拉力螺钉技术操作规范从外侧固定 ,术后行临床与影像学追踪观察。结果　平均追踪 12个月 ,全部患者疗效满意 ,9例痊愈 ,2例轻微错畸形 ,均无关节症状 ,影像检查 3例有髁突轻微骨质吸收和形态异常。结论　侧向拉力螺钉固定髁突囊内矢状骨折的方法简便可靠 ,疗效确切 ,并发症少     

The use of titanium mesh plates for graft fixation in mandibular osteoplasty

Opportunities of the use of mesh titanium plates as fixing devices are considered at reconstruction operations. Data of following up 8 patients with defects of the mandible of various location and extent are analysed. They were operated with reconstruction of the mandible with iliac graft and bone graft fixing with the mesh titanium plates. A technique of the operations is described, a case of successful use of mesh titanium implant modelled by the form of the mandible in repair of the mandible defect. The analysis of long-term results shows the potential efficiency of the use of mesh titanium plates as fixing adaptations in bone plastic operations.     

Limitations and Management of Static-guided Endodontics Failure

Endodontic treatment in severely calcified canals is always a challenging task because it can result in accidents such as deviations or perforations. Recently, guided endodontics has become an alternative approach for pulp canal calcification, facilitating the location of root canals more predictably through the combined use of cone-beam computed tomographic imaging, oral scanning, and endodontic access guides. Although several reports have shown that guided endodontics is safer, faster and can be performed without an operating microscope and by less experienced operators, the technique has limitations, and iatrogenesis may occur. This article describes the limitations of static-guided endodontics and possible causes of failures. In the present case, not fixing the guide to the bone and inaccuracies generated by manually performing mesh merger software led to root perforation. Endodontic microsurgery was effective in resolving this case and should be considered the treatment of choice when guided endodontics cannot be used safely or when it fails.     

Application of the interseptal alveolotomy for closing the oroantral fistula

This article describes a new application of the interseptal alveoplasty to close oroantral fistulae caused by dental extraction. The surgical technique is described, and its advantages are compared with those of other techniques. The technique was used to treat eight patients with comparatively small fistulae in the soft tissue, approximately 1 to 5 mm wide. All fistulae were successfully closed. It is proposed that the technique provides greater flexibility in the treatment of fistulae. In addition, because there is a bony base, this promotes more successful healing than other commonly used procedures.     

Tanzer group IIB constricted ear repair with helical advancement and superior auricular artery chondrocutaneous flap

Constricted ear deformity was first described by Tanzer and classified it into 3 groups according to the degree of constriction. The group IIB deformity involves the helix, scapha, and antihelical fold. The height of the ear is sharply reduced, and the soft tissue envelope is not sufficient to close the cartilage framework after expansion and reshaping.This study describes expanding the cartilage and increasing the height by advancing the helical root superiorly and repairing the skin-cartilage defect with a superior auricular artery chondrocutaneous flap in Tanzer group IIB constricted ear deformity.Six ears of 6 patients were treated with this technique during the past 3 years. All patients were satisfied with the appearance of their corrected ears, and the increase in height was maintained through the follow-up period.The described technique does not have the disadvantages and possible complications of harvesting a costal cartilage graft. Moving and fixing the root of helix to a more superior position provide the auricle with additional length. The superior auricular artery chondrocutaneous flap not only provides adequate soft tissue for primary closure of the anterior portion of the auricle but also aids in repairing the cartilage defect resulting from the superior advancement of the helix as well.     

根管精细印模对桩冠固位力的影响

目的 研究根管印模的不同方法对桩冠固位力的影响。方法 用根内直接法、藻酸盐法、琼脂法三种不同的根管印模方法制作桩核，就位后，用拉力计测量其固住力进行实验。结果 用琼脂精细印模法制作桩核，由于模型最清晰，因而所制作出的桩核固位力最大。结论 选用不同材料印模所制作出来的桩核，其对桩冠固位力的影响是不同的。     

A new technique for imaging the temporomandibular joint with a panoramic x-ray machine. Part I. Description of the technique

A new technique for imaging the temporomandibular joint with rotational panoramic radiography is explained and demonstrated with a tissue-equivalent phantom. In this technique the patient is displaced forward and laterally away from the side under examination. Radiographs made with the proposed technique show the temporomandibular joint with more sharpness and less distortion than do radiographs made with conventional panoramic techniques.     

Removal of titanium plates coated with anodic titanium oxide ceramic: retrospective study

Transformation of the surface of metallic titanium with titanium oxides prepared in various ways is a modern procedure. For more than 15 years, the authors have been utilizing fixing elements coated with titanium oxide ceramics, prepared by anodic oxidation and thermal treatment, for purposes of jawbone osteosynthesis. The aim of the authors' work was to assess the extent to which the titanium oxide ceramic coating influences the fate of the plates used for osteosynthesis within the human organism, in regard to the possible need for their removal. During a 5-year period, 108 of 1,396 plates coated with anodic titanium oxide had to be removed for various reasons: plate exposure (47), osteomyelitis (25), palpable swelling and tenderness (21), patient request for psychological reasons (13), or fracture of the plate (2). In none of these 108 cases was metallosis observed, which otherwise is reported relatively frequently in the vicinity of traditional titanium fixing elements, nor was any tissue damage connected with the surface of the plates. The results indicate the favorable properties of the titanium oxide ceramic surface.     

Long-term outcome of dental implants after maxillary augmentation with and without bone grafting

Background

This study aims to evaluate the technique of sinus bone reformation, which consists of elevating the sinus membrane and placement the implant without bone graft, compared with the widely-used technique involving raising the maxillary sinus and grafting, using animal hydroxyapatite as the filler, while simultaneously fixing the implants.

Material and Methods

This is a retrospective study on two groups of patients who underwent elevation of the sinus membrane and simultaneous placement of the implant. The grafting technique was applied to one group, while the other had no graft. An alveolar ridge height of 4 to 7 mm was necessary. Radiological control was undertaken at 6 months and one year post-prosthetic loading. In each group 38 implants were placed.

Results

No significant behavioural differences were observed in the implants according to the Albrektsson success criteria. Implant failure was observed in 2 implants from the bone grafting group (success rate 93%) and in 1 implant from the reformation group (success rate 97%). In this group, bone formation was observed on both sides of each implant, the bone gain was measured using image management software (2.7±0.9mm mesial and 2.6±0.9mm distal). There was no correlation between mesial and distal bone gain and implant´s length.

Conclusions

The results indicate that bone reformation is a valid technique in cases involving atrophy of the posterior maxilla. Primary stability, maintenance of space by the implant, and the formation of a blood clot are crucial in this technique in order to achieve bone formation around the implant. It is an alternative to the conventional technique of sinus lift with filling material, and has several advantages over this procedure, including a lower infection risk, as it does not involve a biomaterial, reduced cost, a simpler technique, and better acceptance by the patient. Key words:Bone formation, sinus membrane elevation, maxillary sinus, bone grafting.     

Evaluation of a poly-l-lactic acid membrane and membrane fixing pin for guided tissue regeneration on bone defects in dogs

OBJECTIVES: The purpose of the study was to clarify the usefulness of a poly-l-lactic acid and membrane fixing pin, used in combination with guided bone regeneration, on bone defects in dogs. STUDY DESIGN: Osteotomies bone defects were created in 8 beagle dogs. Group I: one defect was covered with test membrane and held by fixing pins. Group II: the other defect was covered test membrane and not held by fixing pins. The control group received no membrane. The dogs were killed after 24 or 36 weeks of healing. Sections were stained and evaluated microscopically. Data were analyzed statistically. RESULTS: The degradation and resorption of test membrane was not observed at 24 weeks but was noted at 36 weeks. After 24 and 36 weeks, most of Group I defects were completely closed with new bone, while in the control defects, only a small amount of new bone was observed at the bottom of the bone defects. After 36 weeks, the percentage of new bone volume (62.2%) in the space beneath the test membrane and membrane fixing pin (Group I) was greater than that without a membrane fixing pin-53.2% (Group II), whereas only 43.9% of the defect area in the control group was filled with new bone. CONCLUSION: The results of this study show that a poly-l-lactic acid membrane and membrane fixing pin permit bone regeneration that can be ensured by excluding surrounding soft tissues from the wound area.     

Histological changes in edentulous oral mucosa under implant-supported overdentures

The microscopic characteristics of the mucosa covering the alveolar ridge that supports a complete denture have long been studied. In this paper, any histological changes in mucosa loaded by a denture before and after a denture has been anchored by implant onto the bone were followed. The results suggest that mechanical loads improve trophism of mucosa, and that fixing a denture to implants leads to a more uniform distribution of loads.     

Protefix~义齿稳固剂对改善义齿咀嚼效能的临床评价

目的评价Protefix○R义齿稳固剂改善总义齿固位的临床效果。方法测定总义齿或黏膜支持式可摘局部义齿修复的多数牙缺失且能熟练戴用活动义齿的患者30例,使用义齿稳固剂前、即刻、4h、8h的吸光度值的变化,并以问卷形式调查患者的主观评价。结果统计数据分析表明,使用Protefix○R义齿稳固剂前、即刻、4h、8h,差异均有显著性(P<0.01)。患者主观评价良好。结论对固位条件差的活动义齿修复患者,可建议使用Protefix○R义齿稳固剂。     

在LeFortI型截骨术中用羟基磷灰石作为嵌入式固定的初步报告

在ＬｅＦｏｒｔＩ型截骨术中，于前移骨的上颌窦底壁和截骨线之上的上颌窦前壁间嵌入羟基磷灰石生物材料，作为防止上颌截骨段后退的“门槛”状阻力块，可以有效地减少复发。５例用此法，早期获得满意效果。     

Disc-repositioning surgery of the temporomandibular joint using bioresorbable screws

For successful disc-repositioning surgery, following arthrotomy and disc recovery by the release of attachments, the disc must be fixed and stabilized in the correct relationship with the condyle and fossa. This report describes a new surgical technique for fixing the disc to the condyle using two resorbable screws.     

Follow-up examinations after removal of titanium plates coated with anodic titanium oxide ceramic

Transformation of the titanium metal surface with titanium oxides produced in various ways belongs among the most up-to-date procedures. The authors as pioneers in this field (e.g. Nobel Biocare TiUnite surface), have been utilizing for more than 15 years dental root implants and fixing elements (for mandibular osteosynthesis) coated with titanium oxide ceramics, produced by anodic oxidation and thermal treatment. The aim of this work was to assess the extent to which a titanium oxide ceramic coating influences the fate of plates applied for osteosynthesis within the human body. During a 5-year period (1995-1999), 108 of 1396 titanium oxide ceramic plates had to be removed for various reasons: loosening of the plate [47], osteomyelitis [25], a palpable swelling and tenderness [21] at the request of the patient for psychological reasons (13) or breaking of the plate [2]. When these 108 plates were removed, it was not possible to detect metallosis in even a single case; nor was there any tissue damage that could be attributed to the surface of the plates, whereas the literature data indicate that such damage is relatively frequent in the environment of traditional titanium fixing elements. The present investigation confirms the favourable properties of the titanium oxide ceramic surface.     

A new technique for decalcifying thin ground specimens of adult human enamel

A new decalcification technique is described for the recovery of the organic matrix from thin ground specimens of adult human enamel. An aqueous solution of chromium sulphate which has both fixing and decalcifying properties is used.

The results are compared with those obtained when an adjacent part of the same ground specimen was decalcified with the hydrochloric acid solution of (1962).

Dependent on slight differences in pH of the chromium solutions, two different appearances of the recovered matrix are obtained: above pH 3.2 a structural matrix which is positively birefringent at refractive index 1.55, whereas below this pH a matrix which is homogeneous and non-birefringent and almost similar to the matrix obtained after hydrochloric acid decalcification. The two types of matrices are discussed and the one favoured on morphological grounds, the chromium sulphate structural matrix, is related to present concepts of the structure of the native enamel matrix.