Histomorphometric evaluation of a threaded, sandblasted, acid-etched implant retrieved from a human lower jaw: a case report

The purpose of this study was to histomorphometrically evaluate the bone-to-implant contact and bone area around a titanium implant retrieved from a human lower jaw. A screw-shaped titanium implant (sandblasted and acid-etched surface) was removed from a 68-year-old male after having been in function for 40 months because of a fracture of the abutment screw. Following the implant removal, an undecalcified section was obtained. The histomorphometric analysis showed a rate of 75.40% of bone-to-implant contact and 89.30% of bone area filling within the limits of the implant threads. The surrounding bone healed in a well-organized pattern and could not be differentiated from the original alveolus. The histologic evidence showed a high degree of osseointegration in a threaded, sandblasted, and acid-etched implant retrieved from a human lower jaw after functional loading for 40 months.     

上颌前牙区骨量不足时牙种植技术

临床上对上颌前牙区骨量不足时牙种植常感到束手无策。本文通过对24例这类患者种植36颗BLB种植体进行总结，将种植区骨缺损分为四类，即唇侧齿槽嵴沟状凹陷性骨缺损；种植区骨量宽度不足；上颌前分牙槽后缩以及唇侧齿槽骨进基底部凹陷。采用邻位骨瓣转移术、牙槽膨胀技术、联合正颌外科种植技术等进行牙种植，临床跟踪6至24月均未发现牙龈萎缩及种植体松动，功能行使正常，X线片示：种植体骨界面愈合良好。作者认为，该手术方法简单，创伤小，改善了种植区条件，拓宽适应证，有利于推广使用。     

CGF 联合骨代用品及口腔修复膜在颌骨囊肿手术中的应用

目的：观察浓缩生长因子（ CGF）联合羟基磷灰石生物陶瓷及口腔修复膜在颌骨囊肿手术中促进骨组织愈合的临床效果。方法：45例颌骨囊肿患者行囊肿刮除术,采用浓缩生长因子及羟基磷灰石生物陶瓷混合物填充骨腔,CGF膜及口腔修复膜双层覆盖在骨缺损区表面。术后随访3～12个月,通过临床和影像学检查评估治疗效果。结果：45例患者术后伤口均为Ⅰ期愈合。直径＜2 cm的骨缺损在术后3个月羟基磷灰石生物陶瓷与周围骨组织界限消失,可见正常网纹结构的骨小梁。直径＞2 cm的骨缺损,术后9个月羟基磷灰石生物陶瓷与周围骨组织界限模糊;术后12个月界限消失,充填材料与新生骨及周围骨组织生长良好。结论：CGF联合羟基磷灰石生物陶瓷充填颌骨囊肿骨缺损区同时覆盖口腔修复膜的引导骨再生技术可有效促进骨愈合,修复骨缺损。     

应用GBR生物膜联合羟基磷灰石生物陶瓷与自体静脉血在颌骨局部缺损中的临床疗效观察

目的评价GBR生物膜联合羟基磷灰石生物陶瓷与自体静脉血在颌骨局部缺损中的临床疗效。方法 32例颌骨囊肿、颌骨良性肿瘤的患者,采用GBR生物膜联合羟基磷灰石生物陶瓷与自体静脉血治疗颌骨局部缺损,颌骨缺损范围为1.5cm×1.5 cm¹.5 cm×5.5 cm。结果术后29例患者切口Ⅰ期愈合;3例患者101.5 cm×5.5 cm。结果术后29例患者切口Ⅰ期愈合;3例患者10¹2 d延期拆线,均有部分缝合区裂开,人工骨粉颗粒溢漏,32例患者均未发生术后刀口感染或排异反应。术后6个月,羟基磷灰石生物陶瓷颗粒之间间隙基本消失,缺损区密度与宿主骨密度趋于一致。术后112 d延期拆线,均有部分缝合区裂开,人工骨粉颗粒溢漏,32例患者均未发生术后刀口感染或排异反应。术后6个月,羟基磷灰石生物陶瓷颗粒之间间隙基本消失,缺损区密度与宿主骨密度趋于一致。术后1²年,原颌骨肿物边界完全消失,充填材料与新生骨组织及周围宿主骨生长良好,可见正常的骨小梁网纹结构。结论将GBR生物膜联合羟基磷灰石生物陶瓷与自体静脉血应用于颌骨局部缺损,可以使三者优势最大限度的发挥出来,克服了单独使用所存在的不足,可有效的修复临床上常见的颌骨局部缺损类型。     

β-磷酸三钙用于牙槽嵴裂骨缺损修复的临床研究

目的采用颗粒状β-磷酸三钙(β-TCP)修复牙槽嵴裂,观察其临床效果,探寻一种理想的可代替自体骨修复牙槽嵴裂的人工材料。方法将24例先天性牙槽嵴裂患者分成A、B两组,A组(10例)用自体骼骨松质骨修复牙槽嵴裂骨缺损,B组(14例)用颗粒状β-TCP修复牙槽嵴裂隙。术后7天观察两组患者伤口愈合情况,并于术前、术后4～6个月,采用锥形束CT(CBCT)及三维重建的方法观察牙槽嵴裂骨缺损新骨形成的情况,比较两种植骨材料的植骨效果。结果术后1周,A组1例患者出现感染症状,其余患者伤口均一期愈合,无感染、裂开及排异反应。术后4～6个月CBCT扫描及三维重建显示两种材料植入后均可形成新骨,与原裂隙两侧骨组织部分或完全连续。两种材料修复牙槽嵴裂骨缺损的临床成功率无显著差异。结论颗粒状人工材料β-TCP的成骨效果与自体骼骨骨松质无显著差异,可以代替自体骨修复牙槽嵴裂。     

异种烧结骨修复颌骨缺损的临床观察

本文报告了应用异种烧结骨修复颌骨缺损25例,采用手术前后X线及免疫学、r骨显像等观察,进行了较系统的临床研究.经6～12个月追踪观察,结果表明:创口愈合正常,未见免疫排斥反应.术后3周左右植骨成活,2～3个月有新骨形成、与空白对照组比较,烧结骨有明显加快骨缺损部位成骨作用,新生骨出现早,成骨速度快.证实烧结骨具有良好的组织相容性和骨传导能力,具有较高的临床实用性,是一种较理想的骨移植材料.     

Histomorphometric comparison of implant anchorage for two types of dental implants after 3 and 6 months' healing in baboon jaws

STATEMENT OF PROBLEM: A complete understanding of dental implant prognosis requires better knowledge of the bone anatomy after implant healing. Such baseline data are necessary to compare against load-induced changes in anatomy. PURPOSE: The purpose of this article is to describe and compare measures of implant support (percentage [%] integration and percentage [%] bone area) for various implants in baboon jaws after healing times of 3 and 6 months. MATERIAL AND METHODS: Commercially pure titanium (cpTi) and titanium alloy (Ti-alloy) screw-shaped implants were placed in the posterior jaws of 9 female baboons after 2 months of postextraction healing. Specimens were harvested after 3 months (5 baboons: 8 cpTi, 7 Ti-alloy) and after 6 months (4 baboons: 8 cpTi, 8 Ti-alloy). Each implant provided 6 polished horizontal sections for data collection, which was accomplished from digitized images with the IMAGE analysis system (reliability at 1.6%). Three- and six-month data for each parameter were compared with the use of ANOVA (P<.01). RESULTS: The results revealed a significant increase in the % integration (cpTi 39.1 to 56.2; Ti-alloy 40.0 to 55.2) and the % bone area (cpTi 38.8 to 47.9; Ti-alloy 38.9 to 49.2) from 3 to 6 months for both implants. This significant increase was also true for comparisons by jaw for each implant material (P<.01 for overall and by jaw comparisons). CONCLUSION: A time-dependent increase in jawbone anchorage was measured in this nonhuman primate population, and it was shown that the 6-month maxillary data were comparable to the 3-month mandibular data. These results lend support to the clinical strategy of waiting longer to load implants in the maxilla.     

Guided bone regeneration in mandibular defects in rats using a bioresorbable polymer

The aim of this study was to explore the possibility of obtaining bone regeneration in jaw bone defects in rats after coverage of the defects with an occlusive bioresorbable membrane. The experiment was carried out in 31 rats. The mandibular ramus was exposed in both sides and a 2 x 3 mm defect was produced at its lower border. A gutta‐percha point was placed to indicate the original level of the border. The defect on one side was covered with a polyhydroxybutyrate resorbable membrane, whereas the contralateral side received no membrane before closure of the wound. Macerated jaw specimens representing 3 and 6 months of healing demonstrated minimal bone fill in the control defects, whereas all test defects healed to or close to the gutta‐percha point, indicating the original inferior border of the jaw. The histological analysis demonstrated increasing bone fill in the test specimens from 15–180 days, whereas only 35–40% of the defect area in the control sides was filled with bone after 3–6 months. Ingrowth of muscular. glandular and connective tissue was consistently occurring in the control defects during healing. It can be concluded that selective repopulation of bone defects with bone‐forming cells can be ensured by excluding surrounding soft tissues from the wound area with an occlusive bioresorbable membrane.     

Principles of bone tissue structures interaction with full removable dentures fixed on intraosseous implantates modelling

Math modelling "removable dentures-implantate-bone" with size and density of bone tissue as variables was created. It allowed to study biomechanical bases of mandibular bone tissue structures interaction with full removable dentures of different constructions and fixed on intraosseous implantates. Analysis of the received data showed that in the majority of cases it was expedient to recommend 3 bearing (abutments) system of denture making. Rest on 4 and more implantates was appropriate for patients with reduced density of spongy bone and significant mandibular bone atrophy. 2 abutment system can be used in patients with high density of spongy bone and absence of mandibular bone atrophy.     

β-TCP植入与口腔修复膜覆盖治疗对颌骨囊肿术后骨缺损的修复效果分析

目的:分析β-磷酸三钙人工骨(β-TCP)植入与口腔修复膜覆盖治疗对颌骨囊肿术后骨缺损的修复效果.方法:选取2018年7月～2019年9月我院颌骨囊肿患者116例,采用随机数字表法将其分为对照组和观察组,每组各58例.对照组经囊肿摘除术刮治后对创面采用口腔修复膜覆盖治疗,观察组经囊肿摘除术刮治后放置β-TCP充填骨缺损...     

Long-term stability of jaw bone tuberosities formed by "guided tissue regeneration"

The aim of the present study was to evaluate whether bone tuberosities produced by GTR on the lateral surface of the mandibular ramus in rats are stable on a long-term basis. Thirty male 6-month-old albino rats of the Wistar strain were used in the study. Tissue flaps were elevated on the lateral aspect of the mandibular ramus. The periosteum was preserved (P+) on one side of the jaw while the bone was denuded (P-) on the other. A rigid, non-porous oval-shaped teflon capsule was placed on both sides with its opening facing the ramus. Six months following surgery, 10 rats were sacrificed and prepared for histology while the remaining 20 rats were subjected to a second operation during which the capsules were removed. Standardized radiographs, taken immediately before and after removal of the capsule and after 3, 6, 9 and 12 months, were subjected to planimetric measurements and subtraction radiography. Ten animals were sacrificed and prepared for histological analysis after 6 months following removal of the capsules and the remaining 10 animals after 12 months. Histology revealed that at 6 months after the placement of the capsules, 17 were completely filled with new bone. The remaining 3 capsules which were displaced exhibited only partial bone fill. The radiographic analysis revealed that after 6 months 98.6 +/- 7.6% (mean +/- SD) in average of the cross-sectional area created by the capsules was filled with new bone. Within 3 months after removal of the capsules a slight resorption of the new bone had occurred, thereby reducing the area of the bone tuberosities by 4 to 8%. No further resorption of the bone tuberosities took place from 3 to 12 months. These observations indicating that new bone produced by GTR is stable on a long-term basis, may question the general belief that non-functional bone will resorb over time.     

颌骨囊肿开窗术的临床效果评价

目的:探讨和评估囊肿开窗术在颌骨囊肿临床治疗中的应用。方法:对60例颌骨囊肿患者实行开窗术,吸出囊内容物,不刮除其余囊壁,使囊腔与口腔相通呈开窗状态,碘仿纱条填塞,术后换药,并定期复查和随访。结果:所有病例均未出现长期反复感染,患者颌骨形态良好,未出现神经及邻近重要结构损伤症状。术后6月～3年随访,X线片示骨质再生情况良好,未见有囊肿复发。结论:颌骨囊肿开窗术是一种简便、经济、安全、效果良好的治疗颌骨囊肿的方法。     

同种骨植入材料应用于颌骨缺损的临床效果观察

［摘要］ 目的同种骨植入材料加医用诱导骨基质应用于颌骨术后骨缺损,观察成骨效果的回顾性研究。方法 颌骨手术患者43例,术后骨缺损直径2~5 cm,彻底清除病灶后植入同种骨植入材料及医用诱导骨基质,术后1周、1、3、6个月进行临床检查,术后6个月摄口腔全景片,根据临床症状及影像学结果评价术后感染率及术区骨质愈合情况。 结果 术区愈合不良率2.33%(1/43),6个月术区骨质愈合率 88.37%(38/43)。 结论 同种骨植入材料加医用诱导骨基质具有良好的生物相容性,能够促进硬组织的形成,骨缺损修复临床效果好,术后疼痛、肿胀、感染率低。     

Maxillary single-tooth replacement utilizing a novel ceramic restorative system: results to 30 months

This study reports on the first longitudinal results of an alumina (70%)-zirconia (30%) ceramic restorative system for implant-supported, single-tooth replacement in the anterior maxillary jaw. Eighteen patients (9 men, 9 women, mean age = 42.4 years) were treated with 22 implants placed into 19 extraction sockets and 3 residual ridges. Eight implants were immediately loaded with nonoccluding provisional prostheses. All implants were definitively loaded with fully occluding ceramic restorations after osseointegration and soft tissue maturation. Patients were monitored from 7 to 30 months (mean = 18.1 months) after loading. All implants osseointegrated and were successfully restored. One case of abutment screw loosening occurred because of patient parafunction (bruxing), and another patient reported chewing pain attributed to malocclusion. Both problems were successfully resolved without further incidence. Within the context of this study, single-tooth replacement in the anterior maxillary jaw was successfully achieved with alumina-zirconia ceramic single-tooth restorations with up to 30 months of clinical function.     

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目的探讨开窗术与口内小切口刮除囊肿后填充硫酸钙联合治疗颌骨囊肿的疗效和术后评价,寻求微创治疗青少年中大型颌骨囊肿的方法。方法从安徽医科大学附属口腔医院2010年5月至2011年12月收治的青少年患者中,选取中大型颌骨囊肿10例,开窗6个月至2年不等,之后均采取口内小切口刮除囊肿及填充医用硫酸钙。结果无一例出现感染及其他并发症。开窗待囊肿明显缩小后,行囊肿刮除及硫酸钙充填术;术后6个月颌骨曲面断层片显示原囊腔低密度影像基本消失,新骨形成,与正常骨组织无明显差别。对于开窗后囊肿自行痊愈的患者选择随访。结论对于中大型颌骨囊肿,采用开窗术及二期囊肿刮除后填充医用硫酸钙联合治疗可以更好地修复骨缺损,减少患者的痛苦和并发症,是一种理想的治疗方法。     

Bone regeneration by octacalcium phosphate collagen composites in a dog alveolar cleft model

Octacalcium phosphate (OCP) and porcine atelocollagen sponge composites (OCP/Col) markedly enhanced bone regeneration in a rat cranial defect model. To assess clinical application, the authors examined whether OCP/Col would enhance bone regeneration in an alveolar cleft model in an adult dog, which was assumed to reflect patients with alveolar cleft. Disks of OCP/Col or collagen were implanted into the defect and bone regeneration by OCP/Col or collagen was investigated 4 months after implantation. Macroscopically, the OCP/Col-treated alveolus was obviously augmented and occupied by radio-opacity, and the border between the original bone and the defect was indistinguishable. Histological analysis revealed it was filled and bridged with newly formed bone; a small quantity of the remaining implanted OCP was observed. X-ray diffraction patterns of the area of implanted OCP/Col indicated no difference from those of dog bone. In the collagen-treated alveolus, the hollowed alveolus was mainly filled with fibrous connective tissue, and a small amount of new bone was observed at the defect margin. These results suggest that bone was obviously repaired when OCP/Col was implanted into the alveolar cleft model in a dog, and OCP/Col would be a significant bone regenerative material to substitute for autogeneous bone.     

自体颌骨碎骨移植在即刻种植术中的应用评价

目的：评价自体颌骨碎骨移植在人工种植牙即刻种植术中的应用效果，探讨即刻种植并行自体颌骨碎骨移植填充种植体周围与牙槽骨间隙的可行性。方法：对28例患者的31颗上颌前牙行即刻种植术，采用直径4．0mm的中空钻或骨凿．在种植部位邻近或颏部取骨并碾成碎骨，在种植体未完全就位前充填其间隙，压紧后旋紧种植体，通过种植体的挤压作用达到密切接触，减少骨组织愈合前纤维组织的长人。人工种植牙即刻种植术后3周做临时冠修复，半年后做永久冠修复。结果：治疗后随访1～3．5a，其中3a以上9颗，2～3a14颗，2a以内8颗。31颗种植体合并自体颌骨碎骨移植者，效果达到优22颗，良6颗，失败3颗，保存率为90.3％。结论：在即刻种植术中，应用自体颌骨碎骨填充种植体周围与牙槽骨间隙是可行的有效方法。     

Periodontal aspects of osseointegrated fixtures supporting an overdenture

Abstract 196 Brånemark^TM implants in 86 consecutive patients rehabilitated by means of overdentures (6 upper jaws, 80 lower jaws) were observed longitudinally. In each jaw, only 2 implants were used to anchor the overdenture. 2 implants in the lower jaw showed some mobility at the abutment installation and were removed immediately. During the loading period (mean loading time 19.1 months ranging from 4 to 48 months), none of the implants showed any signs of non-integration. The marginal tissue reaction and plaque accumulation were monitored using conventional indices. Clinical methods and standardized radiographs were used to evaluate the bone level and density. The numbers of approximal surfaces without plaque (40%) or with gingival inflammation (55%) were almost constant throughout the study. The probing pocket depths remained within the range of 2.7 to 3.2 mm during the observation time, whereas the distance of the gingival margin from the top of the abutment clearly increased (from 1.8 to 2.9 mm). For loaded lower jaw implants connected to each other with a straight bar, a radiographic bone loss of 0.8 mm was observed during the first postsurgical year followed by a mean annual bone loss of less than 0.1 mm. For the “sleeping” fixtures, 50% less bone loss was recorded. For loaded but not interconnected implants in the upper jaw, the bone loss during the first 6 months reached 2.0 mm. The loss in marginal bone height did not clearly correlate with parameters such as the plaque index, the gingivitis index, the presence or absence of gingiva around the abutment, or the implant length. The present data, with an observation time up to 4 years, showed that the failure rate for Brånemark^TM implants supporting overdentures in the lower jaw can be limited to 1%. However, the use of 2 unconnected fixtures in the upper jaw cannot presently be advocated since considerable bone loss was observed.     

Guided tissue regeneration in jawbone defects prior to implant placement

The principle of guided tissue regeneration has been successfully applied for the regeneration of bone in various jaw defects in human. The purpose of this study was to assess the bone volume regenerated using nonresorbable membrane barriers. Nineteen patients with jaw bone defects of various sizes and configurations were included in the study. Combined split‐thickness/full‐thickness mucosal flaps were elevated in the area of missing bone. The size of the defects was assessed by measuring the distance from a reference line between 2 adjacent teeth (cementoenamel junctions) to the alveolar crest (a) every 2 or 3 mm. In addition, the crestal width was measured. Consequently, the surface of the triangle formed by a and the width of the crest as well as the volume between all triangles were calculated geometrically. Following the placement of Gore‐Tex® augmentation material as a barrier, the distance (b) to the top of the membrane from the reference line was assessed, and the maximum possible volume for bone regeneration based on (a‐b) and the width of the crest was calculated. At the time of membrane removal (3–8 months later). the same measurements were performed and the percentages of regenerated bone in relation to the possible volume for regeneration determined. In 6 patients in whom the membranes had to be removed early due to an increased risk for infection between 3 and 5 months, bone regeneration varied between 0 and 60%. In 13 patients in whom membranes were left for 6–8 months, regenerated bone filled 90–100% of the possible volume. It was concluded that successful bone regeneration consistently occurred with an undisturbed healing period of at least 6 months.     

Comparative analyses among interfaces of some ceramic materials and bone in sheep

Aim of this work is the evaluation of "in situ" implants in an animal model to study the interfaces that some ceramic materials for dental bone defects develop with bone and to check which material is more osteoconductive. In a sheep's jaw, eight holes were drilled and filled with six ceramic materials in granular shape. Two bilateral holes were left empty as reference. The ceramic materials were: porous tricalcium phosphate (TCP), porous hydroxylapatite (HA) and four bioactive glasses. The glasses differ for doping agents that affect the velocity of biodegradation in the living body. Monthly radiographs were taken and the X-ray pictures analyzed by means of a Video Display Computer in order to quantify the optical density changes occurred in the holes. After 4 months implantation, the segments of the jaw containing the materials were fixed in paraformaldehyde, embedded in methylmethacrylate and sectioned. The results obtained under the microradiograph, the SEM and the X-ray microprobe showed a good bone repair only with TCP granules. A great degradation was seen in HA granules and particularly in glasses. The degradation modified the structure and the composition of the glass granules, but it was not followed by a consequent bone deposition.