Immunohistochemical analysis of soft tissues in implants with healthy and peri-implantitis condition, and aggressive periodontitis

Today, implant-supported prostheses are widely accepted as a reliable treatment modality, but failures in longitudinal studies have been shown. In some cases, peri-implantitis with a progressive periodontal bone loss takes place, and mechanical or load factors and biological or plaque-induced lesions have been claimed as main etiologic factors. We compared five cases of peri-implantitis, with five cases of healthy peri-implant tissues and five cases of aggressive periodontitis in order to give new findings on the osseointegration loss process. Biopsy specimens from the peri-implant tissues including oral (O), sulcular, and junctional epithelium and the underlying and supracrestal connective tissue, were taken in all cases for histological and immunohistochemical analysis. T lymphocytes were the most prominent cell in the peri-implantitis (PG) and aggressive periodontitis (AG) groups, but not in the peri-implant healthy group (HG). CD1a-positive cells (Langerhans and immature dendritic cells) were observed more frequently in the O than in the sulcular-junctional (S-J) epithelium: they were located in the basal and parabasal layers, without any differences between the three groups. Vascular proliferation analysed by immunoreactivity for CD34, Factor VIII, and vascular endothelial growth factor was more prominent in the PG comparing with HG and AG in the S-J area. Apoptosis, analysed by bcl2 and p53 immunoreactivity, was similar in the three groups. In conclusion, we suggest that the osseointegration loss process is due to an inflammatory process similar to that observed in aggressive periodontitis according to the number of T lymphocytes, but not to the vascular proliferation.     

微小RNAs与牙周炎和种植体周围炎相关性的研究进展

牙周炎和种植体周围炎是发生在牙体或种植体周围,以软、硬组织炎症性破坏为特征的一类疾病,两者的发病机制尚不确切,临床上也未找到十分有效的治疗方法。微小RNA(miRNAs)是一类非编码蛋白的小RNA分子,参与调控细胞增殖、分化、凋亡及炎症、肿瘤等多种生理与病理过程。近年来,已有研究证实部分微小RNA在牙周炎发生发展中起重要作用,但对微小RNA在种植体周围炎中的作用机制研究甚少。本文从miRNA与牙周炎、miRNA与种植体周围炎的相关性两方面展开讨论,为治疗牙周炎和种植体周围炎开辟新的思路。     

Clinical and microbiological evaluation of ligature-induced peri-implantitis and periodontitis in dogs

The purpose of this study was to evaluate the attachment loss around teeth and implants by clinical and microbiological analysis. The mandibular premolars were extracted in 5 mongrel dogs and, 3 months later, two titanium implants were installed on each side of the mandible and, after another 3 months, abutment connection was performed. Plaque control in the implants and maxillary premolars was maintained for two weeks prior to the start of the main experiment. On day 0 and 30 days after ligature placement, microbiological samples were obtained and relative attachment level was measured for the teeth and implants. The presence of Porphyromonas gingivalis, Bacteroides forsythus, Actinobacillus actinomycetemcomitans, Prevotella intermedia and Prevotella nigrescens was evaluated by polymerase chain reaction technique on day 0 and 30 days after ligature placement. None of the above bacteria were detected on day 0. Thirty days after ligature placement, P. gingivalis was present in 95% and 85% and B. forsythus was present in 80% and 85% of the implants and teeth sites, respectively. Statistical analysis (one-way RM-ANOVA) showed a significant difference (P<0.01) between pre- and post-induction measurements around teeth and implants. However, there was no significant difference (P=0.41) in the rate of attachment loss, between periodontitis and peri-implantitis. It can be concluded that: (1) P. gingivalis and B. forsythus were strongly associated with induced peri-implantitis and periodontitis, and (2) induced peri-implantitis and periodontitis presented a similar rate of attachment loss.     

白介素-1基因多态性、牙周炎和吸烟因素与种植体周围炎相关性的研究进展

种植体周围炎是指发生在正常行使功能的骨性结合种植体周围组织的炎症,它是引起种植体失败的主要原因。种植体周围炎在临床上表现为种植体周围流脓或者探诊出血、瘘管、牙龈退缩,X线片示种植体周围有骨丧失。引起种植体周围炎的因素很多,包括微生物、生物力学负载过重、患者基因易感性、有牙周炎病史和吸烟史都会增加种植体周围炎的风险。大部分学者认为:吸烟和有牙周炎病史会影响种植体的成功率,但是在患者基因易感性和种植体周围组织炎症之间的关系上未达成统一。本文就白介素-1(IL-1)的基因多态性、牙周炎病史和吸烟因素与种植体周围炎相关性的研究进展作一综述。     

细胞自噬和炎症反应的相互调控与牙周炎

细胞自噬在真核细胞中广泛存在,其通路可将细胞内衰老损伤的蛋白质和细胞器等细胞成分运送至溶酶体进行降解、清除并循环利用降解后的营养物质。炎症反应是机体应答组织损伤和病原微生物感染等有害刺激的一种保护性反应,过度的炎症反应会导致组织损伤和疾病;而自噬可通过降解DNA、活性氧族等内源性刺激来抑制炎性小体聚集,降解白细胞介素（IL）-1β前体来抑制IL-1β等促炎因子的分泌。牙周致病菌的毒力因子参与牙周组织的破坏,通过其自身携带或释放的脂多糖、肽聚糖和细菌DNA等与宿主细胞的Toll样受体（TLR）等相互作用诱发组织局部炎性细胞浸润和释放炎症因子,导致牙周炎。在牙周局部组织中,病原相关分子模式和损伤相关分子模式通过与TRL或核苷酸结合寡聚化结构域蛋白样受体相互作用,在激活先天免疫反应时诱发自噬,而自噬同时可通过负向调控TLR信号来影响炎症反应。本文就自噬与炎症反应的相互调控作用和自噬与牙周炎的相关性等研究进展作一综述,旨在揭示牙周炎等炎症性疾病的发病机制,为其治疗探索新的途径。     

慢性牙周炎与健康牙龈组织中MMP-1的表达和意义

目的:通过检测基质金属蛋白酶-1(MMP-1)在慢性牙周炎牙龈组织中的表达和分布特征,探讨MMP-1在慢性牙周炎发病中的作用和临床意义。方法:收集8例因非牙周疾病而需拔牙患者健康牙龈及24例慢性牙周炎患者牙龈组织,按健康对照、牙周袋深度≤4mm、4~6mm、>6mm分A、B、C、D四组,利用免疫组化方法检测其中MMP-1的表达。结果:正常牙龈组织上皮及固有层MMP-1弱表达,慢性牙周炎患者牙龈组织MMP-1表达明显增高,两者间有显著性差异(P<0.05)。并且MMP-1表达与牙周袋深度间显著正相关(r=0.623,P<0.01)。结论:MMP-1参与慢性牙周炎病变牙周组织的破坏过程,并且其表达随牙周袋深度加深有增加趋势。     

细胞自噬在牙周炎中的作用与机制

牙周炎是由牙菌斑生物膜引起的牙周组织的慢性炎症性疾病。细胞自噬是宿主对抗细菌感染的有效武器。近年来研究发现,细胞自噬不仅可以促进感染细胞对细菌和毒素的清除,而且有助于抑制炎症反应,以维持细胞内环境稳态,与牙周炎的发生发展关系密切。本文从细胞自噬与牙周病原菌感染的相互作用,细胞自噬与免疫炎症反应的相互调控,以及细胞自噬与牙槽骨代谢的关系3个方面,对细胞自噬与牙周炎发生发展的关系进行综述,为深入地研究细胞自噬与牙周炎相关机制提供参考,为牙周炎防治的研究提供新的思路。     

细胞自噬在牙周炎中的作用与机制

牙周炎是由牙菌斑生物膜引起的牙周组织的慢性炎症性疾病。细胞自噬是宿主对抗细菌感染的有效武器。近年来研究发现,细胞自噬不仅可以促进感染细胞对细菌和毒素的清除,而且有助于抑制炎症反应,以维持细胞内环境稳态,与牙周炎的发生发展关系密切。本文从细胞自噬与牙周病原菌感染的相互作用,细胞自噬与免疫炎症反应的相互调控,以及细胞自噬与牙槽骨代谢的关系3个方面,对细胞自噬与牙周炎发生发展的关系进行综述,为深入地研究细胞自噬与牙周炎相关机制提供参考,为牙周炎防治的研究提供新的思路。     

Immunohistochemical study of neutrophil- and fibroblast-type collagenases and stromelysin-1 in adult periodontitis

Eight adult periodontitis (AP) patients were studied immunohistochemically to determine the presence of matrix metalloproteinases (MMPs) MMP-1, MMP-3, and MMP-8 in the marginal gingival and gingival granulation tissue specimens obtained from periodontal flap surgery after scaling and root planing. Clinically healthy gingival tissue specimens obtained from impacted third-molar extraction operations served as controls. MMP-type-specific antisera were applied by the avidin-biotin-peroxidase complex staining method. Moderate immunoreactivity for neutrophil collagenase (MMP-8) was found both in the AP patients' marginal gingival connective tissue and in gingival granulation tissue specimens. Immunoreactivity for fibroblast-type collagenase (MMP-1) and stromelysin-1 (MMP-3) was detected only in the AP patients' gingival granulation tissue specimens. In the control specimens, no immunoreactivity for the MMPs could be detected. For the first time, this finding demonstrates immunohistochemically the presence of MMP-8 in human inflamed gingiva in situ, and further highlights the importance of MMP-8 in periodontal tissue destruction, evidently during the acute phase(s) of the disease. However, our results confirm and extend previous studies indicating that other types of MMPs from resident gingival cell sources also seem to participate in the chronic and destructive course of periodontal inflammation.     

实验性糖尿病牙周炎诱导成骨细胞凋亡的研究

目的观察糖尿病牙周炎条件下成骨细胞的凋亡情况。方法选用SD大鼠62只,随机分为糖尿病牙周炎组（DP）、单纯牙周炎组（P）以及空白对照组（N）。采用一次性腹腔注射链脲佐菌素（STZ）的方法诱导大鼠糖尿病模型,采用丝线结扎联合口内接种细菌的方法建立牙周炎模型。各组动物分别于DP组、P组丝线结扎后第3、6周时分批处死,取标本进行组织学检测,并计算各组成骨细胞凋亡百分率。结果丝线结扎后3、6周时,成骨细胞凋亡百分率由高至低依次为DP组、P组、N组,组间两两比较均有统计学意义（P＜0.05）。在丝线结扎后3周和6周时,DP组成骨细胞凋亡百分率均达到P组的2倍。结论糖尿病可促进牙周炎条件下牙周组织中成骨细胞的凋亡。     

Immunohistochemical expression of RANKL,RANK and OPG in gingival tissue of patients with periodontitis

Abstract

Objectives. To evaluate the expression of the receptor activator of NF-κB (RANK), the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG), in the gingival tissue of patients with periodontitis. Materials and methods. Gingival tissue was obtained from 14 systemically healthy subjects with chronic periodontitis during conventional periodontal surgery. Immunohistochemistry was used to detect the expression of RANK, RANKL and OPG in the oral and periodontal pocket epithelium as well as in the connective tissue cells. Results. RANKL was negatively expressed in both oral and periodontal pocket epithelium. OPG was also negative or weakly positive in the whole epithelium. RANK showed moderate/strong positive staining mainly in the basal and suprabasal layer of oral and periodontal pocket epithelium. In most of the cases, more than 60% of the inflammatory cell infiltrate stained for RANK and RANKL. In these cases the intensity of the stained cells ranged from moderate-to-strong. In less than half of the cases, OPG was positive in more than 60% of the stained cells of the inflammatory cell infiltrate. Conclusion. The RANK, RANKL and OPG proteins are differentially expressed in periodontal tissues and may play a major role in the bone loss occurring in periodontitis.     

Immunohistochemical localization of oncostatin M in epithelialized apical periodontitis lesions

Aim  To investigate the in situ location of oncostatin M (OSM) in epithelialized apical periodontitis lesions.
Methodology  Thirty periapical lesions of pulpal origin were collected with informed consent from patients at the time of apical surgery. Tissue specimens were fixed with 10% buffered formalin overnight, dehydrated in an ascending series of graded alcohol, and embedded in paraffin. Five micron sections from formalin-fixed, paraffin-embedded specimens were examined by immunohistochemistry. In addition, another section from each specimen was stained with haematoxylin and eosin to assess the presence of inflammatory infiltrates. Differences in OSM expression between tissue with low and high levels of inflammation were subsequently analyzed by Fisher's exact test.
Results  Based on histological examination of haematoxylin and eosin stained sections, all specimens revealed the morphology of epithelialized apical periodontitis lesions. The results from immunohistochemistry demonstrated that OSM stain was detected in the inflammatory infiltrates, epithelium, connective tissue, and endothelium. The OSM signal was mainly expressed in endothelial cells (100%) followed by inflammatory cells (93.33%), epithelial cells (53.33%), and fibroblasts (16.67%). In addition, OSM expression was significantly higher in epithelialized apical periodontitis with higher levels of inflammatory infiltrates ( P  < 0.001).
Conclusions  Oncostatin M was found to be expressed in epithelialized apical periodontitis lesions and would form part of the cytokine network involved in the disease process of apical periodontitis.     

老年人牙周炎牙龈组织中凋亡细胞免疫组织化学研究

目的 :观察老年人牙周炎牙龈组织中凋亡细胞分布特点。方法 :采用特异性凋亡细胞免疫组织化学染色法 (TUNEL染色 ) ,对 15例老年人牙周炎患者 ,10例慢性成人牙周炎患者 ,10例青少年牙周炎患者和 11例健康老年人牙龈组织中阳性凋亡细胞的分布及计数进行比较研究。结果 :老年人牙周炎组阳性凋亡细胞总例数明显高于健康老年人组和慢性成人牙周炎组 (P <0 .0 5 ) ;慢性成人牙周炎组和青少年牙周炎组阳性凋亡细胞总例数也明显高于健康老年人组 (P <0 .0 5 ) ;老年人牙周炎组阳性凋亡细胞计数明显高于慢性成人牙周炎组、青少年牙周炎组和健康老年人组 (P <0 .0 5 )。结论 :感染性炎症因素和衰老因素均能促进老年人牙周炎时牙龈组织细胞凋亡 ,这两个因素的双重协同作用造成了老年人牙周炎患者局部牙龈组织对刺激做出过强的细胞凋亡反应。