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.

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.

Histopathological and Immunohistochemical Study of Peri-Implant Epithelium

Background: Human beta-defensins (HBDs), epithelial-derived antimicrobial peptides, contribute to gingival health and periodontal disease. Particularly, the upregulation of HBD-3 expression in periodontal tissues is described to contribute to periodontal tissue regeneration. Specifically, the upregulation of HBD-3 expression in periodontal tissues is described to contribute to periodontal tissue regeneration. But there has been insufficient investigation of the inner epithelium in peri-implantitis, especially the HBD expression patterns as protection against oral infection. Objectives: The purpose of this study was to investigate the histopathological characteristics of the inner implant epithelium in peri-implantitis using histopathological and immunohistochemical methods and to compare it with the inner marginal epithelium in periodontitis. Materials and Methods: The biopsied cases consisted of 10 peri-implantitis, 11 periodontitis, and 10 controls. HE observation, measurement of the thickness of the inner epithelium, and immunohistochemical analysis for Ki-67 and HBD-3 were conducted. Results: Concerning the thickness of the inner epithelium, it was significantly higher in periodontitis (156.2 [138.0, 186.4] μm) than in peri-implantitis and control, 70.7 [67.5, 97.5] μm and 80.7 [76.6, 89.4] μm, respectively (p Conclusion: Decreased production of HBD-3 in keratinocytes composing the inner implant epithelium may be one of the factors affecting tissue repair in peri-implantitis.

In vitro antimicrobial effects of grape seed extract on peri-implantitis microflora in craniofacial implants

Objective:To determine the antimicrobial effects of grape seed on peri-implantitis microflora.Methods:The grape seed extract was tested against peri-implantitis microflora most commonly found in craniofacial implants including reference strains of Staphylococcus aureus(S.aureus),Escherichia coli(E.coli),Candida albicans(C.albicans)and clinical strains of S.aureus,Klebsiella pneumonia(K.pneumonia)and Candida parapsilosis(C.parapsilosis)by disk diffusion test.Minimum inhibitory concentrations(MIC)and minimum cidal concentrations(MCC)were determined using modified agar dilution millpore method.The extract was further combined with polyethylene glycol and propylene glycol,and was tested for antimicrobial effects.Results:Grape seed extract showed positive inhibitory effects with S.aureus at MIC of 0.625 mg/mL and MCC of1.25 mg/mL respectively.However the extracts showed minimal or no reactivity against strains of E.coli,K.pneumonia,C.parapsilosis and C.albicans.The use of grape seed extract in combination with polyethylene glycol and propylene glycol also showed dose dependent inhibitory effect on S.aureus.Conclusions:The results of the study showed that grape seed has potential antimicrobial effects which can be further studied and developed to be used in the treatment of infected skinabutment interface of craniofacial implants.

Peri-implantitis and periodontitis: Use of bacteriological test in dental practice

Peri-implantitis has been defined as an inflamematory condition involving dental implants, surrounding mucosa and bone, which lose supporting bone. Although high success rates for endosseous implants have been reported, failures occur, and some implants are lost or removed. At least 10% of the failures have been suggested to be the result of peri-implantitis. One of the major causes of the peri-implantitis is the bacterial colonization of implant surfaces but additional risk factors such as periodontitis, poor oral hygiene, tobacco consumption, prepost operative therapies and genetic susceptibility should be considered. In the present study a real-time PCR bases assay was designed to detect and quantify red complex species, then used to investigate 307 periodontal pocket samples from 127 periodontitis patients and 180 controls. Results demonstrated a significant higher prevalence of red complex species and increased amount of Porphyromonas gingivalis and Treponema denticolain periodontal pocket of periodontitis. Since a higher risk of peri-implantitis occurs in periodontally affected patients, detection and treatment of bacteria is a fundamental objective to ensure dental implant survival.

Effects of a Single and Low Dose of Mifepristone on Integrin Expression in Human Endometrium During the Peri-implantation Period

Objective In order to gain further information about the mechanism of emergency contraception, during the peri-implantation period the effect of single and low dose of Mifepristone on the expression of integrin level in endometrium of healthy women were observed Materials ＆ Methods Eleven healthy women, proven fertility, were randomly divided into two groups: group LH-2 (n = 5) and LH+ 2 (n = 6). During the control and treatment cycle, placebo or 10 mg Mifepristone were given orally to group LH- 2 on cycle day LH- 2 or to group LH + 2 on cycle day LH - 2, respectively. One endometrial tissue specimen was obtained in both the control and the treatment cycle on cycle day LH+ 7.In this study, the endometrial specimens were assessed by immunohistochemistry analysis to measure the change of integrin α1, α4 and β3 subunits expression on the endometrium after using Mifepristone.Results Mifepristone increased the expression of α1 and α4 subunit in glandular epithelium only in group LH- 2. The expression of β3 integrin subunit remain the same in our experiments.Conclusion Treatment with Mifepristone interferes with integrin distribution during the implantation period, which may imply that the contraceptive effect of Mi fepristone is primarily due to impaired endometrial receptivity.

Health Indicator Bacteria That Is Useful for Risk Assessment of Peri-Implantitis

We established a novel identification method for oral Rothia species using one-step multiplex PCR analysis to investigate whether the monitoring of oral Rothia species levels is useful for peri-implantitis risk assessment, and to examine the oxygen concentration that these organisms need for growth in vitro. The mean number and proportion of Rothia aeria in peri-implant sulcus fluid (PISF) samples was significantly higher in the healthy implant group than in the peri-implantitis group (P < 0.05). Moreover, R. aeria under aerobic conditions vigorously grew compared with those under anaerobic conditions, and this organism grew only at the upper layer where high oxygen concentrations existed in a semi-liquid nutrient medium. Therefore, the monitoring of R. aeria levels may be suitable as an indicator of healthy peri-implant tissue conditions for the prevention of peri-implantitis.

Effect of tea polyphenols combined with photodynamic therapy on the efficacy and RANKL and Shh levels in patients with early peri-implantitis

Objective: To analyze the effect of tea polyphenols combined with photodynamic therapy on the efficacy and RANKL and Shh levels in patients with early peri-implantitis. Methods:Eighty patients with early peri-implantitis admitted to our hospital from January 2017 to December 2018 were randomly divided into the observation group and the control group;the control group was treated with photodynamic therapy, and the observation group was treated with tea polyphenols combined with photodynamic therapy. The levels of mPLI, PPD, mSBI and BOP were measured before treatment and 3 months after the treatment, and the levels of CRP, TNF-α, IL-6, RANKL and Shh in the gingival crevicular fluid were measured. Results:The levels of mPLI, PPD, mSBI and BOP in the observation group were significantly lower than those in the control group, and the difference was statistically significant (P<0.05). The levels of CRP, TNF-α, IL-6, RANKL and Shh in the gingival crevicular fluid were observed in the observation group. The differences were significantly lower than the control group, and the difference was statistically significant (P<0.05). Conclusions: The combination of tea polyphenols and photodynamic therapy for patients with early peri-implantitis can significantly improve clinical efficacy and reduce the inflammatory response, and can effectively improve the levels of RANKL and Shh in gingival crevicular fluid.

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.

Dental Implant Patients Grouped by the Brinkman Index: Their Attitude toward Smoking, Nicotine Dependence, and Knowledge of Peri-Implantitis

Purpose: This study investigated the attitude of patients, grouped by the Brinkman index, towards smoking by using the Kano Test for Social Nicotine Dependence (KTSND) and their knowledge of peri-implantitis. Methods: The participants were 3093 new patients who visited the Tokyo Medical and Dental University Hospital from January 2012 to December 2013 for an oral implant. The methodology included a questionnaire about sex, age, smoking status, daily average number of cigarettes, years of smoking, knowledge of peri-implantitis, and the KTSND. The patients were grouped according to their smoking status by calculating their Brinkman index (over 200 or not): current smokers with the possibility of nicotine dependence (BI(+)CS), current smokers with no possibility of nicotine dependence (BI(-)CS), ex-smokers (ES), and non-smokers (NS). The Brinkman index is obtained by multiplying one’s daily average number of cigarettes by the number of years they have been smoking. Results: Data were collected from 2182 respondents (response rate = 71%). The KTSND scores of BI(+)CS (16.89 ± 4.26) were significantly higher than the scores of ES (11.99 ± 4.52) and NS (11.53 ± 5.01). In current smokers, there were no significant differences between BI(+)CS and BI(-)CS. The patients replied “I don’t know” about peri-implantitis most often in all groups;however, there were no significant differences between the groups. Discussion: BI(+)CS were more dependent on nicotine in social situations than the other groups were. In Japan, a Brinkman index over 200 is required for a nicotine-dependence management fee to be instituted for health insurance treatment. This is a major concern for young smokers, who may be excluded from treatment because their years of smoking are substantially less. Results revealed that there were no significant differences between BI(+)CS and BI(-)CS. Therefore, it was suggested that the Brinkman index did not sufficiently group the participants.

Expression of cellular fibronectin mRNA in adult periodontitis and peri-implantitis: a real-time polymerase chain reaction study

Cellular fibronectin(cFn) is a type of bioactive non-collagen glycoprotein regarded as the main substance used to maintain periodontal attachment. The content of cFn in some specific sites can reflect the progress of periodontitis or peri-implantitis. This study aims to evaluate the expression of cFn messenger RNA(mRNA) in tissues of adult periodontitis and peri-implantitis by real-time fluorescent quantitative polymerase chain reaction(PCR) and to determine its clinical significance. A total of 30 patients were divided into three groups of 10: healthy, adult periodontitis and peri-implantitis. Periodontal tissue biopsies(1 mm31 mm31 mm) from each patient were frozen in liquid nitrogen. Total RNA was extracted from these tissues, and the content, purity and integrity were detected. Specific primers were designed according to the sequence, and the mRNA expression levels of cellular fibronectin were detected by real-time PCR. The purity and integrity of the extracted total RNA were both high, and the specificity of amplified genes was very high with no other pollution. The mRNA expression of cFn in the adult periodontitis group(1.52660.441) was lower than that in the healthy group(3.25360.736). However, the mRNA expression of cFn in the peri-implantitis group(3.96560.537) was significantly higher than that in the healthy group. The difference revealed that although both processes were destructive inflammatory reactions in the periodontium, the pathomechanisms were different and the variation started from the transcription level of the cFn gene.

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 fol-low-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 ob-served after implant loading, 29 have failed with the failure rate being 22.14 %. There was no sig-nificant 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 sta-tistically tested, however smoking was still a mainly significant factor.

Peri-implant femoral fractures:Challenges,outcomes,and proposal of a treatment algorithm

Purpose:Non-prosthetic peri-implant fractures are challenging injuries.Multiple factors must be care-fully evaluated for an adequate therapeutic strategy,such as the state of bone healing,the type of implant,the time and performed personnel of previous surgery,and the stability of fixation.The aim of this study is to propose a rationale for the treatment.Methods:The peri-implant femoral fractures(PIFFs)system,a therapeutic algorithm was developed for the management of all patients presenting a subtype A PIFF,based on the type of the original implant(extra-vs.intra-medulllary),implant length and fracture location.The adequacy and reliability of the proposed algorithm and the fracture healing process were assessed at the last clinical follow-up using the Parker mobility score and radiological assessment,respectively.In addition,all complications were noticed.Continuous variables were expressed as mean and standard deviation,or median and range according to their distribution.Categorical variables were expressed as frequency and percentages.Results:This is a retrospective case series of 33 PIFFs,and the mean post-operative Parker mobility score was(5.60±2.54)points.Five patients(15.1%)achieved complete mobility without aids(9 points)and 1(3.0%)patient was not able to walk.Two other patients(6.1%)were non-ambulatory prior to PPIF.The mean follow-up was(21.51±9.12)months(range 6-48 months).There were 7(21.2%)complications equally distributed between patients managed either with nailing or plating.There were no cases of nonunion or mechanical failure of the original implant.Conclusion:The proposed treatment algorithm shows adequate,reliable and straightforward to assist the orthopaedic trauma surgeon on the difficult decision-making process regarding the management of PIFF occurring in previously healed fractures.In addition,it may become a useful tool to optimize the use of the classification,thus potentially improving the outcomes and minimizing complications.

Sustained local delivery of insulin for potential improvement of peri-implant bone formation in diabetes

Dental implantation is an effective standard treatment modality to restore missing teeth and maxillofacial defects. However, in diabetics there is an increased risk for implant failure due to impaired peri-implant osseous healing. Early topical insulin treat- ment was recently shown to normalize diabetic bone healing by rectifying impairments in osteoblastic activities. In this study, insulin/poly(lactic-co-glycolic acid) (PLGA) microspheres were prepared by a double-emulsion solvent evaporation method. Microspheres were then incorporated in fibrin gel to develop a local drug delivery system for diabetic patients requiring im- plant treatment. In vitro release of insulin from fibrin gel loaded with these microspheres was assessed, and sustained prolonged insulin release over 21 days ascertained. To assess the bioactivity of released insulin and determine whether slow release might improve impaired diabetic bone formation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), alkaline phosphatase (ALP) activity, mineralized nodule formation, and ELISA (enzyme-linked immunosorbent assay) assays were performed. The insulin released from the drug delivery system stimulated cell growth in previously inhibited cells, and ameliorated the impaired bone-forming ability of human MG-63 cells under high glucose conditions. Fibrin gel loaded with insulin/PLGA microspheres shows potential for improving peri-implant bone formation in diabetic patients.

内窥镜辅助龈下刮治联合赤藓糖醇龈下喷砂治疗种植体周围炎的疗效评价

目的:研究内窥镜辅助龈下刮治联合赤藓糖醇龈下喷砂技术治疗种植体周围炎的临床疗效,为种植体周围炎的有效治疗提供理论依据。方法:选择本院牙周科就诊并接受治疗的种植体周围炎患者,按就诊时间共有58例种植体周围炎患者陆续进入观察,按随机数字表法分为对照组(28例)和微创组(30例);对照组患者采用传统盲视龈下刮治治疗,微创组患者采取内窥镜辅助龈下刮治联合赤藓糖醇龈下喷砂治疗。分析2组患者治疗前后探诊深度(PD)、改良菌斑指数(mPLI)和改良龈沟出血指数(mSBI)以及龈沟液中白细胞介素1β(IL-1β)、白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α)水平。结果:治疗前2组患者PD、mPLI和mSBI及龈沟液中IL-1β、IL-6和TNF-α水平比较差异无统计学意义(P>0.05),具有可比性。治疗后2组患者PD、mPLI和mSBI,龈沟液中IL-1β、IL-6和TNF-α水平均较治疗前明显下降(P<0.05)。与对照组比较,微创组患者治疗后PD、mPLI和mSBI明显降低(P<0.05);龈沟液中IL-1β、IL-6和TNF-α水平也明显降低(P<0.05)。结论:在短期内采用内窥镜辅助龈下刮治联合赤藓糖醇龈下喷砂技术治疗种植体周围炎更有助于控制种植体周围组织的炎症,改善临床症状。

单轴及同轴载盐酸米诺环素骨支架抑菌性能的评价

背景:由于单轴骨支架的药物缓释速率不稳定,近年来国内外开始寻求多结构复合型打印方式,目前有将载药缓释系统与骨移植修复技术相结合的同轴载药骨支架,其在植入体内后不仅替代了缺损骨,还可缓慢释放药物,为植入部位提供一个利于成骨的微环境。目的:探讨并评价单轴及同轴载盐酸米诺环素骨支架的体外抑菌性能。方法:采用快速成型技术分别制备单轴羟基磷灰石/丝素蛋白-聚乙烯醇支架、单轴载米诺环素的羟基磷灰石/丝素蛋白-聚乙烯醇支架、同轴羟基磷灰石/丝素蛋白-聚乙烯醇支架、同轴载米诺环素的羟基磷灰石/丝素蛋白-聚乙烯醇支架,分别命名为S1、S2、T1、T2,表征支架的形态、孔隙率、降解性能、体外缓释性能及细胞毒性。将4种骨支架浸泡于PBS中制备不同时间点(1,3,5,7,14,21,28 d)的浸提液,再将定性滤纸片置入浸提液中浸提24 h,将滤纸片分别与牙龈卟啉单胞菌、具核梭酸杆菌共培养72 h,采用琼脂扩散法检测4组支架的抑菌作用。结果与结论:①支架表征:4组支架均成型良好,扫描电镜下可见,S1、S2组微观丝材表面致密且光滑,T1、T2组微观丝材表面呈现粗糙状,孔隙率大小在40%-47%之间,均满足骨支架的要求;与S2比较,T2的缓释时间更长,且药物缓释浓度长期处于1-10μg/mL之间,更有利于抑菌及成骨;体外浸泡于PBS中10周,同轴打印骨支架的降解速率快于对应的单轴打印骨支架,并且同轴载药支架的降解率低于同轴不载药组;将4组支架浸提液分别与成骨细胞共培养,CCK-8检测显示细胞增殖率均大于75%,均满足生物相容性要求;②支架抑菌作用:S1、T1不具有抑菌性能,S2、T2具有抑菌性能,在第28天的浸提液下,S2组对牙龈卟啉单胞菌、具核梭酸杆菌的抑菌圈直径均小于T2组(P<0.05);③结果表明:同轴载米诺环素的羟基磷灰石/丝素蛋白-聚乙烯醇支架具有良好的物理性能及抑菌性能。

种植体周病风险评估的研究进展

种植体周病是最常见的种植修复生物学并发症。对种植体周病进行风险评估,能够有效协助临床医师发现并干预可能存在的危险因素,并制定合理的种植体周支持治疗计划。本文通过回顾有关种植体周病风险评估的相关文献,总结归纳种植体周病的危险因素,并对3种种植体周病风险评估模型进行简要介绍,为种植体周病风险评估在临床诊疗中的应用提供依据。

基于随机森林和人工神经网络构建种植体周炎的诊断模型

目的 本研究旨在揭示种植体周炎发生发展过程中参与调控的关键基因,并通过随机森林(RF)和人工神经网络(ANN)构建种植体周炎的诊断模型。方法本研究从GEO数据库中获取GSE33774、GSE106090和GSE57631数据集。对GSE33774和GSE106090数据集进行差异表达和功能富集分析,通过蛋白质互作网络(PPI)和RF筛选出关键基因,利用ANN建立种植体周炎的诊断模型,并在GSE33774和GSE57631数据集中进行验证。同时,构建转录因子-基因相互作用网络和转录因子-微小RNA (miRNA)调控网络。结果 本研究共筛选出124个参与调控种植体周炎的差异表达基因(DEGs)。富集分析结果表明,DEGs主要和免疫受体活性蛋白及细胞因子受体活性相关,主要参与白细胞和中性粒细胞迁移的过程。PPI和RF筛选出6个关键基因,分别为CD38、CYBB、FCGR2A、SELL、TLR4和CXCL8。受试者操作特征曲线(ROC)表明ANN模型具有较好的诊断性。本研究还发现FOXC1、GATA2和NF-κB1可能是种植体周炎中重要的转录因子,hsa-miR-204可能是关键的miRNA。结论 RF和ANN构建的种植体周炎的诊断模型可信度高,CD38、CYBB、FCGR2A、SELL、TLR4和CXCL8是潜在的诊断标志物。FOXC1、GATA2和NF-κB1可能是种植体周炎中重要的转录因子,hsa-miR-204作为关键的miRNA在其中扮演着重要角色。

基于生物信息学分析探索种植体周围炎的免疫特征基因及其对免疫细胞的调控机制

目的:基于生物信息学分析探究种植体周围炎(peri-implantitis)疾病发展中明显浸润的免疫细胞及关键的免疫相关基因。方法:整合美国国家生物技术信息中心基因表达数据库(gene expression omnibus,GEO)中的GSE106090、GSE33774及GSE57631数据集,通过单样本基因集富集分析(single-sample gene set enrichment analysis,ssGSEA)评估种植体周围炎及健康牙龈组织中的免疫细胞浸润分数,并利用套索算法(least absolute shrinkage and selection operator,LASSO)筛选关键的免疫基因。结果:整合3个数据集并去批次效应后,使用“ClusterProfiler”包实现种植体周围炎的基因本体论(gene ontology,GO)及京都基因与基因组百科全书(kyoto encyclopedia of genes and genomes,KEGG)数据库的富集分析,以识别在种植体周围炎中主要上调和下调的信号通路及生物学过程。本研究进一步将差异基因与ImmPort数据库中获得的免疫相关基因取交集,通过LASSO回归筛选变量后,成功鉴定关键的疾病免疫特征性基因,包括趋化因子CC配体18(C-C motif chemokine ligand 18,CCL18)、白细胞介素-1β(interleukin 1 beta,IL-1β)、补体C3(complement C3,C3)、白细胞介素-6(interleukin 6,IL6)、利钠肽受体-3(natriuretic peptide receptor 3,NPR3)、肽酶抑制因子-3(peptidase inhibitor 3,PI3)、白细胞免疫球蛋白样受体-B3(leukocyte immunoglobulin like receptor B3,LILRB3)、富亮氨酸重复序列G蛋白偶联受体-4(leucine rich repeat containing G proteincoupled receptor 4,LGR4)。随后,本研究进行与ssGSEA免疫浸润分数的相关性分析,这些基因与种植体周围软组织内明显增加的23种免疫细胞呈现出不同程度的相关性。通过GO和KEGG数据库的富集分析,发现IL1B、IL6、CCL18、C3、LGR4、PI3、LILRB3等基因主要参与体液免疫、适应性免疫、白细胞迁移以及皮肤表皮发育等生物过程,而NPR3主要与白细胞增殖和体液水平调节等生物过程相关。结论:通过运用生物信息学的方法对免疫相关差异基因进行筛选,本研究成功识别出8个关键的免疫特征性基因,参与了种植体周围炎免疫应答及炎症响应的多个环节,并对种植体周围炎疾病背景具有较高敏感性。这些免疫特征性基因的识别为深入理解种植体周围炎的发病机制以及开发新的治疗策略提供重要的分子靶标。

负载外泌体的可注射水凝胶修复种植体周围骨缺损

背景:大量的研究已证实,外泌体具有促进成骨与血管化的作用,但是单纯的外泌体治疗存在靶向性差、负载分子含量无法达到治疗浓度等问题。目的:将外泌体负载于可注射葡萄糖酸内酯-海藻酸钠/β-磷酸三钙-聚乙二醇水凝胶中,通过体内与体外实验观察该水凝胶在种植体周围骨缺损中的作用。方法:从骨髓间充质干细胞中提取外泌体,并将其包裹于可注射葡萄糖酸内酯-海藻酸钠/β-磷酸三钙-聚乙二醇水凝胶中。①体外实验:将负载与未负载外泌体的水凝胶分别与内皮祖细胞共培养,进行外泌体摄取实验、小管形成实验以及细胞增殖、迁移能力、成血管基因检测。②体内实验:选取雄性新西兰大白兔12只,在一侧股骨长轴制备2个标准种植体窝洞及对应的骨缺损,在近心端的窝洞内植入种植体后,在骨缺损部位植入负载外泌体的水凝胶(实验组);在远心端的种植窝洞内植入种植体后,在骨缺损部位植入未负载外泌体的水凝胶(对照组),术后3,6,9周取带种植体的骨缺损部位,进行苏木精-伊红、Masson染色,同时,术后9周时进行成骨基因与成血管基因检测。结果与结论:①体外实验:外泌体可进入内皮祖细胞中,负载外泌体水凝胶组内皮祖细胞的增殖能力、迁移能力、成血管能力及成血管基因(CD31、血管内皮生长因子及碱性成纤维细胞生长因子)表达均高于未未负载外泌体水凝胶组(P<0.05)。②体内实验:苏木精-伊红、Masson染色显示,术后3周时,两组仅见少量新生骨,材料部分降解;术后6周时,两组新生骨量增加,其中实验组可见大量的新生骨,钙盐沉积明显;术后9周时,相较于对照组,实验组可见大量粗大于成熟的骨小梁,钙盐沉积更加明显,骨小梁周围可见大量排列的成骨细胞。实验组术后9周骨缺损部位的CD31、血管内生长因子、碱性成纤维细胞生长因子、骨形态发生蛋白2、Ⅰ型胶原及骨钙素的蛋白表达均高于对照组(P<0.05)。③负载外泌体的萄糖酸内酯-海藻酸钠/β-磷酸三钙-聚乙二醇水凝胶可促进内皮祖细胞的增殖、迁移与成血管分化,促进种植体周围骨缺损的修复再生。