Ultrastructural and immunohistochemical evaluation of hyperplastic soft tissues surrounding dental implants in fibular jaws.

In reconstructive surgery, complications post-fibula free flap (FFF) reconstruction, notably peri-implant hyperplasia, are significant yet understudied. This study analyzed peri-implant hyperplastic tissue surrounding FFF, alongside peri-implantitis and foreign body granulation (FBG) tissues from patients treated at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Using light microscopy, pseudoepitheliomatous hyperplasia, anucleate and pyknotic prickle cells, and excessive collagen deposition were observed in FFF hyperplastic tissue. Ultrastructural analyses revealed abnormal structures, including hemidesmosome dilation, bacterial invasion, and endoplasmic reticulum (ER) swelling. In immunohistochemical analysis, unfolded protein-response markers ATF6, PERK, XBP1, inflammatory marker NFκB, necroptosis marker MLKL, apoptosis marker GADD153, autophagy marker LC3, epithelial-mesenchymal transition, and angiogenesis markers were expressed variably in hyperplastic tissue surrounding FFF implants, peri-implantitis, and FBG tissues. NFκB expression was higher in peri-implantitis and FBG tissues compared to hyperplastic tissue surrounding FFF implants. PERK expression exceeded XBP1 significantly in FFF hyperplastic tissue, while expression levels of PERK, XBP1, and ATF6 were not significantly different in peri-implantitis and FBG tissues. These findings provide valuable insights into the interconnected roles of ER stress, necroptosis, apoptosis, and angiogenesis in the pathogenesis of oral pathologies, offering a foundation for innovative strategies in dental implant rehabilitation management and prevention.

Comparative Assessment of Catalase Levels in Peri-Implant Health and Disease.

Peri-implant disease pathogenesis is similar to periodontal disease pathogenesis resulting in production of pro-inflammatory mediators. These mediators alter the redox balance leading to decrease in antioxidants, among which catalase is one of the enzymatic antioxidants. The aim of the study was to compare the levels of catalase in peri-implant health and disease. The present observational study was carried out from June 2022 to December 2022 in the Department of Implantology, Saveetha Dental College and Hospitals, Chennai, India. A total of 60 patients with peri-implant health (Group 1; n = 20), peri-implant mucositis (Group 2; n = 20) and peri-implantitis (Group 3; n = 20) were enrolled. Unstimulated salivary samples were collected and subjected to ELISA for catalase analysis. Catalase levels were then compared between the groups using ANOVA. The mean catalase level in peri-implant health, peri-implant mucositis, peri-implanti-tis were 25.07 ± 0.44 U/mL, 18.5 6 ± 0.65 U/mL, and 11.25 ± 0.76 U/mL respectively. The difference between the three groups were statistically significant (P < 0.05). Catalase level decreases with severity of peri-implant diseases. Therefore, catalase can be used as a diagnostic marker for peri-implant diseases.

Correlation of C-Reactive Protein and Severity of Peri-Implant Diseases.

Peri-implant disease pathogenesis is similar to periodontal disease pathogenesis resulting in production of pro-inflammatory mediators. These mediators are released during the inflammation phase, among which C-reactive protein (CRP) is one of the acute phase reactants. The aim of the study was to correlate the levels of CRP with the severity of peri-implant diseases. The present observational study was carried out from June 2022 to December 2022 in the Department of Implantology, Saveetha Dental College and Hospitals, Chennai, India. A total of 60 patients with peri-implant health (n = 20), peri-mucositis (n = 20) and peri-implantitis (n = 20) were enrolled. Unstimulated salivary samples were collected and subjected to latex agglutination assay for CRP analysis. CRP levels were then correlated with severity of peri-implant diseases. The mean CRP level in peri-implant health, peri-implant mucositis, peri-implantitis were 0.25 ± 0.36 mg/dl, 3.56 ± 0.85 mg/dl and 5.07 ± 0.74 mg/dl, respectively. Pearson correlation coefficient analysis revealed a strong positive correlation between CRP and peri-implant parameters suggesting that the CRP level increased as the severity of peri-implant disease increased. CRP level increases with severity of peri-implant diseases and there exists a positive correlation between CRP level and peri-implant parameters. Therefore, CRP can be used as a diagnostic marker for peri-implant diseases.

Application of Immediate Implant Placement Techniques in Peri-implantitis Modeling.

OBJECTIVES: To explore the use of immediate implant placement technique in peri-implantitis modeling, shorten the modeling period, and obtain similar effects. MATERIALS AND METHODS: Eighty rats were divided into 4 groups: immediate placement (IP), delayed placement (DP), IP-ligation (IP-L) and DP-ligation (DP-L). In the DP and DP-L groups, implants were placed 4 weeks after tooth extraction. In the IP and IP-L groups, implants were placed immediately. Four weeks later, the implants were ligated to induce peri-implantitis in the DP-L and IP-L groups. RESULTS: Nine implants were lost (3 in the IP-L and 2 each in the IP, DP, and DP-L group). The bone level decreased after ligation, and the buccal and lingual bone levels were lower in IP-L versus DP-L. The implant pullout strength was decreased after ligation. Micro-CT showed bone parameters were decreased after ligation, and the percent bone volume was higher in IP versus DP. Histology showed that the percent of CD4 + cells and IL-17 + cells was increased after ligation and higher in IP-L versus DP-L. CONCLUSIONS: We successfully introduced immediate implant placement into the modeling of peri-implantitis and observed similar bone resorption and more soft tissue inflammation in a shorter time.

AdipoAI suppresses osteoclastogenesis by activating AdipoR1/APPL1: An in vivo experimental study in diabetes-associated peri-implantitis.

AIM: Diabetics experience severe peri-implant inflammatory bone damage. We aimed to provide powerful evidence supporting the novel adiponectin receptor agonist AdipoAI in treating diabetes-associated peri-implantitis. MATERIALS AND METHODS: Twenty-four ZDF-Leprfa/Crl rats were randomly allocated to three groups (N = 8). After feeding with a high-fat diet to establish diabetic rats, experimental peri-implantitis was induced by implanting titanium rods (1.5 mm diameter and 20 mm length) contaminated with Staphylococcus aureus into the femurs. Radiographic evaluation, microCT, histological analyses and qRT-PCR were used to detect inflammatory infiltration and bone destruction. In vitro, the inhibition by AdipoAI of osteoclastogenesis, including the number and function of osteoclasts, was investigated by TRAP staining, immunofluorescence, qRT-PCR and Western blotting. Immunofluorescence, qRT-PCR and Western blotting were also utilized to explore AdipoR1, APPL1, NF-κB and Wnt5a-Ror2 signalling molecules in this process. One-way ANOVA with Tukey's post hoc test was used to compare the data. RESULTS: AdipoAI reduced inflammation and bone destruction caused by peri-implantitis in diabetic rats, which were manifested by a reduction in F4/80-positive macrophage infiltration by 72%, the number of osteoclasts by 58% and the levels of cytokines (p < .05) in disease group. In vitro, 1 µM AdipoAI decreased the number of osteoclasts to 51%, inhibited F-actin ring formation and reduced the levels of related markers (p < .05). Mechanistically, AdipoAI activated AdipoR1/APPL1 and conversely suppressed the phosphorylation of IκB-α, nuclear translocation of P65 and the Wnt5a-Ror2 signalling pathway (p < .05). CONCLUSIONS: AdipoAI suppressed osteoclastogenesis in diabetes-associated peri-implantitis by inhibiting the NF-κB and Wnt5a-Ror2 pathways via the AdipoR1/APPL1 axis.

[Comparison of three methods for establishing rat peri-implantitis model].

OBJECTIVE: To compare the efficiency and effect of establishing rat peri-implantitis model by traditional cotton thread ligation and local injection of Porphyromonas gingivalis lipopolysaccharide (LPS) around the implant, as well as the combination of the two methods. METHODS: Left side maxillary first molars of 39 male SD rats were extracted, and titanium implants were implanted after four weeks of healing. After 4 weeks of implant osseointegration, 39 rats were randomly divided into 4 groups. Cotton thread ligation (n=12), local injection of LPS around the implant (n=12), and the two methods combined (n=12) were used to induce peri-implantitis, the rest 3 rats were untreated as control group. All procedures were conducted under 5% isoflurane inhalation anesthesia. The rats were sacrificed 2 weeks and 4 weeks after induction through carbon dioxide asphyxiation method. The maxilla of the rats in the test groups were collected and marginal bone loss was observed by micro-CT. The gingival tissues around the implants were collected for further real time quantitative PCR (RT-qPCR) analysis, specifically the expression of tumor necrosis factor-alpha (TNF-α) as well as interleukin-1ß (IL-1ß). The probing depth (PD), bleeding on probing (BOP) and gingival index (GI) of each rat in the experimental group were recorded before induction of inflammation and before death. RESULTS: After 4 weeks of implantation, the osseointegration of implants were confirmed. All the three test groups showed red and swollen gums, obvious marginal bone loss around implants. After 2 weeks and 4 weeks of inflammation induction, PD, GI and BOP of the three test groups increased compared with those before induction, but only BOP was statistically significant among the three test groups (P < 0.05). At the end of 2 weeks of inflammation induction, marginal bone loss was observed at each site in the cotton thread ligation group and the combined group. At each site, the bone resorption in the combined group was greater than that in the cotton thread ligation group, but the difference was not statistically significant (P > 0.05), bone resorption was observed at some sites of some implants in LPS local injection group. At the end of 4 weeks of inflammation induction, marginal bone loss was observed at all sites in each group. The marginal bone loss in the cotton thread ligation group and the combined group was greater than that in the LPS local injection group, and the difference was statistically significant (P < 0.05). At the end of 2 weeks and 4 weeks of induction, the expression of TNF-α and IL-1ß in the test groups were higher than those in the control group (P < 0.05). CONCLUSION: Compared with local injection of LPS around the implant, cotton thread ligature and the two methods combined can induce peri-implantitis in rats better and faster.

Detecting lymphadenopathy affected by peri-implantitis using diffusion-weighted magnetic resonance imaging.

PURPOSE: This study aimed to assess peri-implantitis-induced lymphadenopathy on diffusion-weighted imaging (DWI). METHODS: This retrospective study was conducted from October 2017 to March 2020 in patients with and without peri-implantitis who underwent magnetic resonance imaging (MRI). Patients in the peri-implantitis group had radiographically confirmed loss of alveolar bone > 2.0 mm and clinical findings such as bleeding on probing, suppuration of tissues surrounding the teeth, probing-pocket depth of > 4 mm, pain on implant function, and clinical implant mobility, whereas those without peri-implantitis had none of the abovementioned clinical findings. The Mann-Whitney U test was used to compare groups, using lymph node (LN) short-axis diameters and apparent diffusion coefficients (ADCs) as the criterion variables and presence or absence of peri-implantitis as the explanatory variable. Receiver operating characteristic (ROC) analysis was done to investigate the effectiveness of LN size and ADC use in detecting peri-implantitis-induced lymphadenopathy. Statistical significance was established at P < 0.05. RESULTS: There were 66 lymph nodes from 12 patients analyzed. The mean LN size and ADC were significantly higher in patients with peri-implantitis than in those without (P < 0.01). ROC curve analysis showed cut-off LN sizes of 4.78 and 4.84 mm and cut-off ADCs of 1.12 and 1.09 for lymphadenopathy affected by peri-implantitis corresponding to levels IB and II, respectively. CONCLUSIONS: Cervical lymphadenopathy may be an inflammatory finding associated with peri-implantitis.

Hybrid system with stable structure of hard/soft tissue substitutes induces re-osseointegration in a rat model of biofilm-mediated peri-implantitis.

Re-osseointegration of an infected/contaminated dental implant poses major clinical challenges. We tested the hypothesis that the application of an antibiotic-releasing construct, combined with hard/soft tissue replacement, increases the efficacy of reconstructive therapy. We initially fabricated semi-flexible hybrid constructs of ß-TCP/PHBHHx, with tetracycline (TC) (TC amounts: 5%, 10%, and 15%). Thereafter, using in vitro assays, TC release profile, attachment to rat bone marrow-derived stem cells (rBMSCs) and their viability as well as anti-bacterial activity were determined. Thereafter, regenerative efficacies of the three hybrid constructs were assessed in a rat model of peri-implantitis induced by Aggregatibacter actinomycetemcomitans biofilm; control animals received ß-TCP/Bio-Gide and TC injection. Eight weeks later, maxillae were obtained for radiological, histological, and histomorphometric analyses of peri-implant tissues. Sulcus bleeding index was chronologically recorded. Serum cytokines levels of IL-6 and IL-1ß were also evaluated by enzyme-linked immunosorbent assay. Substantial amounts of tetracycline, from hybrid constructs, were released for 2 weeks. The medium containing the released tetracycline did not affect the adhesion or viability of rBMSCs; however, it inhibited the proliferation of A. actinomycetemcomitans. Osteogenesis and osseointegration were more marked for the 15% hybrid construct group than the other two groups. The height of attachment and infiltration of inflammatory cells within fibrous tissue was significantly reduced in the experimental groups than the control group. Our protocol resulted in re-osseointegration on a biofilm-contaminated implant. Thus, an antibiotic releasing inorganic/organic construct may offer a therapeutic option to suppress infection and promote guided tissue regeneration thereby serving as an integrated multi-layer substitute for both hard/soft tissues.

Study on the immunopathological effect of titanium particles in peri-implantitis granulation tissue: A case-control study.

OBJECTIVES: To identify titanium particles (TPs) in biopsy specimens harvested from peri-implantitis lesions and secondarily to study the histopathological characteristics in peri-implantitis compared to periodontitis, in order to evaluate whether the presence of TPs could alter respective inflammatory patterns. MATERIAL AND METHODS: Biopsies containing granulation tissue were harvested during routine surgical treatment in 39 peri-implantitis cases and 35 periodontitis controls. Serial sections were obtained using titanium-free microtome blades. The first and last sections of the peri-implantitis specimens were used for identification of TPs by scanning electron microscopy coupled with dispersive X-ray spectrometry. Intermediate sections and periodontitis specimens were processed for descriptive histological study using haematoxylin-eosin staining and for immunohistochemical analysis using CD68, IL-6, Nf-kB and VEGF markers. RESULTS: TPs were identified in all peri-implantitis specimens as free metal bodies interspersed within granulation tissue. However, presence of macrophages or multinucleated giant cells engulfing the TPs were not identified in any specimen. Peri-implantitis granulations were characterized by a chronic inflammatory infiltrate rich in neutrophils. About half of peri-implantitis patients exhibited a subacute infiltrate characterized with lymphocytes interweaved with neutrophils and eosinophils. When compared to periodontitis, peri-implantitis tissues showed higher proportions of macrophages and a more intense neovascularization, based on significantly higher expression of CD68 and VEGF respectively. CONCLUSION: TPs were identified in all peri-implantitis specimens, but without evidencing any foreign body reaction suggestive for direct pathological effects of TPs. The peri-implantitis granulation tissue was characterized by intense neovascularization and presence of a chronic inflammatory infiltrate dominated by plasma cells, neutrophils and macrophages.

Accuracy of bone-level assessments following reconstructive surgical treatment of experimental peri-implantitis.

AIMS: The purpose of this study was to evaluate the accuracy of bone-level assessments using either cone-beam computed tomography (CBCT), intra-oral peri-apical (PA) radiographs or histology following reconstructive treatment of experimental peri-implantitis. MATERIALS AND METHODS: Six Labrador dogs were used. Experimental peri-implantitis was induced 3 months after implant placement. Surgical treatment of peri-implantitis was performed and peri-implant defects were allocated to one of four treatment categories; no augmentation, bone graft materials with or without a barrier membrane. Six months later, intra-oral PA radiographs and block biopsies from all implants sites were obtained. Marginal bone levels (MBLs) were measured using PA radiographs, CBCT and histology. RESULTS: Significant correlations of MBL assessments were observed between the three methods. The measurements in PA radiographs consistently resulted in an overestimation of the bone level of about 0.3-0.4 mm. The agreement between the methods was not influenced by the use of bone substitute materials in the management of the osseous defects. CONCLUSIONS: Although MBL assessments obtained from PA radiographs showed an overestimation compared to MBL assessments on corresponding CBCT images and histological sections, PA radiographs can be considered a reliable technique for peri-implant bone-level evaluations following reconstructive surgical therapy of experimental peri-implantitis.

Uptake of Nanotitania by Gingival Epithelial Cells Promotes Inflammatory Response and Is Accelerated by Porphyromonas gingivalis Lipopolysaccharide: An In Vitro Study.

Titanium is often used in the medical field and in dental implants due to its biocompatibility, but it has a high rate of leading to peri-implantitis, which progresses faster than periodontitis. Therefore, in the present study, the expression of cytokines from gingival epithelial cells by nanotitania was investigated, which is derived from titanium in the oral cavity, and the additional effect of Porphyromonasgingivalis (periodontopathic bacteria) lipopolysaccharide (PgLPS) was investigated. Ca9-22 cells were used as a gingival epithelial cell model and were cultured with nanotitania alone or with PgLPS. Cytokine expression was examined by reverse transcription-quantitative polymerase chain reaction and enzyme-linked immunosorbent assay. In addition, cellular uptake of nanotitania was observed in scanning electron microscopy images. The expression of interleukin (IL)-6 and IL-8 significantly increased in Ca9-22 cells by nanotitania treatment alone, and the expression was further increased by the presence of PgLPS. Nanotitania was observed to phagocytose Ca9-22 cells in a dose- and time-dependent manner. Furthermore, when the expression of IL-11, related to bone resorption, was investigated, a significant increase was confirmed by stimulation with nanotitania alone. Therefore, nanotitania could be associated with the onset and exacerbation of peri-implantitis, and the presence of periodontal pathogens may worsen the condition. Further clinical reports are needed to confirm these preliminary results.

Caspase-3 and gasdermin E detection in peri-implantitis.

Peri-implantitis could lead to progressive bone loss and implant failure; however, the mechanism of peri-implantitis remains unclear. Based on emerging evidence, pyroptosis, a novel proinflammatory programmed death, contributes to different oral infectious diseases. In the present study, we investigated the involvement of cleaved caspase-3 and gasdermin E (GSDME) in peri-implantitis and established a pyroptosis model in vitro. By collecting and examining the inflamed biopsies around peri-implantitis, we found that the pyroptosis-related markers (caspase-3, GSDME, and IL-1ß) were enhanced relative to levels in control individuals. Furthermore, human gingival epithelium cells (HGECs) induced by tumor necrosis factor-α (TNF-α) exhibited pyroptosis morphological changes (cell swelling and balloon-shaped bubbles) and upregulated expression of pyroptosis-related markers. Pretreated with Ac-DEVD-CHO (a caspase-3 inhibitor) or GSDME small interference RNA (siRNA) were found to attenuate pyroptosis in HGECs. In conclusion, our findings revealed a high expression of caspase-3 and GSDME in the inflamed biopsies of peri-implantitis and confirmed that the caspase-3/GSDME pathway mediates TNF-α-triggered pyroptosis in human gingival epithelium cells, which provides a new target for peri-implantitis treatment.

The Effects of NF-kB Inhibition with p65-TMD-Linked PTD on Inflammatory Responses at Peri-implantitis Sites.

The objective of this study was to find out if suppression of NF-kB complex function by p65-TMD-linked PTD could reduce host inflammation and bone resorption at peri-implantitis sites in rats. Twenty-one male 5-week-old SD rats were divided into three groups: untreated control group (A), silk-induced peri-implantitis group (B), and nt (nucleus transducible)-p65-TMD-treated, silk-induced peri-implantitis group (C). Implant sulcus of a rat in group C were divided into two groups, namely group Cp and Cb. Palatal implant sulcus where nt-p65-TMD solution was applied with an insulin syringe were assigned to group Cp. Buccal implant sulcus without topical nt-p65-TMD application were assigned to group Cb. H&E staining, TRAP staining, and immunohistological staining were done. The crestal bone levels of group A were significantly higher than those of group B at p<0.01. The crestal bone levels of group Cp were significantly higher than those of group Cb at p<0.05. H-E staining showed increased apical migration of junctional epithelium and inflammatory cells in group Cb. TRAP staining revealed more multinucleated osteoclasts in group Cb. As for immunohistological staining, group Cb showed many IL-6-positive cells while group Cp had none. In this study, p65-TMD-linked PTD inhibited NF-kB functions and reduced inflammation and bone resorption at peri-implantitis sites in rats.

Collagen quantification in peri-implant soft tissues in human peri-implantitis lesions / Cuantificación de colágeno en tejidos blandos periimplantarios en lesiones de periimplantitis en humanos

SUMMARY: Peri-implantitis is an inflammatory lesion of bacterial etiology characterized by inflammation of the mucosa and bone loss. Chronic inflammation is characterized by neovascularization and collagen neoformation. Mast cells have been shown to participate in the inflammatory process by releasing mediators and proteases such as chymase and tryptase, important in the collagen neoformation process. Although a higher percentage of collagen has been described in periodontal disease, the literature is scarce about the percentage of collagen in peri-implantitis. The aim of this study was to quantify the percentage of collagen fibers present in the peri- implant soft tissue of patients with peri-implantitis lesions. A descriptive observational cross-sectional study was performed. Samples of peri-implant soft tissue were collected from eleven patients with peri-implantitis and then processed by Masson's Trichrome Technique. In microscopic analysis, collagen fibers were observed in all samples, with an average percentage of 39.89 %, standard deviation of 17.02 %, with a minimum value of 8.99 % and a maximum value of 75.65 % density. From these results, it can be concluded that in human peri-implantitis lesions with bone loss greater than 50 %, there is an important percentage of collagen fibers, which is interpreted as connective tissue in a permanent process of reparative response, in the presence of inflammatory infiltrate.

RESUMEN: La periimplantitis es una lesión inflamatoria de etiología bacteriana caracterizada por inflamación de la mucosa y pérdida ósea. La inflamación crónica se caracteriza por neovascularización y neoformación de colágeno. Se ha demostrado que los mastocitos participan en el proceso inflamatorio liberando mediadores y proteasas como quimasa y triptasa, importantes en el proceso de neoformación del colágeno. Aunque se ha descrito un mayor porcentaje de colágeno en la enfermedad periodontal, la literatura sobre el porcentaje de colágeno en la periimplantitis es escasa. El objetivo de este estudio fue cuantificar el porcentaje de fibras de colágeno presentes en el tejido blando periimplantario de pacientes con lesiones de periimplantitis. Se realizó un estudio observacional descriptivo transversal. Se recogieron muestras de tejido blando periimplantario de once pacientes con periimplantitis y luego se procesaron mediante la técnica tricrómica de Masson. En el análisis microscópico, se observaron fibras de colágeno en todas las muestras, con un porcentaje promedio de 39,89 %, desviación estándar de 17,02%, con un valor mínimo de 8,99 % y un valor máximo de 75,65% de densidad. De estos resultados se puede concluir que en las lesiones de periimplantitis humana con pérdida ósea superior al 50 %, existe un porcentaje importante de fibras de colágeno, que se interpreta como tejido conectivo en un proceso permanente de respuesta reparadora, en presencia de infiltrado inflamatorio.

Profiles of inflammation factors and inflammatory pathways around the peri-miniscrew implant.

BACKGROUND: Peri-miniscrew implant is a temporary assistant armamentarium for the treatment of severe malocclusion and complex tooth movement, the inflammation around it is the main reason for the failure of orthodontic treatment due to the implant loosening and falling out. Inflammation around the peri-miniscrew implant is associated with the release of pro-inflammatory cytokines. These pro-inflammatory cytokines, in turn, recruit immune cells (such as macrophages, dendritic cells, T cells, and B cells), which can produce and release inflammatory biomarkers, regulate the interaction between immune cells, periodontal ligament cells, osteoblasts, and so on. However, there is currently no effective clinical treatment plan to prevent inflammation around implants. PURPOSE: To investigate the potentially essential factors in the inflammatory response around the peri-miniscrew implant and explore the signaling pathways involved. METHODS: Here, we review the studies focused on inflammatory biomarkers (Interleukins, tumor necrosis factor-α (TNF-α), receptor activator of NF-κB ligand (RANKL), matrix metalloproteinases (MMPs), and cellular adhesion molecules (CAMs)) in peri-miniscrew implant crevicular fluid (PMICF), as well as inflammatory signaling pathways (Wnt5a, JNK, Erk1/2, NF-κBp65 and TAB/TAK) in periodontal cells from 1998 to 2020. RESULTS: A literature search revealed TLR-2, TLR-4, LOX-1, and BMPs are involved in regulating ILs (IL-1ß, IL-6, IL-8, and IL-17), TNF-α, RANKL, MMP-2, MMP-9 expression via JNK, Erk1/2, Wnt5a, NF-κBp65, OPN, and TAB/TAK signaling pathways. Among them, IL-1ß and IL-6 are the critical inflammation factors in the signaling pathways inducing the inflammatory reaction surrounding implants. Besides, CAM-1 was also regulated by MMP-9 and IL-17. CONCLUSION: There are considerable potential factors involving regulating inflammatory biomarkers on downstream signaling pathways in peri-minisrew implant crevicular fluid. CLINICAL SIGNIFICANCE: This review provides the substantiation of these cell factors and signaling pathways around peri-miniscrew implants, proposes more practical clinical therapeutic ideas and schemes for improving the stability and clinical efficacy of peri-miniscrew implants.

LINC00968 promotes osteogenic differentiation in vitro and bone formation in vivo via regulation of miR-3658/RUNX2.

Osteogenic differentiation of dental pulp stem cells (DPSCs) is considered as a promising strategy in posterior maxilla tooth implantation. Information on the function and mechanisms of long non-coding RNAs (lncRNAs) in osteogenic differentiation of DPSCs is growing, however, the mechanism of LINC00968 and miR-3658 in regulating osteogenic differentiation of DPSCs still needs to be explored. In this study, the LINC00968 and miR-3658 expression level was upregulated and downregulated in DPSCs and peri-implantitis DPSCs (pDPSCs) treated with bone morphogenic protein (BMP)2, respectively. Moreover, the effects of LINC00968 and miR-3658 on BMP2-induced osteogenic differentiation of DPSCs in vitro using Alizarin Red S staining, alkaline phosphatase (ALP) activity, quantitative real time PCR and Western blot assays showed that overexpression of LINC00968 significantly promoted mineralized bone matrix, alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), and osterix (OSX) expression levels for osteogenic differentiation of DPSCs and pDPSCs; and overexpression of miR-3658 showed an opposite result that inhibited osteogenic differentiation of DPSCs and pDPSCs. Luciferase reporter assay showed that luciferase activities of LINC00968-WT reporter and RUNX2-WT reporter were strongly suppressed by miR-3658 overexpression. In addition, the miR-3658 upregulation interfered ectopic bone formation in vivo stimulated by LINC00968. In general, we had identified a novel molecular pathway involving LINC00968/miR-3658/RUNX2 during DPSCs and pDPSCs differentiation into osteoblasts, which might facilitate bone anabolism.

Development of an immunogenomic landscape for the competing endogenous RNAs network of peri-implantitis.

BACKGROUND: Peri-implantitis is an inflammation that occurs around the implant, resulting in varying degrees of inflammatory damage to the soft and hard tissues. The characteristic criterion is the loss of the supporting bone in an inflammatory environment. However, the specific mechanisms and biomarkers involved in peri-implantitis remain to be further studied. Recently, competing endogenous RNAs (ceRNA) and immune microenvironment have been found to play a more important role in the inflammatory process. In our study, we analyzed the expression of immune related microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and message RNAs (mRNAs) in peri-implantitis by analyzing GSE33774 and GSE57631. METHODS: In this study, we explored the expression profile data of immune-related lncRNAs, miRNAs and mRNAs, and constructed immune-related ceRNA network involved in the pathogenesis of peri-implantitis. In addition, the CIBERSORT was used to evaluate the content of immune cells in normal tissues and peri-implantitis to detect the immune microenvironment of peri-implantitis. RESULTS: In the analysis, 14 DElncRNAs, 16 DEmiRNAs, and 18 DEmRNAs were used to establish an immune related ceRNA network and the immune infiltration patterns associated with peri-implantitis was discovered. Through the mutual verification of the two datasets, we found that GSK3B and miR-1297 may have important significance in the immune microenvironment and pathogenesis of peri-implantitis and GSK3B was closely related to four types of immune cells, especially with the highest correlation with resting mast cells (P = 0.0003). CONCLUSIONS: Through immune-related ceRNA network, immune-related genes (IRGs) and immune cell infiltration can further comprehensively understand the pathogenesis of peri-implantitis, which built up an immunogenomic landscape with clinical significance for peri-implantitis.

Histological evaluation of peri-implant mucosal and gingival tissues in peri-implantitis, peri-implant mucositis and periodontitis patients: a cross-sectional clinical study.

Objective: Aim of present study was to evaluate gingival tissue samples obtained from healthy and diseased sites of teeth and dental implants in terms of hypoxia and collagenase activity.Methods: Four study groups were created as Group-1; healthy individuals (H), Group-2; periodontitis patients with stage 3 grade B (P), Group-3; patients with peri-implant mucositis. Group-4; patients with peri-implantitis (P-IMP). Plaque index (PI), gingival index (GI) and probing pocket depth (PPD) were recorded. Gingival and peri-implant mucosal biopsies were obtained. Fibroblast and inflammatory cells were counted. Hypoxia-inducible factor (HIF)-1α, prolyl hydroxylase (PH), matrix metalloproteinase (MMP)-8, tissue inhibitor of MMPs (TIMP)-1, cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) levels were determined via immunohistochemistry.Results: Healthy controls had highest fibroblast cell counts and lowest inflammatory cell counts compared to other groups. Peri-implantitis and periodontitis samples had similar fibroblast and inflammatory cell counts, while peri-implant mucositis had higher fibroblast cells and lowered inflammatory cells compared to periodontitis and peri-implantitis samples. HIF-1α, COX-2 and iNOS levels were lowest in healthy controls and increased in other groups. Peri-implant mucositis samples had significantly lower expressions of HIF-1α, COX-2 and iNOS compared to peri-implantitis and periodontitis groups. PH expressions were lower in periodontitis and peri-implantitis groups compared to healthy controls and peri-implant mucositis groups. MMP-8 levels were lower in healthy group compared to other groups while levels were similar in periodontitis, peri-implant mucositis and peri-implantitis groups. TIMP levels were similar in groups.Conclusion: Periodontitis, peri-implantitis, and peri-implant mucositis samples exhibited higher inflammation and lower fibroblast cell counts and tend to have increased tissue collagenase activity, hypoxia and inflammation compared to healthy samples.