[Advances in Research on the Mechanism of Association Between Periodontitis and Diabetes Mellitus].

Periodontitis and diabetes mellitus are both chronic diseases with a rather high prevalence and they are closely associated with each other. On one hand, diabetes mellitus poses as a risk factor for periodontitis. On the other hand, periodontitis has a negative impact on glucose control in diabetic patients. The two-way relationship has aroused a lot of research interest in recent years. Herein, approaching the issue by looking at the effect of periodontitis on diabetes, we summarized the mechanism of the traditional periodontal pocket-blood circulation pathway and reviewed the role of the oral-gut axis in the mechanism, which has been proposed in recent years. In addition, regarding the impact of diabetes on periodontitis, we summarized new findings concerning changes in oral microbiota, abnormal levels of cytokines and adipokines, oxidative stress, unbalanced osteogenic and osteoclastic activities, and the accumulation of advanced glycation end-products. We hope this paper will be helpful for further studies on the mechanism of association between periodontitis and diabetes.

PHD2 shRNA-Modified Bone Marrow Mesenchymal Stem Cells Facilitate Periodontal Bone Repair in Response to Inflammatory Condition.

OBJECTIVE: To investigate whether bone marrow mesenchymal stem cells (BMMSCs) modulate periodontal bone repair through the hydroxylase domain-containing protein 2 (PHD2)/hypoxia- inducible factor-1 (HIF-1) signalling pathway in response to inflammatory conditions. METHODS: Osteogenic differentiation of PHD2 shRNA-modified BMMSCs and the possible mechanism were explored in an inflammatory microenvironment stimulated by porphyromonas gingivalis lipopolysaccharide (Pg-LPS) in vitro. The effect of PHD2 gene-modified BMMSCs on periodontal bone loss was evaluated with experimental periodontitis. RESULTS: Pg-LPS stimulation greatly impaired the osteogenic differentiation of BMMSCs, whereas the silence of PHD2 significantly enhanced the osteogenesis of BMMSCs. More importantly, increased level of vascular endothelial growth factor (VEGF) was detected under Pg-LPS stimulation, which was verified to be associated with the augmented osteogenesis. In experimental periodontitis, PHD2-modified BMMSCs transplantation elevated osteogenic parameters and the expression of VEGF in periodontal tissue. CONCLUSION: This study highlighted that PHD2 gene silencing could be a feasible approach to combat inflammatory bone loss by rescuing the dysfunction of seed cells.

Multidisciplinary non-surgical treatment of advanced periodontitis: A case report.

BACKGROUND: Patients with severe periodontitis often require multidisciplinary treatment to achieve healthy periodontal tissue, normal occlusion, and optimal aesthetics. In the present study, we aimed to evaluate the efficacy of multidisciplinary non-surgical treatment in a patient with stage IV/ grade C periodontitis, malocclusion, and dentition defects. CASE SUMMARY: A 47-year-old woman visited our periodontology department due to teeth mobility problems and difficulties chewing food. The patient had no history of drug allergies or systemic disease. Initial therapy involved scaling and root planning with a Gracey scaler and periodontal ultrasonic therapeutic apparatus using a periodontal endoscope (Perioscopy, Zest Dental Solutions, United States) to control the periodontal inflammation prior to treatment. Five months later, orthodontic treatment was then performed to treat occlusion and overall aesthetics. After completion, a Maryland bridge was used to restore Nos. 22, 31, and 41 teeth. Florida probing (Florida probe, United States) was performed every 2-3 mo to evaluate the periodontal condition throughout treatment. Overall, multidisciplinary non-surgical treatment resulted in satisfactory aesthetic results with healthy periodontal tissue and stable occlusion. CONCLUSION: In some patients with stage IV/grade C periodontitis, systematic and sequential non-surgical treatment can provide excellent therapeutic results.

Multi-disciplinary treatment of maxillofacial skeletal deformities by orthognathic surgery combined with periodontal phenotype modification: A case report.

BACKGROUND: Maxillofacial deformities are skeletal discrepancies that cause occlusal, functional, and esthetic problems, and are managed by multi-disciplinary treatment, including careful orthodontic, surgical, and periodontal evaluations. However, thin periodontal phenotype is often overlooked although it affects the therapeutic outcome. Gingival augmentation and periodontal accelerated osteogenic orthodontics (PAOO) can effectively modify the periodontal phenotype and improve treatment outcome. We describe the multi-disciplinary approaches used to manage a case of skeletal Class III malocclusion and facial asymmetry, with thin periodontal phenotype limiting the correction of deformity. CASE SUMMARY: A patient with facial asymmetry and weakness in chewing had been treated with orthodontic camouflage, but the treatment outcome was not satisfactory. After examination, gingiva augmentation and PAOO were performed to increase the volume of both the gingiva and the alveolar bone to allow further tooth movement. After orthodontic decompensation, double-jaw surgery was performed to reposition the maxilla-mandibular complex. Finally, implant placement and chin molding were performed to restore the dentition and to improve the skeletal profile. The appearance and function were significantly improved, and the periodontal tissue remained healthy and stable. CONCLUSION: In patients with dentofacial deformities and a thin periodontal phenotype, multi-disciplinary treatment that includes PAOO could be effective, and could improve both the quality and safety of orthodontic-orthognathic therapy.

[Effect of hBMP-7 gene modified bone marrow stromal cells on periodontal tissue regeneration].

OBJECTIVE: To estimate the potential effects of hBMP-7 gene transfected bone marrow stromal cells (BMSC) and to provide a new way for repairing the periodontal defects. METHODS: A total of 30 experimental class II furcation defects in five Beagle dogs were created surgically. The transfected and non-transfected BMSC were seeded in collagen membrane at an initial concentration of 1 x 10(7)/ml and transplanted into experimental class II furcation defects. The animals were sacrificed at 12 weeks post-operation and periodontal regeneration was evaluated by the histological and morphometric analysis. RESULTS: In both experimental and control groups, there were different extents of regeneration. The percentage of new alveolar area in transfected and non-transfected BMSC were significantly higher than the control (P < 0.05). And there was also significant difference between two experimental groups (P < 0.05). The percentage of new cementum length in two experimental groups were significantly higher than the control (P < 0.05). But there was no significant difference between two BMSCs groups (P > 0.05). CONCLUSION: hBMP-7 gene enhanced tissue engineering could be a better way to repair the periodontal defects.

[Clinical effects of scaling and root planing with an adjunctive periodontal endoscope for residual pockets: a randomized controlled clinical study].

OBJECTIVE: To evaluate the efficacy of scaling and root planing (SRP) with a periodontal endoscope in the treatment of residual pockets in patients with periodontitis after initial periodontal therapy. METHODS: Patients with residual pockets [probing depth (PD)≥5 mm] were included and randomly assigned to the endoscope group (SRP with a periodontal endoscope) or SRP group (SRP alone). The PD, attachment loss (AL), and bleeding on probing (BOP) of residual pockets were recorded before treatment and at 3 and 6 months after treatment. Data were analyzed with SPSS 20.0 software. RESULTS: Compared with the baseline values, the percentage of PD≥5 mm sites, PD, AL, and BOP (+)% in the endoscope group and SRP group at 3 and 6 months after treatment decreased (P<0.05). Compared with the values at 3 months after treatment, the percentage of PD≥5 mm sites, PD, AL, and BOP (+)% at 3 and 6 months after treatment decreased in the endoscope group (P<0.05), whereas no statistical difference in these values was observed in the SRP group (P>0.05). Compared with those in the SRP group, the percentage of PD≥5 mm sites and PD at 3 and 6 months after treatment and AL and BOP (+)% at 6 months after treatment in the endoscope group decreased (P<0.05). CONCLUSIONS: SRP with a periodontal endoscope shows a better effect in improving the PD, AL, and BOP of residual pockets (PD≥5 mm) in patients with periodontitis after initial periodontal therapy and has advantages in improving the long-term curative effect of this therapy.

[Accuracy of paralleling technique in measuring the depth of approximal infrabony pocket].

OBJECTIVE: To assess the accuracy of paralleling technique in measuring the depth of approximal infrabony pocket after periodontal flap surgery by comparing the measured and actual depths. METHODS: The study population included 26 patients with infrabony defects who had undergone periodontal flap surgery, bone graft surgery, and guided tissue regene-ration. The measured and actual depths of approximal infrabony pocket after periodontal flap surgery were compared. The 26 infrabony defects were categorized into the following groups according to tooth position: anterior teeth, premolar, and molar groups, and according to type of infrabony pocket: one-walled, two-walled, and three-walled infrabony pocket groups. Paired t-test was used to detect the difference between the two values. RESULTS: Depth measurements of the approximal infrabony pocket depth of the anterior teeth and premolar were not significantly different (P>0.05), whereas those of the molar group were significantly different (P<0.05). In addition, depth measurements in one-walled and two-walled infrabony pocket groups showed no significant differences (P>0.05), whereas those in the three-walled infrabony pocket group were significantly different (P<0.05). CONCLUSIONS: Paral-leling technique can accurately measure the depth of approximal infrabony pockets of anterior teeth and premolar teeth that are one- or two-walled. However, this method cannot accurately measure the approximal infrabony pockets of molar teeth and three-walled infrabony pockets as indicated by significant differences in their depth measurements.

[Time lapse between endodontic and periodontal treatments of combined periodontal-endodontic lesion: a systematic review].

OBJECTIVE: This study aims to evaluate the time lapse between the endodontic and periodontal treatments of the combined periodontal-endodontic lesion to guide the clinical treatment. METHODS: A systemic literature search was performed in articles published from 1980 to March 2017 using the electronic databases, including PubMed, EMbase, Cochrane, Web of Science, CNKI, CBM, and Wanfang Databases. RESULTS: After screening, two randomized controlled trials, two prospective case series studies, and eight case reports were ultimately included. All clinical studies and case reports were treated with root canal therapy and periodontal nonsurgical or periodontal surgical treatment, with root canal therapy as the initial treatment step. Changes in the periodontal probing depth and attachment loss were reported in all clinical studies and case reports. CONCLUSIONS: An observational period between the endodontic and periodontal nonsurgical treatments may not be required. However, given that the quality of several included studies was limited, and the number of randomized controlled trials was small, a large number of randomized controlled trials are needed to verify this result.

[Construction of leptin gene modified tissue engineered composites in vitro].

PURPOSE: To evaluate the feasibility of constructing tissue engineered composites in vitro by combining human leptin (hLEP) gene modified rat bone marrow stromal cells (BMSCs) and guided tissue regeneration collagen membrane (Bio-Gide). METHODS: BMSCs of SD rats were isolated and cultured by whole bone marrow adherent method. BMSCS were transfected with adenovirus carrying hLEP gene (Ad-hLEP-EGFP) and observed under inverted fluorescence microscope. Enzyme linked immunosorbent assay (ELISA) was used to detect the expression of hLEP. The proliferation activity of transfected cells was assessed by MTT assay. Ad-hLEP-EGFP transfected BMSCs were cultured for 24 h in combination with Bio-Gide collagen membrane, hLEP modified tissue engineered composite was observed under laser scanning confocal microscope (LSCM) and scanning electron microscope (SEM). RESULTS: Through Ad-hLEP-EGFP transfection, hLEP was overexpressed in BMSCs, which didn't affect the proliferation of cells. SEM showed hLEP modified BMSCs grew well on Bio-Gide collagen membrane and secreted extracellular matrix. LSCM suggested BMSCs could migrate to different scales of Bio-Gide collagen membrane. CONCLUSIONS: hLEP modified BMSCs can be combined with Bio-Gide collagen membrane and grow well, suggesting that hLEP modified tissue engineered composite can be successfully constructed. The composite might be suitable for periodontal tissue engineering.

Magnetic resonance imaging parameter optimizations for diagnosis of periprosthetic infection and tumor recurrence in artificial joint replacement patients.

To evaluate the efficacy of magnetic resonance imaging (MRI) parameter optimizations for the diagnosis of periprosthetic infection and tumor recurrence in joint replacement patients. We compared the quality of images for 16 joint replacement patients that were recorded using the optimized MRI parameters with and without view angle tilting (VAT) correction at 1.5 T in coronal fast-spin-echo T2-weighted MRI. The optimized MRI data of 86 patients with pain after hip replacement and 67 patients who received tumor resection and joint replacement for bone cancer were retrospectively analyzed to identify MRI features that were useful for the diagnosis of periprosthetic infection and tumor recurrence. Increasing receiver bandwidth and decreasing slice thickness combined with VAT significantly reduced the area of metal-induced artifacts. Irregular soft tissue mass, soft tissue edema, bone destruction, and fistula were significant features of periprosthetic infection, with sensitivities of 47.4-100% and specificities of 73.1-100.0%, which were confirmed based on surgical and pathological findings. Soft tissue mass was a significant feature of tumor recurrence, with 100% sensitivity, 96.0% specificity, and 97.0% consistency. The optimized VAT MRI method demonstrated a high level of diagnostic accuracy for the detection of periprosthetic infection and tumor recurrence in joint replacement patients.

Dental pulp stem cells express tendon markers under mechanical loading and are a potential cell source for tissue engineering of tendon-like tissue.

Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells (DPSCs) for potential application in tendon tissue engineering. The expression of tendon-related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid (PGA) fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a potential stem cell source for tissue engineering of tendon-like tissue.

[Hyperlipidemia inhibited inflammatory response to Porphyromonas gingivalis in apolipoprotein E knockout mice].

PURPOSE: To investigate the effect and mechanism of hyperlipidemia on inflammatory response to Porphyromonas gingivalis(P. gingivalis) in apolipoprotein E knock out(ApoE-/-) mice. METHODS: Long term hyperlipidemia model was established in ApoE-/- mice, and viable P. gingivalis were injected into peritoneal cavity to make peritonitis model. Bacteria clearance capability was detected by serial dilution, production of pro-inflammatory cytokine interleukin-6 (IL-6) and monocyte chemotactic protein-1 (MCP-1) in serum was measured by ELISA, and IL-6 as well as MCP-1 transcription in peritoneal cells was determined by real time PCR. The data was analyzed with SPSS13.0 software package. RESULTS: Hyperlipidemia disrupted P. gingivalis clearance capability in ApoE-/- mice, accompanied by inhibited IL-6 and MCP-1 transcription in peritoneal cells and decreased IL-6 and MCP-1 release into blood. CONCLUSIONS: Hyperlipidemia disrupts inflammatory response to P. gingivalis, leading to decreased bacteria clearance, which may affect periodontitis progression.

[Expression of triggering receptors expressed on myeloid-1 in innate response to Porphyromonas gingivalis in macrophages].

OBJECTIVE: To investigate the role of triggering receptors expressed on myeloid-1(TREM-1) in innate response to Porphyromonas gingivalis(Pg) in mice macrophages and its potential role in periodontitis development. METHODS: Peritoneal macrophages from mice were harvested, separated and cultured, then challenged with viable Pg. Transcription and protein expression in macrophages were assessed with real time PCR and flow cytometry respectively.LP-17 peptide (10, 100 and 1000 µg/L) was utilized to block TREM-1, and tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were detected by enzyme linked absorbent analysis. RESULTS: At 2 h after Pg challenge, transcription of TREM-1 was significantly up-regulated after Pg challenge[(7.99 ± 1.11) fold vs blank]. At 24 h after bacteria infection, increased TREM-1 expression was demonstrated by flow cytometry, with mean fluorescent intensity increasing from (7.05 ± 1.85) in blank group to (13.17 ± 2.33) in experimental group. Proinflammatory cytokine (TNF-α and IL-6) production was significantly decreased after blocking TREM-1 by LP-17 peptide(100 and 1000 µg/L). CONCLUSIONS: TREM-1 enhanced innate immune response to Pg in macrophages, which may facilitate periodontitis development.

[Transient expression of exogenous human platelet-derived growth factor-B in gingival fibroblasts of dog].

OBJECTIVE: To explore transient expression of the eukaryotic expression plasmid carrying human platelet-derived growth factor-B (hPDGF-B) in gingival fibroblasts of Beagle dog. METHODS: Plasmid carrying hPDGF-B (EX-A0380-M03) was amplified and identified, and then transfected into gingival fibroblasts of Beagle dog. Reverse transcription polymerase chain reaction (RT-PCR), immunocytochemistry, enzyme-linked immunosorbent assay (ELISA) and Western bolt were choose to detect the expression of hPDGF-B. RESULTS: Target gene carried by EX-A0380-M03 was hPDGF-B. Green fluorescence protein (GFP) expressed by transfected gingival fibroblasts was observed under inverted phase contrast fluorescence microscope (IPCFM) (after 24 hours) and the transfection efficiency was 18%-38% (after 48 hours). Serials other methods (RT-PCR, immunocytochemistry, and ELISA) mentioned above also convinced that cells expressed hPDGF-B, and the protein that was a kind of fusion protein composed of PDGF-BB and GFP was identified by Western blot. CONCLUSION: Eukaryotic expression plasmid carrying hPDGF-B was transfected into gingival fibroblasts successfully, and a kind of fusion protein was expressed.

[Effects of Porphyromonas gingivalis lipopolysaccharide on apoptotic genes in foam cells].

OBJECTIVE: To investigate the effects of Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) on apoptotic genes in foam cells. METHODS: Macrophages from THP-1 monocytes and foam cells from macrophages by oxLDL inducement were treated with oxidized low density lipoprotein (oxLDL) or oxLDL+ Pg-LPS. Cell apoptosis was detected by acridine orange-ethidium bromide (AO-EB) staining. Eleven atherosclerotic related apoptotic genes were examined with polymerase chain reaction (PCR) array, and apoptotic gene p53, c-Myc and caspase-3 were evaluated with real-time PCR. RESULTS: Pg-LPS enhanced cell apoptosis rate during and after foam cells formation [(5.47+/-0.93)% vs. (7.50+/-0.54)%]. PCR array demonstrated that it increased B-cell CLL-lymphoma 2 (BCL2) related protein A1 (BCL2A1) transcription during foam cells formation (>2 fold), and promoted BCL2 and BCL2A1 transcription after foam cells formation (>2 fold). It promoted p53 and caspase-3 transcription level (4.50x10(-3)+/-4.02x10(-4) vs. 5.30x10(-2)+/-4.58x10(-3)), whereas inhibited c-Myc transcription level (1.53x10(-2)+/-5.77x10(-4)) during foam cells formation. It promoted caspase-3 transcription (6.00x10(-2)+/-6.08x10(-3)), and inhibited p53 transcription (4.23x10(-3)+/-5.85x10(-4)) after foam cells formation. CONCLUSIONS: Pg-LPS affected apoptotic gene transcription during and after foam cells formation and enhanced cell apoptosis.

[The influence of alexithymia in stress on secretory IgA and cortisol in saliva].

PURPOSE: To explore the influence of alexithymia in stress on secretory IgA (SIgA) and cortisol (Cor) in saliva. METHODS: 60 male students in high school were investigated and the psychological conditions were assessed by TAS (Group A was for high score and Group B for low score) and the change of the concentration of SIgA and Cor in saliva were examined by radio-immunoassay. All data was assessed by student's t test and single factor correlation analysis. RESULTS: (1) SIgA in Gr-A was significantly lower than that in Gr-B one month before examination and on the day of examination (P<0.05), and SIgA was similar in the two groups (P>0.05). (2) Cor in Gr-A was significantly higher than that in Gr-B one month before examination and on the day of examination (P<0.05). Cor in the two groups was significantly higher than on the day of examination one month before examination (Gr-A: P<0.01;Gr-B: P<0.05). (3) The change rate of SIgA and Cor in the two groups was significantly different before and after stress (SIgA:<0.05;Cor: P<0.01);(4) The total score of TAS, factor I and II were significantly correlated to the change rate of SIgA and Cor one month before examination (P<0.05);The factor III showed negative correlation to the change rate of Cor (P<0.05);The factor IV showed no significant correlation to the testing indexes (P>0.05). CONCLUSIONS: Stress and alexithymia in stress could result in the changes of SIgA and Cor in saliva.