Mutual promotions between periodontitis and vascular calcification by rat animal model.

OBJECTIVE AND BACKGROUND: To study the relationship between periodontitis and vascular calcification by establishing rat model of chronic periodontitis and vascular calcification. METHODS: Forty male Wistar rats were divided into four groups randomly: control group, periodontitis group, vascular calcification group, and compound periodontitis and calcification group. Each group rats accepted the corresponding manages to establish the animal model. Clinical examinations and hematoxylin and eosin staining of periodontal tissue were taken to test the periodontal model; calcium assay, alkaline phosphatase activity, expression of mineral-related factors including osteopontin, alkaline phosphatase, core-binding factor-α1 and bone sialoprotein, hematoxylin and eosin staining and von Kossa staining of vascular tissue were taken to test the vascular calcification model; inflammatory factors including C-reactive protein, interleukin-1ß, tumor necrosis factor-α, interleukin-6, prostaglandin E2, and serum lipid in serum were also detected at the same time. RESULTS: The rat model was established. Inflammation of periodontal tissue and alveolar bone resorption in compound group and periodontitis group were more obvious than those in control group and vascular calcification group (P < .05). However, the calcium assay, alkaline phosphatase activity, and mineralized deposition in vascular calcification group and compound group were higher than those in control group and periodontitis group (P < .05), and compound group were the highest (P < .05); as for serum lipid, the level of total cholesterol and low-density lipoprotein-cholesterol in compound group and vascular calcification group were higher than that in control group and periodontitis group (P < .05), and compound group was the highest (P <.05); but the level of high-density lipoprotein cholesterol was higher in control group and periodontitis group. Inflammatory factors expression in serum were higher in compound group and periodontitis group, while mineral-related factors expression were higher in compoundgroup and vascular calcification group. CONCLUSION: There are some mutual promotions between periodontitis and vascular calcification, which might be related to the increasing inflammatory factors, lipids level, and mineral-related factors.

Refinement and Evaluation of Modified Minimally Invasive Harvest Technique for Subepithelial Connective Tissue.

INTRODUCTION: The aim of this paper was to refine the modified minimally invasive single-incision technique (MSIT) into 6 steps that are easy to execute. The advantage of this modification was evaluated and compared with the traditional trap-door incision technique (TDIT). Several other harvesting techniques, suturing techniques, indications, contraindications, and limitations were also summarized. MATERIALS AND METHODS: A total of 40 patients presenting with multiple areas of gingival recession were recruited for this study. All patients were randomly assigned to either the MSIT or TDIT group. Standard periodontal instruments and crossed horizontal suspension sutures were used for both procedures. Harvesting and suturing time, verbal rating scale (VRS), and an early wound-healing index (EHI) were recorded. RESULTS: The total operating time, and particularly the suturing time, was shorter in the MSIT group (267.70 ±â€Š20.24 seconds) than the TDIT group (298.20 ±â€Š21.07 seconds), and the difference was statistically significant (P < 0.05). However, there was no significant difference in pain level between the 2 groups according to the VRS evaluation (P = 0.3658). One week postsurgery, the EHI of the MSIT group (2.00 ±â€Š0.95) was significantly lower than the TDIT group (2.85 ±â€Š1.15) (P < 0.05). DISCUSSION: The 6-step MSIT is more predictable and easy to execute, which decreases the challenge for both dentists and patients. Favorable outcomes occurred because of the streamlined minimally invasive procedure and favorable postoperative recovery.

Bactericidal Efficacy of Photon-Induced Photoacoustic Streaming-Erbium:Yttrium-Aluminum-Garnet Laser Combined with Irrigation Solution on Enterococcus faecalis in Curved Root Canals: An In Vitro Study.

Objective: This experiment aimed to study the bactericidal effect of photon-induced photoacoustic streaming (PIPS)-erbium:yttrium-aluminum-garnet (Er:YAG) laser on Enterococcus faecalis in curved root canals. Materials and methods: Sixty-two molars with moderately curved roots (10°-20°) and 62 molars with severely curved roots (25°-40°; one root was selected in each tooth) were assigned to group A and group B, respectively. A curved root canal model with E. faecalis infection was established. Four samples were used for sterility test, and 20 samples were used for testing if the modeling was valid. The remaining 100 samples were randomly divided into 5 subgroups (A1/A2/A3/A4/A5 and B1/B2/B3/B4/B5, n = 10) and treated as follows: A1/B1: PIPS-Er:YAG laser +5.25% sodium hypochlorite (NaOCl); A2/B2: passive ultrasonic irrigation +5.25% NaOCl; A3/B3: PIPS-Er:YAG laser+normal saline (NS); A4/B4: two-hole root canal irrigator +5.25% NaOCl; A5/B5: two-hole root canal irrigator+NS. After treatment, bacterial culture counts and scanning electron microscopic (SEM) observations were carried out for each subgroup, and the bacterial clearance rate of each subgroup was calculated. SPSS 23 software package was used for statistical analysis of the data, and a single-factor analysis of variance was used to compare the subgroups. Results: The bacterial clearance rate in group A was higher than that in group B; however, in each group, A or B, there were significant differences between the subgroups (p < 0.001) except for subgroups 1 and 2 (p > 0.05). SEM revealed that the antibacterial and smear layer removal effect of root canal in subgroups 1 and 2 was better than that in subgroups 3, 4, and 5. Conclusions: PIPS-Er:YAG can significantly enhance the bactericidal effect of NaOCl on E. faecalis in moderately and severely curved root canals.

Effect of Porphyromonas gingivalis lipopolysaccharide on calcification of human umbilical artery smooth muscle cells co-cultured with human periodontal ligament cells.

Periodontitis is an independent risk factor for coronary heart disease. Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) was considered to be one of the main virulence factors. In addition, vascular smooth muscle cells transform into osteoblast-like cells in an arterial calcification process under chronic inflammatory conditions. The present study aimed to determine the calcification induced by Pg-LPS in human umbilical artery smooth muscle cells (HUASMCs) co-cultured with human periodontal ligament cells (HPDLCs). An in vitro co-culture system was established using Transwell inserts. HUASMC proliferation and alkaline phosphatase (ALP) activity were measured with a Cell Counting Kit-8 and an ALP kit, respectively. Calcium nodule formation was detected using alizarin red S staining. The effects of Pg-LPS on the mRNA expression of the calcification genes of ALP, core-binding factor α1 (Runx2) and bone sialoprotein (BSP) were assessed using reverse transcription-quantitative PCR. The results indicated that Pg-LPS increased HUASMC proliferation and ALP activity. Furthermore, among all of the groups, calcium nodule formation was most extensive in co-cultured cells in the mineralization-inducing medium containing Pg-LPS. In addition, the expression of specific osteogenic genes (Runx2, ALP and BSP) significantly increased in the presence of Pg-LPS and mineralization-inducing medium, which was further enhanced in co-culture with HPDLCs. In conclusion, co-culture with HPDLCs increased the effect of Pg-LPS to stimulate the calcification of HUASMCs. It was suggested that besides the inflammation, periodontitis may promote the occurrence of vascular calcification. The study indicated that periodontal treatment of subgingival scaling to reduce and/or control Porphyromonas gingivalis may decrease the occurrence or severity of vascular calcification.

Systematically transplanted human gingiva-derived mesenchymal stem cells regulate lipid metabolism and inflammation in hyperlipidemic mice with periodontitis.

Gingiva-derived mesenchymal stem cells (GMSCs) have been the focus of extensive research due to their numerous distinct properties, including their homing to injury sites and their contribution to tissue regeneration. However, the role of transplanted GMSCs in the regulation of lipid metabolism and inflammation in hyperlipidemic mice with periodontitis has not been demonstrated. In the present study, apolipoprotein E-deficient (ApoE-/-) mice were used to establish a hyperlipidemia model with periodontitis and divided into two groups: Group B and Group C (n=20 per group), and wild-type C57BL/6J mice without any treatment were assigned to Group A (n=20). Animals in Group C were then injected with human GMSCs through the tail vein and animals in Group B were injected with α-MEM as control. Animals were sacrificed at indicated time points. Serum was collected to determine the lipids and inflammatory cytokines. Liver samples were collected to estimate lipid-associated gene expression. Morphometric and histological analyses were performed to maxillaries. The results demonstrated that the delivery of GMSCs led to a significant decrease in triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL), interleukin (IL)-6, tumor necrosis factor (TNF)-α, alveolar bone loss (ABL), and sterol regulatory element binding protein-1c (SREBP-1c) mRNA, and a significant increase in high density lipoprotein cholesterol (HDL), IL-10 and peroxisome proliferator-activated receptor α (PPARα) mRNA in Group C compared to Group B. Histological examination showed increased formation of new bone and higher alveolar bone height in Group C. Systematically transplanted GFP-positive cells were detected through both fluorescence microscope observation and immunohistochemical staining in the periodontal tissues. Overall, systematically transplanted GMSCs attenuated the hyperlipidemia and inflammatory responses in hyperlipidemic mice with periodontitis, and improved periodontal tissue regeneration.

[Dens in dente: report of 3 cases and review of the literature].

PURPOSE: To explore the diagnosis and clinical treatment of dens in dente. METHODS: Preventive resin restoration, root canal treatment, apical barrier technique and apexification were used to treat three cases of dens in dente, respectively. The curative effects were assessed by general examinations and imageological examinations during postoperative follow-up visits. RESULTS: Three patients with different type and degree of dens in dente achieved good therapeutic effect and favorable prognosis through different treatment methods. CONCLUSIONS: Dens in dente is complex clinically and the treatment is difficult. Clinicians should improve the understanding of dens in dente. The keys to successful treatment are early diagnosis and early treatment. In addition, it is important to take proper measures according to the type and degree of dens in dente, to preserve the diseased tooth as much as possible.

[Clinical evaluations of transitional treatment of pulpitis during pregnancy in 60 female patients].

PURPOSE: The present study was aimed to clinically evaluate transitional treatment of pulpitis during pregnancy. METHODS: Sixty pregnant women with pulpitis were divided into the first, second and third trimester. They were anesthetized locally using STA system combined with psychological intervention during treatment. The teeth were given one-appointment root canal preparation and filled with vitapex pasta. Normal obturation of the root canal was conducted after delivery. The effects of dental treatment, pregnancy outcomes and neonatal health status were observed. Data of the survey were analyzed by SPSS 20.0 software package, including Student's t test and chi-square test. RESULTS: The symptoms of pulpitis were significantly improved 24h after treatment,and the effective rate was 96.7%. The difference of VAS before and after treatment was statistically significant (P<0.05). Patients had no discomfort till the end of pregnancy,and the success rate was 98.3%. No adverse pregnancy outcomes were observed after treatment during different periods of pregnancy. Neonatal health was good. Significant differences were not found in birth gestational age, body weight, malformations, and neonatal complications between three treatment periods (P>0.05). CONCLUSIONS: Transitional treatment of pulpitis during pregnancy is a safe and effective procedure and worthy of wide use clinically.

Porphyromonas gingivalis Lipopolysaccharide Stimulation of Vascular Smooth Muscle Cells Activates Proliferation and Calcification.

BACKGROUND: Porphyromonas gingivalis (Pg) is a major etiologic agent of periodontitis, whose virulence has been attributed to different factors, including lipopolysaccharide (LPS). Vascular ectopic calcification as a well-known major risk factor for adverse cardiovascular diseases is a highly prevalent vascular pathophenotype, and vascular smooth muscle cells (VSMCs) play an important role in mediating vascular calcification. It was hypothesized that Pg-LPS may stimulate vascular calcification through a direct effect on VSMC function. To test this hypothesis, the effect of Pg-LPS on VSMC calcification was determined. METHODS: Primary cultures of VSMCs were obtained and identified by immunochemistry in vitro. The proliferation and alkaline phosphatase (ALP) activity of VSMCs were measured using a cell counting kit and an ALP activity test. Mineral deposition was examined using alizarin red staining. Gene (e.g. ALP, core binding factor α1 [Cbfα1], bone sialoprotein [BSP], and osteopontin [OPN]) expression levels altered by Pg-LPS were determined by reverse transcription-polymerase chain reaction array. RESULTS: Pg-LPS could increase the proliferation of VSMCs at different times and enhance ALP activity of VSMCs after 1 day. Alizarin red staining and quantification showed that, with Pg-LPS treatment, VSMCs displayed more obvious calcification nodules. When stimulated with Pg-LPS, the expression of specific osteogenic genes (e.g., ALP, Cbfα1, BSP, and OPN) was significantly promoted in the presence or absence of mineralization-inducing medium, whereas the expression of the OPN gene was inhibited in the mineralization induction group at day 7. CONCLUSION: Pg-LPS can stimulate VSMC calcification, which results in vascular calcification, further proving the precise relationship between periodontitis and vascular calcification.

[The antimicrobial effects of chitosans on oral pathogenic microbes in vitro].

PURPOSE: To study the antimicrobial activities of chitosans of different molecular weights and concentrations on oral pathogenic microbes under pH 6.5 in vitro. METHODS: The inhibition effects of chitosans of different molecular weights and different concentrations (2.0%, 1.5%, 1.0%, 0.5%) on Staphylococcus aureus, Candida albicans, Helicobacter pylori, Streptococcus mutans and Porphyromonas gingivalis in culture were investigated, and the differences of their antimicrobial activities under high temperature and after filtering were compared. One way analysis of variance, randomized block design analysis of variance and t test were used for statistical analysis. RESULTS: Chitosans of different molecular weights all showed bacteriostatic effects on Staphylococcus aureus, Candida albicans, Helicobacter pylori, Streptococcus mutans and Porphyromonas gingivalis. Low molecular weight chitosans showed the strongest effects, but the high molecular weight ones had strong effects on Streptococcus mutans (P<0.05,0.01). The bacteriostatic effects of chitosans were not affected by high temperatures (P>0.05). CONCLUSION: Chitosans have inhibitory effects on oral pathogenic microbes under pH 6.5.