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In this study, a Porphyromonas gingivalis (P.g.)-infected mouse periodontitis model was used to investigate the effect of omega-3 fatty acid intake on differentiation and maturation of cultured osteoclast. Four-week-old C57BL/6JJcl mice were divided into four groups according to the diets they were fed from the beginning of the experiment (i.e., food containing omega-3 or omega-6 fatty acids) and whether they were orally administered P.g. Thirty-three days after beginning the experiment, bone marrow cells were sampled from the femoral bone of mice from each group and differentiated into osteoclasts; the effects of the ingestion of different fatty acids were subsequently investigated. There was no statistical interaction between the different fatty acids and P.g. infection on the number of osteoclasts (P = 0.6). However, the fatty acid type affected the number of osteoclasts in mice (P = 0.0013), with the omega-3 groups demonstrating lower osteoclast numbers than the omega-6 groups. Furthermore, the addition of resolvin E1 (RvE1), which is an omega-3 fatty acid-derived lipid mediator, suppressed the differentiation of mouse cultured osteoclasts (P < 0.0001). Therefore, the ingestion of omega-3 fatty acids may suppress osteoclast differentiation while inhibiting bone resorption and tissue destruction due to periodontitis. [ABSTRACT FROM AUTHOR]

Pycnogenol® (PYC) is a standardized bark extract from French maritime pine ( Pinus pinaster Aiton). We examined the inhibitory effects of PYC on alveolar bone resorption, which is a characteristic feature of periodontitis, induced by Porphyromonas gingivalis ( P. gingivalis) and osteoclast differentiation. In rat periodontitis model, rats were divided into four groups: group A served as the non-infected control, group B was infected orally with P. gingivalis ATCC 33277, group C was administered PYC in the diet (0.025%: w/w), and group D was infected with P. gingivalis and administered PYC. Administration of PYC along with P. gingivalis infection significantly reduced alveolar bone resorption. Treatment of P. gingivalis with 1 µg/ml PYC reduced the number of viable bacterial cells. Addition of PYC to epithelial cells inhibited adhesion and invasion by P. gingivalis. The effect of PYC on osteoclast formation was confirmed by tartrate-resistant acid phosphatase staining. PYC treatment significantly inhibited osteoclast formation. Addition of PYC (1-100 µg/ml) to purified osteoclasts culture induced cell apoptosis. These results suggest that PYC may prevent alveolar bone resorption through its antibacterial activity against P. gingivalis and by suppressing osteoclastogenesis. Therefore, PYC may be useful as a therapeutic and preventative agent for bone diseases such as periodontitis. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the antimicrobial effects of a mouthrinse containing silver nanoparticles (AgNP) on polymicrobial biofilms in vitro., Materials and Methods: Polymicrobial biofilms were grown on glass cover slips following the method of Exterkate. Saliva collected from a healthy human was added to McBain medium (including 0.2% sucrose) to achieve a 50-fold dilution. Glass coverslips were attached to the lid of a 24-well culture plate and suspended in the medium of each well. After 24 h of cultivating, coverslips with biofilms were immersed in each of four treatment solutions or sterile deionized water for 5 min. The control and four treatment groups were as follows: 1) control: sterile deionized water; 2) nanosilver (NS): mouthrinse containing AgNP; 3) 0.05C: 0.05% chlorhexidine gluconate; 4) 0.2C: 0.2% chlorhexidine gluconate; 5) Xyl: 25% xylitol. The biofilms were further regrown for 48 h. After removing the biofilms ultrasonically, they were cultured on blood agar, viable cells were counted, and the amount of lactic acid in the biofilms was analysed using a colorimetric assay., Results: Mouthrinse containing AgNP suppressed viable cells in the biofilm to the same degree or more than with chlorhexidine gluconate. Amounts of lactic acid after 72 h cultivation of biofilms treated with 0.2C and NS showed consistently low values., Conclusion: The mouthrinse containing AgNP suppressed viable cells in polymicrobial biofilms to the same level as 0.2% chlorhexidine or higher.

The study aimed to evaluate the periodontal disease status in different age groups and clarify the relationship between aging and the severity of periodontal disease. The test animals were cynomolgus monkeys that were born and raised at Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition. The participants were divided into three groups: young (5-10 years old), middle (10-19 years old), and old (≥20 years old). The Plaque Index (PLI), Gingival Index (GI), Probing pocket depth (PPD), and Bleeding on probing (BOP) were used for the periodontal examination. Representative teeth were also examined. Polymerase chain reaction (PCR) was used to identify Porphyromonas macacae in dental plaque. Multiple comparisons and regression analyses were used to analyze the relationship between each age group and each oral examination index. Statistically significant differences were found between the age groups and periodontal examination index. Multiple regression analysis revealed that age was strongly correlated with each oral examination index. Based on these results, oral examinations of cynomolgus monkeys kept in the same environment confirmed an association between aging and periodontal disease severity. Monkeys at this facility are expected to serve as new experimental models for elucidating the mechanisms underlying the progression of age-related periodontal disease.

Purpose: To analyze the effects of surface pre-reacted glass-ionomer (S-PRG) filler eluate on polymicrobial biofilm metabolism and live bacterial count., Methods: Biofilm was formed using glass disks 12 mm in diameter and 150 µm in thickness. Stimulated saliva was diluted 50-fold with buffered McBain 2005 and cultured in anaerobic conditions at 37°C for 24 hours in anaerobic conditions (10% CO₂, 10% H₂, 80% N₂) to form the biofilm on the glass disks. Following this, biofilms were treated with (1) sterilized deionized water (control), (2) 0.2% chlorhexidine digluconate (0.2CX), (3) S-PRG eluate diluted to 10% (10% S-PRG)，(4) 20% S-PRG，(5) 40% S-PRG，(6) 80% S-PRG，and (7) S-PRG for 15 minutes (n= 10 per group), and samples were subdivided into two groups for measuring live bacterial count immediately after treatment and after 48 hours of culturing after treatment. The pH of the spent medium collected at the time of culture medium exchange was tested., Results: Immediately after treatment, the live bacterial count of samples treated with drug solutions was significantly lower than the control (8.2 × 10⁸), and the counts of samples treated with 0.2CX (1.3 × 10⁷) and S-PRG (1.4 × 10⁷) were significantly lower than those treated with diluted S-PRG (4.4 × 10⁷-1.4 x 10⁸). When the medium was measured again after culturing for 48 hours, growth was continually inhibited in all treatment groups and the bacterial count of samples treated with S-PRG (9.2 x 10⁷) was significantly lower than that of samples treated with 0.2CX (1.8 × 10⁸). The pH of spent medium immediately after treatment was significantly higher in groups treated with drug solutions (5.5-6.8) than the controls (4.2), and it was highest in the S-PRG-treated group (6.8). Thereafter, when culturing was continued for 48 hours, the pH of all treated groups decreased; however, the pH of the S-PRG-treated group was significantly higher than groups treated with other drug solutions., Clinical Significance: Surface pre-reacted glass-ionomer (S-PRG) filler eluate not only reduced the live bacterial count of polymicrobial biofilm, but also continuously inhibited the lowering of pH., Competing Interests: This research was financially supported by Shofu Inc, but it had no involvement in planning the research methods or interpreting the results., (Copyright©American Journal of Dentistry.)

Purpose: To compare the efficacy of toothpaste containing surface pre-reacted glass-ionomer (S-PRG) filler particles to that of conventional sodium fluoride (NaF) toothpaste for the prevention of dentin demineralization and biofilm regrowth., Methods: Bovine root dentin specimens and glass coverslips were used as biofilm growth substrates. To establish biofilms, glass and dentin specimens were incubated for 72 hours in 0.2% sucrose McBain medium inoculated with stimulated saliva from a single donor. Specimens then received a single 5-minute treatment with S-PRG toothpaste, fluoride toothpaste, or sterilized deionized water and were incubated in McBain medium for 120 hours to allow biofilm regrowth. Output parameters during regrowth (72-192 hours) were pH of spent medium, colony-forming unit (CFU) counts of biofilms, and dentin mineral profiles, integrated mineral loss (IML: vol% × µm), and lesion depth (Ld). Treatment group differences were tested by one-way ANOVA followed by Tukey's multiple range test (P< 0.05)., Results: At 144 hours, medium pH was significantly higher in the S-PRG-treated dentin group than in the NaF-treated dentin group. In addition, at 192 hours, the CFU count, IML, and Ld were lower in the S-PRG-treated dentin group than in the NaF-treated dentin group. There were significant differences of pH among dentin groups at 72 hours. Treatment with S-PRG toothpaste markedly inhibited dentin demineralization compared to that with NaF toothpaste., Clinical Significance: Toothpaste containing multiple ions-releasing filler suppressed bacterial viability and inhibited dentin demineralization., Competing Interests: The study was financially supported by Shofu Inc. (Kyoto, Japan). There were no restrictions with respect to the design of the study or the publication of the results. This work was supported, in part, by a Grant-in-Aid for Scientific Research (C) from the Japan Society for the Promotion of Science (JSPS No. 23592816) and MEXT-Supported Program for the Strategic Research Foundation at Private Universities, S1203004, 2011-2013. Part of this work was supported by MEXT/JSPS KAKENHI Grant Number 26462900 Grant-in-Aid for Scientific Research (C), 2017-2019., (Copyright©American Journal of Dentistry.)

Arterial spin labeling (ASL) is a magnetic resonance imaging (MRI) technique that enables visualizing of cerebral blood flow without need of a contrast medium. In recent years, there have been reports from outside Japan related to ASL use in migraine attacks. We report two cases of acute confusional migraine (ACM) in children. At time of confusion, ASL imaging showed reduced blood flow: for the first patient, in both cerebral hemispheres from the occipital lobe through the parietal lobe to the temporal lobe; for the second patient, throughout the left cerebral hemisphere. T1-, T2-, diffusion-weighted images, and fluid attenuation inversion recovery (FLAIR) images indicated normal results. Subsequent ASL re-examinations for both cases showed recovery from reduced blood flow. In our view, ACM can be characterized by a reduction in blood flow not limited to the occipital lobe but across wide regions of the cerebral hemisphere. We consider ASL to be helpful in the difficult differentiation of ACM from other disturbances of consciousness, in addition to enabling repeated examinations without the risks associated with single-photon emission computed tomography (SPECT) concerning radiation exposure or with contrast MRI concerning contrast media use.

Porphyromonas gulae is considered to be associated with canine periodontitis. We have previously reported that the P. gulae American Type Culture Collection (ATCC) 51700 comprised 41-kDa fimbriae. The purpose of the present study was to demonstrate the roles of 41-kDa fimbrial protein in periodontal disease. In this study, we examined the involvement of the 41-kDa fimbrial protein in osteoclast differentiation and cytokine production in murine macrophages. Furthermore, alveolar bone resorption induced by P. gulae infection in rats was evaluated. To estimate osteoclast differentiation, bone marrow cells and MC3T3-G2/PA6 cells were cultured with or without the 41-kDa fimbrial protein for 7 days. BALB/c mouse peritoneal macrophages were stimulated with the 41-kDa fimbrial protein, and the levels of interleukin (IL)-1β and tumor necrosis factor (TNF)-α production were determined by enzyme-linked immunosorbent assay. Osteoclast differentiation was significantly enhanced by treatment with the 41-kDa fimbrial protein in a dose-dependent manner. The total area of pits formed on the dentine slices with osteoclasts incubated with the 41-kDa fimbrial protein was significantly greater than that of the control. The purified 41-kDa fimbrial protein induced IL-1β and TNF-α production in BALB/c mouse peritoneal macrophages after 6 hr of incubation in a dose-dependent manner. The bone loss level in rats infected with P. gulae was significantly higher than that of the sham-infected rats. These results suggest that P. gulae 41-kDa fimbriae play important roles in the pathogenesis of periodontal disease.

Purpose: To simulate an oral demineralization environment by multiple species of bacteria by inducing subsurface dentin lesions with a polymicrobial biofilm model., Methods: Polymicrobial biofilms consisting of multiple species of bacteria were generated from stimulated saliva using a high-throughput active attachment model. Biofilms were grown on dentin specimens in McBain medium containing 0, 0.2 or 2.5 ppm F and on glass without fluoride for 192 hours. The medium was refreshed twice daily, after 10 and 14 hours, until 72 hours, followed by treatment for 5 minutes with 400 ppm fluoride. Specimens were recovered after 192 hours. The number of colony forming units (CFU) was measured, and integrated mineral loss (IML) was determined by transversal microradiography., Results: Mineral profiles in specimens grown with 0.2F and 2.5F revealed surface layers and initial lesions distinct from those grown with 0F. IML was significantly lower with 0.2F and 2.5F than with 0F (P < 0.05), although CFUs were similar. CFUs of biofilms grown on dentin in medium containing 0F were 10-fold higher than on glass (P < 0.05). Subsurface lesions on dentin formed consistently, with their growth progression inhibited by application of fluoride. To our knowledge, this is the first report describing the induction of subsurface dentin lesions by a polymicrobial biofilm model, and this model may be useful for studies of demineralization supporting in situ and in vivo models.