A radiographic and histological study to compare red (650 nm) versus near infrared (810 nm) diode lasers photobiomodulation for alveolar socket preservation.

Previous findings indicated that the laser photobiomodulation is more effective than the control or placebo in preserving the alveolar socket. This study aimed to compare two different lasers regarding their effectiveness in aiding alveolar socket preservation. Twenty extraction sockets were selected then divided into two equal groups. Group A was exposed to 650 nm Diode laser, and Group B to 810 nm Diode laser following the same protocol and parameters after a standard alveolar socket preservation procedure with collagen plug. Radiographic analysis with cone beam computed tomography was done to compare the alveolar bone surface area immediately after extraction and three months post-operatively, while bone samples collected before implant drilling were histologically examined for newly formed bone evaluation and histomorphometric analysis in terms of percentage of new bone surface area, percentage of unmineralized bone and finally, immunohistochemical analysis of Osteocalcin reaction surface area as well as optical density. Radiographically, infrared (810 nm) Diode effect on alveolar bone surface area has significantly exceeded the red laser, while histologically, red (650 nm) Diode has demonstrated statistical significance regarding all parameters; newly formed bone surface area percentage, unmineralized bone area percentage and finally Osteocalcin bone marker reaction surface area percentage and optical density. Under the specified conditions and laser parameters, photobiomodulation using the 810 nm Diode got the upper hand radiographically, yet histologically, the red 650 nm Diode managed to dominate all histological parameters when both employed as an adjunct to alveolar socket preservation procedures.

Adjuvant effects of Saccharomyces cerevisiae in the treatment of experimental periodontitis in rats undergoing chemotherapy.

Surgical procedures, radiotherapy, and chemotherapy, individually or in association, are current oncological treatments. Among the most used chemotherapy drugs, 5-fluorouracil (5FU) is an antimetabolite with a broad spectrum of action. This study evaluated the effects of probiotics (PRO) as an adjuvant to the treatment of experimental periodontitis (EP) in rats immunosuppressed with 5FU.108 rats were randomly allocated to six different groups: EP; SS - systemic treatment with saline solution (SS); 5FU - systemic treatment with 5FU; 5FU+PRO - systemic treatment with 5FU, followed by the local administration of Saccharomyces cerevisiae ; 5FU+SRP - systemic treatment with 5-FU, followed by scaling and root planing (SRP); and 5FU+SRP+PRO - systemic treatment with 5FU followed by local treatments with SRP and PRO. Immunosuppression was obtained at two points: at the time of ligature installation and after 48 h. Six animals from each group were euthanized at seven, 15, and 30 d and hemimandibles were collected and processed for histopathological, histometric, and immunohistochemical analysis. Data were subjected to statistical analysis (α=5%). At 7 d, the 5FU+PRO group showed less bone resorption and better structured connective tissue compared with the EP, SS, 5FU+SRP, and 5FU+SRP+PRO groups. At 15 d, the 5FU+SRP group showed a greater intensity of the inflammatory response (p<0.05). At 30 d, the 5FU+SRP+PRO group showed better structured bone tissue and a higher percentage of bone tissue (PBT) than the EP, SS, 5FU, and 5FU+PRO groups (p<0.05). The use of Saccharomyces cerevisiae as monotherapy or as an adjuvant to periodontal therapy may have a positive effect on bone repair in immunosuppressed conditions.

Anti-Periodontitis Effects of Dendropanax morbiferus H.Lév Leaf Extract on Ligature-Induced Periodontitis in Rats.

Periodontitis is caused by pathogens in the oral cavity. It is a chronic infectious disease that causes symptoms including gingival bleeding and tooth loss resulting from the destruction of periodontal tissues coupled with inflammation. Dendropanax morbiferus H.Lév (DM) is a natural product that exhibits various biological activities with few side effects. In this study, the potential of DM leaf hot-water extracts (DMWE) as a treatment for periodontitis was determined and its anti-oxidant and anti-inflammatory effects were evaluated. Compounds in DMWE were identified by high-performance liquid chromatography (HPLC) and nitric oxide (NO) and prostaglandin E2 (PGE2) production was measured in RAW 264.7 cells. We measured the gingival index and gingival sulcus depth, and micro-CT was performed in vivo using a ligature-induced periodontitis rat model, which is similar to human periodontitis. The DMWE-treated group exhibited a decrease in cytokine concentration and relieved the gingival index and gingival sulcus depth compared with the periodontitis-induced control group. In addition, micro-CT and histological analysis revealed that DMWE exhibited anti-inflammatory effects and improved alveolar bone loss in periodontitis-induced rats. These findings suggest that DMWE has excellent anti-oxidant and anti-inflammatory effects that protect and prevent periodontal tissue damage and tooth loss caused by the inflammatory response.

The Treatment Efficiency and Microbiota Analysis of Sapindus mukorossi Seed Oil on the Ligature-Induced Periodontitis Rat Model.

Periodontitis is a common oral disease mainly caused by bacterial infection and inflammation of the gingiva. In the prevention or treatment of periodontitis, anti-bacterial agents are used to inhibit pathogen growth, despite increasing levels of bacterial resistance. Sapindus mukorossi Gaertn (SM) seed oil has proven anti-bacterial and anti-inflammation properties. However, the possibility of using this plant to prevent or treat periodontitis has not been reported previously. The aim of this study was to evaluate the effects of SM oil on experimental periodontitis in rats by using micro-CT and microbiota analysis. The distance between cementoenamel junction (CEJ) and alveolar bone crest (ABC) on the sagittal micro-CT slide showed that total bone loss (TBL) was significantly lower in CEJ-ABC distances between SM oil and SM oil-free groups on Day 14. Histology data also showed less alveolar bone resorption, a result consistent result with micro-CT imaging. The microbiota analyzed at phylum and class levels were compared between the SM oil and SM oil-free groups on Day 7 and Day 14. At the phylum level, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were the dominant bacterium. Firmicutes in box plot analysis was significantly less in the SM oil group than in the SM oil-free group on Day 7. At the class level, Bacteroidia, Gammaproteobacteria, Bacilli, Clostridia, and Erysipelotrichia were the dominant bacteria. The bacteria composition proportion of Bacilli, Clostridiay, and Erysipelotrichia could be seen in the SM oil group significantly less than in t SM oil-free group on Day 7. Overall, the present results show that topical application of SM oil can reduce bone resorption and change bacteria composition in the ligature-induced periodontitis model. According to these results, it is reasonable to suggest SM oil as a potential material for preventing oral disease.

Efficacy and safety of P11-4 for the treatment of periodontal defects in dogs.

OBJECTIVES: This study's aim was to investigate the safety and performance of a self-assembling peptide matrix (SAPM) P11-4 for the treatment of periodontal disease in a controlled pre-clinical study. MATERIALS AND METHODS: Acute buccal bony dehiscence defects (LxW: 5 × 3 mm) were surgically created on the distal root of four teeth on one mandible side of 7 beagle dogs followed by another identical surgery 8 weeks later on the contralateral side. SAPM P11-4 (with and without root conditioning with 24% EDTA (T1, T2)), Emdogain® (C) and a sham intervention (S) were randomly applied on the four defects at each time point. Four weeks after the second surgery and treatment, the animals were sacrificed, the mandibles measured by micro-computed tomography (µ-CT) and sections of the tissue were stained and evaluated histologically. RESULTS: Clinically and histologically, no safety concerns or pathological issues due to the treatments were observed in any of the study groups at any time point. All groups showed overall similar results after 4 and 12 weeks of healing regarding new cementum, functionality of newly formed periodontal ligament and recovery of height and volume of the new alveolar bone and mineral density. CONCLUSION: A controlled clinical study in humans should be performed in a next step as no adverse effects or safety issues, which might affect clinical usage of the product, were observed. CLINICAL RELEVANCE: The synthetic SAPM P11-4 may offer an alternative to the animal-derived product Emdogain® in the future.

Effects of infrared light laser therapy on in vivo and in vitro periodontitis models.

BACKGROUND: This study evaluated the effects of infrared light laser therapy (ILLT) on ligature-induced periodontitis in rats using micro-computed tomography (micro-CT), histology, fibroblast migration, and viability analysis. METHODS: Forty-eight rats were randomly distributed into three groups: control (no periodontitis), PDC (periodontitis without laser therapy), and PD+L (periodontitis with laser therapy). Periodontitis was induced by ligature placement for 4 weeks. The 12-week-old rats (baseline) were subjected to laser treatment and euthanized 30 days after. After treatment, the mandibular first molars were prepared for micro-CT scanning, and histological sections were assessed as to the cementoenamel junction, alveolar bone crest, and polymorphonuclear (PMN) cell infiltration. In vitro assays were carried out to examine NIH/3T3 fibroblast viability after laser therapy. RESULTS: Migration and cell viability assays revealed that the ILLT maintained fibroblast cell viability with 4 J/cm2 , reaching 100% healing. The control group (at baseline and 30 days) presented a statistically significant difference from the PDC group at 30 days in terms of distance from the cementoenamel junction to the alveolar bone crest (CEJ-ABC). The PD+L group showed a statistically substantial difference from the PDC group at 30 days in terms of trabecular thickness (Tb.Th), degree of anisotropy (DA), and closed porosity percentage (Po%). CONCLUSION: ILLT seemed to preserve the bone structure in the in vivo periodontitis induction model at 30 days and did not reduce cell viability or increase fibroblast migration in vitro. The ILLT provides positive effects on mandibular bone microstructure.

Carotid sinus nerve stimulation attenuates alveolar bone loss and inflammation in experimental periodontitis.

Baroreceptor and chemoreceptor reflexes modulate inflammatory responses. However, whether these reflexes attenuate periodontal diseases has been poorly examined. Thus, the present study determined the effects of electrical activation of the carotid sinus nerve (CSN) in rats with periodontitis. We hypothesized that activation of the baro and chemoreflexes attenuates alveolar bone loss and the associated inflammatory processes. Electrodes were implanted around the CSN, and bilateral ligation of the first mandibular molar was performed to, respectively, stimulate the CNS and induce periodontitis. The CSN was stimulated daily for 10 min, during nine days, in unanesthetized animals. On the eighth day, a catheter was inserted into the left femoral artery and, in the next day, the arterial pressure was recorded. Effectiveness of the CNS electrical stimulation was confirmed by hypotensive responses, which was followed by the collection of a blood sample, gingival tissue, and jaw. Long-term (9 days) electrical stimulation of the CSN attenuated bone loss and the histological damage around the first molar. In addition, the CSN stimulation also reduced the gingival and plasma pro-inflammatory cytokines induced by periodontitis. Thus, CSN stimulation has a protective effect on the development of periodontal disease mitigating alveolar bone loss and inflammatory processes.

Effect of IgY on Periodontitis and Halitosis Induced by Fusobacterium nucleatum.

Fusobacterium nucleatum is a morbific agent in periodontitis and halitosis. Egg yolk antibody (IgY) was obtained from egg yolks from chickens stimulated with F. nucleatum. This study was to assess the effectiveness of IgY on periodontitis and halitosis caused by F. nucleatum in vitro and in vivo. The growth of F. nucleatum was inhibited (p <0. 05) by different concentrations of IgY in vitro and the results of a Halimeter show volatile sulfur compounds (VSCs) were reduced to 904 ± 57 ppb at a concentration 40 mg/ml of IgY. The changes of fatty acids of F. nucleatum were determined using GC-MS. The scores for odor index of rat saliva were decreased. The major constituent of volatile organic compounds (VOCs) including short-chain acids decreased 46.2% in 10 mg/ml IgY, ammonia decreased 70% in 40 mg/ml IgY, while aldehydes and olefine ketones were almost unchanged. The ELISA assay revealed that IL-6 and TNF-α were decreased after 4 weeks' IgY treatment. Morphometric (X-ray) and histological analyses (HE) showed that IgY reduced alveolar bone loss and collagen fibers became orderly in rat models. As a result, IgY may have the potential to treat periodontitis and halitosis.

Peptides from rice endosperm protein restrain periodontal bone loss in mouse model of periodontitis.

OBJECTIVE: Food-derived peptides have been reported to exhibit antibacterial activity against periodontal pathogenic bacteria. However, no effect has been shown on inflammation and bone resorption in periodontal pathology. The overall objective of the current study was to investigate how rice peptides influence biological defense mechanisms against periodontitis-induced inflammatory bone loss, and identify their novel functions as a potential anti-inflammatory drug. DESIGN: The expression of inflammatory and osteoclast-related molecules was examined in mouse macrophage-derived RAW 264.7 cell cultures using qPCR. Subsequently, the effect of these peptides on inflammatory bone loss in mouse periodontitis was examined using a mouse model of tooth ligation. Briefly, periodontal bone loss was induced for 7 days in mice by ligating the maxillary second molar and leaving the contralateral tooth un-ligated (baseline control). The mice were microinjected daily with the peptide in the gingiva until the day before euthanization. One week after the ligation, TRAP-positive multinucleated cells (MNCs) were enumerated from five random coronal sections of the ligated sites in each mouse. RESULTS: Rice peptides REP9 and REP11 significantly inhibited transcription activity of inflammatory and osteoclast-related molecules. Local treatment with the rice peptides, in mice subjected to ligature-induced periodontitis, inhibited inflammatory bone loss, explaining the decreased numbers of osteoclasts in bone tissue sections. CONCLUSION: Therefore, these data suggested that the rice peptides possess a protective effect against periodontitis.

Effects of the photobiomodulation using different energy densities on the periodontal tissues under orthodontic force in rats with type 2 diabetes mellitus.

To evaluate the impact of the GaAlAs diode laser with energy densities of 160 J/cm2, 320 J/cm2, and 640 J/cm2 on the periodontal tissues under continuous orthodontic force application and on the rate of orthodontic tooth movement in rats with type-2 diabetes mellitus. The intensity of primary alveolar bone formation was also investigated through the immune-positive osteocytes for OPN antibody. Forty adult male Wistar rats were divided into eight groups of 5 rats: normoglycemic (N), 160 J-laser-normoglycemic (160 J-LN), 320 J-laser-normoglycemic (320 J-LN), 640 J-laser-normoglycemic (640 J-LN), diabetic (D), 160 J-laser-diabetic (160 J-LD), 320 J-laser-diabetic (320 J-LD), and 640 J-laser-diabetic (640 J-LD) rats. Diabetes mellitus was induced by a single intravenous injection of 40 mg/kg monohydrated-alloxan. An orthodontic force magnitude of 20cN was applied. The laser parameters were continuous emission of 780-nm wavelength, output power of 20mW, and fiber probe with a spot size of 0.04 cm in diameter. Radiographic, histomorphological, and immunohistochemical analysis were performed after a period of 21 days. The photobiomodulation using the energy density of 640 J/cm2 strongly stimulated the alveolar bone formation and contributed the reorganization of the soft periodontal tissues, followed by the 320 J/cm2. Extensive alveolar bone loss, intense infiltration of inflammatory cells, and degradation of the PDJ tissue were mainly found in the D and 160 J-LD groups. The rate of orthodontic tooth movement was represented by the interdental distance between the cementoenamel junctions of the right mandibular first and second molars . This distance was larger in the diabetic groups (D: 39.98±1.97, 160 J-LD: 34.84±6.01, 320 J-LD: 29.82±1.73, and 640 J-LD: 35.47±4.56) than in the normoglycemic groups (N: 21.13±1.19; 160 J-LN: 22.69±0.72, 320 J-LN: 22.28±0.78, and 640 J-LN: 24.56±2.11). The number of osteopontin-positive osteocytes was significantly greater in the 640 J-LD (14.72 ± 0.82; p < 0.01) and 640 J-LN (13.62 ± 1.33; p < 0.05) groups than with D (9.82 ± 1.17) and 160 J-LD (9.77 ± 1.10) groups. Therefore, the energy density of 640 J/cm2 provided the best maintenance and integrity of the periodontal tissue microarchitecture under continuous orthodontic force when compared with the other dosages, mainly in the uncontrolled diabetic rats. The interdental distance was greater in the D and 160 J-LD groups due to presence of severe periodontitis caused by diabetes plus the mechanical stress generated by continuous orthodontic forces, implying, thus, an insufficient biostimulatory effect for the dosage of 160 J/cm2.

Interplay between P. gingivalis, F. nucleatum and A. actinomycetemcomitans in murine alveolar bone loss, arthritis onset and progression.

Increasing evidence supports the association of periodontitis with rheumatoid arthritis. Even though a prominent role has been postulated for Porphyromonas gingivalis, many bacterial species contribute to the pathogenesis of periodontal disease. We therefore investigated the impact of Porphyromonas gingivalis as well as other major pathobionts on the development of both, periodontitis and arthritis in the mouse. Pathobionts used - either alone or in combination - were Porphyromonas gingivalis, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomintans. Periodontitis was induced via oral gavage in SKG, DBA/1 and F1 (DBA/1 × B10.Q) mice and collagen-induced arthritis was provoked via immunization and boost with bovine collagen type II. Alveolar bone loss was quantified via micro computed tomography, arthritis was evaluated macroscopically and histologically and serum antibodies were assessed. Among the strains tested, only F1 mice were susceptible to P. gingivalis induced periodontitis and showed significant alveolar bone loss. Bone loss was paralleled by antibody titers against P. gingivalis. Of note, mice inoculated with the mix of all three pathobionts showed less alveolar bone loss than mice inoculated with P. gingivalis alone. However, oral inoculation with either F. nucleatum or A. actinomycetemcomintans alone accelerated subsequent arthritis onset and progression. This is the first report of a triple oral inoculation of pathobionts combined with collagen-induced arthritis in the mouse. In this interplay and this particular genetic setting, F. nucleatum and A. actinomycetemcomitans exerted a protective impact on P. gingivalis induced alveolar bone loss. By themselves they did not induce periodontitis yet accelerated arthritis onset and progression.

Inhibitory Effect of Standardized Curcuma xanthorrhiza Supercritical Extract on LPS-Induced Periodontitis in Rats.

Periodontitis, which is a severe inflammatory disease caused by endotoxins secreted from oral pathogens, destructs gingival tissue and alveolar bone. Curcuma xanthorrhiza, commonly called Java turmeric, has been shown to possess anti-bacterial and anti-inflammatory activities. The present study evaluated the inhibitory effect of C. xanthorrhiza supercritical extract (CXS) standardized with xanthorrhizol on lipopolysaccharide (LPS)-induced periodontitis in an animal model. LPS was topically injected into the periodontium of Sprague-Dawley rats to induce periodontitis and CXS (30 and 100 mg·kg-1·day-1) was orally administered after day 12. Histologically, CXS inhibited the collapse of gingival tissue by preventing cell infiltration. CXS significantly downregulated the expression of matrix metalloproteases (MMPs) and inflammation-related biomarkers, such as nuclear factor-kappa B (NF-κB) and interleukin-1 beta (IL-1ß) in gingival tissue. CXS also improved bone remodeling by downregulating osteoclastic transcription factors, such as nuclear factor of activated T-cells c1 (NFATc1), tartrate-resistant acid phosphatase (TRAP), and cathepsin K. In addition, CXS upregulated osteoblast differentiation-related markers, alkaline phosphate (ALP) and collagen type I alpha (COLA1). Thus, CXS can ameliorate periodontitis by inhibiting inflammation and improving bone remodeling.

New Application of Psoralen and Angelicin on Periodontitis With Anti-bacterial, Anti-inflammatory, and Osteogenesis Effects.

Psoralen and angelicin are two effective compounds isolated from psoraleae, a traditional Chinese medicine. They have a wide range of applications for bone disease treatment and immune modulation. In this study, we explored their new applications for the treatment of periodontal diseases. This study aimed to investigate the effects of psoralen and angelicin on Porphyromonas gingivalis growth and P. gingivalis-derived lipopolysaccharide (Pg-LPS)-induced inflammation, and further to evaluate their effects on osteogenesis. Finally, the effects of angelicin on a mouse model of periodontitis were also investigated. The results showed that psoralen and angelicin had beneficial dose-dependent effects regarding the inhibition of planktonic P. gingivalis and biofilms of P. gingivalis. There were no significant differences in the viability of monocyte-like THP-1 cells and human periodontal ligament cells (hPDLCs) treated with either psoralen or angelicin compared to the untreated control cells. Psoralen and angelicin also markedly decreased the mRNA expression and release of inflammatory cytokines (interleukin [IL]-1ß and IL-8) by THP-1 cells in a dose-dependent manner. They significantly enhanced the alkaline phosphatase (ALP) activity of hPDLCs and up-regulated the expression of osteogenic proteins (runt-related transcription factor 2 [RUNX2], distal-less homeobox 5 [DLX5], and osteopontin [OPN]). Angelicin significantly attenuated alveolar bone loss and inflammation response in the mice with periodontitis. In conclusion, our data demonstrated that psoralen and angelicin could inhibit the growth of planktonic P. gingivalis and P. gingivalis biofilm. It is also the first report on the anti-inflammatory effect of psoralen and angelicin against Pg-LPS. They also had an osteogenesis-potentiating effect on hPDLCs. The in vivo study also indicated the effect of angelicin regarding protection against periodontitis. Our study highlighted the potential ability of psoralen and angelicin to act as novel natural agents to prevent and treat periodontitis.

Bone loss and hematological malignancies in adults: a pilot study.

PURPOSE: Bone loss-osteopenia and osteoporosis-is a recognized consequence of solid tumors in adults, of pediatric hematological malignancies, and of the treatment for these diseases, but little research has been published on the adverse effects of hematological malignancies on the bone in adults. The aim of this study is to identify hematological diseases that are associated with the highest prevalence and severity of osteoporosis. METHODS: We evaluated DXA (dual-energy X-ray absorptiometry) in a cross-section of 181 adult patients with hematological neoplasms, excluding multiple myeloma. All patients were over 18 years of age, signed a local institutional review board (IRB)-approved consent form, and had completed a questionnaire regarding predisposing factors to osteoporosis. This data was supplemented by hospital charts. RESULTS: Bone loss as measured by DXA T scores was found in 65% of patients, of whom 38% had osteopenia and 27% osteoporosis. DXA Z scores under - 2.0 were found in 11.4% of patients, compared to the expected 2.5% of the normal population. The DXA Z scores varied by diagnosis, showing bone loss in 49% of chronic lymphocytic leukemia/small lymphocytic lymphoma, compared to 67% of non-Hodgkin lymphoma and 88% of Hodgkin disease; the scores were not affected by the duration of time from diagnosis to DXA (3.6, 2.0, and 1.6 years, respectively). CONCLUSION: Adult patients with hematological malignancies have significant bone loss compared to a normal age-matched population. The type of diagnosis is more important than the time from diagnosis in predicting risk for bone loss. Recognition of bone loss in these patients may warrant prophylactic measures and lifestyle changes before, during, and after therapy.

Tocoyena sellowiana extract decreases bone loss in an experimental model of periodontitis in rats: Putative role for cyclooxygenase-2 and IL-1? inhibition.

Tocoyena sellowiana (Cham. & Schltdl.) K.Schum is one of the most important families of Brazilian medicinal plants. This study aimed to evaluate the effect of Tocoyena sellowiana (Cham. & Schltdl.) K.Schum ethanolic extract in a pre-clinical trial of periodontitis and to investigate possible mechanisms underlying such effects. Periodontitis was induced in Wistar rats by placing a nylon thread ligature around second upper left molars for 11 days. Rats received (per os) Tocoyena sellowiana (0.1, 1 or 10?mg?kg) or vehicle 1?h before ligature and daily until day 11. Macroscopic, histopathological, and COX-2 immunohistochemical analyses were performed to evaluate the periodontium. The gingival tissue was used to quantify the myeloperoxidase (MPO) activity and interleukin (IL)-1? levels by ELISA. Blood samples were collected to evaluate bone-specific alkaline phosphatase (BALP), the dosage of creatinine, aspartate and alanine transaminases. The liver, kidneys, spleen, and body mass variations were also evaluated. Tocoyena sellowiana decreased bone loss, reduced MPO, IL-1? levels as well as COX-2 immunostaining, and increased BALP activity. Moreover, Tocoyena sellowiana did not alter organs nor body weight. Tocoyena sellowiana reduced bone loss in rats and its efficacy was at least partially dependent upon both IL-1? and cyclooxygenase-2 inhibition.

Morphometric and histopathological evaluation of the effect of grape seed proanthocyanidin on alveolar bone loss in experimental diabetes and periodontitis.

OBJECTIVE: Grape seed proanthocyanidine extract (GSPE) is a strong antioxidant derived from the grape seeds (Vitis vinifera, Terral J.F.) and has a polyphenolic structure with a wide range of biological activity. The aim of the present study was to evaluate the effects of GSPE on alveolar bone loss and histopathological changes in rats with diabetes mellitus and ligature-induced periodontitis. MATERIAL AND METHODS: Forty rats were divided into 6 study groups. Control (C, 6 rats) group, periodontitis (P, 6 rats) group, diabetes (D, 6 rats) group, diabetes and periodontitis (D+P, 6 rats) group, diabetes, periodontitis and 100 mg/kg/day GSPE (GSPE-100, 8 rats), and diabetes, periodontitis and 200 mg/kg/day GSPE (GSPE-200, 8 rats) group. Diabetes mellitus was induced by intraperitoneal injection of a single dose of streptozotocin (60 mg/kg). Periodontitis was induced via ligation method. Silk ligatures were placed at the mandibular right first molars. GSPE was administered by oral gavage. After 30 days, all rats were killed. Alveolar bone loss was measured morphometrically via a stereomicroscope. For histopathological analyses, Alizarin red staining, and matrix metalloproteinase (MMP)-8, vascular endothelial growth factor and hypoxia inducible factor (HIF)-1α immunohistochemistry were performed. Tartrate-resistant acid phosphatase-positive osteoclast cells and relative total inflammatory cells were also determined. RESULTS: The highest alveolar bone loss was observed in the D+P group (P < .05). GSP-200 group decreased alveolar bone loss (P < .05). The D+P group had the highest osteoclast counts, but the difference was not significant compared to the P, GSPE-100 and GSPE-200 groups (P > .05). The inflammation in the D+P group was also higher than the other groups (P < .05). The osteoblast numbers increased in the GSPE-100 and GSPE-200 groups compared to the P and D+P groups (P < .05). MMP-8 and HIF-1α levels were highest in the D+P group and GSPE significantly decreased these levels (P < .05). CONCLUSION: Within the limits of this animal study, it can be suggested that GSPE administration may decrease periodontal inflammation and alveolar bone loss via decreasing MMP-8 and HIF-1α levels and increase osteoblastic activity in diabetic rats with experimental periodontitis.

Inhibitory Effects of Boesenbergia pandurata on Age-Related Periodontal Inflammation and Alveolar Bone Loss in Fischer 344 Rats.

Periodontitis, an infective disease caused by oral pathogens and the intrinsic aging process, results in the destruction of periodontal tissues and the loss of alveolar bone. This study investigated whether Boesenbergia pandurata extract (BPE) standardized with panduratin A exerted anti-periodontitis effects, using an aging model representative of naturally occurring periodontitis. In aged rats, the oral administration of BPE (200 mg·kg-1·day-1) for 8 weeks significantly reduced the mRNA and protein expression of interleukin-1ß, nuclear factor-kappa B, matrix metalloproteinase (MMP)-2, and MMP-8 in gingival tissues (p < 0.01). In alveolar bone, histological analysis with staining and micro-computed tomography revealed the attenuation of alveolar bone resorption in the BPE-treated aged group, which led to a significant reduction in the mRNA and protein expression of nuclear factor of activated T-cells c1 (NFATc1), c-Fos, tartrate-resistant acid phosphatase, and cathepsin K (p < 0.01). BPE not only increased the expression of osteoblast differentiation markers, such as alkaline phosphate, and collagen type I (COL1A1), but also increased the ratio of osteoprotegerin to RANKL. Collectively, the results strongly suggested that BPE is a natural resource for the prevention or treatment of periodontal diseases.

Effects of vitamin D status on oral health.

Normal humans of all ages have the innate ability to produce vitamin D following sunlight exposure. Inadequate vitamin D status has shown to be associated with a wide variety of diseases, including oral health disorders. Insufficient sunlight exposure may accelerate some of these diseases, possibly due to impaired vitamin D synthesis. The beneficial effects of vitamin D on oral health are not only limited to the direct effects on the tooth mineralization, but are also exerted through the anti-inflammatory functions and the ability to stimulate the production of anti-microbial peptides. In this article, we will briefly discuss the genesis of various oral diseases due to inadequate vitamin D level in the body and elucidate the potential benefits of safe sunlight exposure for the maintenance of oral and general health.

Local administration of calcitonin inhibits alveolar bone loss in an experimental periodontitis in rats.

Calcitonin (CTN), a calcium regulatory hormone, promotes calcium diuresis from the kidney and suppresses bone resorption. The objective of this study was to evaluate whether the topical and intermittent application of CTN inhibits alveolar bone resorption using ligature-induced experimental periodontitis in rats. Experimental periodontitis was induced by placing a nylon ligature around maxillary molars of 8-week-old male Wistar rats for 20 days. Thirty-two rats were divided into four groups: basal sham control group, periodontitis group, periodontitis plus 0.2 U CTN (low dose), and periodontitis plus 1.0 U CTN (high dose) group. To investigate the effects of CTN on alveolar bone resorption, CTN was topically injected into the palatal gingivae every 2 days after ligature removal (day 0). Micro-computed tomography (CT) analysis was performed for linear parameter assessment of alveolar bone on day 5 and day 14. Periodontal tissues were examined histo-pathologically to assess the differences among the study groups. Micro-CT images showed that alveolar bone resorption was induced statistically around the molar of ligatured rats on day 5 and day 14. The amount of bone resorption was more severe on day 14 than that on day 5. On day 5, only high-dose CTN treatment significantly suppressed bone resorption. In addition, both doses of CTN significantly suppressed bone resorption on day 14. Histological examination clarified that there were fewer TRAP-positive cells in the CTN treatment groups than in the periodontitis group on day 5. Local administration of CTN decreased alveolar bone resorption by regulating osteoclast activation in rats with periodontitis.

Immunoprotective effects of a hemin-binding peptide derived from hemagglutinin-2 against infection with Porphyromonas gingivalis.

The principal etiologic agent in periodontal disease, Porphyromonas gingivalis, generates cysteine proteases that bind heme with domains such as hemagglutinin-2 (HA2). High-affinity HA2-hemin binding supplies the porphyrin and ferric iron needed for growth and virulence. The DHYAVMISK peptide, recently identified at the hemin-binding site of HA2, inhibits hemin binding. We now evaluate the protective effect of vaccination with DGFPGDHYAVMISK (termed DK) against P. gingivalis using a rat infection model. Rats immunized with DK generated anti-peptide serum IgGs and salivary sIgAs (as measured by ELISA). In a subcutaneous abscess model, the protective effect of immunization was then investigated by measuring abscess size following subcutaneous injection with P. gingivalis. In an oral infection model, a ligature inoculated with P. gingivalis was used to induce periodontitis. The degree of bone erosion, ordinarily provoked by infection, was then evaluated by micro-computed tomography. We found that anti-peptide antibody titers of serum IgGs and salivary sIgAs for rats immunized with DK and adjuvant were significantly higher than for sham-immunized rats (injected with adjuvant/PBS alone; P < .05). In the subcutaneous abscess model, the DK + adjuvant-vaccinated rats recovered faster than sham-vaccinated animals, with their abscess sizes significantly smaller (P < .05). Further, in the experimental periodontitis model, bone loss at the molar palatal side for DK + adjuvant-vaccinated rats was significantly lower than for sham-vaccinated animals (P < .05). Collectively, these data demonstrate the potential of (DK) peptide immunization in terms of eliciting an immunoprotective effect against infection with P. gingivalis.