Utility of a haemoglobin test of gingival crevicular fluid: A multicentre, observational study.

OBJECTIVE: The purpose of this study was to verify the accuracy and utility of clinical parameters (plaque index, gingival crevicular fluid volume, probing depth, clinical attachment level, bleeding on probing and gingival index) and biochemical parameters (aspartate aminotransferase, protein and haemoglobin) in a longitudinal analysis during the supportive periodontal therapy period. SUBJECTS AND METHODS: A total of 279 test sites of 128 patients were investigated clinically and biochemically. After the first examination of clinical and biochemical parameters, periodontal support treatments were administered immediately and performed once every three months up to the second examination. RESULTS: All of the clinical and biochemical parameters were significantly lower at the second examination than at the first, except for the plaque index and bleeding on probing. Of these parameters, in particular, aspartate aminotransferase and haemoglobin in the gingival crevicular fluid were significantly reduced compared to those of the first examination in both the ≤4 and ≥5 mm probing depth groups, and they clearly suggested that periodontitis tended to recover. CONCLUSION: Adding the haemoglobin test to the bleeding on probing test strongly improves the accuracy of measurement of clinical parameters after periodontal treatment.

Relationship of oral conditions to the incidence of infective endocarditis in periodontitis patients with valvular heart disease: a cross-sectional study.

OBJECTIVES: Infective endocarditis (IE) is a life-threatening infectious disease, but the pathogenesis of the disease remains uncertain. The objective of this study was to examine whether oral infectious conditions are associated with the occurrence of IE in valvular heart disease (VHD) patients. MATERIALS AND METHODS: A total of 119 periodontitis (P) patients with or without VHD were enrolled, and cross-sectional analyses were performed. Patients were classified as follows: (1) mild-to-moderate P without VHD, (2) mild-to-moderate P with VHD, (3) severe P without VHD, or (4) severe P with VHD. A total of 78 VHD patients were classified as (1) VHD without IE or (2) VHD with IE. Conditional logistic regression analysis was performed to compute the odds ratio (OR) and 95% confidence interval (CI). RESULTS: No significant differences were observed between patients with or without VHD in oral conditions. A significant increase in the percentage of alveolar bone loss in VHD patients with IE was observed compared with that of patients without IE. The ratio of both Porphyromonas gingivalis (Pg) IgG titer > 1.68 and Pg fimA type II genotype in patients with IE was significantly higher than in patients without IE. There was a significant correlation between the occurrence of IE and clinical oral findings (number of remaining teeth: OR, 0.17; rate of alveolar bone loss > 40%: OR, 11.8). CONCLUSIONS: VHD patients with IE might have severe periodontitis compared with patients without IE, although further investigation will be needed because this is based on only 7 VHD patients with IE. CLINICAL RELEVANCE: The patients with IE had fewer remaining teeth, more advanced bone resorption compared with those of patients without IE. These findings suggest a possible association between the occurrence of IE and periodontal infection.

Biological effects of interleukin-6 on Gingival Fibroblasts: Cytokine regulation in periodontitis.

Periodontitis is a bacterial infectious disease, and many inflammatory cytokines regulate periodontitis pathophysiology through a crosstalk between tissue cells and immune cells. Interleukin (IL)-6 is an important cytokine involved in the regulation of host response to bacterial infection. Human Gingival Fibroblasts (HGFs) are the most abundant cells in gingival connective tissues. Various HGF responses to periodontal pathogens or inflammatory cytokines contribute to the development of periodontitis. Lipopolysaccharide derived from Porphyromonas gingivalis (Pg LPS) and IL-1ß significantly increase IL-6 production in HGFs. However, IL-6 cannot function in HGFs without the soluble form of the IL-6 receptor (sIL-6R), because HGFs do not express sufficient cell surface IL-6R to bind appreciable levels of IL-6. Importantly, sIL-6R is essential for IL-6 signaling in HGFs, and the sIL-6R is produced by differentiated THP-1 cells treated with IL-6. Calprotectin, a heterodimer of S100A8 and S100A9, is released during inflammation and significantly induces IL-6 production in HGFs via toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signals. Calprotectin also induces sIL-6R production in differentiated THP-1 cells. IL-6 induces vascular endothelial growth factor (VEGF), matrix-metalloproteinase-1 (MMP-1), and cathepsin L production in HGFs in the presence of sIL-6R. Taken together, calprotectin-induced IL-6 production in HGFs may cause periodontitis progression through a crosstalk of fibroblasts and macrophages. There are many reports that examine how cytokines are released from HGFs to cause beneficial or harmful effects in inflamed periodontal lesions. This review explores the pathophysiology of periodontitis by focusing IL-6-mediated crosstalk of HGFs and macrophages.

High Glucose-Mediated Cytokine Regulation in Gingival Fibroblasts and THP-1 Macrophage: a Possible Mechanism of Severe Periodontitis with Diabetes.

BACKGROUND/AIMS: Diabetic patients are susceptible to severe periodontitis, but the precise mechanism is not fully understood. Aim of this study was to explore the biological pathogenesis of severe periodontitis in diabetic patients focusing on the crosstalk of human gingival fibroblasts (HGFs) and macrophages. METHODS: A total of 70 periodontitis patients with or without diabetes mellitus (DM) were enrolled, and the statistical relationships of diabetic conditions to the periodontal inflammatory parameters were examined by cross-sectional study. In in vitro study, HGFs cell line CRL-2014® (ATCC) and differentiated THP-1 macrophages were cultured with normal glucose (NG: 5.5 mM) or high glucose (HG: 25 mM) condition, and treated with indicated inflammatory factors such as calprotectin (CPT), interleukin (IL)-1ß and IL-6. To examine the effects of HG on soluble IL-6 receptor (sIL-6R) production in THP-1 macrophages, the supernatants were collected and the sIL-6R levels were measured by ELISA. To examine the effects of HG on IL-1ß or IL-6-induced matrix metalloproteinase (MMPs) production in HGFs, the supernatants were collected. Levels of MMP-1 and tissue inhibitor of MMP-1 (TIMP-1) were measured by ELISA. Finally, after conditioned medium (CM) from THP-1 macrophages cultured with NG or HG conditions was collected, HGFs were treated with the CM. The supernatants were collected 24 hours later and the levels of MMP-1 and TIMP-1 were measured. To examine the specific effects of IL-1ß contained in CM on MMP-1 and TIMP-1 production in HGFs, IL-1 receptor antagonist (IL-1ra) was used. RESULTS: There were statistical correlation between IL-1ß and sIL-6R levels in gingival crevicular fluid (GCF) and HbA1c in periodontitis patients with DM (IL-1ß: P=0.035, sIL-6R: P=0.040). HG and CPT significantly induced sIL-6R production in THP-1 macrophages. HG significantly enhanced IL-1ß or IL-6/sIL-6R-induced MMP-1 production in HGFs. The increase of MMP-1 by both IL-1ß and IL-6/sIL-6R was significantly inhibited by specific ERK or IκB inhibitors. Corresponding to the regulation of MMP-1 production, HG condition increased the phosphorylation of p44/42 MAPK and IκBα in HGFs treated with IL-1ß or IL-6/sIL-6R. Finally, MMP-1 production in HGFs cultured with HG increased significantly by CM from THP-1 macrophages cultured with HG. The induction of MMP-1 by the CM from THP-1 macrophages cultured with HG was significantly inhibited by dose dependent of IL-1ra in HGFs cultured with HG. CONCLUSION: Diabetic conditions such as HG induce IL-1ß and sIL-6R production from macrophages in inflammatory periodontal tissues and may exacerbate the periodontitis synergistically via MMP-1 production from HGFs.

ß-carotene suppresses Porphyromonas gingivalis lipopolysaccharide-mediated cytokine production in THP-1 monocytes cultured with high glucose condition.

Periodontitis is associated with development of diabetes mellitus. Although lipopolysaccharide (LPS) of Porphyromonas gingivalis (Pg), a major pathogen of periodontitis, may lead the progression of diabetes complications, the precise mechanisms are unclear. We, therefore, investigated the effects of ß-carotene on production of Pg LPS-induced inflammatory cytokines in human monocytes cultured high glucose (HG) condition. THP-1 cells were cultured under 5.5 mM or 25 mM glucose conditions, and cells were stimulated with Pg LPS. To investigate the productivity of TNF-α, IL-6, and MCP-1, cell supernatants were collected for ELISA. To examine the effects of NF-kB signals on cytokine production, Bay11-7082 was used. HG enhanced Pg LPS-induced production of TNF-α, IL-6, and MCP-1 via NF-kB signals in THP-1. ß-carotene suppressed the enhancement of the Pg LPS-induced cytokine production in THP-1 via NF-κB inactivation. Our results suggest that ß-carotene might be a potential anti-inflammatory nutrient for circulating Pg LPS-mediated cytokine production in diabetic patients with periodontitis.

Calprotectin Induces IL-6 and MCP-1 Production via Toll-Like Receptor 4 Signaling in Human Gingival Fibroblasts.

Calprotectin, a heterodimer of S100A8 and S100A9 molecules, is associated with inflammatory diseases such as inflammatory bowel disease. We have reported that calprotectin levels in gingival crevicular fluids of periodontitis patients are significantly higher than in healthy subjects. However, the functions of calprotectin in pathophysiology of periodontitis are still unknown. The aim of this study is to investigate the effects of calprotectin on the productivity of inflammatory cytokines in human gingival fibroblasts (HGFs). The HGFs cell line CRL-2014® (ATCC) were cultured, and total RNAs were collected to examine the expression of TLR2/4 and RAGE mRNA using RT-PCR. After the cells were treated with S100A8, S100A9, and calprotectin, supernatants were collected and the levels of IL-6 and MCP-1 were measured using ELISA methods. To examine the intracellular signals involved in calprotectin-induced cytokine production, several chemical inhibitors were used. Furthermore, after the siRNA-mediated TLR4 down-regulated cells were treated with S100A8, S100A9, and calprotectin, the levels of IL-6 and MCP-1 were also measured. HGFs showed greater expression of TLR4 mRNA, but not TLR2 and RAGE mRNA compared with human oral epithelial cells. Calprotectin increased significantly the production of MCP-1 and IL-6 in HGFs, and the cytokine productions were significantly suppressed in the cells treated with MAPKs, NF-κB, and TLR4 inhibitors. Furthermore, calprotectin-mediated MCP-1 and IL-6 production were significantly suppressed in TLR4 down-regulated cells. Taken together, calprotectin induces IL-6 and MCP-1 production in HGFs via TLR4 signaling that involves MAPK and NF-κB, resulting in the progression of periodontitis. J. Cell. Physiol. 232: 1862-1871, 2017. © 2016 Wiley Periodicals, Inc.

Antiresorptive agent-related osteonecrosis of the jaw: Position Paper 2017 of the Japanese Allied Committee on Osteonecrosis of the Jaw.

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is an intractable, though rare, complication in cancer patients with bone metastases and patients with osteoporosis who are treated with antiresorptive agents, including bisphosphonates and denosumab. Despite the more than 10 years that have passed since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were reported, our understanding of the epidemiology and pathophysiology of ARONJ remains limited, and data supported by evidence-based medicine are still sparse. However, the diagnosis and staging of ARONJ, identification of risk factors, and development of preventive and therapeutic approaches have advanced significantly over the past decade. The Position Paper 2017 is an updated version of the Position Paper 2010 of the Japanese Allied Committee on Osteonecrosis of the Jaw, which now comprises six Japanese academic societies. The Position Paper 2017 describes a new diagnostic definition for ARONJ, as proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), summarizes our current understanding of the pathophysiology of ARONJ based on a literature search, and suggests methods for physicians and dentists/oral surgeons to manage the disease. In addition, the appropriateness of discontinuing antiresorptive medications (drug holiday) before, during, and after invasive dental treatments is discussed extensively. More importantly, the manuscript also proposes, for the first time, the importance of interactive communication and cooperation between physicians and dentists/oral surgeons for the successful treatment of ARONJ. The Position Paper 2017 is intended to serve as a guide for improving the management of ARONJ patients in Japan.

Gene polymorphism of ß-defensin-1 is associated with susceptibility to periodontitis in Japanese.

Periodontitis is a multifactorial disease associated with genetic and environmental factors. Single-nucleotide polymorphisms (SNPs) are associated with susceptibility to common diseases such as diabetes and periodontitis. Although the oral cavity is exposed to various organisms, the conditions are well controlled by innate and acquired immune systems. Antimicrobial peptides (AMPs) play an important role in the innate immune system; however, the association of AMP-SNPs with periodontitis has not been fully elucidated. This study investigated the relationship between AMP-SNPs and periodontitis in Japanese. One hundred and five Japanese subjects were recruited, which included patients with aggressive, severe, moderate and mild periodontitis, and age-matched healthy controls. Genomic DNA was isolated from peripheral blood and genotypes of SNPs of ß-defensin-1 and lactoferrin genes (DEFB1: rs1799946, rs1800972 and rs11362; and LTF: rs1126478) were investigated using the PCR-Invader assay. Protein level of AMPs in gingival crevicular fluid (GCF) was quantified by ELISA. Case-control studies revealed that the -44 CC genotype of DEFB1 (rs1800972) was associated with periodontitis (OR 2.51), particularly with severe chronic periodontitis (OR 4.15) and with combined severe and moderate chronic periodontitis (OR 4.04). No statistical differences were found in other genotypes. The ß-defensin-1 concentrations in GCF were significantly lower in subjects with the -44 CC genotype of DEFB1 than in those without this genotype. No significant differences between GCF concentrations of AMPs and other genotypes were detected. The -44 CC genotype of the ß-defensin-1 gene (DEFB1 rs1800972) may be associated with susceptibility to chronic periodontitis in Japanese.

Association of gingival recession and other factors with the presence of dentin hypersensitivity.

Dentin hypersensitivity (DH) may be present in association with gingival recession. The aim of this study was to determine quantitatively the association of gingival recession and other factors with the presence of DH. One hundred and four Japanese subjects with or without gingival recession were randomly selected. Intact canines and/or first premolars in both maxillary and mandibular quadrants were analyzed. Gingival recession was measured as a vertical length at the buccal site of the teeth. DH was recorded as an ordered categorical variable registering four increasing levels of pain after cold stimulation; from no discomfort to severe pain during and after stimulation (DH1, 2, 3, and 4). Association of DH with periodontal parameters and daily lifestyle was also investigated. Tooth-based analysis of 446 teeth from 104 subjects revealed that DH level was significantly higher in recessive teeth (1, 2, 3, and 4-8 mm) than in non-recessive teeth (0 mm). DH-positive rate in non-recessive teeth was only 18 % (DH1; 14 %, DH2; 3 %, and DH3; 1 %). Highest DH level was observed in teeth with severe recession (4-8 mm), showing DH0; 21 %, DH1; 33 %, DH2; 31 %, and DH3; 15 %. Recession-dependent increase in DH was observed, showing 18, 49, 52, 60, and 79 % DH-positive in teeth with 0, 1, 2, 3, and 4-8 mm recession, respectively. Plaque-free teeth showed a higher DH level than plaque-stained teeth, suggesting that good plaque control may be associated with the presence of DH. There were no significant differences in DH of teeth on the basis of smoking, probing depth, and bleeding on probing. Multiple logistic regression analysis revealed that gingival recession [odds ratio (OR) = 10.2, 95 % confidence interval (CI) = 5.5-18.9] and plaque deposition (OR = 0.3, 95 % CI = 0.2-0.5) were significant contributors to DH. Multilevel modeling analysis revealed that not only gingival recession and plaque deposition but also V-shaped cervical notch and tooth brushing frequency were associated with DH. These results demonstrate that the progression of gingival recession, plaque-free teeth, V-shaped cervical notch, and frequent brushing may be significant predictors of DH in canines and first premolars.

Evaluation of bleeding on probing and gingival crevicular fluid enzyme activity for detection of periodontally active sites during supportive periodontal therapy.

This study aimed to analyze the enzyme activity in gingival crevicular fluid (GCF) and its association with clinical parameters, especially bleeding on probing (BOP), and thus reconsider the significance and accuracy of recording BOP. A total of 184 patients who had entered supportive periodontal therapy were selected and GCF was collected from 401 sites before recording the clinical parameters, probing pocket depth (PPD), BOP, clinical attachment level, gingival index and plaque index. The enzyme activity of neutrophil elastase and aspartate aminotransferase and amount of protein in GCF were also analyzed. In the clinical parameters for biochemical data, amount of GCF showed the most correlation. A cut-off value for BOP and PPD were determined by the ROC curve and Youden index. Analysis was performed with all clinical parameters and biochemical data. Of the 401 sites, 51 were less than the cut-off value and were BOP-negative. On the other hand, 29 sites had values more than the cut-off value, with 14 BOP-negative sites and 15 BOP-positive sites. A conclusion is as follows: twenty-nine sites with values more than the cut-off value were diagnosed as sites requiring periodontal management, however, 14 of these were BOP-negative. These results suggest that combining other biochemical tests with examination of BOP and PPD may improve the validity of periodontal disease diagnosis. In future studies, it will be essential to find a marker that can precisely detect periodontal disease activity, and to develop a diagnostic tool for chair-side use.

A large-scale observational study to investigate the current status of diabetic complications and their prevention in Japan (JDCP study 6): baseline dental and oral findings.

Japan Diabetes Complication and Prevention prospective (JDCP) study was conducted to examine the association between glycemic control and oral conditions in a large database of Japanese patients with diabetes. It included a total of 6099 patients with diabetes (range, 40-75 years) who had been treated as outpatients between 2007 and 2009. The mean number of present teeth at baseline was 19.8 and women with type 2 diabetes had fewer teeth than men with type 2 diabetes. Within the previous year, 17% of all patients had lost teeth. At baseline, 32% had experienced gingival swelling, 69% had brushed more than twice a day, 37% had used interdental cleaning aids, and 43% had undergone regular dental checkups. Multiple logistic regression analysis indicated that type 1 patients with HbA1c ≥ 7.0% were at higher risk of having fewer than 20 teeth (odds ratio [OR] 2.38; 95% confidence interval [CI] 1.25-4.78), and type 2 patients with HbA1c ≥ 8.0% also were at high risk of having fewer than 20 teeth (OR 1.16; 95% CI 1.00-1.34), after adjustment for nine possible confounding factors. In conclusion, patients with diabetes were found to be at high risk of tooth loss, and the poorer the glycemic control, the higher the risk of tooth loss in these patients.

Bisphosphonate-related osteonecrosis of the jaw: position paper from the Allied Task Force Committee of Japanese Society for Bone and Mineral Research, Japan Osteoporosis Society, Japanese Society of Periodontology, Japanese Society for Oral and Maxillofacial Radiology, and Japanese Society of Oral and Maxillofacial Surgeons.

Bisphosphonates (BPs) have been widely, efficiently, and safely used for the treatment of osteoporosis, malignant hypercalcemia, bone metastasis of solid cancers, and multiple myeloma bone diseases. Accumulating recent reports describe that surgical dental treatments in patients with cancer or osteoporosis who have been receiving intravenous or oral BPs are associated with osteonecrosis of the jaw (bisphosphonate-related osteonecrosis of the jaw, BRONJ). The accurate incidence, clinical backgrounds, and pathogenesis of BRONJ have been unclear and appropriate approaches for prevention and treatment have not been established to date. To address the current situation of BRONJ in Japan, the "Allied Task Force Committee of Bisphosphonate-Related Osteonecrosis of the Jaw," consisting of physicians specializing in bone biology, orthopedic surgery, rheumatology, obstetrics/gynecology, and medical oncology and dentists specializing in oral surgery, periodontology, dental radiology, and oral pathology, was organized. The committee attempted to propose a standard position paper for the treatment of BRONJ. The committee expects that this proposal will provide objective and correct scientific information on BRONJ and will serve as a reference for conducting dental procedures for patients receiving BPs and in designing prevention and treatment of BRONJ. However, because this position paper is not based on direct clinical evidence, it should be used as a reference, and a decision on treatment in each case should be made after an extensive discussion among physicians, dentists/oral surgeons, and the patients.

A low level of lysophosphatidic acid in human gingival crevicular fluid from patients with periodontitis due to high soluble lysophospholipase activity: Its potential protective role on alveolar bone loss by periodontitis.

We previously detected a submicromolar concentration of lysophosphatidic acid (LPA) in human saliva. Here, we compare LPA concentrations in human gingival crevicular fluid (GCF) from patients with periodontitis and healthy controls, and examine how the local LPA levels are regulated enzymatically. The concentrations of LPA and its precursor lysophospholipids in GCF was measured by liquid chromatography-tandem mass spectrometry. The LPA-producing and LPA-degrading enzymatic activities were measured by quantifying the liberated choline and free fatty acid, respectively. The concentration of LPA in GCF of periodontitis patients was lower than that of healthy controls, due to higher soluble lysophospholipase activity toward LPA. LPA was found to prevent survival of Sa3, a human gingival epithelium-derived tumor cell line, activate Sa3 through Ca2+ mobilization, and release interleukin 6 from Sa3 in vitro. Furthermore, local injection of LPA into the gingiva attenuated ligature-induced experimental alveolar bone loss induced by oral bacteria inoculation in a rat model of periodontitis in vivo. A high concentration of LPA in human GCF is necessary to maintain normal gingival epithelial integrity and function, protecting the progression of periodontitis.

[Relationhip between diabetes and periodontal disease].

Periodontal disease is a chronic inflammatory disorder by the anaerobic bacteria invasion into periodontal tissues including gingival connective tissue, periodontal ligament, and alveolar bone. Periodontitis is classified into two types, gingivitis and periodontitis. Diabetic patients tend to suffer from periodontitis with severe alveolar bone loss caused by lowered immune reaction and delayed tissue recovering. Periodontal pathogens such as P. gingivalis lipopolysaccharide (P-LPS) and several cytokines (TNF-alpha, IL-1 and IL-6) stimulate osteoclast differentiation in gingival connective tissue. Then, alveolar bone resorption progresses and the resultant tooth loss falls oral functions. It is confirmed that the incidence of periodontitis is 2- to 3-fold higher in diabetic patients than in non-diabetic subjects. Recently, many researches demonstrated that periodontitis affected diabetic condition, in which periodontal pathogen like P-LPS and TNF-alpha possibly elevated insulin resistance by inhibiting glucose incorporation into smooth muscle cells. Clinical study revealed that serum C-reactive protein (CRP) value increased in periodontitis patients and that periodontal treatment improved the level of HbA(1C) in diabetic patients. These data indicate that periodontal pathogen influenced systemic conditions and these are partly improved by periodontal therapy. Also, periodontal pathogen possibly promotes atherosclerosis formation. Further investigation is necessary to clarify the relationship between diabetes and periodontal disease.

Advanced glycation end-product 2 and Porphyromonas gingivalis lipopolysaccharide increase sclerostin expression in mouse osteocyte-like cells.

Sclerostin is a secreted glycoprotein that is mainly expressed in osteocytes, exerts negative effects on bone formation, and is present at elevated levels in diabetes mellitus (DM). Periodontitis is an infectious disease caused by periodontopathic bacteria, a complication of DM, and sometimes associated with severe inflammation and alveolar bone resorption. Advanced glycation end-products (AGEs) are a major pathogen in DM complications and adversely influence periodontitis in DM patients. In the present study, the effects of AGE2 and Porphyromonas gingivalis lipopolysaccharide (P-LPS) on the expression of sclerostin in mouse osteocyte-like cells (MLO-Y4-A2 cells) and its function in osteoblast differentiation were investigated. AGE2 and P-LPS up-regulated the expressions of receptor of AGE (RAGE) and Toll-like receptor 2 (TLR2), respectively, and significantly up-regulated that of sclerostin and interleukin 6 (IL-6) in osteocytes. Sclerostin, RAGE and TLR2 levels were synergistically increased by AGE2 and P-LPS. The siRNAs of RAGE and TLR2 significantly inhibited AGE2- and P-LPS-induced sclerostin expression. AGE2 up-regulated sclerostin expression in osteocyte-like cells via the RAGE, ERK and JNK, and NF-κB signal pathways. On the other hand, P-LPS elevated sclerostin levels via the TLR2, JNK and p38, and NF-κB signal pathways. When osteocytes pre-treated with AGE2 and P-LPS and osteoblastic cells (MC3T3-E1) were co-cultured in the medium with a sclerostin-neutralizing antibody, AGE2- and P-LPS-induced decreases in alkaline phosphatase activity and Runx2 expression in osteoblastic cells were significantly inhibited by the sclerostin-neutralizing antibody. These results suggest that AGE2 and P-LPS influence bone metabolism and inflammation through the regulation of sclerostin expression, and may aggravate periodontitis with DM.

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.

The KCNQ1 gene polymorphism as a shared genetic risk for rheumatoid arthritis and chronic periodontitis in Japanese adults: A pilot case-control study.

BACKGROUND: A number of studies have suggested a bidirectional relationship of periodontitis with rheumatoid arthritis (RA) and type 2 diabetes mellitus (T2DM). However, the genetic factors that underlie these relationships have not been elucidated. METHODS: We conducted a multicenter case-control study that included 185 patients with RA and chronic periodontitis (CP), 149 patients with T2DM and CP, 251 patients with CP, and 130 systemically and periodontally healthy controls from a cohort of Japanese adults to assess the shared genetic risk factors for RA and CP as well as for T2DM and CP. A total of 17 candidate single nucleotide polymorphisms (SNPs) associated with RA, T2DM, and CP were genotyped. RESULTS: Multiple logistic regression analyses revealed that the KCNQ1 rs2237892 was significantly associated with comorbidity of RA and CP (P = 0.005) after adjustment for age, sex, and smoking status. The carriers of the T allele among patients with RA and CP showed significantly higher disease activity scores including 28 joints using C-reactive protein values than the non-carriers (P = 0.02), although the age, female percentage, and smoking status were comparable. Other SNPs were not associated with comorbidity of RA and CP, T2DM and CP, or susceptibility to CP. CONCLUSION: The results of the present pilot study suggest for the first time that the KCNQ1 rs2237892 may constitute a shared genetic risk factor for RA and CP, but not for T2DM and CP in Japanese adults.

Useful immunochromatographic assay of calprotectin in gingival crevicular fluid for diagnosis of diseased sites in patients with periodontal diseases.

BACKGROUND: Calprotectin, an inflammation-related protein, is present in gingival crevicular fluid (GCF), and the determination of calprotectin is useful for diagnosing periodontal diseases. The authors have recently developed a novel immunochromatographic (IC) chip system to determine calprotectin levels in GCF. In the present study, the usefulness of this diagnostic system is investigated in patients with periodontal diseases. METHODS: Thirty-six patients with periodontal diseases participated in this clinical test at multiple centers. Periodontitis sites (n = 118) and non-periodontitis (healthy) sites (n = 120) were selected after periodontal examination. GCF collection and periodontal examination were performed at baseline, after supragingival and subgingival scaling and root planing. Calprotectin levels in GCF were determined using a novel IC chip system and evaluated as a visual score and an IC reader value. Correlations between GCF calprotectin levels, clinical indicators, and changes in calprotectin levels by periodontal treatments were investigated. Receiver operating characteristic (ROC) analysis of IC reader value for GCF calprotectin was performed to predict periodontal diseases. RESULTS: The visual score of GCF calprotectin was highly correlated with the IC reader value. IC reader values of GCF calprotectin in the periodontitis group were higher than those of the healthy group at three dental examination stages, and they significantly decreased with periodontal treatments. Visual scores and IC reader values of GCF calprotectin were correlated to levels of clinical indicators. ROC analysis for GCF calprotectin showed an optimal cutoff value to predict periodontal diseases. CONCLUSION: Determination of GCF calprotectin using a novel IC chip system is useful for diagnosis of periodontal diseases.