Effects of systemic Bifidobacterium longum and Lactobacillus rhamnosus probiotics on the ligature-induced periodontitis in rat.

Background/purpose: Probiotics might be beneficial in preventing periodontitis. Effects of Bifidobacterium and Lactobacillus on periodontitis were examined using the ligature-induced rat model. Materials and methods: Thirty-five male Sprague-Dawley rats were divided into control, ligation, Bifidobacterium longum (BL986), Lactobacillus rhamnosus (LRH09), and combination groups. Periodontitis was induced in maxillary second molars. From the day before ligation, phosphate-buffered saline (for control and ligation groups) or probiotics (2 × 109 CFU/g for probiotic groups) were fed daily. On day 8, gingival mRNA expressions for interleukin (IL)-1ß, IL-6, tissue necrosis factor (TNF)-α, IL-10, and NF-κB were determined via qPCR. Micro-computed tomography (µCT) and histomorphometry were employed to examine periodontal destruction. Results: Compared to the ligation group, mRNA of IL-1ß, TNF-α, IL-6, and NF-κB in probiotic groups were significantly decreased, but IL-10 was increased. Besides, the IL-10 was more significant in the combination group than in single-use group. Through µCT, the cementoenamel junction (CEJ)-to-bone distance and trabecular separation in combination group were less than that in ligation group, although the bone volume fraction and trabecular number/thickness showed an increase in three probiotic groups. Histopathologically, the combination group had significantly smaller gingival inflammatory cell-infiltrated area and CEJ-to-epithelium distance than the ligation group and the group with BL986 or LRH09. Additionally, the CEJ-to-bone distance was significantly smaller in the combination group than in the ligation and BL986 groups. Conclusion: Systemic combination of BL986 and LRH09 had a synergistic effect on enhancing IL-10 and ameliorating the induced experimental periodontitis, although the single-use still presented partially alleviative effects.

Life satisfaction and peace of mind among dentists: a cross-sectional study.

OBJECTIVES: This study sought to identify the factors associated with the life satisfaction and peace of mind (PoM) of dentists not in full-time clinical training. MATERIALS AND METHODS: Cross-sectional questionnaires were distributed to dentists in Taiwan to collect their life satisfaction, PoM, sociodemographic data, and dental career-related characteristics. Life satisfaction was measured using a 5-item Satisfaction with Life Scale. PoM was measured using a 7-item Peace of Mind Scale. Descriptive statistics and multiple linear regression models were estimated to explore potential associations between the two scales and the examined factors. RESULTS: A total of 1196 dentists (45.6% female; mean age = 44.12) completed the questionnaires. The response rate of completed questionnaires from email invitations was 32.9%. On multivariable analysis, life satisfaction and PoM were associated with age (b = 0.008 in both), better perceived health (b = 0.262 and 0.308, respectively), family interaction (b = 0.264 and 0.207, respectively), and friend relationships (b = 0.076 and 0.091, respectively). Being married (b = 0.191), being specialized (b = 0.127), working in private practice, and spending 10 to 39 h per week with patients (b = 0.101 to 0.162) were associated with a higher level of life satisfaction but not PoM. CONCLUSIONS: Specialists working in private practice without working overtime were associated with better life satisfaction. However, the dentists' health and relationships with family were more related to their subjective well-being than their professional achievements. CLINICAL RELEVANCE: Our findings can help policymakers increase awareness of the well-being of general dentists and those in academia or hospitals to promote their mental health.

Role of ferroptosis in periodontitis: An animal study in rats.

OBJECTIVE: This study aimed to investigate (1) the temporal pattern of ferroptosis, an iron-dependent cell death, in ligation-induced rat periodontitis and (2) the effect of ferrostatin-1, a ferroptosis inhibitor, on the model. BACKGROUND: Ferroptosis may contribute to various diseases. However, the role of ferroptosis in periodontitis is still fully understood. METHODS: In the first experiment, 25 rats with ligation-induced periodontitis were sacrificed on days 0, 1, 2, 7, and 10. Gingivae were obtained to determine tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and ferroptotic biomarkers, including solute carrier family 3 member 2 (SLC3A2) and solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (Gpx4), via immunoblotting. Using microcomputed tomography (µCT) and histology, the periodontal soft and hard tissue lesions, including dental alveolar bone crest level, bony characteristics of the surrounding alveolus, periodontal tissue inflammation, and periodontal tissue losses, were evaluated. In study two, 16 rats with induced periodontitis were grouped according to ferrostatin-1 treatment. The rats were intraperitoneally injected with solvent or ferrostatin-1 (1.5 mg/kg/day) 1 day before ligation and sacrificed on days 7 and 10. Gingival protein changes and periodontal tissue damage were also examined. RESULTS: In study one, SLC3A2/SLC7A11 and Gpx4 decreased since day 1; however, TNF-α/IL-1ß increased on days 7 and 10. Moreover, the µCT/histology revealed resorptive bony characteristics, inflamed gingival tissue, and periodontal attachment loss. In study two, ferrostatin-1-injected rats exhibited significantly increased SLC3A2/SLC7A11 and Gpx4 but decreased TNF-α/IL-1ß than vehicle rats. They also revealed lessened bone resorption, tissue inflammation, and attachment loss. CONCLUSION: This study highlights the role of ferroptosis, via the system Xc/Gpx4 pathway, in experimental periodontitis and may serve as a regulatory strategy.

Type 2 Diabetes Mellitus and Periodontitis: Bidirectional Association in Population-based 15-year Retrospective Cohorts.

OBJECTIVE: A two-way relationship between periodontitis and diabetes has been proposed. However, bidirectional epidemiological observation is limited and inconsistent. OBJECTIVE: Using the National Health Insurance Research Database of Taiwan (covering over 99% of the entire population), we aimed to estimate the development of diabetes in periodontitis patients or that of periodontitis in patients with type 2 diabetes mellitus (T2DM), respectively. METHODS: A total of 11 011 patients with severe periodontitis were recruited from 2000 to 2015. After matching by age, sex, and index date, 11 011 patients with mild periodontitis and 11 011 non-periodontitis controls were registered. Additionally, 157 798 patients with T2DM and 157 798 non-T2DM controls were enrolled, in whom the development of periodontitis was traced. Cox proportional hazards model was performed. RESULTS: Periodontitis patients tended to have a statistically high risk for T2DM. The adjusted hazard ratio was 1.94 (95% CI, 1.49-2.63, P < .01) and 1.72 (95% CI, 1.24-2.52, P < .01) for severe and mild periodontitis groups, respectively. The patients with severe periodontitis had a higher risk of having T2DM relative to those with mild periodontitis (1.17 [95% CI, 1.04-1.26, P < .001]). Conversely, the risk of periodontitis increased significantly in patients with T2DM (1.99 [95% CI, 1.42-2.48, P < .01]). However, high risk was observed for the outcome of severe periodontitis (2.08 [95% CI, 1.50-2.66, P < .001]), but not for mild periodontitis (0.97 [95% CI, 0.38-1.57, P = .462]). CONCLUSION: We suggest that the bidirectional association is between T2DM and severe but not mild periodontitis.

Tooth life expectancy and burden of tooth loss: Two cross-sectional studies in Taiwan.

Background/purpose: Life expectancy (LE) is a hypothetical measure to predict life longevity and the indicator of society's overall health. Tooth loss is a worldwide enigma; however, the LE for tooth (LET) are obscure. LET and the burden of tooth loss in Taiwan were estimated using the scheme of National Health Insurance (NHI). Materials and methods: Using NHI data, mortality rate, age-specific mortality rate, tooth-extraction rate, and age-specific tooth-extraction rate (ASTER) of Taiwanese in 2004 and 2013 were estimated. ASTER for the individual tooth (ASTER-T) was analyzed for each of 28 permanent teeth according to ID code and tooth location. LET and years lived with disability for tooth loss (YLDs-T) of each permanent tooth were estimated following Global Burden Disease study. Results: In 2004, 1,741,228 teeth extracted from 1,078,254 patients among 22,646,835 Taiwanese, whereas 2,012,907 teeth extracted from 1,254,746 patients among 23,344,670 in 2013. In both years, the ASTERs presented an increasing trend as age increased. However, the ASTER-Ts presented varied according to tooth types. The LET and YLDs-T were also varied. The maximum values of YLDs-T were noticed for the first molars. Conclusion: Our findings of this national survey highlight the need for public health policy, particular the early loss of first molars, aiming to increase awareness regarding oral health.

Staphylococcus aureus enhances gelatinase activities in monocytic U937 cells and in human gingival fibroblasts.

Background/purpose: Staphylococcus aureus (S. aureus) has been suggested to be an initiative pathogen in peri-implantitis because of the solid affinity to titanium. However, the detail pathogenesis for the peri-implantitis initiation by S. aureus is still lacking. This study aimed to in vitro examine the gelatinases' activities of monocytic U937 cell and human gingival fibroblast after challenges with S. aureus lipoteichoic acid (LTA) and peptidoglycan (PGN). Materials and methods: Releases of gelatinases, including matrix metalloproteinase (MMP)-2 and -9, from cells were measured by zymography. The releases were further examined after being given the S. aureus LTA/PGN. Roles of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways on the enzyme releases were examined by administrating inhibitors. Results: S. aureus LTA and PGN increased the activities of pro-MMP-9 from U937 cells and pro-MMP-2 and MMP-2 from gingival fibroblasts. By giving the NF-κB inhibitor, the enhanced gelatinase activities in both cells were attenuated. In U937 cells, the enhanced pro-MMP-9 could further be attenuated by MAPK inhibitors, including extracellular signal-regulated kinase 1 and 2 (ERK1/2), P38 MAPK, and c-Jun N-terminal kinase (JNK) inhibitors; however, the attenuation by MAPK inhibitors could not be observed for MMP-2 in gingival fibroblasts. Nevertheless, in gingival fibroblasts, the pro-MMP-2 could be attenuated by JNK inhibitor. Conclusion: S. aureus could enhance gelatinase activities of gingival fibroblasts and U937 cells, via NF-κB. The MAPK pathway was also involved in MMP-9 activity of U937 cells; however, the involvement of MAPK in MMP-2 activity of gingival fibroblasts was questioned.

Association of periodontitis with tinnitus: A population-based cohort study in Taiwan.

AIM: Tinnitus, ringing in the ears, is speculated to be driven by inflammation. This study examined whether periodontitis is a risk factor for tinnitus using Taiwan's National Health Insurance Research Database. MATERIALS AND METHODS: Among the 79,456 patients who visited for dental concerns, 11,055 patients who were diagnosed with periodontitis and underwent periodontal treatment between 2000 and 2015 were enrolled in Group 1. After matching for sex, age, and index year, 11,055 patients with periodontitis who received no treatment were enrolled in Group 2. Similarly, 11,055 participants without periodontitis were included as controls. RESULTS: At the end of the follow-up, 412 and 404 participants in the two periodontitis groups and 321 participants in the control group had tinnitus. Cumulative risk for tinnitus in Group 1 or 2 was significantly greater than in the control group. More periodontitis patients than controls developed tinnitus (adjusted hazard ratios were 1.71 (95% confidence interval [CI]: 1.49-1.97, p < .001) and 1.64 (95% CI: 1.37-1.86, p < .001) in Groups 1 and 2, respectively). The risks were not significantly different between Groups 1 and 2. Similar findings were obtained after excluding data for the first 1 or 5 years. CONCLUSIONS: The study findings indicate that periodontitis is associated with tinnitus.

Life Satisfaction of US-trained Dental Specialists in Taiwan.

OBJECTIVE: A large number of residents in US advanced specialty education programmes are foreign-trained dentists. When faced with the career dilemma of applying for US residency training, foreign-trained dentists may wonder whether it is worth proceeding along that path. In addiditon, studies capturing benefits from receiving US residency training are rare. Therefore, this study compared the life satisfaction amongst 3 dentist groups in Taiwan (ie, US-trained specialists, Taiwan-trained specialists, and general dentists). METHODS: Cross-sectional surveys were distributed to dentists currently residing in Taiwan. Participants were surveyed about demographic information, career-related information, and life satisfaction. Life satisfaction was measured with a structured Satisfaction With Life Scale (SWLS). Nonparametric bivariate analyses and multivariable adjusted generalised linear model (GLM) were used to examine the differences between mean SWLS scores and examined variables. We included 134 US-trained specialists, 134 Taiwan-trained specialists, and 134 general dentists matched for age, sex, and marital status. RESULTS: With the mean age of 51.4 ± 10.8 years old, specialists had significantly higher mean life satisfaction scores than general dentists. US-trained specialists had significantly higher mean life satisfaction scores than Taiwan-trained specialists when health and family relationships were not considered. Career-rated factors (eg, spending more clinical hours with patients, having more expenses related to continuing education, publishing more peer-reviewed articles, and being a frequent speaker) were not associated with better life satisfaction. CONCLUSIONS: US-trained specialists were more likely to be satisfied with their lives than Taiwan-trained specialists and general dentists. However, health and social relationships contribute more to dentists' life satisfaction than do career-rated factors.

Cyanidin-3-O-glucoside downregulates ligation-activated endoplasmic reticulum stress and alleviates induced periodontal destruction in rats.

OBJECTIVE: Cyanidin-3-O-glucoside (C3G), a dietary anthocyanin, possesses various biological properties, including alleviating endoplasmic reticulum (ER) stress. This study examined the effect of C3G on periodontitis via ER stress in rats. DESIGN: Periodontitis was induced by placing silk sutures around maxillary second molars. C3G (0, 3, or 9 mg/kg) was fed on the day before ligation (10 rats/group). Further, 10 non-ligation control rats received deionized water. On day 8, gingivae were obtained to determine CCAAT/enhancer-binding protein homologous protein (CHOP), c-Jun N-terminal kinase (JNK), phospho-JNK (p-JNK), and nuclear factor-κB (NF-κB) by immunoblotting. Periodontal destruction was evaluated using micro-computed tomography (µCT) and histology. RESULTS: Gingival expression of CHOP, p-JNK/JNK, and NF-κB significantly increased in ligation rats (0 mg/kg C3G) than that in controls. However, protein expression in ligation groups presented a negative association with C3G concentration. By µCT, the distance of cemento-enamel junction to bone significantly increased in ligation groups; however, distances showed a negative association with C3G concentration. In the region of interest, bone volume and trabecular thickness and number significantly decreased in ligation groups but they were positively associated with C3G concentration. In terms of trabecular separation, opposite results were found. Histologically, infiltrated connective tissue (ICT) and periodontal destructions increased in ligation groups; however, they were negatively associated with C3G concentration. Moreover, ICT area is positively correlated with µCT- and histologically measured destructions and protein expression of CHOP, p-JNK/JNK, or NF-κB. CONCLUSION: C3G promotes favorable modulation of ER stress and alleviates destruction of periodontitis, which may imply a new strategy.

Is periodontitis a risk factor of benign or malignant colorectal tumor? A population-based cohort study.

OBJECTIVE: To examine the risk of developing benign or malignant colorectal tumors in patients with periodontitis within 15 years using Taiwan's National Health Insurance Database. BACKGROUND: Studies have shown that colorectal carcinoma often develops under inflammatory conditions and changes of microbiota in the gut. Recently, a link between Fusobacterium nucleatum, a periodontal pathogen, and colorectal carcinoma has been proposed. However, whether periodontitis is a risk of developing colorectal tumor remains uncertain. METHODS: In total, 35 124 participants were enrolled from 2000 to 2015 to examine the development risk of benign colorectal tumors, including 11 708 patients with periodontitis who received therapy (group 1), 11 708 patients with periodontitis not receiving periodontal treatment (group 2), and 11 708 non-periodontitis controls after matching for gender, age, and index year. To examine the risk of developing colorectal malignancy, 11 720 participants were assigned to each of the three groups. Cox proportional hazards model and Kaplan-Meier methods were used to compare the risks. Sensitivity analysis was performed, excluding the diagnoses during the first 1 or 5 years. RESULTS: After the follow-up, 177, 154, and 63 participants in group 1, group 2, and control group had benign colorectal tumors. Patients with periodontitis tended to be associated with a greater rate of having a benign colorectal tumor. The adjusted hazard ratios (aHRs) were 3.77 (95% confidence interval [CI] 2.01-4.82, p < .001) and 2.85 (95% CI 1.62-3.74, p < .001) for groups 1 and 2, respectively. Regarding the risk of malignant colorectal tumor, 20, 18, and 14 participants who developed malignant tumors were included in group 1, group 2, and control group; however, no significant increase in malignancy was observed in periodontitis groups (aHR1.92, 95% CI 0.74-2.36, p = .482; aHR 1.50, 95% CI 0.68-1.97, p = .529, for the two periodontitis groups, respectively). CONCLUSIONS: The results of this study suggest that patients with periodontitis may have an increased risk of developing benign, but not malignant, colorectal tumors.

Porphyromonas gingivalis lipopolysaccharide and gingival fibroblast augment MMP-9 expression of monocytic U937 cells through cyclophilin A.

BACKGROUND: Intercellular cross-talking was suggested in matrix metalloproteinase (MMP)-9 expression with unknown mechanisms. Studies showed cyclophilin A (CypA) playing an important role in regulating MMP-9 expression in varied diseases. The aim of the study was to examine the CyPA on the MMP-9 augmentation in monocytic U937 cells after Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) treatment and human gingival fibroblast (hGF) co-culture. METHODS: In independent culture or co-culture of hGF and U937 cell, quantitative real-time polymerase chain reaction (qPCR) and zymography were selected to examine the mRNA and protein activity of MMP-9, respectively. The CyPA expression was determined by qPCR. RESULTS: LPS could enhance MMP-9 mRNA expression and enzyme activity in U937 cell. However, the enhancements were not observed in hGF. Similarly, LPS enhanced CyPA mRNA in U937, but not in hGF. After co-cultured with hGF, however, MMP-9 and CyPA in U937 increased regardless of the presence/absence of LPS. In U937 cells, the extra-supplied CyPA increased MMP-9 mRNA and enzyme activity, whereas the CyPA inhibitor, cyclosporine A, suppressed the LPS- and co-culture-enhanced MMP-9. Moreover, the inhibitors for MAP kinase, including PD98059 (ERK) and SP600125 (JNK), suppressed the CyPA-enhanced MMP-9 in U937. CONCLUSION: Through the CyPA pathway, the LPS and the hGF could augment the MMP-9 expression in the U937 cells.

Bone formation with functionalized 3D printed poly-ε-caprolactone scaffold with plasma-rich-fibrin implanted in critical-sized calvaria defect of rat.

BACKGROUND/PURPOSE: Space-making is one of the essential factors for bone regeneration in severe bony defect. To test the hypothesis that an appropriately designed scaffold may be beneficial for the bone formation in defect, the new bone formed in the critical-size calvarial defect of rat was examined after implanted with a 3D-printed poly-ɛ-caprolactone (PCL) scaffold, retaining with and without plasma rich fibrin (PRF). MATERIALS AND METHODS: Thirty-two rats were divided into four groups (control, PCL, PRF, and PCL-plus-PRF). A custom-made 3D-printed PCL scaffold, 900 µm in pore size, retaining with and without PRF, was implanted into a critical-sized calvarial defect, 6 mm in diameter. Animals were sacrificed at week-4 or 8 after implantation for assessing the new bone formation by dental radiography, micro-computed tomography (µ-CT), and histology. RESULTS: By radiography and µ-CT, significantly greater mineralization areas/volumes were observed in defects with 3D-printed scaffold groups compared to that without the scaffold in both two-time points. However, no advantage was found by adding PRF. Histology showed that bone tissues grew into the central zone of the critical defect when 3D-printed PCL scaffold was present. In contrast, for the groups without the scaffolds, new bones were formed mostly along defect borders, and the central zones of the defects were collapsed and healed with thin connective tissue. CONCLUSION: Our results suggest that the use of a 900 µm pore size 3D-printed PCL scaffold may have the potential in facilitating the new bone formation.

2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside-stimulated dental pulp stem cells-derived conditioned medium enhances cell activity and anti-inflammation.

BACKGROUND/PURPOSE: Dental pulp stem cells (DPSCs) contribute to the regeneration of various tissues and have superior proliferation, immune privilege, and anti-inflammation properties to other mesenchymal stem cells. 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucoside (THSG) not only enhances the aforementioned properties of DPSCs but also promotes self-renewal and reprogramming-like ability. However, whether THSG enhances the aforementioned properties and abilities through direct or indirect interaction mechanisms remains unclear. To address this knowledge gap, we examined the effects of THSG-stimulated DPSC-derived conditioned medium (THSG-CM) on the activity and anti-inflammation properties of cells. MATERIALS AND METHODS: DPSCs were treated with various concentrations of THSG to produce THSG-CM, which was then collected, analyzed, and lyophilized. A cytokine profiling antibody assay was used to compare protein components between THSG-treated and nontreated CM. Human skin fibroblasts (HSFs) and human gingival fibroblasts (HGFs) were used to investigate the effect of THSG-CM on cell proliferation, anti-inflammation, and wound healing abilities; for this investigation, MTS assay, quantitative real-time PCR analysis, and 2-well silicone inserts wound model were conducted. RESULTS: We observed that THSG enhanced the secretion of growth- and immune-associated proteins in THSG-CM and increased the proliferation of HSFs and HGFs. Furthermore, THSG-CM significantly attenuated lipopolysaccharide-stimulated mRNA levels of cytokines in both cells and improved wound healing abilities. CONCLUSION: We conclude that THSG-CM had more beneficial effects on cell activity and anti-inflammation in the HSFs and HGFs than DPSC-derived CM. DPSC-derived CM can be developed into a cell-free regenerative strategy in the future, and its therapeutic efficacy may be improved by THSG-CM.

Antioxidants protect against gingival overgrowth induced by cyclosporine A.

OBJECTIVE: We investigated the importance of reactive oxygen species (ROS) on developing gingival overgrowth (GO) and then introduced the antioxidant strategy to prevent, or even reduce GO. BACKGROUND: Gingival overgrowth is a common side effect of the patients receiving cyclosporine A (CsA), an immune suppressant. Although it has been broadly investigated, the exact pathogenesis of the induced GO is still uncertain. METHODS: We cultured human primary gingival fibroblasts and used animal model of GO to investigate the ameliorative effects of antioxidants on CsA-induced GO. To examine the CsA-induced oxidative stress, associated genes and protein expression, and the overgrown gingiva of rats by using immunocytochemistry, confocal laser scanning microscopy, real-time PCR, ELISA, gelatin zymography, gingival morphological, and immunohistochemical analysis. RESULTS: We found for the first time that ROS was responsible for the CsA-induced oxidative stress and TGF-ß1 expression in human primary gingival fibroblasts, as well as the GO of rats. The antioxidants (oxidative scavenger of vitamin E and an antioxidative enzyme inducer of hemin) ameliorated CsA-induced pathological and morphological alterations of GO without affected the CsA-suppressed il-2 expression in rats. CsA-induced oxidative stress, HO-1, TGF-ß1, and type II EMT were also rescued by antioxidants treatment. CONCLUSIONS: We concluded that CsA repetitively stimulating the production of ROS is the cause of CsA-GO which is ameliorated by treating antioxidants, including vitamin E and sulforaphane. Furthermore, the immunosuppressive effect of CsA is not interfered by antioxidant treatments in rats. This finding may thus help the clinician devise better prevention strategies in patients susceptible to GO.

Association of chronic periodontitis with prostatic hyperplasia and prostatitis: A population-based cohort study in Taiwan.

BACKGROUND: Association between periodontitis and prostate diseases of benign prostatic hyperplasia (BPH) and prostatitis is uncertain. METHODS: From the National Health Insurance Research Database of Taiwan, 5,510 patients with newly diagnosed chronic periodontitis and participated in therapies were selected from 2000 to 2015 as cohort 1. Matched with age and index year, 5,510 patients with periodontitis diagnosis without therapy were selected as cohort 2, and 5,510 participants without diagnosis were used as control. Cox proportional hazard and survival analysis were performed to compare the risks and the survival probabilities among cohorts. RESULTS: In two periodontitis cohorts, 636 and 638 participants compared with 550 in control (1,174 and 1,187 versus 989 per 100,000 person-years) had prostate disorder. Difference was identified for prostatitis (n = 68, 70 versus 34; rate = 125, 130 versus 61 /100,000 person-years; P <0.001) but not for BPH (n = 577, 575, versus 529; rate = 1,065, 1,070 versus 951 /100,000 person-years, respectively). Different survival probabilities for prostate disorder and prostatitis, but not for BPH, were observed among cohorts. Periodontitis patients were more likely to develop prostate disorder after adjustment (adjusted hazard ratio [aHR] of 2.590 to 2.641 by competing model). With stratification, risks between two periodontitis cohorts exhibited no difference. When BPH cases were excluded, the aHRs for prostatitis were 4.611 to 4.798. CONCLUSIONS: Despite treatment, the patients with periodontitis had higher risk of developing prostatitis than patients without periodontitis.

Tensile strength, growth factor content and proliferation activities for two platelet concentrates of platelet-rich fibrin and concentrated growth factor.

BACKGROUND/PURPOSE: Platelet-rich fibrin (PRF) can be obtained by centrifuging fresh blood in the absence of anticoagulants. Varying the centrifugation speeds may produce tougher and richer concentrated growth factors (CGF). This study examines tensile strength, growth factor content, and the potential of CGF and PRF in promoting periodontal cell proliferation. MATERIALS AND METHODS: Blood (40 mL/subject) was collected from 44 healthy subjects. PRF and CGF were prepared by centrifuging at 3000 rpm and switching speeds ranging within 3000 rpm, respectively. Fibrin strip was prepared and its tensile strength was measured. Transforming growth factor beta 1 (TGF-ß1), platelet-derived growth factor BB (PDGF-BB), and epidermal growth factor (EGF) in the residual serum and fibrin clots were determined by enzyme-linked immunosorbent assay, and their effects on the proliferation of hFOB1.19 osteoblasts and human gingival fibroblasts were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. RESULTS: Compared with PRF, tensile strength of CGF was significantly higher. Concentrations and amounts of PDGF-BB and EGF in CGF were significantly higher than those in PRF. Osteoblast number was significantly higher in the cultures with fetal bovine serum (FBS, 10%) and with PRF or CGF fibrin clots (5%, 10%, and 50%) compared to that without FBS. Moreover, osteoblast number in CGF, regardless of the preparation of 10% and 50%, was significantly greater than that in PRF. Similar findings were also observed for gingival fibroblasts among the various subjects. CONCLUSION: Varying centrifugation speeds can modify the tensile strength and biological activities of platelet fibrin clots.

Fibroblast-enhanced cyclophilin A releasing from U937 cell upregulates MMP-2 in gingival fibroblast.

OBJECTIVE: This in vitro study aimed to evaluate the expression of cyclophilin A (CyPA) in U937 monocytic cells after coculturing with the human gingival fibroblasts (HGFs) and the effect of CyPA on the augmentation of MMP-2 expression in the coculture environment. BACKGROUND: Leukocyte infiltration in gingival connective tissue is one of the major findings in the lesions of inflammatory periodontal diseases. A crosstalk between the resident gingival fibroblasts and the recruited inflammatory cells that promote the expression of matrix metalloproteinases (MMPs) was proposed based on recent findings, whereas the cluster of differentiation 147 (CD147)-CyPA pathway was suggested to be involved with the crosstalk. MATERIAL AND METHODS: CyPA was released into media, in the independent or transwell coculture of HGF and U937 cells, as determined by enzyme-linked immunosorbent assay, whereas intracellular mRNA expressions for CyPA and MMP-2 were examined by quantitative real-time polymerase chain reaction, in the transwell coculture or conditional medium models. Zymography was conducted to analyze the activities of pro-MMP-2/MMP-2 released into the media. RESULTS: (a) A significantly increased CyPA protein level was observed in the transwell coculture media compared with that in the independent culture. (b) The transwell coculture-enhanced mRNA expression for CyPA was noticed in U937 cells but not in HGFs. After adding with HGF-conditioned medium, the mRNA enhancement in U937 cells occurred in a dose-dependent manner. (c) Although the MMP-2 activities significantly increased after transwell coculturing, the MMP-2 mRNA enhancement was observed only in HGFs. (d) Exogenous CyPA could enhance MMP-2 activities in HGFs in a dose-dependent manner. However, the CyPA antagonist reduced the MMP-2 activities in the transwell cocultures. (e) Moreover, the CyPA-enhanced MMP-2 activity in HGF was decreased significantly by the pathway inhibitor for c-Jun amino-terminal kinase (JNK). CONCLUSION: Based on the present findings, we suggest that gingival fibroblasts could enhance the CyPA release from U937 cells, via the JNK pathway, resulting in MMP-2 enhancement in fibroblasts. The finding shed light on a new mechanism of cellular interaction involving MMP-2 and CyPA, in two cells.

Association between periodontitis and pulmonary function based on the Third National Health and Nutrition Examination Survey (NHANES III).

OBJECTIVES: The purpose of this study was to investigate the association between impaired pulmonary function and periodontitis. MATERIALS AND METHODS: From the Third National Health and Nutrition Examination Survey data, we examined the association between pulmonary function and severity of periodontitis using the univariate and multivariate regression models. Moreover, the association between obstructive or restrictive spirometry patterns and periodontitis status was also determined by multivariable logistic regression analysis. RESULTS: A total of 10,645 participants were included in our study. The values of predicted FEV1%, predicted FVC%, and FEV1/FVC were found to gradually decline with increasing severity of periodontitis (p < .001). Obstructive and restrictive pulmonary functions were significantly associated with severity of periodontitis. CONCLUSION: Individuals with a greater degree of periodontitis had poor pulmonary function. However, further long-term cohort studies are required for a comprehensive evaluation.

Life satisfaction of Taiwanese dental graduates received residencies in the U.S.: a cross-sectional study.

BACKGROUND: Each year, more than 200 international dental graduates start U.S. specialty trainings to become specialists. It is unknown if their life satisfaction is associated with any dental career-related factor before residencies (e.g. dental school class rank, research experience, or private practice experience) and after residencies (e.g. staying in the U.S., teaching status, workplace, or board certification). This cross-sectional study aimed to identify these potential factors by surveying Taiwanese dental graduates who pursued U.S. residencies. METHODS: Life satisfaction was measured with a structured questionnaire, Satisfaction With Life Scale (SWLS), which includes five statements on a 5-point Likert scale. Online surveys were sent out to 290 Taiwanese dental graduates who were known to pursue U.S. residencies. T-test, one way analysis of variance, and multivariable adjusted generalized linear model (GLM) were used to assess the differences of mean SWLS scores from different variables. RESULTS: Surveys were completed by 158 dentists. Mean SWLS score of 125 specialists was higher (p = 0.0007) than the score of 33 residents. For the 125 specialists, multivariable adjusted GLM demonstrated better life satisfaction was positively associated with multiple independent factors, such as having research experience, being ranked in the top 26 ~ 50% of the class in dental school, starting U.S. residency within 4 years after dental school, starting residency before year 1996, and specializing in endodontics (vs. periodontics). Life satisfaction was not associated with any factors after residency (e.g. staying in the U.S. afterwards, teaching status, or workplace), but better mean life satisfaction score was significantly associated with being American specialty board certified (p < 0.001) for the specialists in the 26 ~ 75% of their class in dental school. For the 33 residents, better mean life satisfaction score was associated with better dental school class rank in both bivariate (p = 0.020) and multivariable adjusted GLM (p = 0.004) analyses. CONCLUSIONS: The life satisfaction of Taiwanese dental graduates pursuing U.S. residencies might be associated with some professional factors, such as research experience, dental school class rank, residency timing, specialty type, and specialty board certification. We hope our results may provide some objective information on making career decisions for international dental graduates/students who are preparing for U.S. residency.

Bone formation following sinus grafting with an alloplastic biphasic calcium phosphate in Lanyu Taiwanese mini-pigs.

BACKGROUND: To evaluate the new bone formation after grafting with a synthetic biphasic calcium phosphate in sinuses with minimal bone height, the alloplastic and xenograft materials were compared after grafting into Lanyu Taiwanese mini-pig sinuses via split-mouth design. METHODS: In six mini-pigs, synthetic hydroxyapatite/tricalcium phosphate (HA/TCP) particles were inserted into one of the sinus cavities using the extra-oral approach, where deproteinized bovine bone mineral (DBBM) particles were placed contralaterally. Fluorescent bony labels of Alizarin and Calcein green were delivered at weeks 4 and 8, respectively. Animals were sacrificed at week 12 and the augmented tissues were evaluated by cone-beam computed tomography, microcomputed tomography, and histology. RESULTS: By radiographic examination, the mean thicknesses of sinus cortexes for DBBM and HA/TCP groups were similar (0.35 versus 0.38 cm) and the mean volumes augmented were also indifferent (1.29 versus 1.64 cm3 ). The distributions of bones, residual particles, and non-mineralized tissues in augmented masses between groups were undistinguishable. Under microscopy, however, macroporosities of osteons were filled with HA/TCP residual particles, whereas the newly formed bones lay on top of DBBM particle surfaces. Although the mineral deposition rates between groups were indifferent, the mean labeled surface in the HA/TCP group was significantly greater than those in the DBBM group at week 4 (35.16% versus 14.00% for HA/TCP and DBBM, respectively) but less than that at week 8 (19.33% versus 39.16%, respectively). CONCLUSION: Sinus augmentation with synthetic HA/TCP and DBBM exhibited similar effectiveness in new bone formation.