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Sample records for aggressive periodontitis lap

  1. Periodontal Treatment Reduces Matrix Metalloproteinase Levels in Localized Aggressive Periodontitis

    PubMed Central

    Gonçalves, Patricia Furtado; Huang, Hong; McAninley, Suzanna; Alfant, Barnett; Harrison, Peter; Aukhil, Ikramuddin; Walker, Clay; Shaddox, Luciana Macchion

    2015-01-01

    Background Matrix metalloproteinases (MMPs) are a family of host-derived proteinases reported to mediate multiple functions associated with periodontal destruction and inflammation. We have previously reported high MMP levels in African-American children with localized aggressive periodontitis (LAP). However, little is known about MMP reductions in gingival crevicular fluid (GCF) after therapy. This study aimed to evaluate MMP levels in the GCF following treatment of LAP and to correlate these levels with clinical response. Methods GCF samples were collected from 29 African-American individuals diagnosed with LAP. GCF was collected from one diseased site (pocket depth [PD]>4mm, bleeding on probing [BoP] and clinical attachment level [CAL] ≥2mm) and one healthy site (PD≤3mm, no BoP) from each individual at baseline, 3 and 6 months after periodontal treatment, which consisted of full-mouth SRP and systemic antibiotics. The volume of GCF was controlled using a calibrated gingival fluid meter and levels of MMP-1, 2, 3, 8, 9, 12 and 13 were assessed using fluorometric kits. Results MMP-1, 8, 9 12, and 13 levels were reduced significantly up to 6 months, at which point were comparable with healthy sites. Significant correlations were noted between MMP-2, 3, 8, 9, 12 and 13 levels and % of sites with PD>4mm. MMP-3, 12 and 13 levels also correlated with mean pocket depth of affected sites. Conclusion Treatment of LAP with SRP and systemic antibiotics was effective in reducing the local levels specific MMPs in African-American individuals, which correlated positively with some clinical parameters. PMID:23537121

  2. Cementogenesis in Patients with Localized Aggressive Periodontitis

    PubMed Central

    Paknejad, Mojgan; Khorsand, Afshin; Yaghobee, Siamak; Motahhari, Pooriya; Etebarian, Arghavan; Mehrfard, Ali

    2015-01-01

    Objectives: The aim of this study was to determine the cementum thickness in the first molars of patients with localized aggressive periodontitis (LAP) compared to healthy individuals. Materials and Methods: This case-control study compared eight first molar teeth affected by LAP with eight third molar teeth of healthy individuals. The teeth were disinfected by immersion in 10% buffered formalin solution for three days and were then sectioned. External mesial root surfaces (middle one-third) were evaluated under a stereomicroscope by a blinded pathologist to determine the mean thickness of cementum. SPSS software (version 16.0) and t-test were used for statistical analysis. Results: Histological examination revealed a significant difference between the two groups in terms of the amount of cementogenesis (P<0.001) .The thickness of cementum was higher in the control group (105.16±11.5 μm) than in LAP patients (86.44±7.3 μm). Conclusion: This study demonstrated the presence of cementum hypoplasia in mesial root surfaces of first molars affected by LAP. PMID:26877730

  3. Aggressive and acute periodontal diseases.

    PubMed

    Albandar, Jasim M

    2014-06-01

    Inflammatory periodontal diseases are highly prevalent, although most of these diseases develop and progress slowly, often unnoticed by the affected individual. However, a subgroup of these diseases include aggressive and acute forms that have a relatively low prevalence but show a rapid-course, high rate of progression leading to severe destruction of the periodontal tissues, or cause systemic symptoms that often require urgent attention from healthcare providers. Aggressive periodontitis is an early-onset, destructive disease that shows a high rate of periodontal progression and distinctive clinical features. A contemporary case definition of this disease is presented. Population studies show that the disease is more prevalent in certain geographic regions and ethnic groups. Aggressive periodontitis is an infectious disease, and recent data show that in affected subjects the subgingival microbiota is composed of a mixed microbial infection, with a wide heterogeneity in the types and proportions of microorganisms recovered. Furthermore, there are significant differences in the microbiota of the disease among different geographic regions and ethnicities. There is also evidence that the Aggregatibacter actinomycetemycomitans-JP2 clone may play an important role in the development of the disease in certain populations. The host response plays an important role in the susceptibility to aggressive periodontitis, where the immune response may be complex and involve multiple mechanisms. Also, genetic factors seem to play an important role in the pathogenesis of this disease, but the mechanisms of increased susceptibility are complex and not yet fully understood. The available data suggest that aggressive periodontitis is caused by mutations either in a few major genes or in multiple small-effect genes, and there is also evidence of gene-gene and gene-environment interaction effects. Diagnostic methods for this disease, based on a specific microbiologic, immunologic or

  4. Localized Aggressive Periodontitis Treatment Response in Primary and Permanent Dentitions

    PubMed Central

    MERCHANT, SHERIN. N.; VOVK, ANDREA.; KALASH, DANNY.; HOVENCAMP, NICOLE; AUKHIL, IKRAMUDDIN.; HARRISON, PETER; ZAPERT, EDWARD; BIDWELL, JOHN; VARNADO, PHYLLIS; SHADDOX, LUCIANA. M.

    2014-01-01

    Background The comparative treatment response of children and young adults with localized aggressive periodontitis (LAP) affecting primary and permanent dentition is unknown. The objective of this study was to evaluate the influence of non-surgical periodontal therapy with adjunctive systemic antibiotics on the clinical outcome of children/young adults with primary versus permanent dentition affected by LAP. Methods A cohort of 97 African-American participants between the ages of 5–21 (30M; 66F; 22 primary and 75 permanent dentition affected), diagnosed with LAP were included. Patients presented with no significant medical history. All patients underwent periodontal therapy, which consisted of full mouth mechanical debridement at baseline, 3, 6, and 12 month appointments. Additionally, all patients were prescribed a one-week regimen of systemic antibiotics at the initial appointment. Clinical parameters were analyzed, including probing depth (PD), clinical attachment levels (CAL), bleeding on probing (BOP) and percentage of visible plaque. Results Overall, periodontal therapy was found to be effective in improving the clinical outcomes of both primary and permanent dentitions. Although baseline CAL were similar between the groups, the reductions in mean CAL at 3, 6 and 12 months as well as reduction in % Plaque at 3 months were significantly greater in primary dentition as compared to permanent dentition. Conclusions Non-surgical therapy with systemic antibiotics is effective for LAP in both primary and permanent dentitions. A greater reduction in CAL in LAP of primary dentition may suggest that younger children may carry a greater propensity for positive treatment outcomes and healing potential as compared to children/young adults with permanent dentition. PMID:25186780

  5. FAM5C Contributes to Aggressive Periodontitis

    PubMed Central

    Carvalho, Flavia M.; Tinoco, Eduardo M. B.; Deeley, Kathleen; Duarte, Poliana M.; Faveri, Marcelo; Marques, Marcelo R.; Mendonça, Adriana C.; Wang, Xiaojing; Cuenco, Karen; Menezes, Renato; Garlet, Gustavo P.; Vieira, Alexandre R.

    2010-01-01

    Aggressive periodontitis is characterized by a rapid and severe periodontal destruction in young systemically healthy subjects. A greater prevalence is reported in Africans and African descendent groups than in Caucasians and Hispanics. We first fine mapped the interval 1q24.2 to 1q31.3 suggested as containing an aggressive periodontitis locus. Three hundred and eighty-nine subjects from 55 pedigrees were studied. Saliva samples were collected from all subjects, and DNA was extracted. Twenty-one single nucleotide polymorphisms were selected and analyzed by standard polymerase chain reaction using TaqMan chemistry. Non-parametric linkage and transmission distortion analyses were performed. Although linkage results were negative, statistically significant association between two markers, rs1935881 and rs1342913, in the FAM5C gene and aggressive periodontitis (p = 0.03) was found. Haplotype analysis showed an association between aggressive periodontitis and the haplotype A-G (rs1935881-rs1342913; p = 0.009). Sequence analysis of FAM5C coding regions did not disclose any mutations, but two variants in conserved intronic regions of FAM5C, rs57694932 and rs10494634, were found. However, these two variants are not associated with aggressive periodontitis. Secondly, we investigated the pattern of FAM5C expression in aggressive periodontitis lesions and its possible correlations with inflammatory/immunological factors and pathogens commonly associated with periodontal diseases. FAM5C mRNA expression was significantly higher in diseased versus healthy sites, and was found to be correlated to the IL-1β, IL-17A, IL-4 and RANKL mRNA levels. No correlations were found between FAM5C levels and the presence and load of red complex periodontopathogens or Aggregatibacter actinomycetemcomitans. This study provides evidence that FAM5C contributes to aggressive periodontitis. PMID:20383335

  6. Isolated cleft lip with generalized aggressive periodontitis: A rare entity

    PubMed Central

    Metgud, Renuka; Kumar, Ajay; Bhat, Kishore

    2015-01-01

    Oro-facial clefts are one of the most common birth defects and may be associated with other genetic anomalies. Aggressive periodontitis is a rare condition that progresses rapidly, but affects only a small percentage of the population. Most of the cases of aggressive periodontitis are familial. Even though, literature has documented the association of various genetic disorders with aggressive periodontitis, the aggressive periodontitis in patients with isolated cleft lip (CL) have never been addressed. Here, we report a rare case of isolated CL with generalized aggressive periodontitis. The concomitant presentation of isolated CL with aggressive periodontitis in an individual has clinical significance for multi-disciplinary care. PMID:25810600

  7. Severe gingival enlargement associated with aggressive periodontitis.

    PubMed

    Padmanabhan, Shyam; Dwarakanath, C D

    2013-01-01

    Enlargement of the gingiva can be due to various causes. Most prevalent are the inflammatory type and drug-induced type of gingival hyperplasia. However, sever enlargement associated with an aggressive type of periodontitis is an infrequent finding. Reported here is a case of a female patient aged 18 years who presented with severe enlargement of the maxillary and mandibular gingiva. Examination revealed enlargement extending up to the incisal edge of all the teeth and also an associated generalized loss of attachment with radiographic evidence of reduced bone height resembling an aggressive type of periodontitis. There were no associated systemic signs and symptoms or any family history except that there was generalized vitiligo of the skin and oral mucous membrane. The case was treated by gross electrosection of the gingiva.

  8. Severe gingival enlargement associated with aggressive periodontitis

    PubMed Central

    Padmanabhan, Shyam; Dwarakanath, C. D.

    2013-01-01

    Enlargement of the gingiva can be due to various causes. Most prevalent are the inflammatory type and drug-induced type of gingival hyperplasia. However, sever enlargement associated with an aggressive type of periodontitis is an infrequent finding. Reported here is a case of a female patient aged 18 years who presented with severe enlargement of the maxillary and mandibular gingiva. Examination revealed enlargement extending up to the incisal edge of all the teeth and also an associated generalized loss of attachment with radiographic evidence of reduced bone height resembling an aggressive type of periodontitis. There were no associated systemic signs and symptoms or any family history except that there was generalized vitiligo of the skin and oral mucous membrane. The case was treated by gross electrosection of the gingiva. PMID:23633785

  9. Evaluation of serum ceruloplasmin in aggressive and chronic periodontitis patients

    PubMed Central

    Harshavardhana, B.; Rath, S. K.; Mukherjee, Manish

    2013-01-01

    Background: Pro-inflammatory markers are seen to increase in inflammatory diseases like periodontitis. Detecting an increase in these markers is one of the diagnostic modality. One such marker, which can be detected, is the ceruloplasmin. Ceruloplasmin induces hypoxia and generates oxygen radicals at the site of aggressive periodontitis. It also causes a state of hypoferremia leading to increase in the natural resistance of the body. The aim of this study was to evaluate the serum levels of cerruloplasmin in both aggressive and chronic periodontitis patients. Materials and Methods: Blood samples were collected from aggressive periodontitis patients (n = 20), chronic periodontitis patients (n = 20) and periodontally healthy patients (n = 20). The serum was extracted from all the blood samples and ceruloplasmin levels were spectroscopically evaluated through a new kinetic method, which used a norfloxacin based reagent. Results: Serum ceruloplasmin levels were found to be significantly higher in aggressive periodontitis patients (P > 0.05) than in chronic periodontitis patients (P > 0.05) even though increase in the level of ceruloplasmin was found in chronic periodontitis. Periodontally healthy patients did not show increase in the levels of serum ceruloplasmin. The levels of serum ceruloplasmin also increased with the disease severity whose manifestations were increased bleeding on probing, increased pocket depth and increased attachment loss. Conclusion: Serum ceruloplasmin levels increased in both aggressive and chronic periodontitis patients, but more in aggressive periodontitis patients making it a potential marker for diagnosis of periodontitis. PMID:24049334

  10. Cytological analysis of the periodontal pocket in patients with aggressive periodontitis and chronic periodontitis

    PubMed Central

    Cecilia, E. Castro; Myriam, A. Koss; María, E. López

    2014-01-01

    Background: Oral exfoliative cytology includes the study and interpretation of the features cells exfoliated from the oral mucosa. The aim of this study was to analyze cytological changes in the periodontal pocket of patients with different clinical stages of aggressive periodontitis (AP) and chronic periodontitis (CP). Materials and Methods: Patients aged 24–54 years, of whom 41 were diagnosed with AP, 40 with CP, sub-classified as mild, moderate and severe periodontitis, and 40 healthy individuals who were the control group. Samples of the epithelium of the periodontal pocket were taken for the cytological study. Results: Superficial and intermediate cell values were significantly greater in patients with AP than in patients with CP or the control group. Histiocyte number was higher in patients with CP than in those with AP, and differed significantly in both types of periodontitis compared to the control group. There were significant differences in polymorphonuclear neutrophil leukocytes when both types of periodontitis were compared to the control group. Microbial flora was statistically higher in patients with CP, and there were differences between patients with periodontitis and the control group. Conclusions: The cytological study demonstrated that patients with AP had greater tissue damage, shown by the increase in intermediate and superficial cells of the epithelium of the periodontal pocket compared to the group of healthy subjects and to a lesser extent, to patients with CP. Only superficial cells made it possible to differentiate the sub-stages of the disease. PMID:25395766

  11. Role of genetic factors in the pathogenesis of aggressive periodontitis.

    PubMed

    Vieira, Alexandre R; Albandar, Jasim M

    2014-06-01

    This article critically reviews the evidence for a role of genetic factors in the pathogenesis of aggressive periodontitis and discusses the study approaches commonly used to identify genetic risk factors of this disease. Available data suggest that aggressive periodontitis is caused by mutations in multiple genes, combined with environmental effects. Syndromic periodontal diseases include certain monogenic disorders that express phenotypes showing aggressive forms of periodontitis, and the genetic triggering factors of most of these syndromes have been identified. Other periodontal disease phenotypes seem to occur through different genetic predisposition patterns. Case-control and genome-wide studies have been used to investigate the association with gene polymorphisms. Association studies and the familial aggregation of aggressive periodontitis suggest a significant genetic component in the increased predisposition to this disease. There is evidence to support the contribution of a few major genes or of multiple small-effects genes. In addition, there is evidence of gene-gene and gene-environment interaction effects. Early studies suggested an X-linked mode of transmission of aggressive periodontitis, and subsequent studies support an autosomal mode. Genetic studies have the potential to improve the screening programs of subjects at risk for developing aggressive periodontitis and may enhance treatment outcome through gene therapy.

  12. Treatment of a Periodontic-Endodontic Lesion in a Patient with Aggressive Periodontitis

    PubMed Central

    2016-01-01

    Case Description. This case report describes the successful management of a left mandibular first molar with a combined periodontic-endodontic lesion in a 35-year-old Caucasian woman with aggressive periodontitis using a concerted approach including endodontic treatment, periodontal therapy, and a periodontal regenerative procedure using an enamel matrix derivate. In spite of anticipated poor prognosis, the tooth lesion healed. This case report also discusses the rationale behind different treatment interventions. Practical Implication. Periodontic-endodontic lesions can be successfully treated if dental professionals follow a concerted treatment protocol that integrates endodontic and periodontic specialties. General dentists can be the gatekeepers in managing these cases. PMID:27418983

  13. [Complete dental care of patients suffering from localized aggressive periodontitis. Case report].

    PubMed

    Nagy, Zsolt; Nemes, Júlia; Nyárasdy, Ida

    2015-12-01

    A 34 years old male patient was referred to our clinic for restorative dental treatment. During detailed consultation and dental examination a relatively rare form of periodontal disease had been diagnosed. Intraoral examination included recording of dental and periodontal status. Based on patient's dental history, measurements of probing pocket depths (PPD), clinical attachment level (CAL), and also the X-ray findings, Localized Aggressive Periodontitis (LAP) unknown by the patient was diagnosed. After patient's consent the comprehensive treatment plan covered the dental prevention, periodontal non-surgical and surgical therapy and rehabilitation. The treatment started with oral hygienic instruction, motivation then supra- and subgingival scaling and rootplaning. Later extraction and elective root canal treatment were performed, followed by open flap periodontal surgery combined with hemisection of two molars. After a full mouth conservative restorative therapy, function and esthetics were restored by fix dental prostheses. This case is a good example to underline the importance of periodontal examination during the dental screening and dental status recording for each patients showing up at dental clinics. Otherwise in many cases this asympthomatic disease can remain undetected. PMID:26863818

  14. Molecular Differences between Chronic and Aggressive Periodontitis

    PubMed Central

    Kebschull, M.; Guarnieri, P.; Demmer, R.T.; Boulesteix, A.L.; Pavlidis, P.; Papapanou, P.N.

    2013-01-01

    The 2 major forms of periodontitis, chronic (CP) and aggressive (AgP), do not display sufficiently distinct histopathological characteristics or microbiological/immunological features. We used molecular profiling to explore biological differences between CP and AgP and subsequently carried out supervised classification using machine-learning algorithms including an internal validation. We used whole-genome gene expression profiles from 310 ‘healthy’ or ‘diseased’ gingival tissue biopsies from 120 systemically healthy non-smokers, 65 with CP and 55 with AgP, each contributing with ≥ 2 ‘diseased’ gingival papillae (n = 241; with bleeding-on-probing, probing depth ≥ 4 mm, and clinical attachment loss ≥ 3 mm), and, when available, a ‘healthy’ papilla (n = 69; no bleeding-on-probing, probing depth ≤ 4 mm, and clinical attachment loss ≤ 4 mm). Our analyses revealed limited differences between the gingival tissue transcriptional profiles of AgP and CP, with genes related to immune responses, apoptosis, and signal transduction overexpressed in AgP, and genes related to epithelial integrity and metabolism overexpressed in CP. Different classifying algorithms discriminated CP from AgP with an area under the curve ranging from 0.63 to 0.99. The small differences in gene expression and the highly variable classifier performance suggest limited dissimilarities between established AgP and CP lesions. Future analyses may facilitate the development of a novel, ‘intrinsic’ classification of periodontitis based on molecular profiling. PMID:24122488

  15. Periodontal and space maintenance considerations for primary teeth presenting with aggressive periodontitis: a case report.

    PubMed

    Hazan-Molina, Hagai; Zigdon, Hadar; Einy, Shmuel; Aizenbud, Dror

    2012-01-01

    Aggressive periodontitis is diagnosed mainly by clinical and radiographic examination. Diagnosis in the primary dentition indicates a choice between conservative and radical treatment that involves extractions, depending on the severity of the case. The purpose of this report was to present a case of aggressive periodontitis in a systemically healthy child and to discuss the periodontal and orthodontic aspects. A 7-year-old girl presented with bleeding on probing of approximately half of the dentition, deep periodontal pockets around all primary molars, and increased tooth mobility. An individual oral hygiene program was initiated. The primary maxillary right molar and all primary mandibular molars were extracted, and clear vacuum-formed removable retainers were fabricated and used as space maintainers. The patient was followed longitudinally for 2 years, and no space loss was recorded. Clear vacuum-formed removable retainers mainly involve occlusal crown attachment and, therefore, decrease the risk of plaque accumulation, gingival irritation, and aggressive periodontitis in the permanent dentition.

  16. Adjunct Antimicrobial Therapy and Periodontal Surgery to Treat Generalized Aggressive Periodontitis: A Case Report.

    PubMed

    Irokawa, Daisuke; Makino-Oi, Asako; Fujita, Takahisa; Yamamoto, Shigeki; Tomita, Sachiyo; Saito, Atsushi

    2016-01-01

    Here we report a case of generalized aggressive periodontitis treated with periodontal therapy including adjunct antimicrobial therapy and periodontal surgery. The patient was a 22-year-old woman who presented with the chief complaint of gingival recession. Baseline examination revealed generalized plaque deposition and gingival inflammation. Thirty-nine percent of the sites had a probing depth (PD) of 4-6 mm and 2% a PD of ≥7 mm; 63% exhibited bleeding on probing (BOP). Radiographic examination revealed vertical bone loss in the molars and horizontal bone loss in other teeth. Microbiological examination of subgingival plaque revealed the presence of Aggregatibacter actinomycetemcomitans and Tannerella forsythia. Oral health-related quality of life was assessed as a measure of patient-reported outcome. Based on a clinical diagnosis of generalized aggressive periodontitis, initial periodontal therapy and adjunct antimicrobial therapy were implemented. After reducing inflammation and subgingival bacteria, open flap debridement was performed for teeth with a PD of ≥4 mm. Reevaluation showed no sites with a PD of ≥5 mm, a minimal level of BOP, and a marked reduction in the level of the targeted periodontal pathogens. The patient's oral health-related quality of life was slightly worsened during supportive periodontal therapy (SPT). Implementation of adjunct antimicrobial therapy targeting periodontal pathogens and subsequent periodontal surgery resulted in improvement in periodontal and microbiological parameters. This improvement has been adequately maintained over a 2-year period. However, additional care is necessary to further improve the patient's oral health-related quality of life during SPT. PMID:27320300

  17. Birth Weight of Infants of Mothers With Aggressive Periodontitis

    PubMed Central

    Schenkein, Harvey A.; Koertge, Thomas E.; Sabatini, Robert; Brooks, Carol N.; Gunsolley, John C.

    2014-01-01

    Background It was hypothesized that if periodontal infections predispose low birth weights and premature birth, then such outcomes should be apparent when the mother has aggressive periodontitis (AgP). Methods Birth weight data were collected by questionnaire from females with AgP, their periodontally healthy siblings, and unrelated periodontally healthy women. Both prospective and retrospective birth outcome data were used. Because many of the periodontal evaluations were performed after the births, there were incomplete data regarding most of the risk factors for low birth weight. We determined associations between mothers’ periodontal diagnoses and clinical variables and the reported birth weights. Results There were no significant differences in mean birth weights of babies born to control subjects or AgP patients. This was true whether all the births were considered or only those reported <1 or 2 years before periodontal examination. For periodontally healthy controls, 13.2% of babies born to siblings of AgP patients and 12.8% of babies born to unrelated mothers weighed <2,500 g, whereas 9.9% of those born to mothers with generalized AgP and 10.3% of those born to mothers with localized AgP weighed <2,500 g. Conclusions Because of the relative rarity of AgP in the population, and attendant difficulties in performing a prospective study of its association with pregnancy outcomes, we used a compromised approach using prospective data as well as weaker retrospective data assuming that disease onset was likely before the births. Our results, within the limitations of this approach, indicate no evidence that AgP in the mother predisposes low birth weights. AgP has many unique biologic characteristics that differentiate it from chronic forms of periodontal disease, and the possible lack of its association with birth weight may be another such characteristic. PMID:21819247

  18. Periodontal parameters following orthodontic treatment in patients with aggressive periodontitis: A before-after clinical study

    PubMed Central

    Khorsand, Afshin; Paknejad, Mojgan; Yaghobee, Siamak; Ghahroudi, Amir Alireza Rasouli; Bashizadefakhar, Hourieh; Khatami, Masoomeh; Shirazi, Mohsen

    2013-01-01

    Background: The success of combined periodontal and orthodontic approach in the treatment of aggressive periodontitis patients with the pathologic extruded anterior teeth is a main concern and stability of the treatment results is an important factor to evaluate the treatment. The present study investigated the periodontal parameters at the end of the orthodontic treatment in patients with the aggressive periodontitis. Materials and Methods: Eight patients with an aggressive periodontal disease, extruded maxillary incisors, infrabony defects and probing depth of ≥5 mm were enrolled in this clinical trial (before, after). After periodontal therapy, orthodontic treatment was carried out for intrusion and alignment of teeth. Plaque index (PI), probing pocket depth (PPD), distance between incisal edge and interdental papilla, root length (RL), and defect dimensions (depth and width) were examined at the end of treatment and three as well as 6 months afterward. The data were subjected to repeated measure ANOVA test. P < 0.05 was considered as significant. Results: There was statistically significant decrease in PPD, PI, and depth of the defects during T0, T3 and T6 (P < 0.05). No significant differences were observed in the RL and distance between incisal edge and interdental papilla (P = 0.95). Furthermore, width of the defects demonstrated significant decrease up to T3 (P = 0.042) while no significant changes from 3 months to 6 months were noted (P = 0.59). Conclusion: The results showed that combined periodontal and orthodontic approach would be a successful treatment with acceptable stability in the case of regular follow-up visits and controlled oral hygiene habits. PMID:24379862

  19. Interleukin polymorphisms in aggressive periodontitis: A literature review

    PubMed Central

    Maney, Pooja; Owens, Jessica Leigh

    2015-01-01

    Aggressive periodontitis (AgP), occurs in a younger age group (≤35 years) and is associated with the rapid destruction of periodontal attachment and supporting bone. Genetic polymorphisms are allelic variants that occur in at least 1% of the population that could potentially alter the function of the proteins that they encode. Interleukins are a group of cytokines that have complex immunological functions including proliferation, migration, growth and differentiation of cells and play a key role in the immunopathogenesis of periodontal disease. The aim of this review was to summarize the findings of studies that reported associations or potential associations of polymorphisms in the interleukin family of cytokines, specifically with AgP. PMID:26015661

  20. Idiopathic gingival enlargement associated with generalized aggressive periodontitis in a 19-year-old female

    PubMed Central

    Shetty, Arvind; Gupta, Neha; Shetty, Devanand; Kadakia, Rukshit

    2014-01-01

    Gingival enlargement, one of the manifestations of gingival and periodontal disease, is also known as gingival overgrowth. Idiopathic gingival enlargement is a rare gingival overgrowth, which is of an undetermined cause. This unknown etiology has now been linked to specific genes and idiopathic gingival enlargement is at times referred to as hereditary gingival enlargement. This condition is a benign, slow growing proliferation of gingival tissues. Aggressive periodontitis is the rapid form of periodontal disease which is characterized by extensive periodontal tissue destruction, increased host-susceptibility toward periodontal disease progress and a genetic predilection toward disease occurrence. We present a rare case of idiopathic gingival fibromatosis associated with generalized aggressive periodontitis in a young female. The patient presented with classic clinical and radiographic presentation associated with gingival enlargement and aggressive periodontitis. The diagnosis was then confirmed by histopathological and neutrophil functions tests. PMID:24872638

  1. Implants and all-ceramic restorations in a patient treated for aggressive periodontitis: a case report

    PubMed Central

    Hong, Jin-Sun; Yeo, In-Sung; Kim, Sung-Hun; Lee, Jai-Bong; Han, Jung-Suk

    2010-01-01

    A 23-year-old female with aggressive periodontitis was treated using dental implants and LAVA system. The severely compromised teeth were extracted irrespective of initial conservative periodontal treatment. An implant-supported overdenture with 4 implants was fabricated for the maxilla and all-ceramic restorations for the mandible. Esthetic and functional goals were achieved with team approach involving periodontists and prosthodontists. This case report describes a treatment procedure for a generalized aggressive periodontitis patient with severe bone resorption. PMID:21165277

  2. A Consortium of Aggregatibacter actinomycetemcomitans, Streptococcus parasanguinis, and Filifactor alocis Is Present in Sites Prior to Bone Loss in a Longitudinal Study of Localized Aggressive Periodontitis

    PubMed Central

    Markowitz, Kenneth; Fairlie, Karen; Tischio-Bereski, Debbie; Ferrendiz, Javier; Furgang, David; Paster, Bruce J.; Dewhirst, Floyd E.

    2013-01-01

    Aggregatibacter actinomycetemcomitans-induced localized aggressive periodontitis (LAP) in African-American adolescents has been documented but is poorly understood. Two thousand fifty-eight adolescents aged 11 to 17 years were screened for their periodontal status and the presence of A. actinomycetemcomitans in their oral cavity. Seventy-one A. actinomycetemcomitans-negative and 63 A. actinomycetemcomitans-positive periodontally healthy subjects were enrolled, sampled, examined, and radiographed yearly for 3 years. Gingival and periodontal pocket depth and attachment levels were recorded. Disease presentation was characterized by bone loss (BL). Subgingival sites were sampled every 6 months to assess (i) the role of A. actinomycetemcomitans in BL and (ii) the association of A. actinomycetemcomitans and other microbes in their relationships to BL. Sixteen of 63 subjects with A. actinomycetemcomitans developed BL (the other 47 subjects with A. actinomycetemcomitans had no BL). No A. actinomycetemcomitans-negative subjects developed BL. Human oral microbe identification microarray (HOMIM) was used for subgingival microbial assessment. On a subject level, pooled data from A. actinomycetemcomitans-positive subjects who remained healthy had higher prevalences of Streptococcus and Actinomyces species, while A. actinomycetemcomitans-positive subjects with BL had higher prevalences of Parvimonas micra, Filifactor alocis, A. actinomycetemcomitans, and Peptostreptococcus sp. human oral taxon 113 (HOT-113). At vulnerable sites, A. actinomycetemcomitans, Streptococcus parasanguinis, and F. alocis levels were elevated prior to BL. In cases where the three-organism consortium (versus A. actinomycetemcomitans alone) was detected, the specificity for detecting sites of future BL increased from 62% to 99%, with a sensitivity of 89%. We conclude that detecting the presence of A. actinomycetemcomitans, S. parasanguinis, and F. alocis together indicates sites of future BL in LAP. A

  3. Expression Profile of IL-35 mRNA in Gingiva of Chronic Periodontitis and Aggressive Periodontitis Patients: A Semiquantitative RT-PCR Study

    PubMed Central

    Kalburgi, Nagaraj B.; Muley, Akshay; Shivaprasad, B. M.; Koregol, Arati C.

    2013-01-01

    Background. Proinflammatory and anti-inflammatory cytokines play a key role in the pathogenesis of periodontal diseases. Secretion of bioactive IL-35 has been described by T regulatory cells (Tregs) and is required for their maximal suppressive activity. Tregs are involved in the modulation of local immune response in chronic periodontitis patients. Objective. Hence, the present study was aimed to investigate the expression of IL-35 mRNA in chronic periodontitis and aggressive periodontitis patients. Materials and Methods. The present study was carried out in 60 subjects, which included 20 chronic periodontitis patients, 20 aggressive periodontitis patients, and 20 periodontally healthy controls. IL-35 mRNA expression in gingival tissue samples of all subjects was semiquantitatively analyzed using Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). Results. The present study demonstrated the expression of IL-35 mRNA in gingival tissues of all the three groups. IL-35 mRNA expression was highest in chronic periodontitis subjects (6.87 ± 2.32) as compared to the aggressive periodontitis group (4.71 ± 1.43) and least seen in healthy patients (3.03 ± 1.91). Conclusion. The increased expression of IL-35 in chronic and aggressive periodontitis suggests its possible role in pathogenesis of periodontitis. Future studies done on large samples with intervention will strengthen our result. PMID:24376289

  4. The novel role of HtrA1 in gingivitis, chronic and aggressive periodontitis.

    PubMed

    Lorenzi, Teresa; Niţulescu, Elena Annabel; Zizzi, Antonio; Lorenzi, Maria; Paolinelli, Francesca; Aspriello, Simone Domenico; Baniţă, Monica; Crăiţoiu, Stefania; Goteri, Gaia; Barbatelli, Giorgio; Lombardi, Tommaso; Di Felice, Roberto; Marzioni, Daniela; Rubini, Corrado; Castellucci, Mario

    2014-01-01

    Proteolytic tissue degradation is a typical phenomenon in inflammatory periodontal diseases. HtrA1 (High temperature requirement A 1) has a serine protease activity and is able to degrade fibronectin whose fragments induce the expression and secretion of several matrix metalloproteinases (MMPs). The aim of this study was to investigate for the first time if HtrA1 has a role in gingivitis and in generalized forms of chronic and aggressive periodontitis. Expression of HtrA1 was investigated in 16 clinically healthy gingiva, 16 gingivitis, 14 generalized chronic periodontitis and 10 generalized aggressive periodontitis by immunohistochemistry and real-time PCR. Statistical comparisons were performed by the Kruskall-Wallis test. Significantly higher levels of HtrA1 mRNA and protein expression were observed in pathological respect to healthy tissues. In particular, we detected an increase of plasma cell HtrA1 immunostaining from gingivitis to chronic and aggressive periodontitis, with the higher intensity in aggressive disease. In addition, we observed the presence of HtrA1 in normal and pathological epithelium, with an increased expression, particularly in its superficial layer, associated with increasingly severe forms of periodontal disease. We can affirm that HtrA1 expression in plasma cells could be correlated with the destruction of pathological periodontal tissue, probably due to its ability to trigger the overproduction of MMPs and to increase the inflammatory mediators TNF-α and IL-1β by inhibition of TGF-β. Moreover, epithelial HtrA1 immunostaining suggests a participation of the molecule in the host inflammatory immune responses necessary for the control of periodontal infection.

  5. Implant Rehabilitation in Advanced Generalized Aggressive Periodontitis: A Case Report and Literature Review

    PubMed Central

    Rasaeipour, Sasan; Siadat, Hakimeh; Rasouli, Amiralireza; Sajedinejadd, Neda

    2015-01-01

    Dental implants have provided exceptional rehabilitative options for edentulous and partially edentulous patients. However, as more implants come into play, the more the clinicians come across problems where specific considerations must be taken into account to meet expectations. The Toronto Bridge is a treatment modality proposed for restoring several teeth lost in patients with increased crown height (interarch) space. Herein, we applied the Toronto Bridge to rehabilitate a patient with generalized aggressive periodontitis; this article suggests that an implant-supported Toronto Bridge can be a reliable and acceptable treatment modality for patients suffering from tooth loss and vertical bone loss as the result of generalized aggressive periodontal disease. PMID:27123022

  6. Association of interleukin-1 α (–889) gene polymorphism in patients with generalized aggressive and chronic periodontitis

    PubMed Central

    Puri, Komal; Chhokra, Mehak; Dodwad, Vidya; Puri, Nikhil

    2015-01-01

    Background: There is a strong evidence that genetic as well as environmental factors affect the age of onset, severity and lifetime risk of developing periodontitis. The objective of the present study was to compare and to evaluate the association between interleukin (IL)-1α(-889) and gene polymorphisms in patients with generalized aggressive periodontitis, chronic periodontitis and healthy controls. Materials and Methods: A total of 60 Indian patients, with 20 aggressive periodontitis, 20 chronic periodontitis and 20 healthy controls were recruited for this study. From each patient, a volume of 2 ml of blood was collected by venipuncture in the ante-cubital fossa and was stored in sodium EDTA vacutainers and was used for genotyping assays with the polymerase chain reaction restriction fragment length polymorphism technique. Clinical parameters such as oral hygiene index, gingival index and clinical attachment loss (CAL) were evaluated for each patient. Genotype distribution between different groups were analyzed using Chi-square test. A P = 0.05 or less was set for significance. Results: The mean oral hygiene index was 3.7 ± 0.86 and 3.25 ± 0.30 for chronic and aggressive periodontitis cases respectively. The CAL was 4.29 ± 0.63 mm for chronic periodontitis and 6.44 ± 0.57 mm for aggressive periodontitis. Homozygous genotype 2,2 was more predominant in cases of aggressive periodontitis whereas in chronic periodontitis, heterozygous genotype 1,2 was more predominant when compared with others (P < 0.001). Odds ratio for aggressive versus chronic periodontitis was calculated as 6.2 (95% confidence interval 6.019-7.892). Conclusion: The results of the present study support a positive association between aggressive periodontitis and the presence of the IL-1α-889, allele 2 polymorphism in Indian patients. PMID:25709679

  7. Congenital adrenal hyperplasia with localized aggressive periodontitis and amelogenesis imperfecta.

    PubMed

    Ajlan, Sumaiah Abdulbaqi

    2015-11-01

    Congenital adrenal hyperplasia (CAH) is an inherited medical condition that implies defects in steroid biosynthesis. The dental findings of a female patient with CAH are reported. The patient suffered from severe periodontal tissue destruction, obvious enamel defects, as well as some occlusal problems. The management approach is presented and the possibility of interrelation of her dental findings with her medical condition is discussed.

  8. Role of antibiotics in generalized aggressive periodontitis: A review of clinical trials in humans

    PubMed Central

    Ahuja, Annapurna; Baiju, C. S.; Ahuja, Vipin

    2012-01-01

    Background: It is well-recognized fact that periodontal diseases are caused by multifactorial etiologies, in which microorganisms play an important role. An essential component of therapy is to eliminate or manage these pathogens. This has been traditionally accomplished through mechanical means by scaling and root planning which is ineffective in some of the aggressive periodontal diseases. These aggressive diseases involve particular groups of microorganisms which are not eliminated by mechanical means; and they require anti-infective therapy, which includes local and systemic antimicrobials. This approach of therapy is of interest to periodontist due to the aforementioned shortcomings of conventional methods. Materials and Methods: A manual and electronic search was made for human studies up to March 2011 that presented clinical and microbiological data for the efficacy of a systemic antibiotics in generalized aggressive periodontitis along with scaling and root planning. A systematic approach was followed by two independent reviewers and included eligibility criteria for study inclusion, quality assessment, and determination of outcome measures, data extraction, data synthesis, and drawing of conclusion. Results: Only three randomized controlled human trials qualified, and they concluded that both scaling and root planing (SRP) mono-therapy and SRP with antibiotics proves beneficial in improving clinical and microbiological parameters in aggressive periodontitis. Better results were seen in SRP with antibiotic groups as compared with SRP alone. Conclusion: Because of the insufficient quantity and heterogenecity of studies, no adequate evidence could be gathered to use the beneficial effects of these antibiotics along with SRP in aggressive periodontitis compared with SRP alone. PMID:23162322

  9. Detection and comparison of Selenomonas sputigena in subgingival biofilms in chronic and aggressive periodontitis patients

    PubMed Central

    Nagpal, Disha; Prakash, Shobha; Bhat, Kishore Gajanan; Singh, Gagandeep

    2016-01-01

    Background: With the advent of DNA-based culture-independent techniques, a constantly growing number of Selenomonas phylotypes have been detected in patients with destructive periodontal diseases. However, the prevalence levels that have been determined in different studies vary considerably. Aim: The present study was undertaken to detect and compare the presence of Selenomonas sputigena in the subgingival plaque samples from generalized aggressive periodontitis (GAP), chronic generalized periodontitis, and periodontally healthy patients using conventional polymerase chain reaction (PCR) technique. Materials and Methods: A total of 90 patients were categorized as periodontally healthy individuals (Group I, n = 30), chronic generalized periodontitis (Group II, n = 30), and GAP (Group III, n = 30). The clinical parameters were recorded and subgingival plaque samples were collected. These were then subjected to conventional PCR analysis. Statistical Analysis Used: Kruskal–Wallis ANOVA test was used for multiple group comparisons followed by Mann–Whitney U-test for pairwise comparison. Results: On comparison between three groups, all the clinical parameters were found to be statistically highly significant. Comparing Groups I-II and I-III, the difference in detection was found to be statistically highly significant whereas in Groups II-III, it was statistically nonsignificant. On comparison of S. sputigena detected and undetected patients to clinical parameters in various study groups, the difference was found to be nonsignificant. Conclusion: S. sputigena was found to be significantly associated with chronic and aggressive periodontitis. Although the difference in its detection frequency in both groups was statistically nonsignificant when compared clinically, S. sputigena was more closely associated with the GAP. PMID:27563202

  10. Are herpes virus associated to aggressive periodontitis? A review of literature

    PubMed Central

    Rodrigues, Patrícia Maria de Sousa; Teixeira, Ana Luísa; Kustner, Eduardo Chimenos; Medeiros, Rui

    2015-01-01

    Periodontal Disease includes a wide variety of infectious entities with various clinical manifestations in the oral cavity and responses to treatment. The determinants of clinical manifestations of periodontal disease include the type of infectious agent, the host immune response and environmental factors. Aggressive periodontitis (AP) is defined as a type of inflammation with specific clinical and laboratory features, which distinguish it from other types of periodontitis, with high incidence rates in a sub-group of individuals. Bacteria have been frequently mentioned as the agent inciting gingival inflammation and tissue destruction that underlies the pathogenesis of periodontitis. However, recent studies, with some controversial results, have suggested that the herpes family of viruses, including CMV and EBV-1 as well as papillomaviruses, HIV, Human T-lymphotropic virus type 1, Torquetenovirus and hepatitis B and C occur with high frequency in active periodontal lesions. There is a lack of information about this disease and the role of herpesviruses in its pathophysiology. This review provides a critical analysis of the scientific evidence linking bacteria and viruses with AP and their potential impact on clinical characteristics, prognosis and therapy. PMID:26980964

  11. Are herpes virus associated to aggressive periodontitis? A review of literature.

    PubMed

    Rodrigues, Patrícia Maria de Sousa; Teixeira, Ana Luísa; Kustner, Eduardo Chimenos; Medeiros, Rui

    2015-01-01

    Periodontal Disease includes a wide variety of infectious entities with various clinical manifestations in the oral cavity and responses to treatment. The determinants of clinical manifestations of periodontal disease include the type of infectious agent, the host immune response and environmental factors. Aggressive periodontitis (AP) is defined as a type of inflammation with specific clinical and laboratory features, which distinguish it from other types of periodontitis, with high incidence rates in a sub-group of individuals. Bacteria have been frequently mentioned as the agent inciting gingival inflammation and tissue destruction that underlies the pathogenesis of periodontitis. However, recent studies, with some controversial results, have suggested that the herpes family of viruses, including CMV and EBV-1 as well as papillomaviruses, HIV, Human T-lymphotropic virus type 1, Torquetenovirus and hepatitis B and C occur with high frequency in active periodontal lesions. There is a lack of information about this disease and the role of herpesviruses in its pathophysiology. This review provides a critical analysis of the scientific evidence linking bacteria and viruses with AP and their potential impact on clinical characteristics, prognosis and therapy. PMID:26980964

  12. [Markers of periodontal diseases and sensitivity to taromentine in patients with aggressive periodontitis].

    PubMed

    Iverieli, M V; Abashidze, N O; Gogishvili, Kh B

    2009-04-01

    The aim of the research was to study sensitivity of specific microorganisms from the periodontal pockets of patients with rapidly progressive periodontal disease to Taromentine. 95 patients aged 21 to 35 years (50 women (52,6+/-33,62) and 45 men (47,36+/-3,62)) with rapidly progressive form of periodontal desease were observed. Porphiromonas gingivalis was identifide in 83 out of 95 patients (87,36+/-2,06). Prevotella intermedia - in 31 patients (32,6+/-2,750); Actinobacillus actinomycetemcomitans - in 23 patients (24,2+/-2,050); Bacteroides forsythus - in 19 patients (20,0+/-2,360); Treponema denticola - in 16 patients (16,84+/-2,190); Candida - in 11 patients (11,57+/-1,80). The sensitivity of all cultures to Taromentine was investigated: 134 (77,9+/-1,89) out of 183 identified markers demonstrated sensitivity to Taromentine. Demostrated sensitivity to Taromentine: 64 (37,2+/-1,06) out of 83 identified cultures of Porphiromonas gingivalis, 24 (13,95+/-1,85) out of 31 identified cultures of Prevotela intermedia, 18 (10,47+/-1,05) out of 23 identified cultures of Actinobacillus actinomycetemcomitans, 15 (8,7+/-1,86) out of 19 identified cultures of Bacteroides forsythus, and 13 (7,84+/-1,09) out of 16 identified cultures of Treponema denticola. Totally 38 (22,1+/-1,59) out of 172 identified periodontal markers demonstrated resistence to Taromentine. The results of analysis showed that Taromentine could be recommended in complex treatment of periodontal diseases. PMID:19430039

  13. C-Reactive Protein in Peripheral Blood of Patients with Chronic and Aggressive Periodontitis, Gingivitis, and Gingival Recessions.

    PubMed

    Podzimek, Stepan; Mysak, Jaroslav; Janatova, Tatjana; Duskova, Jana

    2015-01-01

    CRP is a plasma protein that reflects a measure of the acute phase response to inflammation and is one of the markers of choice in monitoring this response. CRP can be used for the prediction and early detection of periodontal disease. The aim of this study was to compare and evaluate the systemic levels of CRP in the peripheral blood samples of patients with chronic and aggressive periodontitis, gingivitis, and gingival recessions and compare them with periodontal clinical parameters. All patients (N = 158) were examined prior to the initiation of periodontal treatment. Patients were divided into four groups. Group A consisted of 26 patients with aggressive periodontitis, Group B consisted of 111 patients with chronic periodontitis, Group C consisted of 13 patients with gingivitis, and Group D consisted of 8 patients with gingival recessions. Our study results indicate that CRP levels increase subsequently with the severity of the periodontal disease and that the bleeding on probing index showed much better positive correlation with the CRP levels compared to the pocket depth index in both periodontitis patients groups, especially in aggressive periodontitis patients.

  14. C-Reactive Protein in Peripheral Blood of Patients with Chronic and Aggressive Periodontitis, Gingivitis, and Gingival Recessions

    PubMed Central

    Podzimek, Stepan; Mysak, Jaroslav; Janatova, Tatjana; Duskova, Jana

    2015-01-01

    CRP is a plasma protein that reflects a measure of the acute phase response to inflammation and is one of the markers of choice in monitoring this response. CRP can be used for the prediction and early detection of periodontal disease. The aim of this study was to compare and evaluate the systemic levels of CRP in the peripheral blood samples of patients with chronic and aggressive periodontitis, gingivitis, and gingival recessions and compare them with periodontal clinical parameters. All patients (N = 158) were examined prior to the initiation of periodontal treatment. Patients were divided into four groups. Group A consisted of 26 patients with aggressive periodontitis, Group B consisted of 111 patients with chronic periodontitis, Group C consisted of 13 patients with gingivitis, and Group D consisted of 8 patients with gingival recessions. Our study results indicate that CRP levels increase subsequently with the severity of the periodontal disease and that the bleeding on probing index showed much better positive correlation with the CRP levels compared to the pocket depth index in both periodontitis patients groups, especially in aggressive periodontitis patients. PMID:26346216

  15. Nonsyndromic localized aggressive periodontitis of primary dentition: A rare case report.

    PubMed

    Muppa, Radhika; Nallanchakrava, Srinivas; Chinta, Mahesh; Manthena, Ravi Teja

    2016-01-01

    Periodontitis is an inflammatory disease of the gingiva and tissues of the periodontium. It is characterized by pocket formation and destruction of supporting alveolar bone. Periodontal diseases of aggressive nature are not very common in children. They are usually associated with systemic conditions. The present case report is of a 5-year-old male child who reported with rapid attachment loss and bony defects of the gingiva and supporting structures. His family and medical history gave no contribution for the diagnosis. Blood investigations did not reveal any abnormality. The microbial examination of culture revealed the presence of periodontal pathogen Aggregatibacter actinomycetemcomitans. The treatment objective in the present case was to prevent the further progress of the condition, restore esthetic and function in the child which would psychologically benefit the child. PMID:27307682

  16. Nonsyndromic localized aggressive periodontitis of primary dentition: A rare case report

    PubMed Central

    Muppa, Radhika; Nallanchakrava, Srinivas; Chinta, Mahesh; Manthena, Ravi Teja

    2016-01-01

    Periodontitis is an inflammatory disease of the gingiva and tissues of the periodontium. It is characterized by pocket formation and destruction of supporting alveolar bone. Periodontal diseases of aggressive nature are not very common in children. They are usually associated with systemic conditions. The present case report is of a 5-year-old male child who reported with rapid attachment loss and bony defects of the gingiva and supporting structures. His family and medical history gave no contribution for the diagnosis. Blood investigations did not reveal any abnormality. The microbial examination of culture revealed the presence of periodontal pathogen Aggregatibacter actinomycetemcomitans. The treatment objective in the present case was to prevent the further progress of the condition, restore esthetic and function in the child which would psychologically benefit the child. PMID:27307682

  17. Photodynamic therapy in the treatment of aggressive periodontitis: A systematic review

    PubMed Central

    Doufexi, Aikaterini-Ellisavet

    2016-01-01

    Background Aggressive periodontitis (AgP) is a severe form of periodontal diseases with rapid destruction of the supporting bone around teeth. The efficacy of PDT in suppressing periodontal pathogens may be crucial in adopting new protocols for the treatment of AgP. Thus, the aim of this systematic review was to investigate the possible role of PDT in the treatment of AgP as an adjunctive therapy or monotherapy. Material and Methods A systematic search of the literature was performed. Additionally, the references from all the selected full-text studies were searched for relevant articles. Two reviewers screened independently titles and abstracts or full text copies. Quality assessment of all the included studies was held. Results Initial screening of electronic databases yielded 418 potentially relevant publications. After screening of the titles and full-text examination, five studies were included in the systematic review. Four publications evaluated the effects of PDT adjunctive to SRP in patients with AgP: two of them compared the clinical outcomes of SRP and PDT with a control group that received therapy with SRP and antibiotics (metronidazole and amoxicillin); two publications included SRP and PDT in the test group, and SRP alone in the control group. In one study, PDT was tested as a monotherapy compared with SRP alone. Conclusions Within the limitations of this review, PDT may exhibit a beneficial role in the therapy of aggressive periodontitis after repeated applications. In the future, more methodologically sound, long-term randomized clinical trials are needed to be conducted. Key words:Photodynamic therapy, periodontitis, systematic review. PMID:26595837

  18. Aggressive periodontitis: An appraisal of systemic effects on its etiology-genetic aspect

    PubMed Central

    Debabrata, Kundu; Prasanta, Bandyopadhyay; Vineet, Nair; Anshul, Garg; Arindam, Saha; Satadal, Das

    2015-01-01

    Background: Myeloperoxidase (MPO) is a lysosomal enzyme found in the azurophilic granules of polymorphonuclear leukocytes and is able to mediate inflammatory tissue destruction in aggressive and chronic periodontitis (CP). Human telomerase is a multi subunit ribonucleoprotein enzyme concerned with telomeric lengthening and homeostasis in man and has been found to be elevated in inflammatory conditions such as rheumatoid arthritis and periodontitis. The aim of this study was to explore in aggressive periodontitis (AP) subjects: (i) The role of MPO-463G/A gene polymorphism and (ii) the level of telomerase expression. These parameters have been compared with the subjects of CP and that of the healthy controls. Materials and Methods: A total of 45 subjects of the age group 20–50 years and free from any known systemic disease were included in the study. They were divided into three groups – Group I-periodontally healthy control (n = 15), Group II-CP (n = 15) and Group III-AP (n = 15). Peripheral blood samples and gingival tissue samples were collected for MPO gene polymorphism and telomerase expression, respectively, for detection by reverse transcriptase polymerase chain reaction. Results: The frequencies of AG and AA genotypes in the MPO gene polymorphism were more common in the AP subjects when compared to the controls. The m-RNA expression of human telomerase reverse transcriptase (hTERT) was undetectable in the gingival tissue of the control group. Its expression in AP subjects was significantly higher than that of CP group (83.61 ± 2.94 in CP and 104.27 ± 6.06 in AP) (P < 0.0001). Conclusions: Our data suggest that MPO-463G/A may be associated with increased risk of AP. The level of tissue hTERT was elevated in AP subjects as compared to CP and healthy control groups. PMID:26015667

  19. Lapping slurry

    DOEpatents

    Simandl, Ronald F.; Upchurch, Victor S.; Leitten, Michael E.

    1999-01-01

    Improved lapping slurries provide for easier and more thorough cleaning of alumina workpieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid.

  20. Lapping slurry

    DOEpatents

    Simandl, R.F.; Upchurch, V.S.; Leitten, M.E.

    1999-01-05

    Improved lapping slurries provide for easier and more thorough cleaning of alumina work pieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid. 1 fig.

  1. Pathogenicity of the highly leukotoxic JP2 clone of Aggregatibacter actinomycetemcomitans and its geographic dissemination and role in aggressive periodontitis.

    PubMed

    Haubek, Dorte; Johansson, Anders

    2014-01-01

    For decades, Aggregatibacter actinomycetemcomitans has been associated with aggressive forms of periodontitis in adolescents. In the middle of the 1990s, a specific JP2 clone of A. actinomycetemcomitans, belonging to the cluster of serotype b strains of A. actinomycetemcomitans and having a number of other characteristics, was found to be strongly associated with aggressive forms of periodontitis, particularly in North Africa. Although several longitudinal studies still point to the bacterial species, A. actinomycetemcomitans as a risk factor of aggressive periodontitis, it is now also widely accepted that the highly leukotoxic JP2 clone of A. actinomycetemcomitans is implicated in rapidly progressing forms of aggressive periodontitis. The JP2 clone strains are highly prevalent in human populations living in Northern and Western parts of Africa. These strains are also prevalent in geographically widespread populations that have originated from the Northwest Africa. Only sporadic signs of a dissemination of the JP2 clone strains to non-African populations have been found despite Africans living geographically widespread for hundreds of years. It remains an unanswered question if a particular host tropism exists as a possible explanation for the frequent colonization of the Northwest African population with the JP2 clone. Two exotoxins of A. actinomycetemcomitans are known, leukotoxin (LtxA) and cytolethal distending toxin (Cdt). LtxA is able to kill human immune cells, and Cdt can block cell cycle progression in eukaryotic cells and thus induce cell cycle arrest. Whereas the leukotoxin production is enhanced in JP2 clone strains thus increasing the virulence potential of A. actinomycetemcomitans, it has not been possible so far to demonstrate such a role for Cdt. Lines of evidence have led to the understanding of the highly leukotoxic JP2 clone of A. actinomycetemcomitans as an aetiological factor of aggressive periodontitis. Patients, who are colonized with the JP2

  2. Pathogenicity of the highly leukotoxic JP2 clone of Aggregatibacter actinomycetemcomitans and its geographic dissemination and role in aggressive periodontitis

    PubMed Central

    Haubek, Dorte; Johansson, Anders

    2014-01-01

    For decades, Aggregatibacter actinomycetemcomitans has been associated with aggressive forms of periodontitis in adolescents. In the middle of the 1990s, a specific JP2 clone of A. actinomycetemcomitans, belonging to the cluster of serotype b strains of A. actinomycetemcomitans and having a number of other characteristics, was found to be strongly associated with aggressive forms of periodontitis, particularly in North Africa. Although several longitudinal studies still point to the bacterial species, A. actinomycetemcomitans as a risk factor of aggressive periodontitis, it is now also widely accepted that the highly leukotoxic JP2 clone of A. actinomycetemcomitans is implicated in rapidly progressing forms of aggressive periodontitis. The JP2 clone strains are highly prevalent in human populations living in Northern and Western parts of Africa. These strains are also prevalent in geographically widespread populations that have originated from the Northwest Africa. Only sporadic signs of a dissemination of the JP2 clone strains to non-African populations have been found despite Africans living geographically widespread for hundreds of years. It remains an unanswered question if a particular host tropism exists as a possible explanation for the frequent colonization of the Northwest African population with the JP2 clone. Two exotoxins of A. actinomycetemcomitans are known, leukotoxin (LtxA) and cytolethal distending toxin (Cdt). LtxA is able to kill human immune cells, and Cdt can block cell cycle progression in eukaryotic cells and thus induce cell cycle arrest. Whereas the leukotoxin production is enhanced in JP2 clone strains thus increasing the virulence potential of A. actinomycetemcomitans, it has not been possible so far to demonstrate such a role for Cdt. Lines of evidence have led to the understanding of the highly leukotoxic JP2 clone of A. actinomycetemcomitans as an aetiological factor of aggressive periodontitis. Patients, who are colonized with the JP2

  3. 16S rRNA based microarray analysis of ten periodontal bacteria in patients with different forms of periodontitis.

    PubMed

    Topcuoglu, Nursen; Kulekci, Guven

    2015-10-01

    DNA microarray analysis is a computer based technology, that a reverse capture, which targets 10 periodontal bacteria (ParoCheck) is available for rapid semi-quantitative determination. The aim of this three-year retrospective study was to display the microarray analysis results for the subgingival biofilm samples taken from patient cases diagnosed with different forms of periodontitis. A total of 84 patients with generalized aggressive periodontitis (GAP,n:29), generalized chronic periodontitis (GCP, n:25), peri-implantitis (PI,n:14), localized aggressive periodontitis (LAP,n:8) and refractory chronic periodontitis (RP,n:8) were consecutively selected from the archives of the Oral Microbiological Diagnostic Laboratory. The subgingival biofilm samples were analyzed by the microarray-based identification of 10 selected species. All the tested species were detected in the samples. The red complex bacteria were the most prevalent with very high levels in all groups. Fusobacterium nucleatum was detected in all samples at high levels. The green and blue complex bacteria were less prevalent compared with red and orange complex, except Aggregatibacter actinomycetemcomitas was detected in all LAP group. Positive correlations were found within all the red complex bacteria and between red and orange complex bacteria especially in GCP and GAP groups. Parocheck enables to monitoring of periodontal pathogens in all forms of periodontal disease and can be alternative to other guiding and reliable microbiologic tests.

  4. Comparison of the Salivary and the Serum Nitric Oxide Levels in Chronic and Aggressive Periodontitis: A Biochemical Study

    PubMed Central

    Sundar, N. Mani; Krishnan, V; Krishnaraj, S; Hemalatha, V.T.; Alam, Md Nazish

    2013-01-01

    Background and Objectives: Nitric oxide (NO) is a ubiquitous intercellular messenger molecule with important cardiovascular, neurological, and immune functions. In addition, it has been postulated that the pharmacological inhibition of NO or its actions may be therapeutically valuable in the disease management. The levels of nitric oxide may provide clues about the severity and the state of the underlying disease process. It could be an inflammatory biomarker that may enable clinicians to direct the environmentally based prevention or treatment programmes and to establish whether NO plays a role in the pathogenesis of periodontitis or not. Hence, the aim of the present study was to evaluate the salivary and the serum levels of NO in generalized chronic and aggressive periodontitis. The Study Design: Unstimulated whole saliva and serum samples were collected from a total of 60 subjects who were in the age group of 18-45 years, who participated in this study. They were divided into three equal groups with 20 subjects in each group; group A (healthy controls), group B (chronic periodontitis) and group C (aggressive periodontitis). The clinical parameters were assessed, based on the oral hygiene index simplified (OHI-S), the gingival index (GI), the probing pocket depth and the clinical attachment loss (CAL). A biochemical analysis was performed to evaluate and compare the salivary and the serum nitric oxide levels of the above groups. Statistical Analysis and Results: The statistical comparisons were done under the Griess Reaction. There were statistically significant salivary and serum levels of NO in the groups of periodontitis (group B and C) as compared to those in the healthy controls (group A). A significant positive correlation was found between the values of the salivary and the serum NO levels in chronic and aggressive periodontitis. Conclusion: Nitric oxide is a potent modulator of the inflammatory disease processes and under pathological conditions, NO has

  5. Linkage disequilibrium analysis of case-control data: an application to generalized aggressive periodontitis.

    PubMed

    Scapoli, C; Trombelli, L; Mamolini, E; Collins, A

    2005-02-01

    Several studies have shown a role for the involvement of interleukin (IL)-1 gene cluster polymorphisms in the risk of periodontal diseases. In the present study, we tested polymorphisms, derived from genes of the IL-1 cluster, for association with generalized aggressive periodontitis (GAP) through both allelic association and by constructing a linkage disequilibrium (LD) map of the 2q13-14 disease candidate region. The IL-1RN (VNTR) genotype distribution observed was significantly different in GAP and control subjects (P=0.019). We also observed some evidence for an association between GAP and the IL-1B(+3953) polymorphism (P=0.039). The pattern of association in the region, represented as an LD map, identifies a recombination hot area between the IL-1B(+3953) and IL-1B(-511) polymorphisms. Multilocus modelling of association with disease gives a location for the peak association at the IL-1B(+3953) marker, although support for the peak is not significant. Haplotype analysis identifies a IL-1B(+3953)-IL-1B(-511) haplotype as having the lowest P-value in the region. Recognition of the presence of a recombination hot area between the IL-1B(+3953) and IL-1B(-511) polymorphisms will have an important bearing on future efforts to develop higher resolution SNP analysis in this region for both this and other diseases for which this cluster is implicated.

  6. Evaluation of interleukin -1B (+3954) gene polymorphism in patients with chronic and aggressive periodontitis: A genetic association study

    PubMed Central

    Masamatti, Sujata S.; Kumar, Ashish; Baron, Tarun Kumar A.; Mehta, Dhoom S.; Bhat, Kishore

    2012-01-01

    Background: IL-1 cytokines have central roles in the pathogenesis of periodontal disease. Polymorphism in the locus +3954 (C/T) of the human IL-1B gene has been shown to affect the levels of this cytokine. Aim: The aim of the present study was to investigate the association between the IL-1 B (+3954) gene polymorphism and the occurrence of different clinical forms of periodontitis. Materials and Methods: Genomic DNA was obtained from 90 individuals and amplified using the PCR with specific primers flanking the locus +3954 of IL-1B. PCR products were submitted to restriction endonuclease digestion and analyzed by gel electrophoresis, allowing for the determination of the genotypes and detection of the polymorphism. Statistical Analysis: Fisher's exact test was used for comparing the frequency of genotype distributions between groups. Results: The chronic periodontitis group displayed a higher percentage of T alleles (38%) when compared to the aggressive periodontitis group (20%) and to the control group (19%). Conclusion: Our study data states that polymorphism in the locus +3954 of IL-1B gene could be a risk factor for chronic periodontitis in a sample of Indian population of Karnataka state. PMID:22919211

  7. Interleukin-1β rs1143634 polymorphism and aggressive periodontitis susceptibility: a meta-analysis

    PubMed Central

    Chen, Yong-Ji; Han, Ying; Mao, Min; Tan, Ya-Qin; Leng, Wei-Dong; Zeng, Xian-Tao

    2015-01-01

    Multiple studies had focused on the association between interleukin-1 (IL-1) rs1143634 polymorphism and aggressive periodontitis (AgP) susceptibility, but the results remained inconclusive. Therefore, this meta-analysis was conducted to explore its role in the development of AgP. PubMed and Embase databases were searched up to April 15, 2014. After study selection and data extraction form eligible studies, meta-analysis was performed. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the association. All the analysis was performed using Comprehensive Meta-Analysis software. Finally a total of 25 case-control studies were included. The pooled results showed non-association between AgP susceptibility and IL-1 rs1143634 polymorphism [for T vs. C: OR = 0.99, 95% CI = 0.79-1.23; for TT vs. CC: OR = 1.14, 95% CI = 0.78-1.66; for CT vs. CC: OR = 0.97, 95% CI = 0.70-1.36; for (CT + TT) vs. CC: OR = 1.02, 95% CI = 0.76-1.37; for TT vs. (CT + CC): OR = 1.22, 95% CI = 0.85-1.75]. Subgroup analyses remain did not find any association. No publication bias was detected. Hence, our meta-analysis showed that IL-1β rs1143634 polymorphism is not linked to AgP susceptibility, regardless of ethnicity. PMID:25932167

  8. Periodontitis

    MedlinePlus

    Pyorrhea - gum disease; Inflammation of gums - involving bone ... Periodontitis occurs when inflammation or infection of the gums ( gingivitis ) occurs and is not treated. Infection and inflammation spreads from the gums (gingiva) ...

  9. OCCURRENCE OF ACTINOBACILLUS ACTINOMYCETEMCOMITANS IN PATIENTS WITH CHRONIC PERIODONTITIS, AGGRESSIVE PERIODONTITIS, HEALTHY SUBJECTS AND CHILDREN WITH GINGIVITIS IN TWO CITIES OF THE STATE OF SÃO PAULO, BRAZIL

    PubMed Central

    Jardim, Elerson Gaetti; Bosco, Joseane Maria Dias; Lopes, Angélica Marquezim; Landucci, Luís Fernando; Jardim, Ellen Cristina Gaetti; Carneiro, Sílvia Rosana Soares

    2006-01-01

    The aim of this study was to determine the frequency of isolation of Actinobacillus actinomycetemcomitans (Aa) in 100 patients with chronic periodontitis, 14 patients with aggressive periodontitis, 142 pre-school children with gingivitis and 134 periodontally healthy subjects. Samples of subgingival plaque were taken using sterilized paper points introduced into periodontal pockets or gingival crevice for 60 seconds and inoculated on TSBV agar, which was incubated under anaerobiosis at 37°C, for 4 days. Microbial identification was performed through biochemical methods and morphocellular and morphocolonial analysis. Aa was detected in 40.3% of healthy subjects, 68% of patients with chronic periodontitis, 92.86% of patients with aggressive periodontitis and 40.14% of children with gingivitis. The rate of recovery of Aa in the tested human groups proved to be higher than previously reported and in agreement with participation of this facultative anaerobe as a member of native microbiota of the periodontium and its relation with aggressive and chronic periodontitis in Brazil. PMID:19089064

  10. A Putative Association of a Single Nucleotide Polymorphism in GPR126 with Aggressive Periodontitis in a Japanese Population

    PubMed Central

    Asano, Yoshihiro; Imai, Atsuko; Kawai, Shinji; Michikami, Ikumi; Yamashita, Motozo; Yamada, Satoru; Kitamura, Masahiro; Murakami, Shinya

    2016-01-01

    Periodontitis is an inflammatory disease causing loss of tooth-supporting periodontal tissue. Disease susceptibility to the rapidly progressive form of periodontitis, aggressive periodontitis (AgP), appears to be influenced by genetic risk factors. To identify these in a Japanese population, we performed whole exome sequencing of 41 unrelated generalized or localized AgP patients. We found that AgP is putatively associated with single nucleotide polymorphism (SNP) rs536714306 in the G-protein coupled receptor 126 gene, GPR126 [c.3086 G>A (p.Arg1029Gln)]. Since GPR126 activates the cAMP/PKA signaling pathway, we performed cAMP ELISA analysis of cAMP concentrations, and found that rs536714306 impaired the signal transactivation of GPR126. Moreover, transfection of human periodontal ligament (HPDL) cells with wild-type or mutant GPR126 containing rs536714306 showed that wild-type GPR126 significantly increased the mRNA expression of bone sialoprotein, osteopontin, and Runx2 genes, while mutant GPR126 had no effect on the expression of these calcification-related genes. The increase in expression of these genes was through the GPR126-induced increase of bone morphogenic protein-2, inhibitor of DNA binding (ID) 2, and ID4 expression. These data indicate that GPR126 might be important in maintaining the homeostasis of periodontal ligament tissues through regulating the cytodifferentiation of HPDL cells. The GPR126 SNP rs536714306 negatively influences this homeostasis, leading to the development of AgP, suggesting that it is a candidate genetic risk factor for AgP in the Japanese population. PMID:27509131

  11. Genetic polymorphisms of TNFA and IL-1A and generalized aggressive periodontitis.

    PubMed

    Barnea, Teodora Virginia; Sava, Anca; Gentimir, Carmen; Goriuc, Ancuţa; Boişteanu, Otilia; Chelaru, Liliana; Iancu, Roxana Irina; Avram, Cătălina Anda; Acatrinei, Dragoş Daniel; Bogza, Elena Geanina; Răducanu, Oana Cristina; Cioloca, Daniel Petru; Vasincu, Decebal; Costuleanu, Marcel

    2015-01-01

    Virulent bacteria could cause gingival fibroblasts apoptosis through lipopolysaccharide release during generalized aggressive periodontitis (GAgP) development and evolution. We showed that treatment with lipopolysaccharide (LPS, 1 μg/mL) for 30 days induced the decrease in the number of cultured rat gingival fibroblasts as compared to control group, which received no treatment. GAgP is considered to have also a genetic etiology, so the aim of our study was to evaluate if some polymorphisms of tumor necrosis factor-alpha (TNFA) and interleukin 1A (IL-1A) genes are associated with GAgP in a sample of Romanian population. We selected a group of 32 subjects (22 cases and 10 controls) for studying the TNFA (-857) polymorphism and 97 subjects (66 cases and 31 controls) for IL-1A (-889) polymorphism. The single nucleotide polymorphisms were genotyped by real-time polymerase chain reaction for all subjects. The genotype and allelic distribution tended to be equally between the cases and the controls group. Similar results were obtained for the dominant and recessive model. The difference between the two groups did not reach statistic significance for neither of the two studied polymorphisms [p=0.76 for TNFA (-857) and p=0.84 for IL-1A (-889)]. The data suggest that TNFA (-857) C/T and IL-1A (-889) C/T polymorphisms are not associated with susceptibility to GAgP in this Romanian population, potentially because of the small sample size. This is the first such study for Romanian northeastern population. PMID:26193214

  12. Treatment of intrabony defects with anorganic bone matrix/p-15 or guided tissue regeneration in patients with aggressive periodontitis.

    PubMed

    Queiroz, Adriana C; Nóbrega, Priscila Brasil da; Oliveira, Fabíola S; Novaes, Arthur B; Taba, Mário; Palioto, Daniela B; Grisi, Márcio F M; Souza, Sergio L S

    2013-01-01

    Intrabony periodontal defects present a particular treatment problem, especially in patients with generalized aggressive periodontitis (G-AgP). Regenerative procedures have been indicated for this clinical situation. The aim of this study was to compare treatment outcomes of intrabony periodontal defects with either anorganic bone matrix/cell binding peptide (ABM/P-15) or guided tissue regeneration (GTR) in patients with G-AgP. Fifteen patients, with two intrabony defects ≥3 mm deep, were selected. Patients were randomly allocated to be treated with ABM/P-15 or GTR. At baseline and at 3 and 6 months after surgery, clinical and radiographic parameters and IL-1β and IL-6 gingival fluid concentrations were recorded. There was a significant probing pocket depth reduction (p<0.001) for both groups (2.27 ± 0.96 mm for ABM/P-15 group and 2.57 ± 1.06 mm for GTR group). Clinical attachment level gain (1.87 ± 0.94 mm for ABM/P-15 group and 2.09 ± 0.88 mm for GTR group) was also observed. There were no statistically significant differences in clinical parameters between the groups. The radiographic bone fill was more expressive in ABM/P-15 group (2.49 mm) than in GTR group (0.73 mm). In subtraction radiographs, the areas representing gain in density were 93.16% of the baseline defect for ABM/P-15 group versus 62.03% in GRT group. There were no statistically significant differences in inter-group and intra-group comparisons with regards to IL-1β and IL-6 quantification. Treatment of intrabony periodontal defects in patients with G-AgP with ABM/P-15 and GTR improved significantly the clinical outcomes. The use of ABM/P-15 promoted a better radiographic bone fill. PMID:23969907

  13. Gingival Inflammation and Aggressive Periodontitis in a Child with a Specific Antibody Deficiency.

    PubMed

    Liyange, Singithi; Edgar, David; Shields, Michael D; Linden, Gerard J

    2016-03-01

    Exuberant gingival inflammation accompanied by periodontitis is a rare finding in a very young child and may indicate a defect in the host response. Affected children should be referred to appropriate specialists to establish a definitive diagnosis. A 5-year-old girl presented with persistent gingival inflammation and periodontal destruction. Immunological investigations identified specific polysaccharide antibody deficiency which, when treated, resulted in a significant improvement in the gingival condition. This case illustrates the need for integrated management by a wide range of dental and medical specialists. Antibody deficiency is rare but, if not identified and treated effectively, can be associated with chronic ill health and decreased life expectancy. CPD/Clinical Relevance: This article describes a rare case of gingival inflammation accompanied by periodontitis in a very young child secondary to an underlying host antibody deficiency and details the investigation, management and clinical outcomes. PMID:27188128

  14. Increased systemic elastase and C-reactive protein in aggressive periodontitis (CLOI-D-00160R2).

    PubMed

    Wohlfeil, Martin; Scharf, Susanne; Siegelin, Yasemin; Schacher, Beate; Oremek, Gerhard M; Sauer-Eppel, Hildegund; Schubert, Ralf; Eickholz, Peter

    2012-08-01

    The inflammatory mediators, serum elastase and C-reactive protein (CRP), are associated with an increased risk for coronary heart disease. Thus, the aim of this study is to compare systemic inflammatory mediators in periodontally healthy controls (C), patients with untreated aggressive (AgP) and chronic (ChP) periodontitis. C [periodontal pocket probing depth (PPD)  <3.6 or <5 mm without bleeding (BOP), BOP < 10%], ChP (PDD ≥ 3.6 mm and probing attachment loss ≥5 mm at >30% of sites; age >35 years), and AgP (clinically healthy; PDD ≥ 3.6 mm at >30% of sites, bone loss ≥50% at ≥2 teeth; age ≤35 years) were examined clinically, and the body mass index was assessed. Blood was sampled for assessment of serum levels of elastase, CRP, lipopolysaccharide binding protein (LBP), interleukin (IL) 6, 8, and leukocyte counts. Thirty C, 31 ChP, and 29 AgP were analyzed. Elastase, CRP, LBP, and IL-6 levels were elevated in AgP compared to C (p < 0.013), whereas leukocyte counts and IL-8 were similar. Multiple regression analysis identified AgP (p < 0.001) and education level (p < 0.001) to explain 47% of the variation of elastase. AgP (p = 0.003), African origin (p = 0.006), female sex (p = 0.002), and BMI (p < 0.001) explained 39% of the variation of CRP. Serum elastase and CRP are significantly elevated in AgP compared to C. AgP patients exhibit a stronger systemic inflammatory burden than C patients. PMID:22009184

  15. Analysis of IL-1α(−889) and IL-1B(+3953) Gene Polymorphism in Syrian Patients with Aggressive Periodontitis: A Pilot Study

    PubMed Central

    Shibani, Kenan; Shhab, Reem; Khattab, Razan

    2011-01-01

    Polymorphisms in IL-1 gene have been suggested to influence transcription of IL-1α and IL-1B and thereby the pathophysiology of periodontitis. Using genotyping IL-1 test, a pilot study was conducted on 32 Syrian patients with aggressive periodontitis (AgP) and 35 healthy controls to investigate the association between the IL-1α(−889), IL-1B(+3953) gene polymorphisms and AgP among schoolchildren. The results revealed a similar distribution of genotypes between patients and controls, and did not support an association between IL-1 gene polymorphisms and AgP, however, the association was significant in male patients only. To determine and confirm any susceptible or resistant genes for AgP, future studies should use many target genes and well-defined related periodontal outcomes. PMID:22203911

  16. Interleukin-1 and tumor necrosis factor-alpha gene polymorphisms in Turkish patients with localized aggressive periodontitis.

    PubMed

    Guzeldemir, Esra; Gunhan, Meral; Ozcelik, Onur; Tastan, Hakki

    2008-06-01

    Localized aggressive periodontitis (LAgP) is a complex multifactorial periodontal disease to which genetic factors are thought to predispose individuals. Interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) are potent immunomodulators and proinflammatory cytokines that have been implicated in the pathogenesis of autoimmune and infectious diseases and proposed to be risk factors for LAgP. Our aim was to investigate IL-1 alpha (+4845), IL-1 beta (+3954), and TNF-alpha (-308) gene polymorphisms in Turkish LAgP patients. We genotyped 31 LAgP patients and 31 healthy controls for IL-1alpha(+4845), IL-1beta(+3954), and TNF-alpha(-308) using standard PCR amplification followed by restriction enzyme digestion and gel electrophoresis. Higher prevalence of heterozygosity for IL-1alpha(+4845) was found in cases (65%) when compared to controls (35%) (P < 0.05). While homozygous allele 1 of IL-1beta(+3954) was the most frequent genotype in cases (62%), no controls were homozygous for this allele (P < 0.001). Homozygous allele 1 was the most common TNF-alpha genotype in both groups, however no significant difference in TNF-alpha genotypes was found between groups. In conclusion, in this Turkish population, susceptibility to LAgP is increased by heterozygosity for allele 1 of IL-1alpha(+4845) or homozygosity for allele 1 of IL-1beta(R+3954). Moreover, IL-1 gene polymorphisms appear to have a role in susceptibility to LAgP, and the above-mentioned genotypes could be an important risk factor for LAgP in the Turkish population.

  17. The Outcome of a Preventive Dental Care Programme on the Prevalence of Localized Aggressive Periodontitis in Down's Syndrome Individuals

    ERIC Educational Resources Information Center

    Zigmond, Maora; Stabholz, A.; Shapira, J.; Bachrach, G.; Chaushu, G.; Becker, A.; Yefenof, E.; Merrick, J.; Chaushu, S.

    2006-01-01

    Background: Periodontal disease in Down's syndrome (DS) individuals develops earlier and is more rapid and extensive than in age-matched normal individuals. The present study evaluated a group of DS patients, who had been participating in a 10-year preventive dental programme, for the impact of the programme on their periodontal status. Methods:…

  18. Interaction of IL1B and IL1RN polymorphisms, smoking habit, gender, and ethnicity with aggressive and chronic periodontitis susceptibility

    PubMed Central

    Ribeiro, Magali Silveira Monteiro; Pacheco, Renata Botelho Antunes; Fischer, Ricardo Guimarães; Macedo, Jacyara Maria Brito

    2016-01-01

    Background: Although the interleukin-1 (IL-1) plays a critical role in the pathogenesis of periodontitis, associations between IL1 gene cluster polymorphisms and the disease remains unclear. Aims: To investigate the importance of IL1B-511C>T (rs16944), IL1B +3954C>T (rs1143634), and IL1RN intron 2 variable number tandem repeat (VNTR) (rs2234663) polymorphisms, individually or in combination, as the risk factors of periodontitis in a Southeastern Brazilian population with a high degree of miscegenation. Subjects and Methods: A total of 145 individuals, with aggressive (aggressive periodontitis [AgP], n = 43) and chronic (chronic periodontitis [CP], n = 52) periodontitis, and controls (n = 50) were genotyped by polymerase chain reaction (PCR) (IL1RN intron 2 VNTR) or PCR-restriction fragment length polymorphism (PCR-RFLP) (IL1B-511 C>T and IL1B + 3954C>T) techniques. Statistical Analysis: The independent t-test, Chi-square, and Fisher's exact tests were used. The SNPStats program was used for haplotype estimation and multiplicative interaction analyses. Results: The IL1B +3954T allele represented risk for CP (odds ratio [OR] = 2.84), particularly in smokers (OR = 4.43) and females (OR = 6.00). The minor alleles IL1RN*2 and *3 increased the risk of AgP (OR = 2.18), especially the IL1RN*2*2 genotype among  white Brazilians (OR = 7.80). Individuals with the combinations of the IL1B + 3954T and IL1RN*2 or *3-containing genotypes were at increased risk of developing CP (OR = 4.50). Considering the three polymorphisms (rs16944, rs1143634, and rs2234663), the haplotypes TC2 and CT1 represented risk for AgP (OR = 3.41) and CP (OR = 6.39), respectively. Conclusions: Our data suggest that the IL1B +3954C>T and IL1RN intron 2 VNTR polymorphisms are potential candidates for genetic biomarkers of periodontitis, particularly in specific groups of individuals. PMID:27630500

  19. Interaction of IL1B and IL1RN polymorphisms, smoking habit, gender, and ethnicity with aggressive and chronic periodontitis susceptibility

    PubMed Central

    Ribeiro, Magali Silveira Monteiro; Pacheco, Renata Botelho Antunes; Fischer, Ricardo Guimarães; Macedo, Jacyara Maria Brito

    2016-01-01

    Background: Although the interleukin-1 (IL-1) plays a critical role in the pathogenesis of periodontitis, associations between IL1 gene cluster polymorphisms and the disease remains unclear. Aims: To investigate the importance of IL1B-511C>T (rs16944), IL1B +3954C>T (rs1143634), and IL1RN intron 2 variable number tandem repeat (VNTR) (rs2234663) polymorphisms, individually or in combination, as the risk factors of periodontitis in a Southeastern Brazilian population with a high degree of miscegenation. Subjects and Methods: A total of 145 individuals, with aggressive (aggressive periodontitis [AgP], n = 43) and chronic (chronic periodontitis [CP], n = 52) periodontitis, and controls (n = 50) were genotyped by polymerase chain reaction (PCR) (IL1RN intron 2 VNTR) or PCR-restriction fragment length polymorphism (PCR-RFLP) (IL1B-511 C>T and IL1B + 3954C>T) techniques. Statistical Analysis: The independent t-test, Chi-square, and Fisher's exact tests were used. The SNPStats program was used for haplotype estimation and multiplicative interaction analyses. Results: The IL1B +3954T allele represented risk for CP (odds ratio [OR] = 2.84), particularly in smokers (OR = 4.43) and females (OR = 6.00). The minor alleles IL1RN*2 and *3 increased the risk of AgP (OR = 2.18), especially the IL1RN*2*2 genotype among  white Brazilians (OR = 7.80). Individuals with the combinations of the IL1B + 3954T and IL1RN*2 or *3-containing genotypes were at increased risk of developing CP (OR = 4.50). Considering the three polymorphisms (rs16944, rs1143634, and rs2234663), the haplotypes TC2 and CT1 represented risk for AgP (OR = 3.41) and CP (OR = 6.39), respectively. Conclusions: Our data suggest that the IL1B +3954C>T and IL1RN intron 2 VNTR polymorphisms are potential candidates for genetic biomarkers of periodontitis, particularly in specific groups of individuals.

  20. A telescopic crown concept for the restoration of partially edentulous patients with aggressive generalized periodontitis: a 3-year prospective longitudinal study.

    PubMed

    Mengel, Reiner; Kreuzer, Gerd; Lehmann, Klaus M; Flores-de-Jacoby, Lavin

    2007-06-01

    This prospective longitudinal 3-year study compared clinical parameters and implant success rates of removable superstructures supported by both teeth and implants in patients with treated generalized aggressive periodontitis (GAP) and of cemented, implant-retained fixed superstructures in periodontally healthy patients. A total of 17 partially edentulous patients with 54 implants took part in the study. Nine patients with treated GAP received removable superstructures according to the Marburg double crown system, and eight periodontally healthy patients received fixed superstructures. Teeth were examined 2 to 4 weeks before extraction of the nonretainable teeth (baseline) and 3 weeks after insertion of the definitive abutments. Every 3 months over a 3-year period, clinical parameters were recorded and the composition of the subgingival microflora was determined. Intraoral radiographs were obtained at baseline, just after insertion of the superstructure, and 1 and 3 years later. Both groups showed mean plaque and gingival indices below 0.43 at implants and teeth. Mean probing depths around implants increased by approximately 0.7 mm and remained virtually constant for the teeth. Mean attachment loss at implants was 0.9 mm in GAP patients and 0.5 mm in healthy patients. The morphologic distribution of microorganisms in both groups showed healthy conditions. Moderate bone loss at teeth and implants was registered. Implant success rates were 100% in the healthy patients and 97.6% in the GAP patients. No significant differences were seen in the results between the groups.

  1. Study of neutrophils isolated from peripheral blood of patients suffering from aggressive periodontitis at the cellular level: Receptors and cytoskeletal reorganization

    PubMed Central

    Mukherjee, Saswati; Kundu, Debabrata

    2012-01-01

    Background: Aggressive periodontitis (AgP) has been associated with polymorphonuclear leukocyte's (PMNL) dysfunction and periodontal pathogens possess variety of virulence factors that can impair PMNL's function. This study investigated the possible association between defective neutrophil adhesion and β2 -integrin expression and defective neutrophil migration and actin polymerization level in the peripheral blood of neutrophils from the patients with AgP. Materials and Methods: A total of 30 individuals both male and female, age ranges between 13 – 48 years, were included in the study. Healthy controls (group I, n=10), chronic periodontitis (ChP) (group II, n=10), and AgP (group III, n=10), all without any systemic diseases and non-smokers, were recruited. Peripheral blood samples were taken and β2 -integrin expression and actin polymerization levels were estimated by using fluorescence activated cell sorter analysis. Results: In AgP cases, both average values (β2 -integrin and actin level) were significantly less than that of normal subjects (<0.001). But for ChP cases, only the average value of actin level is significantly lower than that of normal subjects (<0.025). Conclusion: Lower β2 -integrin expression in the AgP cases signifies lower neutrophil adhesion in AgP cases than normal, and the lower average value of actin polymerization for the AgP cases suggest lower migration capacity of neutrophils in AgP cases than normal. PMID:22628965

  2. Clinical and radiographic evaluation of intra-bony defects in localized aggressive periodontitis patients with platelet rich plasma/hydroxyapatite graft: A comparative controlled clinical trial

    PubMed Central

    Gupta, Geeti

    2014-01-01

    Background: Aggressive periodontitis is a characterized by rapid attachment loss, bone destruction and familial aggregation. Platelet-rich plasma (PRP) has been proposed to promote regeneration of the lost periodontal tissues. The aim of this study was to evaluate and compare the efficacy of PRP combined with hydroxyapatite (HA) graft in the treatment of intra-bony defects in localized aggressive periodontitis (L-AgP) patients. Materials and Methods: Ten L-AgP patients having bilateral intra-bony defect ≥2 mm and probing depth (PD) ≥6 mm were randomly treated either with the PRP/HA graft or HA graft alone. The clinical (plaque control record, bleeding on probing index, PD, and relative attachment level [RAL]), and radiographic parameters (size of the bone defect) were recorded pre- and post-operatively at 3, 6, and 12 months. Results: After 12 months, for both maxillary and mandibular arches, the mean PD decrease was significantly more (P < 0.05) for the test group than the control group (3.2 mm vs. 1.9 mm and 3.6 mm vs. 1.9 mm, respectively). Furthermore, the mean RAL decrease in both maxillary and mandibular arches was significantly more (P < 0.05) for the test group than the control group (3.0 mm vs. 1.2 mm and 3.1 mm vs. 1.4 mm, respectively). Radiographically, the test group showed significantly more defect fill as compared with the control group. Conclusion: Both treatments provided significant improvements in clinical and radiographic parameters in a 12-month postoperative period. PRP/HA group presented superior results regarding PD reduction, clinical attachment gain and radiographic bone fill than HA group. PMID:25395757

  3. Lap seat belt injuries.

    PubMed

    Hingston, G R

    1996-08-01

    Over a 4 month period, three patients presented acutely to Whangarei Area Hospital after receiving severe abdominal injuries caused directly by lap seat belts. They were involved in road traffic crashes and were all seated in the middle rear seat of the car. The aim of this paper is to alert people to the injuries that can occur from two point lap belts. To this end, the patients and injuries sustained are described and a review of the literature is presented.

  4. Interleukin-1α -899 (+4845) C→T polymorphism is not associated with aggressive periodontitis susceptibility: A meta-analysis based on 19 case-control studies

    PubMed Central

    WANG, WAN-FEN; SHI, JUN; CHEN, SHAO-JUAN; NIU, YU-MING; ZENG, XIAN-TAO

    2014-01-01

    A number of published studies investigated the association between interleukin-1α (IL-1α) −899 (+4845) C→T polymorphism and susceptibility to aggressive periodontitis (AgP). However, the results from different studies are controversial. This study was conducted to further investigate the association between IL-1α −899 (+4845) C→T polymorphism and AgP using a meta-analysis. A search was conducted through PubMed up to May 1, 2013 and a total of 19 relevant case-control studies were identified. The results of this meta-analysis demonstrated that IL-1α −899 (+4845) C→T polymorphism is not associated with susceptibility to AgP under allele T vs. C [odds ratio (OR)=1.00, 95% confidence interval (CI): 0.88–1.14, P=0.98; I2=28.86%] or allele A vs. C comparison (OR=0.99, 95% CI: 0.85–1.14, P=0.85; I2=33.66%). The subgroup analyses based on ethnicity, source of controls and Hardy-Weinberg equilibrium (HWE) also revealed no such association. There existed a weak publication bias (Egger’s test P=0.02). In conclusion, based on the currently available evidence, there is no association between IL-1α −899 (+4845) C→T polymorphism and susceptibility to AgP. PMID:24748978

  5. Tumor necrosis factor-α G-308A (rs1800629) polymorphism and aggressive periodontitis susceptibility: a meta-analysis of 16 case-control studies

    PubMed Central

    Wei, Xue-Mei; Chen, Yong-Ji; Wu, Lan; Cui, Li-Jun; Hu, Ding-Wei; Zeng, Xian-Tao

    2016-01-01

    Association between tumor necrosis factor-α (TNF-α) G-308A (rs1800629) polymorphism and susceptibility to aggressive periodontitis (AgP) were inconsistent, hence we performed this meta-analysis to clarify the association between them using Comprehensive Meta-Analysis v2.2 software. 16 case-control studies were searched from the PubMed, Embase and CNKI databases up to February 2, 2015. The meta-analysis showed a significantly increased risk in A vs. G (OR = 1.23, 95%CI = 1.04–1.44), AA vs. GG (OR = 2.07, 95%CI = 1.11–3.87), and AA vs. AG+GG genetic models (OR = 2.09, 95%CI = 1.13–3.86); however, the non-significantly increased risk was shown in AG vs. GG (OR = 1.06, 95%CI = 0.85–1.32) and AA+AG vs. GG genetic models (OR = 1.06, 95%CI = 0.85–1.31). Cumulative analysis showed that the association changed from non-significant to significant with new studies accumulated and the CIs became more and more narrow, sensitivity analysis indicated results were statistically robust. Stratified analyses of confirmed of HWE, Asians, Caucasians, and population-based controls obtained results similar to that of overall analysis. There was no evidence of publication bias. In summary, current evidence demonstrates that TNF-a G-308A polymorphism might be associated with AgP susceptibility, especially in Asians and Caucasians. PMID:26750615

  6. Alternative Splicing Generates a Diacylglycerol Kinase α Transcript That Acts as a Dominant-Negative Modulator of Superoxide Production in Localized Aggressive Periodontitis

    PubMed Central

    Batista, Eraldo L.; Kantarci, Alpdogan I.; Hasturk, Hatice; Van Dyke, Thomas E.

    2015-01-01

    Background Diacylglycerol (DAG), levels of which are tightly regulated by diacylglycerol kinases (DGKs), is a lipid mediator linked to key biologic functions. Members of the DGK family undergo alternative splicing, generating the protein diversity necessary to control different intracellular DAG pools. DGKα function is altered in polymorphonuclear neutrophils (PMNs) of patients with localized aggressive periodontitis (LAgP), suggesting a genetic basis. Here, the authors assess DGKα spliced transcripts in human LAgP neutrophils. Methods In an expression library of a patient with LAgP, PMNs were screened for different DGKα transcripts. Real-time polymerase chain reaction and in vitro expression assays were performed to assess the fate of different transcripts on protein translocation and superoxide production in human leukemia cells (HL-60) and COS-7 cells. Results A DGKα transcript that lacks exon 10 (DGKαΔ10) and generates a premature stop codon and a truncated protein was identified as being upregulated in LAgP neutrophils. In vitro assays revealed that DGKαΔ10 translocation occurred even in the absence of important regulatory motifs. Transfection of HL-60 neutrophil-like cells with the DGKαΔ10 spliced variant induced an increase in the stimulated production of su-peroxide anion replicating the phenotype of LAgP PMNs. Conclusion DGKαΔ10 can act as a dominant-negative transcript that can modulate superoxide production and provides an example of genetic regulation of the inflammatory response that may be relevant to human inflammatory diseases such as LAgP. J Periodontol 2014;85:934-943. PMID:24171497

  7. Lap belt injuries in children.

    PubMed

    McGrath, N; Fitzpatrick, P; Okafor, I; Ryan, S; Hensey, O; Nicholson, A J

    2010-01-01

    The use of adult seat belts without booster seats in young children may lead to severe abdominal, lumbar or cervical spine and head and neck injuries. We describe four characteristic cases of lap belt injuries presenting to a tertiary children's hospital over the past year in addition to a review of the current literature. These four cases of spinal cord injury, resulting in significant long-term morbidity in the two survivors and death in one child, arose as a result of lap belt injury. These complex injuries are caused by rapid deceleration characteristic of high impact crashes, resulting in sudden flexion of the upper body around the fixed lap belt, and consequent compression of the abdominal viscera between the lap belt and spine. This report highlights the dangers of using lap belts only without shoulder straps. Age-appropriate child restraint in cars will prevent these injuries.

  8. Nonsurgical periodontal treatment.

    PubMed

    Aimetti, Mario

    2014-01-01

    The primary goal of nonsurgical periodontal therapy is to control microbial periodontal infection by removing bacterial biofilm, calculus, and toxins from periodontally involved root surfaces. A review of the scientific literature indicates that mechanical nonsurgical periodontal treatment predictably reduces the levels of inflammation and probing pocket depths, increases the clinical attachment level and results in an apical shift of the gingival margin. Another parameter to be considered, in spite of the lack of scientific evidence, is the reduction in the degree of tooth mobility, as clinically experienced. It is important to point out that nonsurgical periodontal treatment presents limitations such as the long-term maintainability of deep periodontal pockets, the risk of disease recurrence, and the skill of the operator. A high number of posttreatment residual pockets exhibiting bleeding on probing and > 5 mm deep are related to lower clinical stability. The successful treatment of plaque-induced periodontitis will restore periodontal health, but with reduced periodontium. In such cases, anatomical damage from previous periodontal disease will persist and inverse architecture of soft tissue may impair home plaque removal. The clinician can select one of the following therapeutic options according to the individual patient's needs: - Quadrant/sextant wise instrumentation (conventional staged debridement, CSD). - Instrumentation of all pockets within a 24-hour period with (full mouth disinfection [FMD]) or without (full mouth scaling and root planing [FMSRP]) local antiseptics. Both procedures can be associated with systemic antimicrobials. -CSD or FMD in combination with laser or photodynamic therapy. Patients with aggressive periodontitis constitute a challenge to the clinician. To date there are no established protocols for controlling the disease. However, data from the literature on the application of the FMD protocol combined with amoxicillin

  9. Cashier/Checker Learning Activity Packets (LAPs).

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    Twenty-four learning activity packets (LAPs) are provided for six areas of instruction in a cashier/checker program. Section A, Orientation, contains an LAP on exploring the job of cashier-checker. Section B, Operations, has nine LAPs, including those on operating the cash register, issuing trading stamps, and completing the cash register balance…

  10. Additive manufacturing of tools for lapping glass

    NASA Astrophysics Data System (ADS)

    Williams, Wesley B.

    2013-09-01

    Additive manufacturing technologies have the ability to directly produce parts with complex geometries without the need for secondary processes, tooling or fixtures. This ability was used to produce concave lapping tools with a VFlash 3D printer from 3D Systems. The lapping tools were first designed in Creo Parametric with a defined constant radius and radial groove pattern. The models were converted to stereolithography files which the VFlash used in building the parts, layer by layer, from a UV curable resin. The tools were rotated at 60 rpm and used with 120 grit and 220 grit silicon carbide lapping paste to lap 0.750" diameter fused silica workpieces. The samples developed a matte appearance on the lapped surface that started as a ring at the edge of the workpiece and expanded to the center. This indicated that as material was removed, the workpiece radius was beginning to match the tool radius. The workpieces were then cleaned and lapped on a second tool (with equivalent geometry) using a 3000 grit corundum aluminum oxide lapping paste, until a near specular surface was achieved. By using lapping tools that have been additively manufactured, fused silica workpieces can be lapped to approach a specified convex geometry. This approach may enable more rapid lapping of near net shape workpieces that minimize the material removal required by subsequent polishing. This research may also enable development of new lapping tool geometry and groove patterns for improved loose abrasive finishing.

  11. Guidelines for periodontal care and follow-up during orthodontic treatment in adolescents and young adults

    PubMed Central

    LEVIN, Liran; EINY, Shmuel; ZIGDON, Hadar; AIZENBUD, Dror; MACHTEI, Eli E.

    2012-01-01

    Aggressive periodontitis is characterized by non-contributory medical history, rapid attachment loss and bone destruction and familial aggregation of cases. Aggressive periodontitis (both localized and generalized) is usually diagnosed in a young population. This is frequently the age that an orthodontic care is provided to this population. The aim of the present paper is to draw guidelines for periodontal evaluation and monitoring prior to and during active orthodontic treatment. Strict adherence to these guidelines as a routine protocol for periodontal examination prior, during and following orthodontic treatment may dramatically decrease the severity and improve the prognosis of patients with aggressive periodontitis in orthodontic clinics. PMID:23032199

  12. Loose abrasive slurries for optical glass lapping

    SciTech Connect

    Neauport, Jerome; Destribats, Julie; Maunier, Cedric; Ambard, Chrystel; Cormont, Philippe; Pintault, B.; Rondeau, Olivier

    2010-10-20

    Loose abrasive lapping is widely used to prepare optical glass before its final polishing. We carried out a comparison of 20 different slurries from four different vendors. Slurry particle sizes and morphologies were measured. Fused silica samples were lapped with these different slurries on a single side polishing machine and characterized in terms of surface roughness and depth of subsurface damage (SSD). Effects of load, rotation speed, and slurry concentration during lapping on roughness, material removal rate, and SSD were investigated.

  13. Pediatric lap belt injuries: care and prevention.

    PubMed

    Shoemaker, B L; Ose, M

    1997-01-01

    Motor vehicle collisions are the leading cause of death from injury during childhood. As children outgrow their toddler car seats, they are often restrained by two-point lap belts, which are fashioned for adult body proportions. Those children restrained by two-point lap belts are at risk for intraabdominal and spinal injury during an auto collision. This article explores the mechanisms of injury and identification of "lap belt syndrome." Aspects of nursing care and prevention strategies will be discussed. A case study illustrates and summarizes the cogent aspects of lap belt related injury and child/family care.

  14. Iatrogenic Damage to the Periodontium Caused by Periodontal Treatment Procedures

    PubMed Central

    Latheef, P; Sirajuddin, Syed; Gundapaneni, Veenadharini; MN, Kumuda; Apine, Ashwini

    2015-01-01

    Periodontitis is an inflammatory disease affecting the periodontium i.e. the tissues that surround and support the teeth. Periodontitis manifests as progressive loss of the alveolar bone around the teeth, and if left untreated, can cause loosening and subsequent loss of teeth. Periodontitis is initiated by microorganisms that adhere to and grow on the tooth's surfaces, besides an over -aggressive immune response against these microorganisms. The primary goal of periodontal therapy is to preserve the natural dentition by accomplishing and preserving a healthy functional periodontium. Many treatment modalities have been introduced to improve the therapeutic result of periodontal treatment which may also damage the periodontiumiatrogenically. PMID:26312087

  15. Quadruple Lap Shear Processing Evaluation

    NASA Technical Reports Server (NTRS)

    Thornton, Tony N.; McCool, A. (Technical Monitor)

    2000-01-01

    The Thiokol, Science and Engineering Huntsville Operations (SEHO) Laboratory has previously experienced significant levels of variation in testing Quadruple Lap Shear (QLS) specimens. The QLS test is used at Thiokol / Utah for the qualification of Reusable Solid Rocket Motor (RSRM) nozzle flex bearing materials. A test was conducted to verify that process changes instituted by SEHO personnel effectively reduced variability, even with normal processing variables introduced. A test matrix was designed to progress in a series of steps; the first establishing a baseline, then introducing additional solvents or other variables. Variables included normal test plan delay times, pre-bond solvent hand-wipes and contaminants. Each condition tested utilized standard QLS hardware bonded with natural rubber, two separate technicians and three replicates. This paper will report the results and conclusions of this investigation.

  16. Automated system for periodontal disease diagnosis

    NASA Astrophysics Data System (ADS)

    Albalat, Salvador E.; Alcaniz-Raya, Mariano L.; Juan, M. Carmen; Grau Colomer, Vincente; Monserrat, Carlos

    1997-04-01

    Evolution of periodontal disease is one of the most important data for the clinicians in order to achieve correct planning and treatment. Clinical measure of the periodontal sulcus depth is the most important datum to know the exact state of periodontal disease. These measures must be done periodically study bone resorption evolution around teeth. Time factor of resorption indicates aggressiveness of periodontitis. Manual probes are commonly used with direct reading. Mechanical probes give automatic signal but this method uses complicated and heavy probes that are only limited for University researchers. Probe position must be the same to have right diagnosis. Digital image analysis of periodontal probing provides practical, accurate and easy tool. Gum and plaque index could also be digitally measured with this method.

  17. Scope of photodynamic therapy in periodontics.

    PubMed

    Kumar, Vivek; Sinha, Jolly; Verma, Neelu; Nayan, Kamal; Saimbi, C S; Tripathi, Amitandra K

    2015-01-01

    Periodontal disease results from inflammation of the supporting structure of the teeth and in response to chronic infection caused by various periodontopathic bacteria. The mechanical removal of this biofilm and adjunctive use of antibacterial disinfectants and antibiotics have been the conventional methods of periodontal therapy. However, the removal of plaque and the reduction in the number of infectious organisms can be impaired in sites with difficult access. Photodynamic therapy (PDT) is a powerful laser-initiated photochemical reaction, involving the use of a photoactive dye (photosensitizer) activated by light of a specific wavelength in the presence of oxygen. Application of PDT in periodontics such as pocket debridement, gingivitis, and aggressive periodontitis continue to evolve into a mature clinical treatment modality and is considered as a promising novel approach for eradicating pathogenic bacteria in periodontitis. PMID:26481895

  18. CrossLaps and beta-glucuronidase in peri-implant and gingival crevicular fluid.

    PubMed

    Schubert, U; Kleber, B M; Strietzel, F P; Dörfling, P

    2001-01-01

    Collagen degradation products of the carboxyterminal region possibly reflect bone and attachment loss. In the present study, the Serum CrossLaps One-Step enzyme-linked immunosorbent assay was used to determine a specific part of the carboxyterminal region of type I collagen, the CrossLaps. Samples of peri-implant and gingival crevicular fluid of 111 implants and 53 teeth from 47 partially or completely edentulous patients were examined in reference to levels of CrossLaps and beta-glucuronidase (beta G), an established marker of periodontal disease. Clinical probing pocket depth (PPD), bleeding on probing (BOP), plaque accumulation, mobility, radiographic bone loss, and the occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia were assessed. The mean values were: for PPD at implants 3.76 +/- 1.41 mm, at teeth 3.44 +/- 0.88 mm; for beta G at implants 0.364 +/- 0.392 pU/min, at teeth 0.314 +/- 0.209 pU/min; for CrossLaps at implants 0.069 +/- 0.059 pmol/min, at teeth 0.082 +/- 0.053 pmol/min. Bleeding on probing was significantly higher on implants than on teeth (McNemar test, P = .004). No significant difference of beta G levels was found between teeth and implants (Wilcoxon test). A negative correlation was found between beta G levels and CrossLaps levels at teeth (Pearson-rank correlation, P = .002). On implants, no significant correlation of these 2 parameters was seen, but significant correlations were found between sulcus fluid flow rate and PPD (P = .012), beta G levels and bone loss (P < 0.0005), and CrossLaps levels and PPD (P = .011). CrossLaps can be detected in both gingival and peri-implant crevicular fluid. While rising levels of beta G may indicate acute peri-implantitis, CrossLaps may not, but could play a role as a marker of ongoing attachment loss.

  19. Role of the NK Cell-Activating Receptor CRACC in Periodontitis

    PubMed Central

    Krämer, Benjamin; Kebschull, Moritz; Nowak, Michael; Demmer, Ryan T.; Haupt, Manuela; Körner, Christian; Perner, Sven; Jepsen, Søren

    2013-01-01

    Periodontitis is a highly prevalent, biofilm-mediated chronic inflammatory disease that results in the loss of the tooth-supporting tissues. It features two major clinical entities: chronic periodontitis, which is more common, and aggressive periodontitis, which usually has an early onset and a rapid progression. Natural killer (NK) cells are a distinct subgroup of lymphocytes that play a major role in the ability of the innate immune system to steer immune responses. NK cells are abundant in periodontitis lesions, and NK cell activation has been causally linked to periodontal tissue destruction. However, the exact mechanisms of their activation and their role in the pathophysiology of periodontitis are elusive. Here, we show that the predominant NK cell-activating molecule in periodontitis is CD2-like receptor activating cytotoxic cells (CRACC). We show that CRACC induction was significantly more pronounced in aggressive than chronic periodontitis and correlated positively with periodontal disease severity, subgingival levels of specific periodontal pathogens, and NK cell activation in vivo. We delineate how Aggregatibacter actinomycetemcomitans, an oral pathogen that is causally associated with aggressive periodontitis, indirectly induces CRACC on NK cells via activation of dendritic cells and subsequent interleukin 12 (IL-12) signaling. In contrast, we demonstrate that fimbriae from Porphyromonas gingivalis, a principal pathogen in chronic periodontitis, actively attenuate CRACC induction on NK cells. Our data suggest an involvement of CRACC-mediated NK cell activation in periodontal tissue destruction and point to a plausible distinction in the pathobiology of aggressive and chronic periodontitis that may help explain the accelerated tissue destruction in aggressive periodontitis. PMID:23250953

  20. LAPS Grid generation and adaptation

    NASA Astrophysics Data System (ADS)

    Pagliantini, Cecilia; Delzanno, Gia Luca; Guo, Zehua; Srinivasan, Bhuvana; Tang, Xianzhu; Chacon, Luis

    2011-10-01

    LAPS uses a common-data framework in which a general purpose grid generation and adaptation package in toroidal and simply connected domains is implemented. The initial focus is on implementing the Winslow/Laplace-Beltrami method for generating non-overlapping block structured grids. This is to be followed by a grid adaptation scheme based on Monge-Kantorovich optimal transport method [Delzanno et al., J. Comput. Phys,227 (2008), 9841-9864], that equidistributes application-specified error. As an initial set of applications, we will lay out grids for an axisymmetric mirror, a field reversed configuration, and an entire poloidal cross section of a tokamak plasma reconstructed from a CMOD experimental shot. These grids will then be used for computing the plasma equilibrium and transport in accompanying presentations. A key issue for Monge-Kantorovich grid optimization is the choice of error or monitor function for equi-distribution. We will compare the Operator Recovery Error Source Detector (ORESD) [Lapenta, Int. J. Num. Meth. Eng,59 (2004) 2065-2087], the Tau method and a strategy based on the grid coarsening [Zhang et al., AIAA J,39 (2001) 1706-1715] to find an ``optimal'' grid. Work supported by DOE OFES.

  1. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... 49 Transportation 4 2013-10-01 2013-10-01 false Lap-joint seam boilers. 230.30 Section...

  2. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... 49 Transportation 4 2014-10-01 2014-10-01 false Lap-joint seam boilers. 230.30 Section...

  3. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... 49 Transportation 4 2012-10-01 2012-10-01 false Lap-joint seam boilers. 230.30 Section...

  4. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... 49 Transportation 4 2011-10-01 2011-10-01 false Lap-joint seam boilers. 230.30 Section...

  5. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... 49 Transportation 4 2010-10-01 2010-10-01 false Lap-joint seam boilers. 230.30 Section...

  6. Familial periodontal disease in the Cayo Santiago rhesus macaques.

    PubMed

    Gonzalez, Octavio A; Orraca, Luis; Kensler, Terry B; Gonzalez-Martinez, Janis; Maldonado, Elizabeth; Ebersole, Jeffrey L

    2016-01-01

    Substantial ongoing research continues to explore the contribution of genetics and environment to the onset, extent and severity of periodontal disease(s). Existing evidence supports that periodontal disease appears to have an increased prevalence in family units with a member having aggressive periodontitis. We have been using the nonhuman primate as a model of periodontal disease for over 25 years with these species demonstrating naturally occurring periodontal disease that increases with age. This report details our findings from evaluation of periodontal disease in skulls from 97 animals (5-31 years of age) derived from the skeletons of the rhesus monkeys (Macaca mulatta) on Cayo Santiago. Periodontal disease was evaluated by determining the distance from the base of the alveolar bone defect to the cemento-enamel junction on 1st/2nd premolars and 1st/2nd molars from all four quadrants. The results demonstrated an increasing extent and severity of periodontitis with aging across the population of animals beyond only compensatory eruption. Importantly, irrespective of age, extensive heterogeneity in disease expression was observed among the animals. Linking these variations to multi-generational matriarchal family units supported familial susceptibility of periodontitis. As the current generations of animals that are descendants from these matrilines are alive, studies can be conducted to explore an array of underlying factors that could account for susceptibility or resistance to periodontal disease. PMID:25708960

  7. Thermal shock testing of lapped optical glass

    NASA Astrophysics Data System (ADS)

    Zhang, Yingrui; Wu, Yuansun; Liu, Han; Lambropoulos, John C.

    2007-09-01

    We have measured and modeled the thermal shock fracture of the commercially available BK-7 borosilicate crown optical glass as a function of surface finish prior to thermal shock testing. For surfaces lapped with alumina abrasives in the range 5 μm to 40 μm, the critical temperature drop for fracture in thin disk samples increases with diminishing abrasive size, and changes from 123.7+/-1.1 °C (for surfaces lapped with 40 μm abrasives) to 140.2+/-2.8 °C (for surfaces lapped with 5 μm abrasives.) We correlate the measured thermal shock (critical) temperature drop with the glass thermal and mechanical properties, including the fracture toughness, and the depth of surface cracks induced by the lapping process. We distinguish between "severe" and "mild" thermal shock conditions in terms of the applicable heat transfer coefficient and Biot number. We estimate that the depth of the strength controlling cracks on the edge of the disk samples was about 55-70 μm.

  8. Microbial Signature Profiles of Periodontally Healthy and Diseased Patients

    PubMed Central

    Lourenço, Talita Gomes Baêta; Heller, Débora; da Silva-Boghossian, Carina Maciel; Cotton, Sean L.; Paster, Bruce J.; Colombo, Ana Paula Vieira

    2014-01-01

    Aim To determine microbial profiles that discriminate periodontal health from different forms of periodontal diseases. Methods Subgingival biofilm was obtained from patients with periodontal health (27), gingivitis (11), chronic periodontitis (35) and aggressive periodontitis (24), and analyzed for the presence of >250 species/phylotypes using HOMIM. Microbial differences among groups were examined by Mann-Whitney. Regression analyses were performed to determine microbial risk indicators of disease. Results Putative and potential new periodontal pathogens were more prevalent in subjects with periodontal diseases than periodontal health. Detection of Porphyromonas endodontalis/Porphyromonas spp. (OR 9.5 [1.2–73.1]) and Tannerella forsythia (OR 38.2 [3.2–450.6]), and absence of Neisseria polysaccharea (OR 0.004 [0–0.15]) and Prevotella denticola (OR 0.014 [0–0.49], p<0.05) were risk indicators of periodontal disease. Presence of Aggregatibacter actinomycetemcomitans (OR 29.4 [3.4–176.5]), Cardiobacterium hominis (OR 14.9 [2.3–98.7]), Peptostreptococcaceae sp. (OR 35.9 [2.7–483.9]), P. alactolyticus (OR 31.3 [2.1–477.2]), and absence of Fretibacterium spp. (OR 0.024 [0.002–0.357]), Fusobacterium naviforme/Fusobacterium nucleatum ss vincentii (OR 0.015 [0.001–0.223]), Granulicatella adiacens/Granulicatella elegans (OR 0.013 [0.001–0.233], p<0.05) were associated with aggressive periodontitis. Conclusion There were specific microbial signatures of the subgingival biofilm that were able to distinguish between microbiomes of periodontal health and diseases. Such profiles may be used to establish risk of disease. PMID:25139407

  9. Gingival Tissue Transcriptomes Identify Distinct Periodontitis Phenotypes

    PubMed Central

    Kebschull, M.; Demmer, R.T.; Grün, B.; Guarnieri, P.; Pavlidis, P.; Papapanou, P.N.

    2014-01-01

    The currently recognized principal forms of periodontitis—chronic and aggressive—lack an unequivocal, pathobiology-based foundation. We explored whether gingival tissue transcriptomes can serve as the basis for an alternative classification of periodontitis. We used cross-sectional whole-genome gene expression data from 241 gingival tissue biopsies obtained from sites with periodontal pathology in 120 systemically healthy nonsmokers with periodontitis, with available data on clinical periodontal status, subgingival microbial profiles, and serum IgG antibodies to periodontal microbiota. Adjusted model-based clustering of transcriptomic data using finite mixtures generated two distinct clusters of patients that did not align with the current classification of chronic and aggressive periodontitis. Differential expression profiles primarily related to cell proliferation in cluster 1 and to lymphocyte activation and unfolded protein responses in cluster 2. Patients in the two clusters did not differ with respect to age but presented with distinct phenotypes (statistically significantly different whole-mouth clinical measures of extent/severity, subgingival microbial burden by several species, and selected serum antibody responses). Patients in cluster 2 showed more extensive/severe disease and were more often male. The findings suggest that distinct gene expression signatures in pathologic gingival tissues translate into phenotypic differences and can provide a basis for a novel classification. PMID:24646639

  10. Pseudomonas putida Fis Binds to the lapF Promoter In Vitro and Represses the Expression of LapF

    PubMed Central

    Lahesaare, Andrio; Moor, Hanna; Kivisaar, Maia; Teras, Riho

    2014-01-01

    The biofilm matrix of the rhizospheric bacterium Pseudomonas putida consists mainly of a proteinaceous component. The two largest P. putida proteins, adhesins LapA and LapF, are involved in biofilm development but prevail in different developmental stages of the biofilm matrix. LapA is abundant in the initial stage of biofilm formation whereas LapF is found in the mature biofilm. Although the transcriptional regulation of the adhesins is not exhaustively studied, some factors that can be involved in their regulation have been described. For example, RpoS, the major stress response sigma factor, activates, and Fis represses LapF expression. This study focused on the LapF expression control by Fis. Indeed, using DNase I footprint analysis a Fis binding site Fis-F2 was located 150 bp upstream of the lapF gene coding sequence. The mapped 5′ end of the lapF mRNA localized the promoter to the same region, overlapping with the Fis binding site Fis-F2. Monitoring the lapF promoter activity by a β-galactosidase assay revealed that Fis overexpression causes a 4-fold decrease in the transcriptional activity. Furthermore, mutations that diminished Fis binding to the Fis-F2 site abolished the repression of the lapF promoter. Thus, these data suggest that Fis is involved in the biofilm regulation via repression of LapF expression. PMID:25545773

  11. Large-scale Advanced Propfan (LAP) program

    NASA Technical Reports Server (NTRS)

    Sagerser, D. A.; Ludemann, S. G.

    1985-01-01

    The propfan is an advanced propeller concept which maintains the high efficiencies traditionally associated with conventional propellers at the higher aircraft cruise speeds associated with jet transports. The large-scale advanced propfan (LAP) program extends the research done on 2 ft diameter propfan models to a 9 ft diameter article. The program includes design, fabrication, and testing of both an eight bladed, 9 ft diameter propfan, designated SR-7L, and a 2 ft diameter aeroelastically scaled model, SR-7A. The LAP program is complemented by the propfan test assessment (PTA) program, which takes the large-scale propfan and mates it with a gas generator and gearbox to form a propfan propulsion system and then flight tests this system on the wing of a Gulfstream 2 testbed aircraft.

  12. Analysis of lap times in international swimming competitions.

    PubMed

    Robertson, Eileen; Pyne, David; Hopkins, Will; Anson, Judith

    2009-02-15

    Swimming performances were analysed for the top 16 finishers (semi-finalists, finalists) in nine international competitions over a 7-year period (1530 males, 1527 female). Total race time and intermediate lap times were log-transformed and analysed for effects of sex (male, female), stroke (freestyle, form strokes, individual medley), event (100, 200, and 400 m), and place (1-16). Between-athlete correlations characterized the relationship of each lap to final time, and within-athlete estimates quantified the effect of lap time on improvements in final time. Finalists exhibited very large correlations (r = 0.7-0.9) with final time in the second 50-m lap of 100-m events and the middle two 50-m and 100-m laps of 200-m and 400-m events respectively. For an individual swimmer, an achievable change in lap time was associated with an approximate 0.4-0.8% improvement in final time for finalists and an approximate 0.5-1.1% improvement in final time for semi-finalists, depending on sex, stroke, and event. The pattern of lap times was similar for the top 16 swimmers and between the best and worst swims for finalists. These findings indicate that substantial improvements can be made via the final lap in sprints and the middle two laps of 200- to 400-m events, but the overall pattern of lap times should not be changed. PMID:19214862

  13. Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica.

    PubMed

    Ambrosis, Nicolás; Boyd, Chelsea D; O Toole, George A; Fernández, Julieta; Sisti, Federico

    2016-01-01

    Biofilm formation is important for infection by many pathogens. Bordetella bronchiseptica causes respiratory tract infections in mammals and forms biofilm structures in nasal epithelium of infected mice. We previously demonstrated that cyclic di-GMP is involved in biofilm formation in B. bronchiseptica. In the present work, based on their previously reported function in Pseudomonas fluorescens, we identified three genes in the B. bronchiseptica genome likely involved in c-di-GMP-dependent biofilm formation: brtA, lapD and lapG. Genetic analysis confirmed a role for BrtA, LapD and LapG in biofilm formation using microtiter plate assays, as well as scanning electron and fluorescent microscopy to analyze the phenotypes of mutants lacking these proteins. In vitro and in vivo studies showed that the protease LapG of B. bronchiseptica cleaves the N-terminal domain of BrtA, as well as the LapA protein of P. fluorescens, indicating functional conservation between these species. Furthermore, while BrtA and LapG appear to have little or no impact on colonization in a mouse model of infection, a B. bronchiseptica strain lacking the LapG protease has a significantly higher rate of inducing a severe disease outcome compared to the wild type. These findings support a role for c-di-GMP acting through BrtA/LapD/LapG to modulate biofilm formation, as well as impact pathogenesis, by B. bronchiseptica. PMID:27380521

  14. Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica

    PubMed Central

    Ambrosis, Nicolás; Boyd, Chelsea D.; O´Toole, George A.; Fernández, Julieta; Sisti, Federico

    2016-01-01

    Biofilm formation is important for infection by many pathogens. Bordetella bronchiseptica causes respiratory tract infections in mammals and forms biofilm structures in nasal epithelium of infected mice. We previously demonstrated that cyclic di-GMP is involved in biofilm formation in B. bronchiseptica. In the present work, based on their previously reported function in Pseudomonas fluorescens, we identified three genes in the B. bronchiseptica genome likely involved in c-di-GMP-dependent biofilm formation: brtA, lapD and lapG. Genetic analysis confirmed a role for BrtA, LapD and LapG in biofilm formation using microtiter plate assays, as well as scanning electron and fluorescent microscopy to analyze the phenotypes of mutants lacking these proteins. In vitro and in vivo studies showed that the protease LapG of B. bronchiseptica cleaves the N-terminal domain of BrtA, as well as the LapA protein of P. fluorescens, indicating functional conservation between these species. Furthermore, while BrtA and LapG appear to have little or no impact on colonization in a mouse model of infection, a B. bronchiseptica strain lacking the LapG protease has a significantly higher rate of inducing a severe disease outcome compared to the wild type. These findings support a role for c-di-GMP acting through BrtA/LapD/LapG to modulate biofilm formation, as well as impact pathogenesis, by B. bronchiseptica PMID:27380521

  15. Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica.

    PubMed

    Ambrosis, Nicolás; Boyd, Chelsea D; O Toole, George A; Fernández, Julieta; Sisti, Federico

    2016-01-01

    Biofilm formation is important for infection by many pathogens. Bordetella bronchiseptica causes respiratory tract infections in mammals and forms biofilm structures in nasal epithelium of infected mice. We previously demonstrated that cyclic di-GMP is involved in biofilm formation in B. bronchiseptica. In the present work, based on their previously reported function in Pseudomonas fluorescens, we identified three genes in the B. bronchiseptica genome likely involved in c-di-GMP-dependent biofilm formation: brtA, lapD and lapG. Genetic analysis confirmed a role for BrtA, LapD and LapG in biofilm formation using microtiter plate assays, as well as scanning electron and fluorescent microscopy to analyze the phenotypes of mutants lacking these proteins. In vitro and in vivo studies showed that the protease LapG of B. bronchiseptica cleaves the N-terminal domain of BrtA, as well as the LapA protein of P. fluorescens, indicating functional conservation between these species. Furthermore, while BrtA and LapG appear to have little or no impact on colonization in a mouse model of infection, a B. bronchiseptica strain lacking the LapG protease has a significantly higher rate of inducing a severe disease outcome compared to the wild type. These findings support a role for c-di-GMP acting through BrtA/LapD/LapG to modulate biofilm formation, as well as impact pathogenesis, by B. bronchiseptica.

  16. Fis overexpression enhances Pseudomonas putida biofilm formation by regulating the ratio of LapA and LapF.

    PubMed

    Moor, Hanna; Teppo, Annika; Lahesaare, Andrio; Kivisaar, Maia; Teras, Riho

    2014-12-01

    Bacteria form biofilm as a response to a number of environmental signals that are mediated by global transcription regulators and alarmones. Here we report the involvement of the global transcription regulator Fis in Pseudomonas putida biofilm formation through regulation of lapA and lapF genes. The major component of P. putida biofilm is proteinaceous and two large adhesive proteins, LapA and LapF, are known to play a key role in its formation. We have previously shown that Fis overexpression enhances P. putida biofilm formation. In this study, we used mini-Tn5 transposon mutagenesis to select potential Fis-regulated genes involved in biofilm formation. A total of 90 % of the studied transposon mutants carried insertions in the lap genes. Since our experiments showed that Fis-enhanced biofilm is mostly proteinaceous, the amounts of LapA and LapF from P. putida cells lysates were quantified using SDS-PAGE. Fis overexpression increases the quantity of LapA 1.6 times and decreases the amount of LapF at least 4 times compared to the wild-type cells. The increased LapA expression caused by Fis overexpression was confirmed by FACS analysis measuring the amount of LapA-GFP fusion protein. Our results suggest that the profusion of LapA in the Fis-overexpressed cells causes enhanced biofilm formation in mature stages of P. putida biofilm and LapF has a minor role in P. putida biofilm formation.

  17. Systematic Construction of Real Lapped Tight Frame Transforms

    PubMed Central

    Sandryhaila, Aliaksei; Chebira, Amina; Milo, Christina; Kovčcević, Jelena; Püschel, Markus

    2010-01-01

    We present a constructive algorithm for the design of real lapped equal-norm tight frame transforms. These transforms can be efficiently implemented through filter banks and have recently been proposed as a redundant counterpart to lapped orthogonal transforms, as well as an infinite-dimensional counterpart to harmonic tight frames. The proposed construction consists of two parts: First, we design a large class of new real lapped orthogonal transforms derived from submatrices of the discrete Fourier transform. Then, we seed these to obtain real lapped tight frame transforms corresponding to tight, equal-norm frames. We identify those frames that are maximally robust to erasures, and show that our construction leads to a large class of new lapped orthogonal transforms as well as new lapped tight frame transforms. PMID:20607116

  18. Dogs lap using acceleration-driven open pumping

    PubMed Central

    Gart, Sean; Socha, John J.; Vlachos, Pavlos P.; Jung, Sunghwan

    2015-01-01

    Dogs lap because they have incomplete cheeks and cannot suck. When lapping, a dog’s tongue pulls a liquid column from the bath, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured lapping in 19 dogs and used the results to generate a physical model of the tongue’s interaction with the air–fluid interface. These experiments help to explain how dogs exploit the fluid dynamics of the generated column. The results demonstrate that effects of acceleration govern lapping frequency, which suggests that dogs curl the tongue to create a larger liquid column. Comparing lapping in dogs and cats reveals that, despite similar morphology, these carnivores lap in different physical regimes: an unsteady inertial regime for dogs and steady inertial regime for cats. PMID:26668382

  19. Dogs lap using acceleration-driven open pumping.

    PubMed

    Gart, Sean; Socha, John J; Vlachos, Pavlos P; Jung, Sunghwan

    2015-12-29

    Dogs lap because they have incomplete cheeks and cannot suck. When lapping, a dog's tongue pulls a liquid column from the bath, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured lapping in 19 dogs and used the results to generate a physical model of the tongue's interaction with the air-fluid interface. These experiments help to explain how dogs exploit the fluid dynamics of the generated column. The results demonstrate that effects of acceleration govern lapping frequency, which suggests that dogs curl the tongue to create a larger liquid column. Comparing lapping in dogs and cats reveals that, despite similar morphology, these carnivores lap in different physical regimes: an unsteady inertial regime for dogs and steady inertial regime for cats.

  20. Periodontal Plastic Surgery

    MedlinePlus

    ... Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain ... Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain ...

  1. Gum (Periodontal) Disease

    MedlinePlus

    ... forms of gum disease are gingivitis and periodontitis. Gingivitis and Periodontitis In gingivitis, the gums become red, swollen and can bleed easily. Gingivitis can usually be reversed with daily brushing and ...

  2. New design deforming controlling system of the active stressed lap

    NASA Astrophysics Data System (ADS)

    Ying, Li; Wang, Daxing

    2008-07-01

    A 450mm diameter active stressed lap has been developed in NIAOT by 2003. We design a new lap in 2007. This paper puts on emphases on introducing the new deforming control system of the lap. Aiming at the control characteristic of the lap, a new kind of digital deforming controller is designed. The controller consists of 3 parts: computer signal disposing, motor driving and force sensor signal disposing. Intelligent numeral PID method is applied in the controller instead of traditional PID. In the end, the result of new deformation are given.

  3. Effects of periodontal therapy on white blood cell count and levels of transforming growth factor beta in serum of subjects with severe periodontitis.

    PubMed

    Leite, A C E; Carneiro, V M A; Morandini, A C; Ramos-Junior, E S; Guimarães, M C M

    2015-03-28

    This study aimed to investigate the effects of nonsurgical periodontal therapy on white blood cell (WBC) count and levels of transforming growth factor beta (TGF—β) in serum from subjects with severe periodontitis. Serum from 28 subjects with periodontitis (mean age: 34.36±6.24; 32% men) and 27 healthy controls (mean age: 33.18±6.42; 33% men) were collected prior to therapy. Blood samples were obtained from 23 subjects who completed therapy (9—12 months). A well—controlled periodontal treatment protocol was established in three stages: mechanical periodontal therapy (scaling and root planning), reinstrumentation of dental sites, and supportive periodontal therapy. Periodontal and systemic parameters such as the total number of WBCs and TGF—β levels, accessed by enzyme—linked immunosorbent assay (ELISA), were included. After therapy, all clinical periodontal parameters decreased (p<0.0001). There were no statistical differences in WBC count between experimental and control groups before or after therapy. However, after therapy, the mean value of lymphocytes in patients with localized aggressive periodontitis (LAgP) was statistically higher than that of patients with generalized chronic periodontitis (GCP) (p<0.0357). Additionally, TGF—β levels in LAgP and GCP patients were higher compared to controls before therapy (p<0.05 and p<0.01, respectively). In LAgP patients, periodontal therapy was associated with increased number of lymphocytes.

  4. Role of multidisciplinary approach in a case of Langerhans cell histiocytosis with initial periodontal manifestations

    PubMed Central

    Cisternino, Angelo; Asa’ad, Farah; Fusco, Nicola; Ferrero, Stefano; Rasperini, Giulio

    2015-01-01

    Introduction: Langerhans cell histiocytosis (LCH) is a rare inflammatory myeloid neoplasia of unknown etiology occurring in both children and adults. This condition is characterized by an abnormal proliferation of Langerhans cells that may virtually affect all sites in the human body. Oral manifestations of LCH could be the first clinical sign of disease and its periodontal localization could be easily mistaken for other more common entities, such as chronic periodontitis, aggressive periodontitis, and necrotizing ulcerative periodontitis. Case presentation: A 32-years old female visited a private dental practice with a chief complaint of sensitivity in the mandibular left first molar. Clinical and radiographic examination revealed deep periodontal pocket, recession, furcation involvement, mobility, severe alveolar bone destruction and a diagnosis of aggressive periodontitis was rendered. Multiple tooth extractions were carried out due to progressive periodontal destruction with impaired healing and development of ulcerative lesions. Multidisciplinary investigation demonstrated that the periodontal involvement was a manifestation of an underlying systemic disease. A biopsy of a bone lesion was therefore performed, revealing the presence of multifocal single system LCH. Conclusion: The identification of periodontal LCH is not trivial given that it may clinically resemble other periodontal disease entities. The dentist can be the first health care personnel to unravel the presence of an underlying systemic LCH. PMID:26722570

  5. Identification of biomarkers for periodontal disease using the immunoproteomics approach

    PubMed Central

    Kerishnan, Jesinda P.; Mohammad, Sani; Alias, Muhamad Shaifunizam; Mu, Alan Kang-Wai; Vaithilingam, Rathna Devi; Baharuddin, Nor Adinar; Safii, Syarida H.; Abdul Rahman, Zainal Ariff; Chen, Yu Nieng

    2016-01-01

    Background Periodontitis is one of the most common oral diseases associated with the host’s immune response against periodontopathogenic infection. Failure to accurately diagnose the stage of periodontitis has limited the ability to predict disease status. Therefore, we aimed to look for reliable diagnostic markers for detection or differentiation of early stage periodontitis using the immunoprotemic approach. Method In the present study, patient serum samples from four distinct stages of periodontitis (i.e., mild chronic, moderate chronic, severe chronic, and aggressive) and healthy controls were subjected to two-dimensional gel electrophoresis (2-DE), followed by silver staining. Notably, we consistently identified 14 protein clusters in the sera of patients and normal controls. Results Overall, we found that protein levels were comparable between patients and controls, with the exception of the clusters corresponding to A1AT, HP, IGKC and KNG1 (p < 0.05). In addition, the immunogenicity of these proteins was analysed via immunoblotting, which revealed differential profiles for periodontal disease and controls. For this reason, IgM obtained from severe chronic periodontitis (CP) sera could be employed as a suitable autoantibody for the detection of periodontitis. Discussion Taken together, the present study suggests that differentially expressed host immune response proteins could be used as potential biomarkers for screening periodontitis. Future studies exploring the diagnostic potential of such factors are warranted. PMID:27635317

  6. Identification of biomarkers for periodontal disease using the immunoproteomics approach

    PubMed Central

    Kerishnan, Jesinda P.; Mohammad, Sani; Alias, Muhamad Shaifunizam; Mu, Alan Kang-Wai; Vaithilingam, Rathna Devi; Baharuddin, Nor Adinar; Safii, Syarida H.; Abdul Rahman, Zainal Ariff; Chen, Yu Nieng

    2016-01-01

    Background Periodontitis is one of the most common oral diseases associated with the host’s immune response against periodontopathogenic infection. Failure to accurately diagnose the stage of periodontitis has limited the ability to predict disease status. Therefore, we aimed to look for reliable diagnostic markers for detection or differentiation of early stage periodontitis using the immunoprotemic approach. Method In the present study, patient serum samples from four distinct stages of periodontitis (i.e., mild chronic, moderate chronic, severe chronic, and aggressive) and healthy controls were subjected to two-dimensional gel electrophoresis (2-DE), followed by silver staining. Notably, we consistently identified 14 protein clusters in the sera of patients and normal controls. Results Overall, we found that protein levels were comparable between patients and controls, with the exception of the clusters corresponding to A1AT, HP, IGKC and KNG1 (p < 0.05). In addition, the immunogenicity of these proteins was analysed via immunoblotting, which revealed differential profiles for periodontal disease and controls. For this reason, IgM obtained from severe chronic periodontitis (CP) sera could be employed as a suitable autoantibody for the detection of periodontitis. Discussion Taken together, the present study suggests that differentially expressed host immune response proteins could be used as potential biomarkers for screening periodontitis. Future studies exploring the diagnostic potential of such factors are warranted.

  7. Analysis of adhesively bonded composite lap joints

    SciTech Connect

    Tong, L.; Kuruppu, M.; Kelly, D.

    1994-12-31

    A new nonlinear formulation is developed for the governing equations for the shear and peel stresses in adhesively bonded composite double lap joints. The new formulation allows arbitrary nonlinear stress-strain characteristics in both shear and peel behavior. The equations are numerically integrated using a shooting technique and Newton-Raphson method behind a user friendly interface. The failure loads are predicted by utilizing the maximum stress criterion, interlaminar delamination and the energy density failure criteria. Numerical examples are presented to demonstrate the effect of the nonlinear adhesive behavior on the stress distribution and predict the failure load and the associated mode.

  8. Diamond machine tool face lapping machine

    DOEpatents

    Yetter, H.H.

    1985-05-06

    An apparatus for shaping, sharpening and polishing diamond-tipped single-point machine tools. The isolation of a rotating grinding wheel from its driving apparatus using an air bearing and causing the tool to be shaped, polished or sharpened to be moved across the surface of the grinding wheel so that it does not remain at one radius for more than a single rotation of the grinding wheel has been found to readily result in machine tools of a quality which can only be obtained by the most tedious and costly processing procedures, and previously unattainable by simple lapping techniques.

  9. Signaling aggression.

    PubMed

    van Staaden, Moira J; Searcy, William A; Hanlon, Roger T

    2011-01-01

    From psychological and sociological standpoints, aggression is regarded as intentional behavior aimed at inflicting pain and manifested by hostility and attacking behaviors. In contrast, biologists define aggression as behavior associated with attack or escalation toward attack, omitting any stipulation about intentions and goals. Certain animal signals are strongly associated with escalation toward attack and have the same function as physical attack in intimidating opponents and winning contests, and ethologists therefore consider them an integral part of aggressive behavior. Aggressive signals have been molded by evolution to make them ever more effective in mediating interactions between the contestants. Early theoretical analyses of aggressive signaling suggested that signals could never be honest about fighting ability or aggressive intentions because weak individuals would exaggerate such signals whenever they were effective in influencing the behavior of opponents. More recent game theory models, however, demonstrate that given the right costs and constraints, aggressive signals are both reliable about strength and intentions and effective in influencing contest outcomes. Here, we review the role of signaling in lieu of physical violence, considering threat displays from an ethological perspective as an adaptive outcome of evolutionary selection pressures. Fighting prowess is conveyed by performance signals whose production is constrained by physical ability and thus limited to just some individuals, whereas aggressive intent is encoded in strategic signals that all signalers are able to produce. We illustrate recent advances in the study of aggressive signaling with case studies of charismatic taxa that employ a range of sensory modalities, viz. visual and chemical signaling in cephalopod behavior, and indicators of aggressive intent in the territorial calls of songbirds.

  10. How lamina-associated polypeptide 1 (LAP1) activates Torsin

    PubMed Central

    Sosa, Brian A; Demircioglu, F Esra; Chen, James Z; Ingram, Jessica; Ploegh, Hidde L; Schwartz, Thomas U

    2014-01-01

    Lamina-associated polypeptide 1 (LAP1) resides at the nuclear envelope and interacts with Torsins, poorly understood endoplasmic reticulum (ER)-localized AAA+ ATPases, through a conserved, perinuclear domain. We determined the crystal structure of the perinuclear domain of human LAP1. LAP1 possesses an atypical AAA+ fold. While LAP1 lacks canonical nucleotide binding motifs, its strictly conserved arginine 563 is positioned exactly where the arginine finger of canonical AAA+ ATPases is found. Based on modeling and electron microscopic analysis, we propose that LAP1 targets Torsin to the nuclear envelope by forming an alternating, heterohexameric (LAP1-Torsin)3 ring, in which LAP1 acts as the Torsin activator. The experimental data show that mutation of arginine 563 in LAP1 reduces its ability to stimulate TorsinA ATPase hydrolysis. This knowledge may help scientists understand the etiology of DYT1 primary dystonia, a movement disorder caused by a single glutamate deletion in TorsinA. DOI: http://dx.doi.org/10.7554/eLife.03239.001 PMID:25149450

  11. How dogs lap: open pumping driven by acceleration

    NASA Astrophysics Data System (ADS)

    Gart, Sean; Socha, John; Vlachos, Pavlos; Jung, Sunghwan

    2015-11-01

    Dogs drink by lapping because they have incomplete cheeks and cannot suck fluids into the mouth. When lapping, a dog's tongue pulls a liquid column from a bath, which is then swallowed, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured the kinematics of lapping from nineteen dogs and used the results to generate a physical model of the tongue's interaction with the air-fluid interface. These experiments with an accelerating rod help to explain how dogs exploit the fluid dynamics of the generated column. The results suggest that effects of acceleration govern lapping frequency, and that dogs curl the tongue ventrally (backwards) and time their bite on the column to increase fluid intake per lap. Comparing lapping in dogs and cats reveals that though they both lap with the same frequency scaling with respect to body mass and have similar morphology, these carnivores lap in different physical regimes: a high-acceleration regime for dogs and a low-acceleration regime for cats.

  12. Learning Activity Package, Chemistry I, (LAP) Study 29.

    ERIC Educational Resources Information Center

    Jones, Naomi

    Presented is a Learning Activity Package (LAP) study concerned with carbon and its compounds. This LAP in chemistry includes a rationale for studying the chemical element of carbon, a list of student objectives (stated in behavioral terms), of activities (reading, laboratory experiments, model construction, etc.), a two-page worksheet, a…

  13. Experimental dynamic deformation analysis of active stressed lap.

    PubMed

    Zhao, Hongshen; Li, Xiaojin; Fan, Bin; Zeng, Zhige

    2016-02-20

    We introduce a method to measure the dynamic surface deformation of an active stressed lap for fabricating a 4  mf/1.5  mirror. Lap surface accuracy working in some typical deformation velocities is put forward. Experimental results indicate that dynamic lap surface accuracy is worse than that of a static surface, and dynamic surface accuracy gets worse if deformation velocity increases, while the difference of lap surface error RMS is less than 1 μm. An optimization of the processing strategy is feasible through changing the deformation velocity of the active stressed lap depending on the processing schedule. After optimizing the grinding and polishing strategy, efficiency is expected to have a significant increase. PMID:26906568

  14. Identification of a Novel Human LAP1 Isoform That Is Regulated by Protein Phosphorylation

    PubMed Central

    Santos, Mariana; Domingues, Sara C.; Costa, Patrícia; Muller, Thorsten; Galozzi, Sara; Marcus, Katrin; da Cruz e Silva, Edgar F.; da Cruz e Silva, Odete A.; Rebelo, Sandra

    2014-01-01

    Lamina associated polypeptide 1 (LAP1) is an integral protein of the inner nuclear membrane that is ubiquitously expressed. LAP1 binds to lamins and chromatin, probably contributing to the maintenance of the nuclear envelope architecture. Moreover, LAP1 also interacts with torsinA and emerin, proteins involved in DYT1 dystonia and X-linked Emery-Dreifuss muscular dystrophy disorder, respectively. Given its relevance to human pathological conditions, it is important to better understand the functional diversity of LAP1 proteins. In rat, the LAP1 gene (TOR1AIP1) undergoes alternative splicing to originate three LAP1 isoforms (LAP1A, B and C). However, it remains unclear if the same occurs with the human TOR1AIP1 gene, since only the LAP1B isoform had thus far been identified in human cells. In silico analysis suggested that, across different species, potential new LAP1 isoforms could be generated by alternative splicing. Using shRNA to induce LAP1 knockdown and HPLC-mass spectrometry analysis the presence of two isoforms in human cells was described and validated: LAP1B and LAP1C; the latter is putatively N-terminal truncated. LAP1B and LAP1C expression profiles appear to be dependent on the specific tissues analyzed and in cultured cells LAP1C was the major isoform detected. Moreover, LAP1B and LAP1C expression increased during neuronal maturation, suggesting that LAP1 is relevant in this process. Both isoforms were found to be post-translationally modified by phosphorylation and methionine oxidation and two LAP1B/LAP1C residues were shown to be dephosphorylated by PP1. This study permitted the identification of the novel human LAP1C isoform and partially unraveled the molecular basis of LAP1 regulation. PMID:25461922

  15. Quercetin inhibits inflammatory bone resorption in a mouse periodontitis model.

    PubMed

    Napimoga, Marcelo H; Clemente-Napimoga, Juliana T; Macedo, Cristina G; Freitas, Fabiana F; Stipp, Rafael N; Pinho-Ribeiro, Felipe A; Casagrande, Rubia; Verri, Waldiceu A

    2013-12-27

    Periodontitis is a disease that leads to bone destruction and represents the main cause of tooth loss in adults. The development of aggressive periodontitis has been associated with increased inflammatory response that is induced by the presence of a subgingival biofilm containing Aggregatibacter actinomycetemcomitans. The flavonoid quercetin (1) is widespread in vegetables and fruits and exhibits many biological properties for possible medical and clinical applications such as its anti-inflamatory and antioxidant effects. Thus, in the present study, the properties of 1 have been evaluated in bone loss and inflammation using a mouse periodontitis model induced by A. actinomycetemcomitans infection. Subcutaneous treatment with 1 reduced A. actinomycetemcomitans-induced bone loss and IL-1β, TNF-α, IL-17, RANKL, and ICAM-1 production in the gingival tissue without affecting bacterial counts. These results demonstrated that quercetin exhibits protective effects in A. actinomycetemcomitans-induced periodontitis in mice by modulating cytokine and ICAM-1 production.

  16. Tubular lap joints for wind turbine applications

    SciTech Connect

    Reedy, E.D. Jr.; Guess, T.R.

    1990-01-01

    A combined analytical/experimental study of the strength of thick- walled, adhesively bonded PMMA-to-aluminum and E-glass/epoxy composite-to-aluminum tubular lap joints under axial load has been conducted. Test results include strength and failure mode data. Moreover, strain gages placed along the length of the outer tubular adherend characterize load transfer from one adherend to the other. The strain gage data indicate that load transfer is nonuniform and that the relatively compliant PMMA has the shorter load transfer length. Strains determined by a finite element analysis of the tested joints are in excellent agreement with those measured. Calculated bond stresses are highest in the region of observed failure, and extensive bond yielding is predicted in the E- glass/epoxy composite-to-aluminum joint prior to joint failure. 4 refs., 13 figs., 1 tab.

  17. Ozone therapy in periodontics

    PubMed Central

    Gupta, G; Mansi, B

    2012-01-01

    Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of ozone well indicated in all stages of gingival and periodontal diseases. The primary objective of this article is to provide a general review about the clinical applications of ozone in periodontics. The secondary objective is to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. This objective would be of importance to future researchers in terms of what has been tried and what the potentials are for the clinical application of ozone in Periodontics. PMID:22574088

  18. New mathematical model for error reduction of stressed lap

    NASA Astrophysics Data System (ADS)

    Zhao, Pu; Yang, Shuming; Sun, Lin; Shi, Xinyu; Liu, Tao; Jiang, Zhuangde

    2016-05-01

    Stressed lap, compared to traditional polishing methods, has high processing efficiency. However, this method has disadvantages in processing nonsymmetric surface errors. A basic-function method is proposed to calculate parameters for a stressed-lap polishing system. It aims to minimize residual errors and is based on a matrix and nonlinear optimization algorithm. The results show that residual root-mean-square could be >15% after one process for classical trefoil error. The surface period errors close to the lap diameter were removed efficiently, up to 50% material removal.

  19. Periodontal considerations for children.

    PubMed

    Song, H Jung

    2013-01-01

    This article reviews periodontal disease and gingival disease and also explores issues relating to mucogingival defects such as gingival hyperplasia, gingival recession, and exposure of impacted canines.

  20. INTERIOR OF WEST SPAN LOOKING WEST (SHADOW OF VERTICAL LAPS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF WEST SPAN LOOKING WEST (SHADOW OF VERTICAL LAPS PLACED ON ZONE III; ASPHALT ZONE IX) - Honey Run Bridge, Spanning Butte Creek, bypassed section of Honey Run Road (originally Carr Hill Road), Paradise, Butte County, CA

  1. FRICTION STIR LAP WELDING OF ALUMINUM - POLYMER USING SCRIBE TECHNOLOGY

    SciTech Connect

    Upadhyay, Piyush; Hovanski, Yuri; Fifield, Leonard S.; Simmons, Kevin L.

    2015-02-16

    Friction Stir Scribe (FSS) technology is a relatively new variant of Friction Stir Welding (FSW) which enables lap joining of dissimilar material with very different melting points and different high temperature flow behaviors. The cutter scribe attached at the tip of FSW tool pin effectively cuts the high melting point material such that a mechanically interlocking feature is created between the dissimilar materials. The geometric shape of this interlocking feature determines the shear strength attained by the lap joint. This work presents first use of scribe technology in joining polymers to aluminum alloy. Details of the several runs of scribe welding performed in lap joining of ~3.175mm thick polymers including HDPE, filled and unfilled Nylon 66 to 2mm thick AA5182 are presented. The effect of scribe geometry and length on weld interlocking features is presented along with lap shear strength evaluations.

  2. Double-Lap Shear Test For Honeycomb Core

    NASA Technical Reports Server (NTRS)

    Nettles, Alan T.; Hodge, Andrew J.

    1992-01-01

    Double-lap test measures shear strength of panel made of honeycomb core with 8-ply carbon-fiber/epoxy face sheets. Developed to overcome three principal disadvantages of prior standard single-lap shear test: specimen had to be more than 17 in. long; metal face sheets had to be used; and test introduced torque, with consequent bending and peeling of face sheets and spurious tensile or compressive loading of honeycomb.

  3. Defining periodontal health

    PubMed Central

    2015-01-01

    Assessment of the periodontium has relied exclusively on a variety of physical measurements (e.g., attachment level, probing depth, bone loss, mobility, recession, degree of inflammation, etc.) in relation to various case definitions of periodontal disease. Periodontal health was often an afterthought and was simply defined as the absence of the signs and symptoms of a periodontal disease. Accordingly, these strict and sometimes disparate definitions of periodontal disease have resulted in an idealistic requirement of a pristine periodontium for periodontal health, which makes us all diseased in one way or another. Furthermore, the consequence of not having a realistic definition of health has resulted in potentially questionable recommendations. The aim of this manuscript was to assess the biological, environmental, sociological, economic, educational and psychological relationships that are germane to constructing a paradigm that defines periodontal health using a modified wellness model. The paradigm includes four cardinal characteristics, i.e., 1) a functional dentition, 2) the painless function of a dentition, 3) the stability of the periodontal attachment apparatus, and 4) the psychological and social well-being of the individual. Finally, strategies and policies that advocate periodontal health were appraised. I'm not sick but I'm not well, and it's a sin to live so well. Flagpole Sitta, Harvey Danger PMID:26390888

  4. Adhesive-bonded scarf and stepped-lap joints

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.

    1973-01-01

    Continuum mechanics solutions are derived for the static load-carrying capacity of scarf and stepped-lap adhesive-bonded joints. The analyses account for adhesive plasticity and adherend stiffness imbalance and thermal mismatch. The scarf joint solutions include a simple algebraic formula which serves as a close lower bound, within a small fraction of a per cent of the true answer for most practical geometries and materials. Digital computer programs were developed and, for the stepped-lap joints, the critical adherend and adhesive stresses are computed for each step. The scarf joint solutions exhibit grossly different behavior from that for double-lap joints for long overlaps inasmuch as that the potential bond shear strength continues to increase with indefinitely long overlaps on the scarf joints. The stepped-lap joint solutions exhibit some characteristics of both the scarf and double-lap joints. The stepped-lap computer program handles arbitrary (different) step lengths and thickness and the solutions obtained have clarified potentially weak design details and the remedies. The program has been used effectively to optimize the joint proportions.

  5. An Ultrasonographic Periodontal Probe

    NASA Astrophysics Data System (ADS)

    Bertoncini, C. A.; Hinders, M. K.

    2010-02-01

    Periodontal disease, commonly known as gum disease, affects millions of people. The current method of detecting periodontal pocket depth is painful, invasive, and inaccurate. As an alternative to manual probing, an ultrasonographic periodontal probe is being developed to use ultrasound echo waveforms to measure periodontal pocket depth, which is the main measure of periodontal disease. Wavelet transforms and pattern classification techniques are implemented in artificial intelligence routines that can automatically detect pocket depth. The main pattern classification technique used here, called a binary classification algorithm, compares test objects with only two possible pocket depth measurements at a time and relies on dimensionality reduction for the final determination. This method correctly identifies up to 90% of the ultrasonographic probe measurements within the manual probe's tolerance.

  6. Nicotine and periodontal tissues

    PubMed Central

    Malhotra, Ranjan; Kapoor, Anoop; Grover, Vishakha; Kaushal, Sumit

    2010-01-01

    Tobacco use has been recognized to be a significant risk factor for the development and progression of periodontal disease. Its use is associated with increased pocket depths, loss of periodontal attachment, alveolar bone and a higher rate of tooth loss. Nicotine, a major component and most pharmacologically active agent in tobacco is likely to be a significant contributing factor for the exacerbation of periodontal diseases. Available literature suggests that nicotine affects gingival blood flow, cytokine production, neutrophil and other immune cell function; connective tissue turnover, which can be the possible mechanisms responsible for overall effects of tobacco on periodontal tissues. Inclusion of tobacco cessation as a part of periodontal therapy encourages dental professionals to become more active in tobacco cessation counseling. This will have far reaching positive effects on our patients’ oral and general health. PMID:20922084

  7. Understanding Aggression.

    ERIC Educational Resources Information Center

    Scott, J. P.

    Research in many fields of the social and biological sciences indicates that there are ecological, cultural, social, psychological, physiological, and genetic causes of aggression. The agonistic behavior system, which adapts to situations of social conflict, includes several patterns of conduct ranging from overt fighting to complete passivity. In…

  8. TLR4 polymorphism and periodontitis susceptibility

    PubMed Central

    Jin, Su-Han; Guan, Xiao-Yan; Liang, Wen-Hong; Bai, Guo-Hui; Liu, Jian-Guo

    2016-01-01

    Abstract Background: Many primary and secondary studies reported the association between Toll-like receptor 4 (TLR4) polymorphism and periodontitis susceptibility, which mainly focused on TLR4–299A>G or TLR4–399C>T of Caucasian, however, these studies had different conclusions. The aim of this study was to reassess relative studies about TLR4 polymorphism and periodontitis susceptibility, and update meta-analysis. Methods: We searched the electronic database including CNKI (Chinese National Knowledge Infrastructure), PubMed, Embase, and hand searched relative studies until January 4, 2016. Two authors selected studies according to inclusion and exclusion criteria, assessed studies using Newcastle-Ottawa Scale case control study (NOS), and calculated the combined effect size using STATA software, version 12.0. Results: This meta-analysis included 18 studies, containing 2453 healthy participants and 2987 patients with chronic periodontitis (CP) and 462 patients with aggressive periodontitis (AP). There was a significance between TLR4C>G (rs7873784) allele and CP in Asian, and its recessive model was also significant (for C vs G: odds ratio [OR] = 0.72, 95% confidence interval [CI] = 0.54–0.95, I2 = 0%; for CC + CG vs GG: OR = 0.66, 95% CI = 0.49–0.89, I2 = 0%). However, we did not detect any significant relevance between other TLR4 polymorphism and periodontitis susceptibility in overall and subgroup analyses. The sensitive analysis showed that dropping any single studies did not affect the pooled-analysis results. Publication bias was not detected. Conclusions: The meta-analysis found association between TLR4C>G (rs7873784) allele and CP in Asian and it may passed on to offsprings in the form of recessiveness. However, further studies about the association between TLR4C>G (rs7873784) and CP is warranted to confirm. PMID:27603404

  9. Flaw Tolerance in Lap Shear Brazed Joints. Part 1

    NASA Technical Reports Server (NTRS)

    Flom, Yury; Wang, Li-Qin

    2003-01-01

    Furnace brazing is a joining process used in the aerospace and other industries to produce strong permanent and hermetic structural joints. As in any joining process, brazed joints have various imperfections and defects. At the present time, our understanding of the influence of the internal defects on the strength of the brazed joints is not adequate. The goal of this 3-part investigation is to better understand the properties and failure mechanisms of the brazed joints containing defects. This study focuses on the behavior of the brazed lap shear joints because of their importance in manufacturing aerospace structures. In Part 1, an average shear strength capability and failure modes of the single lap joints are explored. Stainless steel specimens brazed with pure silver are tested in accordance with the AWS C3.2 standard. Comparison of the failure loads and the ultimate shear strength with the Finite Element Analysis (FEA) of the same specimens as a function of the overlap widths shows excellent correlation between the experimental and calculated values for the defect-free lap joints. A damage zone criterion is shown to work quite well in understanding the failure of the braze joints. In Part 2, the findings of the Part 1 will be verified on the larger test specimens. Also, various flaws will be introduced in the test specimens to simulate lack of braze coverage in the lap joints. Mechanical testing and FEA will be performed on these joints to verify that behavior of the flawed ductile lap joints is similar to joints with a reduced braze area. Finally, in Part 3, the results obtained in Parts 1 and 2 will be applied to the actual brazed structure to evaluate the load-carrying capability of a structural lap joint containing discontinuities. In addition, a simplified engineering procedure will be offered for the laboratory testing of the lap shear specimens.

  10. Use of two-dimensional transmission photoelastic models to study stresses in double-lap bolted joints: Load transfer and stresses in the inner lap

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.

    1980-01-01

    The determination of the stress distribution in the inner lap of double-lap, double-bolt joints using photoelastic models of the joint is discussed. The principal idea is to fabricate the inner lap of a photoelastic material and to use a photoelastically sensitive material for the two outer laps. With this setup, polarized light transmitted through the stressed model responds principally to the stressed inner lap. The model geometry, the procedures for making and testing the model, and test results are described.

  11. LAP5 and LAP6 Encode Anther-Specific Proteins with Similarity to Chalcone Synthase Essential for Pollen Exine Development in Arabidopsis1[W][OA

    PubMed Central

    Dobritsa, Anna A.; Lei, Zhentian; Nishikawa, Shuh-ichi; Urbanczyk-Wochniak, Ewa; Huhman, David V.; Preuss, Daphne; Sumner, Lloyd W.

    2010-01-01

    Pollen grains of land plants have evolved remarkably strong outer walls referred to as exine that protect pollen and interact with female stigma cells. Exine is composed of sporopollenin, and while the composition and synthesis of this biopolymer are not well understood, both fatty acids and phenolics are likely components. Here, we describe mutations in the Arabidopsis (Arabidopsis thaliana) LESS ADHESIVE POLLEN (LAP5) and LAP6 that affect exine development. Mutation of either gene results in abnormal exine patterning, whereas pollen of double mutants lacked exine deposition and subsequently collapsed, causing male sterility. LAP5 and LAP6 encode anther-specific proteins with homology to chalcone synthase, a key flavonoid biosynthesis enzyme. lap5 and lap6 mutations reduced the accumulation of flavonoid precursors and flavonoids in developing anthers, suggesting a role in the synthesis of phenolic constituents of sporopollenin. Our in vitro functional analysis of LAP5 and LAP6 using 4-coumaroyl-coenzyme A yielded bis-noryangonin (a commonly reported derailment product of chalcone synthase), while similar in vitro analyses using fatty acyl-coenzyme A as the substrate yielded medium-chain alkyl pyrones. Thus, in vitro assays indicate that LAP5 and LAP6 are multifunctional enzymes and may play a role in both the synthesis of pollen fatty acids and phenolics found in exine. Finally, the genetic interaction between LAP5 and an anther gene involved in fatty acid hydroxylation (CYP703A2) demonstrated that they act synergistically in exine production. PMID:20442277

  12. Periodontitis and osteoporosis.

    PubMed

    Straka, Michal; Straka-Trapezanlidis, Michaela; Deglovic, Juraj; Varga, Ivan

    2015-01-01

    Today's knowledge and studies show a firm correlation between osteoporosis and periodontitis, particularly in postmenopausal women. This review study deals with epidemiological and etiopathogenetic association between chronic periodontitis and an osteoporosis. A special emphasis is put on explanation of possible relations between a premature tooth loss and decrease of length and density of jaw bones, particularly their alveolar prolongations. The second part of the paper deals with principles of treatment in patients suffering of osteoporosis. Osteoporosis reduces density of jaw bones and decreases a number of teeth in jaws, but it does not affect other clinical signs and markers of periodontitis such as inflammation, bleeding and the depth of periodontal pockets and microbial plaque.

  13. Subgingival microbial profile and production of proinflammatory cytokines in chronic periodontitis.

    PubMed

    Dosseva-Panova, Velichka T; Popova, Christina L; Panov, Vladimir E

    2014-01-01

    This review examines literature data concerning the bacterial findings in chronic periodontitis depending on pocket depth, and presents the latest published information on the presence of proinflammatory factors in periodontal environment. It has been found that chronic periodontitis affects as much as 80% of the middle-aged population; by comparison, the prevalence of aggressive periodontitis reaches up to 1-1.5%. It is accepted that this social disease is multifactorial in etiology, but the evidence in the literature suggests that the levels of specific Gram-negative organisms in subgingival plaque biofilm play a major role in the initiation and progression of the disease. Of the many bacterial species inhabiting the periodontal environment, three types--Porphyromonas gingivalis (PG), Treponema denticola (TD), Tannerella forsythia (TF)--are strongly associated with the initiation and progression of periodontitis. Microbiological studies suggest that Porphyromonas gingivalis should be considered a major etiologic agent. Currently, Porphyromonas gingivalis is strongly associated with the pathogenesis of chronic periodontitis. On the other hand, the presence of Aggregatibacter actinomycetemeomitans in patients with chronic periodontitis may be related to the severity of the disease and thus modify the therapeutic plan. The increased amount of periodontal pathogens in the subgingival area can activate a cascade of defense mechanisms of the body associated with the production of factors causing inflammation and destruction, which suggests a correlation between the bacterial findings and the body response implemented by enhancing the local cytokine expression. Studies in the literature show that the presence of certain micro-organisms in the periodontal environment is associated to increased levels of proinflammatory cytokines in the gingival fluid and gingival tissue. These levels have been associated with destructive tissues response. There is little evidence in the

  14. Stress increases periodontal inflammation

    PubMed Central

    RIVERA, CÉSAR; MONSALVE, FRANCISCO; SUAZO, IVÁN; BECERRA, JAVIERA

    2012-01-01

    This study aimed to examine the effect of chronic restraint stress (RS) on the severity of experimental periodontal disease in rats. A total of 32 male Sprague Dawley (SD) rats were divided into four groups: i) Rats receiving two treatment regimens, chronic stress induced by movement restriction in acrylic cylinders for 1–1.5 h daily and induction of experimental periodontal disease, using a nylon ligature which was placed around the first left mandibular molars (n=8); ii) induction of periodontal disease, without RS (n=8); iii) RS (n=8) and iv) control (n=8). After 15 days, blood samples were obtained, and blood glucose levels and the corticosterone concentration were measured as stress markers. The severity of periodontal disease was analyzed according to the level of gingival and bone inflammation, leading to compromise of the teeth involved. Chronic stress was induced with movement restriction (P≤0.05, Mann-Whitney U-test) and increased the severity (P≤0.05, Mann-Whitney U-test) of experimental perio dontal disease in rats, according to the level of gingival and bone inflammation around the first left mandibular molars. The results of the present study showed that RS modulates periodontal inflammation and that the rat model described herein is suitable for investigating the association between stress and periodontal disease. PMID:23226743

  15. Biomaterials for periodontal regeneration

    PubMed Central

    Shue, Li; Yufeng, Zhang; Mony, Ullas

    2012-01-01

    Periodontal disease is characterized by the destruction of periodontal tissues. Various methods of regenerative periodontal therapy, including the use of barrier membranes, bone replacement grafts, growth factors and the combination of these procedures have been investigated. The development of biomaterials for tissue engineering has considerably improved the available treatment options above. They fall into two broad classes: ceramics and polymers. The available ceramic-based materials include calcium phosphate (eg, tricalcium phosphate and hydroxyapatite), calcium sulfate and bioactive glass. The bioactive glass bonds to the bone with the formation of a layer of carbonated hydroxyapatite in situ. The natural polymers include modified polysaccharides (eg, chitosan,) and polypeptides (collagen and gelatin). Synthetic polymers [eg, poly(glycolic acid), poly(L-lactic acid)] provide a platform for exhibiting the biomechanical properties of scaffolds in tissue engineering. The materials usually work as osteogenic, osteoconductive and osteoinductive scaffolds. Polymers are more widely used as a barrier material in guided tissue regeneration (GTR). They are shown to exclude epithelial downgrowth and allow periodontal ligament and alveolar bone cells to repopulate the defect. An attempt to overcome the problems related to a collapse of the barrier membrane in GTR or epithelial downgrowth is the use of a combination of barrier membranes and grafting materials. This article reviews various biomaterials including scaffolds and membranes used for periodontal treatment and their impacts on the experimental or clinical management of periodontal defect. PMID:23507891

  16. [Aggressive fibromatoses].

    PubMed

    Döhler, J R; Hamelmann, H; Lasson, U

    1984-03-01

    Benign by nature, aggressive fibromatoses (desmoid fibromas) may represent as difficult therapeutic problems as malignant tumours. When subtotally resected they tend to recur. But spontaneous regression is possible. Expense and limits of their surgical treatment are discussed with reference to seven patients. In five cases primary affliction of bone was evident. There are three reports given in detail: In the first, malignant transformation may be due to radiation therapy and hemipelvectomy could not prevent recurrence. In the second, spontaneous regression of untreated pelvic affection may have occurred. In the third, several resections and amputation of the leg failed to cure congenital infantile fibromatosis.

  17. Lap time optimisation of a racing go-kart

    NASA Astrophysics Data System (ADS)

    Lot, Roberto; Dal Bianco, Nicola

    2016-02-01

    The minimum lap time optimal control problem has been solved for a go-kart model. The symbolic algebra software Maple has been used to derive equations of motion and an indirect method has been adopted to solve the optimal control problem. Simulation has been successfully performed on a full track lap with a multibody model endowed with seven degrees of freedom. Geometrical and mechanical characteristics of a real kart have been measured by a lab test to feed the mathematical model. Telemetry recorded in an entire lap by a professional driver has been compared to simulation results in order to validate the model. After the reliability of the optimal control model was proved, the simulation has been used to study the peculiar dynamics of go-karts and focus to tyre slippage dynamics, which is highly affected by the lack of differential.

  18. Inflammatory Myofibroblastic Tumor Mimicking Apical Periodontitis.

    PubMed

    Adachi, Makoto; Kiho, Kazuki; Sekine, Genta; Ohta, Takahisa; Matsubara, Makoto; Yoshida, Takakazu; Katsumata, Akitoshi; Tanuma, Jun-ichi; Sumitomo, Shinichiro

    2015-12-01

    Inflammatory myofibroblastic tumors (IMTs) are rare. IMTs of the head and neck occur in all age groups, from neonates to old age, with the highest incidence occurring in childhood and early adulthood. An IMT has been defined as a histologically distinctive lesion of uncertain behavior. This article describes an unusual case of IMT mimicking apical periodontitis in the mandible of a 42-year-old man. At first presentation, the patient showed spontaneous pain and percussion pain at teeth #28 to 30, which continued after initial endodontic treatment. Panoramic radiography revealed a radiolucent lesion at the site. Cone-beam computed tomographic imaging showed osteolytic lesions, suggesting an aggressive neoplasm requiring incisional biopsy. Histopathological examination indicated an IMT. The lesion was removed en bloc under general anesthesia, and the patient manifested no clinical evidence of recurrence for 24 months. Lesions of nonendodontic origin should be included in the differential diagnosis of apical periodontitis. Every available diagnostic tool should be used to confirm the diagnosis. Cone-beam computed tomographic imaging is very helpful for differential diagnosis in IMTs mimicking apical periodontitis. PMID:26602450

  19. The Immediate Aesthetic and Functional Restoration of Maxillary Incisors Compromised by Periodontitis Using Short Implants with Single Crown Restorations: A Minimally Invasive Approach and Five-Year Follow-Up

    PubMed Central

    Marincola, Mauro; Lombardo, Giorgio; Pighi, Jacopo; Corrocher, Giovanni; Mascellaro, Anna; Lehrberg, Jeffrey; Nocini, Pier Francesco

    2015-01-01

    The functional and aesthetic restoration of teeth compromised due to aggressive periodontitis presents numerous challenges for the clinician. Horizontal bone loss and soft tissue destruction resulting from periodontitis can impede implant placement and the regeneration of an aesthetically pleasing gingival smile line, often requiring bone augmentation and mucogingival surgery, respectively. Conservative approaches to the treatment of aggressive periodontitis (i.e., treatments that use minimally invasive tools and techniques) have been purported to yield positive outcomes. Here, we report on the treatment and five-year follow-up of patient suffering from aggressive periodontitis using a minimally invasive surgical technique and implant system. By using the methods described herein, we were able to achieve the immediate aesthetic and functional restoration of the maxillary incisors in a case that would otherwise require bone augmentation and extensive mucogingival surgery. This technique represents a conservative and efficacious alternative to the aesthetic and functional replacement of teeth compromised due to aggressive periodontitis. PMID:26649207

  20. Characterization studies on the additives mixed L-arginine phosphate monohydrate (LAP) crystals

    NASA Astrophysics Data System (ADS)

    Haja Hameed, A. S.; Karthikeyan, C.; Ravi, G.; Rohani, S.

    2011-04-01

    L-arginine phosphate monohydrate (LAP), potassium thiocyanate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na 2SO 3) mixed LAP (LAP:Na 2SO 3) single crystals were grown by slow cooling technique. The effect of microbial contamination and coloration on the growth solutions was studied. The crystalline powders of the grown crystals were examined by X-ray diffraction and the lattice parameters of the crystals were estimated. From the FTIR spectroscopic analysis, various functional group frequencies associated with the crystals were assigned. Vickers microhardness studies were done on {1 0 0} faces for pure and additives mixed LAP crystals. From the preliminary surface second harmonic generation (SHG) results, it was found that the SHG intensity at (1 0 0) face of LAP:KSCN crystal was much stronger than that of pure LAP.

  1. RPC-LAP: The Rosetta Langmuir Probe Instrument

    NASA Astrophysics Data System (ADS)

    Eriksson, A. I.; Boström, R.; Gill, R.; Åhlén, L.; Jansson, S.-E.; Wahlund, J.-E.; André, M.; Mälkki, A.; Holtet, J. A.; Lybekk, B.; Pedersen, A.; Blomberg, L. G.

    2007-02-01

    The Rosetta dual Langmuir probe instrument, LAP, utilizes the multiple powers of a pair of spherical Langmuir probes for measurements of basic plasma parameters with the aim of providing detailed knowledge of the outgassing, ionization, and subsequent plasma processes around the Rosetta target comet. The fundamental plasma properties to be studied are the plasma density, the electron temperature, and the plasma flow velocity. However, study of electric fields up to 8 kHz, plasma density fluctuations, spacecraft potential, integrated UV flux, and dust impacts is also possible. LAP is fully integrated in the Rosetta Plasma Consortium (RPC), the instruments of which together provide a comprehensive characterization of the cometary plasma.

  2. Auto Mechanics I. Learning Activity Packets (LAPs). Section C--Engine.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains five learning activity packets (LAPs) that outline the study activities for the "engine" instructional area for an Auto Mechanics I course. The five LAPs cover the following topics: basic engine principles, cooling system, engine lubrication system, exhaust system, and fuel system. Each LAP contains a cover sheet that…

  3. Learning Activity Package, Physical Science 92, LAPs 1-9.

    ERIC Educational Resources Information Center

    Williams, G. J.

    This set of nine teacher-prepared Learning Activity Packages (LAPs) for individualized instruction in physical science covers the topics of scientific equipment and procedures; measure of time, length, area, and volume; water; oxygen and oxidation; atmospheric pressure; motion; machines; carbon; and light and sound. Each unit contains a rationale…

  4. Insights: A LAP on Moles: Teaching an Important Concept.

    ERIC Educational Resources Information Center

    Ihde, John

    1985-01-01

    Describes a learning activity packet (LAP) designed to help students understand the basic concept of the mole as a chemical unit; know relationships between the mole and atomic weights in the periodic table; and solve basic conversion problems involving moles, atoms, and molecules. (JN)

  5. Learning Activity Package, Algebra 124, LAPs 46-55.

    ERIC Educational Resources Information Center

    Holland, Bill

    A series of 10 teacher-prepared Learning Activity Packages (LAPs) in advanced algebra and trigonometry, these units cover absolute value, inequalities, exponents, radicals, and complex numbers; functions; higher degree equations and the derivative; the trigonometric functions; graphs and applications of the trigonometric functions; sequences and…

  6. Diabetes and periodontal disease

    PubMed Central

    Daniel, Rajkumar; Gokulanathan, Subramanium; Shanmugasundaram, Natarajan; Lakshmigandhan, Mahalingam; Kavin, Thangavelu

    2012-01-01

    Diabetes mellitus is a systemic disease characterized by increased blood glucose levels and abnormalities of lipid metabolism due to absence or decreased level of insulin. It affects all the body organs and their functions either directly or indirectly. Every dentist should have a basic understanding of the etiopathogenesis, oral and systemic manifestations of this disease. The periodontal diseases are a consequence of extension of the gingival inflammation into the underlying supporting structures of the periodontium, initiated by the presence of plaque and its products on the surfaces of the teeth and the adjoining structures. The progression of periodontal disease is influenced by variety of factors like microorganisms, host response, systemic background, and genetic makeup of the host. Amongst them, diabetes mellitus tops the list. Diabetes and periodontitis influence the clinical outcome of each other and control of both influences the clinical improvement of each. PMID:23066270

  7. CONCEPT ANALYSIS: AGGRESSION

    PubMed Central

    Liu, Jianghong

    2006-01-01

    The concept of aggression is important to nursing because further knowledge of aggression can help generate a better theoretical model to drive more effective intervention and prevention approaches. This paper outlines a conceptual analysis of aggression. First, the different forms of aggression are reviewed, including the clinical classification and the stimulus-based classification. Then the manifestations and measurement of aggression are described. Finally, the causes and consequences of aggression are outlined. It is argued that a better understanding of aggression and the causal factors underlying it are essential for learning how to prevent negative aggression in the future. PMID:15371137

  8. Lasers in periodontics.

    PubMed

    Elavarasu, Sugumari; Naveen, Devisree; Thangavelu, Arthiie

    2012-08-01

    Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20(th) century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics.

  9. Periodontitis in Chronic Heart Failure.

    PubMed

    Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A; Zugck, Christian; Frankenstein, Lutz

    2016-08-01

    Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases. PMID:27547136

  10. Periodontitis in Chronic Heart Failure.

    PubMed

    Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A; Zugck, Christian; Frankenstein, Lutz

    2016-08-01

    Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases.

  11. Periodontitis in Chronic Heart Failure

    PubMed Central

    Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A.; Zugck, Christian

    2016-01-01

    Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases. PMID:27547136

  12. Periodontal disease and systemic complications.

    PubMed

    Oppermann, Rui Vicente; Weidlich, Patricia; Musskopf, Marta Liliana

    2012-01-01

    Periodontal diseases comprise a number of infectious and inflammatory conditions brought about by the interaction between supragingival and subgingival biofilms and the host inflammatory response. Periodontal diseases should be considered systemic conditions. This means that they are both modulated by the body's systems and play a role as a risk factor for systemic derangements. The current evidence supports some of these interactions, such as smoking as a risk factor for periodontal disease and diabetes mellitus, as both influenced by and influencing inflammatory changes in the periodontal tissue. Other potential associations are still being researched, such as obesity, hormonal changes, cardiovascular disease, and adverse outcomes in pregnancy. These, and others, still require further investigation before the repercussions of periodontal disease can be fully elucidated. Nevertheless, at the present time, the treatment of periodontal diseases-and, most importantly, their prevention-enables adequate intervention as a means of ensuring periodontal health. PMID:23318743

  13. Structural Features of the Pseudomonas fluorescens Biofilm Adhesin LapA Required for LapG-Dependent Cleavage, Biofilm Formation, and Cell Surface Localization

    PubMed Central

    Boyd, Chelsea D.; Smith, T. Jarrod; El-Kirat-Chatel, Sofiane; Newell, Peter D.; Dufrêne, Yves F.

    2014-01-01

    The localization of the LapA protein to the cell surface is a key step required by Pseudomonas fluorescens Pf0-1 to irreversibly attach to a surface and form a biofilm. LapA is a member of a diverse family of predicted bacterial adhesins, and although lacking a high degree of sequence similarity, family members do share common predicted domains. Here, using mutational analysis, we determine the significance of each domain feature of LapA in relation to its export and localization to the cell surface and function in biofilm formation. Our previous work showed that the N terminus of LapA is required for cleavage by the periplasmic cysteine protease LapG and release of the adhesin from the cell surface under conditions unfavorable for biofilm formation. We define an additional critical region of the N terminus of LapA required for LapG proteolysis. Furthermore, our results suggest that the domains within the C terminus of LapA are not absolutely required for biofilm formation, export, or localization to the cell surface, with the exception of the type I secretion signal, which is required for LapA export and cell surface localization. In contrast, deletion of the central repetitive region of LapA, consisting of 37 repeats of 100 amino acids, results in an inability to form a biofilm. We also used single-molecule atomic force microscopy to further characterize the role of these domains in biofilm formation on hydrophobic and hydrophilic surfaces. These studies represent the first detailed analysis of the domains of the LapA family of biofilm adhesin proteins. PMID:24837291

  14. Prescribing for periodontal disease.

    PubMed

    Blair, Fiona M; Chapple, Iain L C

    2014-11-01

    With concerns about the ever-increasing development of antimicrobial resistance, it is imperative that antimicrobials are prescribed responsibly and used appropriately. This article provides an overview and simple guidelines for antimicrobial prescribing in the management of periodontal diseases. PMID:25668374

  15. Periodontics II: Course Proposal.

    ERIC Educational Resources Information Center

    Dordick, Bruce

    A proposal is presented for Periodontics II, a course offered at the Community College of Philadelphia to give the dental hygiene/assisting student an understanding of the disease states of the periodontium and their treatment. A standardized course proposal cover form is given, followed by a statement of purpose for the course, a list of major…

  16. Serotypes of Aggregatibacter actinomycetemcomitans in relation to periodontal status and geographic origin of individuals-a review of the literature

    PubMed Central

    da Silveira, Virginia R S.; Rego, Rodrigo O.; Nogueira, Nádia A P.

    2014-01-01

    Objectives: Several studies have focused on the relationship among serotype distribution, ethnical status and geographic populations, and periodontal conditions. Studies that have investigated the prevalence and the distribution of A. actinomycetemcomitans serotypes and the relation between the different serotypes of the bacterium and periodontal status were reviewed. Material and Methods: A systematic literature search for publications regarding the distribution of A. actinomycetemcomitans serotypes in subgingival samples of periodontitis patients and periodontally healthy subjects by employing polymerase chain reaction (PCR) was conducted. Results: From the 85 studies identified in the first analysis, only 12 met all inclusion and exclusion criteria. Clinical isolates from diverse geographic populations with different periodontal conditions were evaluated. Serotypes a, b and c were largely found, and serotype c was the most prevalent. They were isolated from various periodontal conditions, including aggressive periodontitis. Conclusions: The available literature suggests that serotypes a, b, and c are globally dominant, serotypes d and e are rare, and the prevalence of the most recently identified serotype fis still unknown. It is widely accepted that distribution patterns of A. actinomycetemcomitans vary among subjects of different ethnicity and geographic regions. The correlation of different serotypes with various periodontal conditions remains unclear. Key words:Aggregatibacter actinomycetemcomitans, serotypes, periodontal disease, prevalence. PMID:24316700

  17. Material characterization of structural adhesives in the lap shear mode

    NASA Technical Reports Server (NTRS)

    Sancaktar, E.; Schenck, S. C.

    1983-01-01

    A general method for characterizing structual adhesives in the bonded lap shear mode is proposed. Two approaches in the form of semiempirical and theoretical approaches are used. The semiempirical approach includes Ludwik's and Zhurkov's equations to describe respectively, the failure stresses in the constant strain rate and constant stress loading modes with the inclusion of the temperature effects. The theoretical approach is used to describe adhesive shear stress-strain behavior with the use of viscoelastic or nonlinear elastic constitutive equations. Two different model adhesives are used in the single lap shear mode with titanium adherends. These adhesives (one of which was developed at NASA Langley Research Center) are currently considered by NASA for possible aerospace applications. Use of different model adhesives helps in assessment of the generality of the method.

  18. FRICTION-STIR-LAP-WELDS OF AA6111 ALUMINUM ALLOY

    SciTech Connect

    Yadava, Manasij; Mishra, Rajiv S.; Chen, Y. L.; Gayden, X.; Grant, Glenn J.

    2007-01-09

    Lap joints of 1 mm thick AA6111 aluminum sheets were made by friction stir welding, using robotic and conventional machines. Welds were made for advancing as well as retreating side loading. Thinning in welds was quantified. Lap shear test of welds was conducted in as-welded and paint-baked conditions. Conventional machine welds showed less thinning and better strength than robotic machine welds. Process forces in conventional machine welding were higher. Paint bake treatment improved the weld strength; but the improvement varied with process parameters. Advancing side loaded welds achieved higher strength than the retreating side loaded welds. Fracture location was found to occur on the loaded side of the weld and along the thinning defect.

  19. The impact of lubricants on the precision lapping process.

    PubMed

    Jiang, Xionghua; Chen, Zhenxing; Wolfram, Joy; Wei, Zhongxian; Shen, Yuqiu; Yang, Zhizhou

    2014-12-01

    The impact of lubricants on pole-tip recession and surface morphology of hard disk drive heads in the precision lapping process was investigated with atomic force microscopy, scanning electron microscopy, and auger electron spectroscopy. In particular, the effects of deionized water, hydrocarbon oil, ethanediol, isopropanol, and ethanol lubricants were evaluated. The results reveal that proper selection of lubricant is critical for achieving optimal performance in the lapping process. A mixture of 68% hydrocarbon oil, 30% isopropanol, and 2% octadecenoic acid was found to yield the most favorable results, displaying a writer shield recession, first shield of reader recession, and surface roughness of 0.423, 0.581, and 0.242 nm, respectively. PMID:25387606

  20. Using Big Data to Evaluate the Association between Periodontal Disease and Rheumatoid Arthritis.

    PubMed

    Grasso, Michael A; Comer, Angela C; DiRenzo, Dana D; Yesha, Yelena; Rishe, Naphtali D

    2015-01-01

    An association between periodontal disease and rheumatoid arthritis is believed to exist. Most investigations into a possible relationship have been case-control studies with relatively low sample sizes. The advent of very large clinical repositories has created new opportunities for data-driven research. We conducted a retrospective cohort study to measure the association between periodontal disease and rheumatoid arthritis in a population of 25 million patients. We demonstrated that subjects with periodontal disease were roughly 1.4 times more likely to have rheumatoid arthritis. These results compare favorably with those of previous studies on smaller cohorts. Additional work is needed to identify the mechanisms behind this association and to determine if aggressive treatment of periodontal disease can alter the course of rheumatoid arthritis. PMID:26958193

  1. Using Big Data to Evaluate the Association between Periodontal Disease and Rheumatoid Arthritis

    PubMed Central

    Grasso, Michael A.; Comer, Angela C.; DiRenzo, Dana D.; Yesha, Yelena; Rishe, Naphtali D.

    2015-01-01

    An association between periodontal disease and rheumatoid arthritis is believed to exist. Most investigations into a possible relationship have been case-control studies with relatively low sample sizes. The advent of very large clinical repositories has created new opportunities for data-driven research. We conducted a retrospective cohort study to measure the association between periodontal disease and rheumatoid arthritis in a population of 25 million patients. We demonstrated that subjects with periodontal disease were roughly 1.4 times more likely to have rheumatoid arthritis. These results compare favorably with those of previous studies on smaller cohorts. Additional work is needed to identify the mechanisms behind this association and to determine if aggressive treatment of periodontal disease can alter the course of rheumatoid arthritis. PMID:26958193

  2. Aggressive behavior problems.

    PubMed

    Beaver, B V

    1986-12-01

    Accurate diagnosis of the cause of aggression in horses is essential to determining the appropriate course of action. The affective forms of aggression include fear-induced, pain-induced, intermale, dominance, protective, maternal, learned, and redirected aggressions. Non-affective aggression includes play and sex-related forms. Irritable aggression and hypertestosteronism in mares are medical problems, whereas genetic factors, brain dysfunction, and self-mutilation are also concerns. PMID:3492250

  3. Periodontal regeneration using periodontal ligament stem cell-transferred amnion.

    PubMed

    Iwasaki, Kengo; Komaki, Motohiro; Yokoyama, Naoki; Tanaka, Yuichi; Taki, Atsuko; Honda, Izumi; Kimura, Yasuyuki; Takeda, Masaki; Akazawa, Keiko; Oda, Shigeru; Izumi, Yuichi; Morita, Ikuo

    2014-02-01

    Periodontal disease is characterized by the destruction of tooth supporting tissues. Regeneration of periodontal tissues using ex vivo expanded cells has been introduced and studied, although appropriate methodology has not yet been established. We developed a novel cell transplant method for periodontal regeneration using periodontal ligament stem cell (PDLSC)-transferred amniotic membrane (PDLSC-amnion). The aim of this study was to investigate the regenerative potential of PDLSC-amnion in a rat periodontal defect model. Cultured PDLSCs were transferred onto amniotic membranes using a glass substrate treated with polyethylene glycol and photolithography. The properties of PDLSCs were investigated by flow cytometry and in vitro differentiation. PDLSC-amnion was transplanted into surgically created periodontal defects in rat maxillary molars. Periodontal regeneration was evaluated by microcomputed tomography (micro-CT) and histological analysis. PDLSCs showed mesenchymal stem cell-like characteristics such as cell surface marker expression (CD90, CD44, CD73, CD105, CD146, and STRO-1) and trilineage differentiation ability (i.e., into osteoblasts, adipocytes, and chondrocytes). PDLSC-amnion exhibited a single layer of PDLSCs on the amniotic membrane and stability of the sheet even with movement and deformation caused by surgical instruments. We observed that the PDLSC-amnion enhanced periodontal tissue regeneration as determined by micro-CT and histology by 4 weeks after transplantation. These data suggest that PDLSC-amnion has therapeutic potential as a novel cell-based regenerative periodontal therapy. PMID:24032400

  4. Periodontal regeneration using periodontal ligament stem cell-transferred amnion.

    PubMed

    Iwasaki, Kengo; Komaki, Motohiro; Yokoyama, Naoki; Tanaka, Yuichi; Taki, Atsuko; Honda, Izumi; Kimura, Yasuyuki; Takeda, Masaki; Akazawa, Keiko; Oda, Shigeru; Izumi, Yuichi; Morita, Ikuo

    2014-02-01

    Periodontal disease is characterized by the destruction of tooth supporting tissues. Regeneration of periodontal tissues using ex vivo expanded cells has been introduced and studied, although appropriate methodology has not yet been established. We developed a novel cell transplant method for periodontal regeneration using periodontal ligament stem cell (PDLSC)-transferred amniotic membrane (PDLSC-amnion). The aim of this study was to investigate the regenerative potential of PDLSC-amnion in a rat periodontal defect model. Cultured PDLSCs were transferred onto amniotic membranes using a glass substrate treated with polyethylene glycol and photolithography. The properties of PDLSCs were investigated by flow cytometry and in vitro differentiation. PDLSC-amnion was transplanted into surgically created periodontal defects in rat maxillary molars. Periodontal regeneration was evaluated by microcomputed tomography (micro-CT) and histological analysis. PDLSCs showed mesenchymal stem cell-like characteristics such as cell surface marker expression (CD90, CD44, CD73, CD105, CD146, and STRO-1) and trilineage differentiation ability (i.e., into osteoblasts, adipocytes, and chondrocytes). PDLSC-amnion exhibited a single layer of PDLSCs on the amniotic membrane and stability of the sheet even with movement and deformation caused by surgical instruments. We observed that the PDLSC-amnion enhanced periodontal tissue regeneration as determined by micro-CT and histology by 4 weeks after transplantation. These data suggest that PDLSC-amnion has therapeutic potential as a novel cell-based regenerative periodontal therapy.

  5. Investigation into Interface Lifting Within FSW Lap Welds

    SciTech Connect

    K. S. Miller; C. R. Tolle; D. E. Clark; C. I. Nichol; T. R. McJunkin; H. B. Smartt

    2008-06-01

    Friction stir welding (FSW) is rapidly penetrating the welding market in many materials and applications, particularly in aluminum alloys for transportation applications. As this expansion outside the research laboratory continues, fitness for service issues will arise, and process control and NDE methods will become important determinants of continued growth. The present paper describes research into FSW weld nugget flaw detection within aluminum alloy lap welds. We present results for two types of FSW tool designs: a smooth pin tool and a threaded pin tool. We show that under certain process parameters (as monitored during welding with a rotating dynamometer that measures x, y, z, and torque forces) and tooling designs, FSW lap welds allow significant nonbonded interface lifting of the lap joint, while forming a metallurgical bond only within the pin region of the weld nugget. These lifted joints are often held very tightly together even though unbonded, and might be expected to pass cursory NDE while representing a substantial compromise in joint mechanical properties. The phenomenon is investigated here via radiographic and ultrasonic NDE techniques, with a copper foil marking insert (as described elsewhere) and by the tensile testing of joints. As one would expect, these results show that tool design and process parameters significantly affect plactic flow and this lifted interface. NDE and mechanical strength ramifications of this defect are discussed.

  6. Residual Strength Analyses of Riveted Lap-Splice Joints

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.

    2000-01-01

    The objective of this paper was to analyze the crack-linkup behavior in riveted-stiffened lap-splice joint panels with small multiple-site damage (MSD) cracks at several adjacent rivet holes. Analyses are based on the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. To account for high constraint around a crack front, the "plane strain core" option in STAGS was used. The importance of modeling rivet flexibility with fastener elements that accurately model load transfer across the joint is discussed. Fastener holes are not modeled but rivet connectivity is accounted for by attaching rivets to the sheet on one side of the cracks that simulated both the rivet diameter and MSD cracks. Residual strength analyses made on 2024-T3 alloy (1.6-mm thick) riveted-lap-splice joints with a lead crack and various size MSD cracks were compared with test data from Boeing Airplane Company. Analyses were conducted for both restrained and unrestrained buckling conditions. Comparison of results from these analyses and results from lap-splice-joint test panels, which were partially restrained against buckling indicate that the test results were bounded by the failure loads predicted by the analyses with restrained and unrestrained conditions.

  7. TNFA and IL10 Gene Polymorphisms are not Associated with Periodontitis in Brazilians

    PubMed Central

    Moreira, P. R; Costa, J. E; Gomez, R. S; Gollob, K. J; Dutra, W. O

    2009-01-01

    IL-10 and TNF-α are cytokines that have complex and opposing roles in the inflammatory responses. G/A polymorphisms at position –1082 of IL10 and –308 of TNFA genes have been reported to influence the expression of IL-10 and TNF-α, respectively. The aim of this study was to investigate the association between the IL10 (-1082) and TNFA (- 308) gene polymorphisms with different clinical forms or severity of periodontitis in a sample of Brazilian individuals. DNA was obtained from oral swabs of 165 Brazilian individuals, which were divided into three groups: individuals with chronic periodontitis, aggressive periodontitis and individuals without clinical evidence of periodontitis. Evaluation of IL10 and TNFA polymorphisms was performed by RFLP analysis. Statistical analysis of data was performed using the χ2 likelihood ratio and Fisher`s exact test. No significant differences in the genotype and allele distribution of either IL10 or TNFA were observed among individuals with different clinical forms or with different degrees of severity of periodontitis. Moreover, combined analysis of IL10 and TNFA polymorphisms did not show any association with periodontal status. As conclusion, the IL10 and TNFA gene promoter polymorphisms investigated are not associated with different clinical forms of periodontitis or with severity of the disease in the Brazilian population polymorphisms. PMID:19771178

  8. Assembly of Lipopolysaccharide in Escherichia coli Requires the Essential LapB Heat Shock Protein*

    PubMed Central

    Klein, Gracjana; Kobylak, Natalia; Lindner, Buko; Stupak, Anna; Raina, Satish

    2014-01-01

    Here, we describe two new heat shock proteins involved in the assembly of LPS in Escherichia coli, LapA and LapB (lipopolysaccharide assembly protein A and B). lapB mutants were identified based on an increased envelope stress response. Envelope stress-responsive pathways control key steps in LPS biogenesis and respond to defects in the LPS assembly. Accordingly, the LPS content in ΔlapB or Δ(lapA lapB) mutants was elevated, with an enrichment of LPS derivatives with truncations in the core region, some of which were pentaacylated and exhibited carbon chain polymorphism. Further, the levels of LpxC, the enzyme that catalyzes the first committed step of lipid A synthesis, were highly elevated in the Δ(lapA lapB) mutant. Δ(lapA lapB) mutant accumulated extragenic suppressors that mapped either to lpxC, waaC, and gmhA, or to the waaQ operon (LPS biosynthesis) and lpp (Braun's lipoprotein). Increased synthesis of either FabZ (3-R-hydroxymyristoyl acyl carrier protein dehydratase), slrA (novel RpoE-regulated non-coding sRNA), lipoprotein YceK, toxin HicA, or MurA (UDP-N-acetylglucosamine 1-carboxyvinyltransferase) suppressed some of the Δ(lapA lapB) defects. LapB contains six tetratricopeptide repeats and, at the C-terminal end, a rubredoxin-like domain that was found to be essential for its activity. In pull-down experiments, LapA and LapB co-purified with LPS, Lpt proteins, FtsH (protease), DnaK, and DnaJ (chaperones). A specific interaction was also observed between WaaC and LapB. Our data suggest that LapB coordinates assembly of proteins involved in LPS synthesis at the plasma membrane and regulates turnover of LpxC, thereby ensuring balanced biosynthesis of LPS and phospholipids consistent with its essentiality. PMID:24722986

  9. Assembly of lipopolysaccharide in Escherichia coli requires the essential LapB heat shock protein.

    PubMed

    Klein, Gracjana; Kobylak, Natalia; Lindner, Buko; Stupak, Anna; Raina, Satish

    2014-05-23

    Here, we describe two new heat shock proteins involved in the assembly of LPS in Escherichia coli, LapA and LapB (lipopolysaccharide assembly protein A and B). lapB mutants were identified based on an increased envelope stress response. Envelope stress-responsive pathways control key steps in LPS biogenesis and respond to defects in the LPS assembly. Accordingly, the LPS content in ΔlapB or Δ(lapA lapB) mutants was elevated, with an enrichment of LPS derivatives with truncations in the core region, some of which were pentaacylated and exhibited carbon chain polymorphism. Further, the levels of LpxC, the enzyme that catalyzes the first committed step of lipid A synthesis, were highly elevated in the Δ(lapA lapB) mutant. Δ(lapA lapB) mutant accumulated extragenic suppressors that mapped either to lpxC, waaC, and gmhA, or to the waaQ operon (LPS biosynthesis) and lpp (Braun's lipoprotein). Increased synthesis of either FabZ (3-R-hydroxymyristoyl acyl carrier protein dehydratase), slrA (novel RpoE-regulated non-coding sRNA), lipoprotein YceK, toxin HicA, or MurA (UDP-N-acetylglucosamine 1-carboxyvinyltransferase) suppressed some of the Δ(lapA lapB) defects. LapB contains six tetratricopeptide repeats and, at the C-terminal end, a rubredoxin-like domain that was found to be essential for its activity. In pull-down experiments, LapA and LapB co-purified with LPS, Lpt proteins, FtsH (protease), DnaK, and DnaJ (chaperones). A specific interaction was also observed between WaaC and LapB. Our data suggest that LapB coordinates assembly of proteins involved in LPS synthesis at the plasma membrane and regulates turnover of LpxC, thereby ensuring balanced biosynthesis of LPS and phospholipids consistent with its essentiality.

  10. Bacteraemia caused by periodontal probing.

    PubMed

    Daly, C; Mitchell, D; Grossberg, D; Highfield, J; Stewart, D

    1997-04-01

    Bacteraemia of oral origin may result in infective endocarditis in susceptible individuals. The aim of this pilot study was to investigate the occurrence of bacteraemia due to periodontal probing. Thirty patients (15 male, 15 female; mean age 42.7 years) with untreated periodontitis were investigated. All were free of significant medical disorders and none had taken antibiotics in the previous month. Prior to and immediately following periodontal probing, 20 mL of venous blood were obtained from each patient and inoculated into aerobic and anaerobic blood culture bottles and incubated. Negative bottles were monitored continuously for three weeks before being discarded. Periodontal probing consisted of measuring pockets at six points around each tooth and recording the presence or absence of bleeding. A positive bacteraemia was recorded for three of the patients prior to probing. One patient exhibited Prevotella species whilst two exhibited skin commensals. Following probing, 13 patients (43 per cent) exhibited bacteraemia of oral origin. Viridans streptococci were the most common isolates (45 per cent). No significant correlations were found between bacteraemia and the severity of periodontitis or extent of bleeding on probing. The results indicate that periodontal probing can cause bacteraemia in patients with periodontitis. It would be advisable for patients considered at risk of developing infective endocarditis to receive antibiotic prophylaxis for periodontal probing if they have radiographic evidence of periodontitis.

  11. Lasers in periodontics

    PubMed Central

    Elavarasu, Sugumari; Naveen, Devisree; Thangavelu, Arthiie

    2012-01-01

    Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20th century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics. PMID:23066266

  12. Laser therapy for periodontitis

    NASA Astrophysics Data System (ADS)

    Efanov, O. I.

    2001-04-01

    An investigation was made of applying pulsed (lambda) equals 0.89 micrometers laser radiation in the treatment for early diagnosed periodontitis. The investigation was made on 65 patients (47 patients constituted the experimental group and 18 patients constituted a control group) affected by periodontitis. Clinical and functional tests revealed that laser therapy produced a string effect on the course of the illness. It reduced bleeding, inflammation, and pruritus. However, it did not produce an affect on electroexcitation. Biomicroscopic examinations and periodontium rheography revealed that the gingival blood flow became normal after the course of laser therapy. The capillary permeability and venous congestion decreased, which was confirmed by the increased time of vacuum tests, raised gingival temperature, reduced tissue clearance, and increased oxygen tension. Apart from that, laser therapy subsided fibrinolysis, proteolytic tissue activity, and decreased the exudative inflammation of periodontium.

  13. Apparatus and method for lapping an edge surface of an object

    NASA Technical Reports Server (NTRS)

    Rossi, Vito N. (Inventor)

    1989-01-01

    An apparatus for lapping an edge surface of an object comprises a block having a side adapted to engage a wide surface of an object, adjustable spacers disposed on the block and adapted to engage a lap plate, and a weighted spring disposed on the block for urging the spacers and the object edge surface towards the lap plate. A method for lapping comprises setting surfaces of adjustable spacers disposed on a block to be substantially the same distance from the block, affixing a wide surface of an object to the block, urging an edge surface of the object and the spacers towards a lap plate, lapping the edge of the object, inspecting the edge for parallelism to a reference line, resetting the spacers and relapping the edge surface.

  14. Optimal tubular adhesive-bonded lap joint of the carbon fiber epoxy composite shaft

    NASA Astrophysics Data System (ADS)

    Kim, Ki S.; Kim, Won T.; Lee, Dai G.; Jun, Eui J.

    The effects of the adhesive thickness and the adherend surface roughness on the fatigue strength of a tubular adhesive-bonded single lap joint were investigated using fatigue test specimens whose adherends were made of S45C carbon steel. Results of fatigue tests showed that the optimal arithmetic surface roughness of the adherends is about 2 microns and the optimal adhesive thickness is about 0.15 mm. Using these values, the prototype torsional adhesive joints were manufactured for power transmission shafts of an automotive vehicle or a small helicopter, and static tests under torque were performed on a single-lap joint, a single-lap joint with scarf, a double-lap joint, and a double-lap joint with scarf. It was found that the double-lap joint was superior among the joints, in terms of torque capacity and manufacturing cost.

  15. Minimally invasive periodontal therapy.

    PubMed

    Dannan, Aous

    2011-10-01

    Minimally invasive dentistry is a concept that preserves dentition and supporting structures. However, minimally invasive procedures in periodontal treatment are supposed to be limited within periodontal surgery, the aim of which is to represent alternative approaches developed to allow less extensive manipulation of surrounding tissues than conventional procedures, while accomplishing the same objectives. In this review, the concept of minimally invasive periodontal surgery (MIPS) is firstly explained. An electronic search for all studies regarding efficacy and effectiveness of MIPS between 2001 and 2009 was conducted. For this purpose, suitable key words from Medical Subject Headings on PubMed were used to extract the required studies. All studies are demonstrated and important results are concluded. Preliminary data from case cohorts and from many studies reveal that the microsurgical access flap, in terms of MIPS, has a high potential to seal the healing wound from the contaminated oral environment by achieving and maintaining primary closure. Soft tissues are mostly preserved and minimal gingival recession is observed, an important feature to meet the demands of the patient and the clinician in the esthetic zone. However, although the potential efficacy of MIPS in the treatment of deep intrabony defects has been proved, larger studies are required to confirm and extend the reported positive preliminary outcomes.

  16. Indirect porcelain veneers in periodontally compromised teeth. The hybrid technique: a case report.

    PubMed

    Garcia-Baeza, David; Saavedra, Carlos; Garcia-Adámez, Ramón

    2015-01-01

    The loss of periodontal structure causes an esthetic problem for many patients, especially when the esthetic zone is compromised. Among the various types of solutions is the use of composite resins. While this procedure is not aggressive towards tooth structure, it does require the clinician to have a precise technique, and demands strict longterm maintenance. 1 Another way of treating the compromised teeth is with porcelain veneers. This procedure is especially difficult, however, if carried out on periodontal teeth, as it requires preparation along the roots. 2 The intention of the hybrid technique described in this article is to combine both of these procedures in order to obtain a less aggressive treatment with precise management of the soft tissue and an adequate esthetic outcome. The hybrid technique consists of enlarging the root portion of the teeth with composite resin to obtain a less aggressive tooth preparation, and thereafter placing porcelain veneers.

  17. Indirect porcelain veneers in periodontally compromised teeth. The hybrid technique: a case report.

    PubMed

    Garcia-Baeza, David; Saavedra, Carlos; Garcia-Adámez, Ramón

    2015-01-01

    The loss of periodontal structure causes an esthetic problem for many patients, especially when the esthetic zone is compromised. Among the various types of solutions is the use of composite resins. While this procedure is not aggressive towards tooth structure, it does require the clinician to have a precise technique, and demands strict longterm maintenance. 1 Another way of treating the compromised teeth is with porcelain veneers. This procedure is especially difficult, however, if carried out on periodontal teeth, as it requires preparation along the roots. 2 The intention of the hybrid technique described in this article is to combine both of these procedures in order to obtain a less aggressive treatment with precise management of the soft tissue and an adequate esthetic outcome. The hybrid technique consists of enlarging the root portion of the teeth with composite resin to obtain a less aggressive tooth preparation, and thereafter placing porcelain veneers. PMID:26171444

  18. Mechanisms Involved in the Association between Periodontitis and Complications in Pregnancy

    PubMed Central

    Zi, Marcela Yang Hui; Longo, Priscila Larcher; Bueno-Silva, Bruno; Mayer, Marcia Pinto Alves

    2015-01-01

    The association between periodontitis and some of the problems with pregnancy such as premature delivery, low weight at birth, and preeclampsia (PE) has been suggested. Nevertheless, epidemiological data have shown contradictory data, mainly due to differences in clinical parameters of periodontitis assessment. Furthermore, differences in microbial composition and immune response between aggressive and chronic periodontitis are not addressed by these epidemiological studies. We aimed to review the current data on the association between some of these problems with pregnancy and periodontitis, and the mechanisms underlying this association. Shifts in the microbial composition of the subgingival biofilm may occur during pregnancy, leading to a potentially more hazardous microbial community. Pregnancy is characterized by physiological immune tolerance. However, the infection leads to a shift in maternal immune response to a pathogenic pro-inflammatory response, with production of inflammatory cytokines and toxic products. In women with periodontitis, the infected periodontal tissues may act as reservoirs of bacteria and their products that can disseminate to the fetus-placenta unit. In severe periodontitis patients, the infection agents and their products are able to activate inflammatory signaling pathways locally and in extra-oral sites, including the placenta-fetal unit, which may not only induce preterm labor but also lead to PE and restrict intrauterine growth. Despite these evidences, the effectiveness of periodontal treatment in preventing gestational complications was still not established since it may be influenced by several factors such as severity of disease, composition of microbial community, treatment strategy, and period of treatment throughout pregnancy. This lack of scientific evidence does not exclude the need to control infection and inflammation in periodontitis patients during pregnancy, and treatment protocols should be validated. PMID:25688342

  19. Periodontal-disease-associated biofilm: A reservoir for pathogens of medical importance.

    PubMed

    Vieira Colombo, Ana Paula; Magalhães, Clarissa Bichara; Hartenbach, Fátima Aparecida Rocha Resende; Martins do Souto, Renata; Maciel da Silva-Boghossian, Carina

    2016-05-01

    The ecological diversity of the periodontal microenvironment may provide suitable conditions for the colonization of species not usually considered members of the oral microbiota. In this investigation, we aimed to determine the prevalence and levels of pathogenic species of medical relevance in the microbiota of individuals with distinct periodontal clinical status. Subgingival biofilm was obtained from patients with periodontal health (H, n = 81), gingivitis (G, n = 55), generalized aggressive (AgP, n = 36) or chronic periodontitis (CP, n = 98), and analyzed for 39 microbial taxa using a checkerboard DNA-DNA hybridization technique. Microbial differences among groups, as well as associations between clinical and microbiological parameters were sought by non-parametric and univariate correlation tests. Neisseria spp., Peptostreptococus anaerobius, Candida albicans, enterobacteria, Pseudomonas aeruginosa, Eubacterium saphenum, Clostridium difficile and Olsenella uli were detected in high mean prevalence and counts in the subgingival microbiota of the study population. Species that were more related to periodontal inflammation and tissue destruction at the patient and site levels included enterobacteria, C. albicans, Neisseria spp., P. aeruginosa, O. uli, Hafnia alvei, Serratia marcescens and Filifactor alocis (p < 0.05). In contrast, Fusobacterium necrophorum, Lactobacillus acidophilus, Staphylococcus aureus and Streptococcus pneumoniae were associated with periodontal health (p < 0.05). Pathogenic species of medical importance may be detected in high prevalence and levels in the periodontal microbiota. Regardless of their role in periodontal health or disease, the periodontal biofilm may be a source for dissemination and development of systemic infections by these pathogenic microorganisms. PMID:26416306

  20. Periodontal Dressing: A Review Article

    PubMed Central

    Baghani, Zahra; Kadkhodazadeh, Mahdi

    2013-01-01

    The purpose of this paper was to review the commercially available periodontal dressings, their physical and chemical properties, biocompatibility and therapeutic effects. Electronic search of scientific papers from 1956 to 2012 was carried out using PubMed, Scopus and Wiley InterScience search engines using the searched terms periodontal dressing, periodontal pack. Numerous in vitro and in vivo studies have evaluated various properties of periodontal dressings. Physical and chemical properties of dressings are directly related to their dimensional changes and adhesion properties. Their biocompatibility and therapeutic effect are among the other factors evaluated in the literature. Chlorhexidine is the most commonly used antibacterial agent in studies. In general, when comparing the advantages with the disadvantages, application of periodontal dressing seems to be beneficial. Numerous factors are involved in selection of an optimal dressing such as surgeon’s intention, required time for the dressing to remain on the surgery site and its dimensional changes. PMID:24578815

  1. Numerical solutions for heat flow in adhesive lap joints

    NASA Technical Reports Server (NTRS)

    Howell, P. A.; Winfree, William P.

    1992-01-01

    The present formulation for the modeling of heat transfer in thin, adhesively bonded lap joints precludes difficulties associated with large aspect ratio grids required by standard FEM formulations. This quasi-static formulation also reduces the problem dimensionality (by one), thereby minimizing computational requirements. The solutions obtained are found to be in good agreement with both analytical solutions and solutions from standard FEM programs. The approach is noted to yield a more accurate representation of heat-flux changes between layers due to a disbond.

  2. [The importance of periodontal evaluation in orthodontics].

    PubMed

    Pré, P

    1998-01-01

    The orthodontist is in fact a periodontal-therapist since his aim is to move the teeth with and through the periodontal tissues. It is most important for the orthodontist to be able to determine at the initial clinical examination what are the various periodontal risk factors. When the pathology is obvious with inflammation, periodontal pockets, gingival hyperplasia, edema of the papillae, gingival recessions, the need for periodontal treatment is manifest. But many times, the periodontal evaluation is complicated by the presence of slight variations of the quality of the marginal tissue that represent a risk of developing periodontal defects during the orthodontic treatment. The aim of this presentation is to put forward the importance of the periodontal evaluation during the initial examination of the patient so that, if necessary, an adequate periodontal therapy can be initiated to stabilize the periodontal tissues and thus improves the esthetical outcome.

  3. Occurrence of periodontal pathogens among patients with chronic periodontitis

    PubMed Central

    Farias, B.C.; Souza, P.R.E.; Ferreira, B.; Melo, R.S.A.; Machado, F.B.; Gusmão, E.S.; Cimões, R.

    2012-01-01

    The aim of the present study was to evaluate the presence of the periodontal pathogens that form the red complex (Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola) and Aggregatibacter actinomycetemcomitans in patients with chronic periodontitis. The sample consisted of 29 patients with a clinical and radiographic diagnosis of chronic periodontitis based on the criteria of the American Academy of Periodontology (3). Samples for microbiological analysis were collected from the four sites of greatest probing depth in each patient, totaling 116 samples. These samples were processed using conventional polymerase chain reaction, which achieved the following positive results: 46.6% for P. gingivalis, 41.4% for T. forsythia, 33.6% for T. denticola and 27.6% for A. actinomycetemcomitans. P. gingivalis and T. forsythia were more prevalent (p < 0.05) in periodontal pockets ≥ 8 mm. The combinations T. forsythia + P. gingivalis (23.2%) and T. forsythia + P. gingivalis + T. denticola (20.0%) were more frequent in sites with a probing depth ≥ 8 mm. Associations with the simultaneous presence of A. actinomycetemcomitans + P. gingivalis, A. actinomycetemcomitans + T. forsythia, P. gingivalis + T. forsythia and T. forsythia + T. denticola were statistically significant (p < 0.05). It was concluded that the red complex pathogens are related to chronic periodontitis, presenting a higher occurrence in deep periodontal pockets. Moreover, the simultaneous presence of these bacteria in deep sites suggests a symbiotic relationship between these virulent species, favoring, in this way, a further progression of periodontal disease. PMID:24031906

  4. Coordinated Pediatric and Periodontal Dental Care of a Child with Down syndrome.

    PubMed

    Byrd, Gentry; Quinonez, Rocio B; Offenbacher, Steven; Keels, Martha Ann; Guthmiller, Janet M

    2015-01-01

    The purpose of this report was to describe the management of an eight-year-old Bulgarian male with Down syndrome presenting with periodontitis as a manifestation of systemic disease in the early mixed dentition. Treatment involved full-mouth mechanical debridement and extraction of hopeless teeth under general anesthesia followed by systemic antibiotics and chemical adjunctive therapy. Microbial culture and sensitivity testing aided in diagnosis and guided treatment decisions. This case report demonstrates a multidisciplinary approach in the management of aggressive periodontal disease in an internationally adopted pediatric patient with special health care needs. PMID:26314608

  5. Relational aggression in marriage.

    PubMed

    Carroll, Jason S; Nelson, David A; Yorgason, Jeremy B; Harper, James M; Ashton, Ruth Hagmann; Jensen, Alexander C

    2010-01-01

    Drawing from developmental theories of relational aggression, this article reports on a study designed to identify if spouses use relationally aggressive tactics when dealing with conflict in their marriage and the association of these behaviors with marital outcomes. Using a sample of 336 married couples (672 spouses), results revealed that the majority of couples reported that relationally aggressive behaviors, such as social sabotage and love withdrawal, were a part of their marital dynamics, at least to some degree. Gender comparisons of partner reports of their spouse's behavior revealed that wives were significantly more likely to be relationally aggressive than husbands. Structural equation modeling demonstrated that relational aggression is associated with lower levels of marital quality and greater marital instability for both husbands and wives. Implications are drawn for the use of relational aggression theory in the future study of couple conflict and marital aggression.

  6. Genome-wide association study of biologically informed periodontal complex traits offers novel insights into the genetic basis of periodontal disease

    PubMed Central

    Offenbacher, Steven; Divaris, Kimon; Barros, Silvana P.; Moss, Kevin L.; Marchesan, Julie T.; Morelli, Thiago; Zhang, Shaoping; Kim, Steven; Sun, Lu; Beck, James D.; Laudes, Matthias; Munz, Matthias; Schaefer, Arne S.; North, Kari E.

    2016-01-01

    Genome-wide association studies (GWAS) of chronic periodontitis (CP) defined by clinical criteria alone have had modest success to-date. Here, we refine the CP phenotype by supplementing clinical data with biological intermediates of microbial burden (levels of eight periodontal pathogens) and local inflammatory response (gingival crevicular fluid IL-1β) and derive periodontal complex traits (PCTs) via principal component analysis. PCTs were carried forward to GWAS (∼2.5 million markers) to identify PCT-associated loci among 975 European American adult participants of the Dental ARIC study. We sought to validate these findings for CP in the larger ARIC cohort (n = 821 participants with severe CP, 2031—moderate CP, 1914—healthy/mild disease) and an independent German sample including 717 aggressive periodontitis cases and 4210 controls. We identified six PCTs with distinct microbial community/IL-1β structures, although with overlapping clinical presentations. PCT1 was characterized by a uniformly high pathogen load, whereas PCT3 and PCT5 were dominated by Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, respectively. We detected genome-wide significant signals for PCT1 (CLEC19A, TRA, GGTA2P, TM9SF2, IFI16, RBMS3), PCT4 (HPVC1) and PCT5 (SLC15A4, PKP2, SNRPN). Overall, the highlighted loci included genes associated with immune response and epithelial barrier function. With the exception of associations of BEGAIN with severe and UBE3D with moderate CP, no other loci were associated with CP in ARIC or aggressive periodontitis in the German sample. Although not associated with current clinically determined periodontal disease taxonomies, upon replication and mechanistic validation these candidate loci may highlight dysbiotic microbial community structures and altered inflammatory/immune responses underlying biological sub-types of CP. PMID:26962152

  7. [Clinical variations of chronic generalized periodontitis, genetic polymorphism and systemic production of inflammatory cytokines].

    PubMed

    Grigorovich, E Sh; Pomorgailo, E G; Khomutova, E Yu; Stepanov, S S

    2015-01-01

    Carriage of polymorphic alleles of genes of cytokines-interleukines IL-1β, IL-1RN, TNFα, IL-4 can be a specific feature of chronic periodontitis patients. Genetic tests can be used to predict the course of the disease at its early manifestations. Objective: To establish the relationship of clinical manifestations of periodontal disease, inflammatory cytokines gene polymorphism and systemic levels of cytokine production. Periodontal tissue assessment and cone-beam computed tomography (CBCT) were performed in 150 periodontitis patients. A molecular--genetic testing for the presence of polymorphic alleles of genes IL-1β -511 C>T and +3953 C>T, IL-1RN (VNTR intron 2), IL-4 (VNTR intron 3), TNFα-308 G>A; content determined IL-1β, TNFα, IL-4 in peripheral blood was carried out in 150 patients with periodontitis and 150 healthy donors. Based on the analysis of the speed and nature of the supporting bone resorption and clinical manifestations patients are divided in "aggressive", "moderately progressive" and "slowly progressive" periodontits course groups. Disease severity was associated with distribution of genotypes and alleles of polymorphic genes cytokine IL-1RN (VNTR intron 2), TNFα-308 G>A and IL-4 (VNTR intron 3); haplotype IL-1β-511 TIL-1β +3953 T/IL-1RN 2R. There was no statistically significant difference in systemic level of IL-1β, TNFα and IL-4 between periodontitis groups but the donor level of cytokines was 2-4 times less.

  8. Auto Mechanics I. Learning Activity Packets (LAPs). Section A--Orientation and Safety.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains seven learning activity packets (LAPs) that outline the study activities for the orientation and safety instructional area for an Auto Mechanics I course. The seven LAPs cover the following topics: orientation, safety, hand tools, arc welding, oxyacetylene cutting, oxyacetylene fusion welding, and oxyacetylene braze welding.…

  9. Improvement of transformer core magnetic properties using the step-lap design

    NASA Astrophysics Data System (ADS)

    Valkovic, Z.; Rezic, A.

    1992-07-01

    Magnetic properties of the step-lap joints have been investigated experimentally on two three-phase three-leg transformer cores. Using the step-lap joint design, a reduction of the total core loss of 2 to 4.4% and of the exciting power of 31 to 37% has been obtained.

  10. Mechanistic Features of Nanodiamonds in the Lapping of Magnetic Heads

    PubMed Central

    Jiang, Xionghua; Chen, Zhenxing; Wolfram, Joy; Yang, Zhizhou

    2014-01-01

    Nanodiamonds, which are the main components of slurry in the precision lapping process of magnetic heads, play an important role in surface quality. This paper studies the mechanistic features of nanodiamond embedment into a Sn plate in the lapping process. This is the first study to develop mathematical models for nanodiamond embedment. Such models can predict the optimum parameters for particle embedment. From the modeling calculations, the embedded pressure satisfies p0 = (3/2)·(W/πa2) and the indentation depth satisfies δ=k1P/HV. Calculation results reveal that the largest embedded pressure is 731.48 GPa and the critical indentation depth δ is 7 nm. Atomic force microscopy (AFM), scanning electron microscopy (SEM), and Auger electron spectroscopy (AES) were used to carry out surface quality detection and analysis of the disk head. Both the formation of black spots on the surface and the removal rate have an important correlation with the size of nanodiamonds. The results demonstrate that an improved removal rate (21 nm·min−1) can be obtained with 100 nm diamonds embedded in the plate. PMID:25045730

  11. Large-Scale Advanced Prop-Fan (LAP)

    NASA Technical Reports Server (NTRS)

    Degeorge, C. L.

    1988-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel efficiency. Analytical studies and research with wind tunnel models have demonstrated that the high inherent efficiency of low speed turboprop propulsion systems may now be extended to the Mach .8 flight regime of today's commercial airliners. This can be accomplished with a propeller, employing a large number of thin highly swept blades. The term Prop-Fan has been coined to describe such a propulsion system. In 1983 the NASA-Lewis Research Center contracted with Hamilton Standard to design, build and test a near full scale Prop-Fan, designated the Large Scale Advanced Prop-Fan (LAP). This report provides a detailed description of the LAP program. The assumptions and analytical procedures used in the design of Prop-Fan system components are discussed in detail. The manufacturing techniques used in the fabrication of the Prop-Fan are presented. Each of the tests run during the course of the program are also discussed and the major conclusions derived from them stated.

  12. Ultrasonic guided wave inspection of Inconel 625 brazed lap joints

    NASA Astrophysics Data System (ADS)

    Comot, Pierre; Bocher, Philippe; Belanger, Pierre

    2016-04-01

    The aerospace industry has been investigating the use of brazing for structural joints, as a mean of reducing cost and weight. There therefore is a need for a rapid, robust, and cost-effective non-destructive testing method for evaluating the structural integrity of the joints. The mechanical strength of brazed joints depends mainly on the amount of brittle phases in their microstructure. Ultrasonic guided waves offer the possibility of detecting brittle phases in joints using spatio-temporal measurements. Moreover, they offer the opportunity to inspect complex shape joints. This study focused on the development of a technique based on ultrasonic guided waves for the inspection of Inconel 625 lap joints brazed with BNi-2 filler metal. A finite element model of a lap joint was used to optimize the inspection parameters and assess the feasibility of detecting the amount of brittle phases in the joint. A finite element parametric study simulating the input signal shape, the center frequency, and the excitation direction was performed. The simulations showed that the ultrasonic guided wave energy transmitted through, and reflected from, the joints was proportional to the amount of brittle phases in the joint.

  13. Nonlinear Analysis of Bonded Composite Single-LAP Joints

    NASA Technical Reports Server (NTRS)

    Oterkus, E.; Barut, A.; Madenci, E.; Smeltzer, S. S.; Ambur, D. R.

    2004-01-01

    This study presents a semi-analytical solution method to analyze the geometrically nonlinear response of bonded composite single-lap joints with tapered adherend edges under uniaxial tension. The solution method provides the transverse shear and normal stresses in the adhesive and in-plane stress resultants and bending moments in the adherends. The method utilizes the principle of virtual work in conjunction with von Karman s nonlinear plate theory to model the adherends and the shear lag model to represent the kinematics of the thin adhesive layer between the adherends. Furthermore, the method accounts for the bilinear elastic material behavior of the adhesive while maintaining a linear stress-strain relationship in the adherends. In order to account for the stiffness changes due to thickness variation of the adherends along the tapered edges, their in-plane and bending stiffness matrices are varied as a function of thickness along the tapered region. The combination of these complexities results in a system of nonlinear governing equilibrium equations. This approach represents a computationally efficient alternative to finite element method. Comparisons are made with corresponding results obtained from finite-element analysis. The results confirm the validity of the solution method. The numerical results present the effects of taper angle, adherend overlap length, and the bilinear adhesive material on the stress fields in the adherends, as well as the adhesive, of a single-lap joint

  14. Lap Shear Testing of Candidate Radiator Panel Adhesives

    NASA Technical Reports Server (NTRS)

    Ellis, David; Briggs, Maxwell; McGowan, Randy

    2013-01-01

    During testing of a subscale radiator section used to develop manufacturing techniques for a full-scale radiator panel, the adhesive bonds between the titanium heat pipes and the aluminum face sheets failed during installation and operation. Analysis revealed that the thermal expansion mismatch between the two metals resulted in relatively large shear stresses being developed even when operating the radiator at moderate temperatures. Lap shear testing of the adhesive used in the original joints demonstrated that the two-part epoxy adhesive fell far short of the strength required. A literature review resulted in several candidate adhesives being selected for lap shear joint testing at room temperature and 398 K, the nominal radiator operating temperature. The results showed that two-part epoxies cured at room and elevated temperatures generally did not perform well. Epoxy film adhesives cured at elevated temperatures, on the other hand, did very well with most being sufficiently strong to cause yielding in the titanium sheet used for the joints. The use of an epoxy primer generally improved the strength of the joint. Based upon these results, a new adhesive was selected for the second subscale radiator section.

  15. The Teacher's Lap--A Site of Emotional Well-Being for the Younger Children in Day-Care Groups

    ERIC Educational Resources Information Center

    Hännikäinen, Maritta

    2015-01-01

    This study focuses on a particular relationship between teachers and one- to three-year-old children: the child in the teacher's lap. When, in what situations, does this happen? Who are the children in the teacher's lap? Why are they there? How do children express emotional well-being when in the teacher's lap? Relational, sociocultural and…

  16. C/EBPβ-LAP*/LAP Expression Is Mediated by RSK/eIF4B-Dependent Signalling and Boosted by Increased Protein Stability in Models of Monocytic Differentiation

    PubMed Central

    Christmann, Martin; Friesenhagen, Judith; Westphal, Andreas; Pietsch, Daniel; Brand, Korbinian

    2015-01-01

    The transcription factor C/EBPβ plays a key role in monocytic differentiation and inflammation. Its small isoform LIP is associated with proliferation at early premonocytic developmental stages and regulated via mTOR-dependent signalling. During later stages of (pre)monocytic differentiation there is a considerable increase in the large C/EBPβ isoforms LAP*/LAP which inhibit proliferation thus supporting terminal differentiation. Here, we showed in different models of monocytic differentiation that this dramatic increase in the LAP*/LAP protein and LAP/LIP ratio was accompanied by an only modest/retarded mRNA increase suggesting an important role for (post)translational mechanisms. We found that LAP*/LAP formation was induced via MEK/RSK-dependent cascades, whereas mTOR/S6K1 were not involved. Remarkably, LAP*/LAP expression was dependent on phosphorylated eIF4B, an acceleratory protein of RNA helicase eIF4A. PKR inhibition reduced the expression of eIF4B and C/EBPβ in an eIF2α-independent manner. Furthermore, under our conditions a marked stabilisation of LAP*/LAP protein occurred, accompanied by reduced chymotrypsin-like proteasome/calpain activities and increased calpastatin levels. Our study elucidates new signalling pathways inducing LAP*/LAP expression and indicates new alternative PKR functions in monocytes. The switch from mTOR- to RSK-mediated signalling to orchestrate eIF4B-dependent LAP*/LAP translation, accompanied by increased protein stability but only small mRNA changes, may be a prototypical example for the regulation of protein expression during selected processes of differentiation/proliferation. PMID:26646662

  17. Inquiry Teaching in Clinical Periodontics.

    ERIC Educational Resources Information Center

    Heins, Paul J.; Mackenzie, Richard S.

    1987-01-01

    An adaptation of the inquiry method of teaching, which develops skills of information retrieval and reasoning through systematic questioning by the teacher, is proposed for instruction in clinical periodontics. (MSE)

  18. Punishment of elicited aggression.

    PubMed

    Azrin, N H

    1970-07-01

    Aversive shocks are known to produce aggression when the shocks are not dependent on behavior and to suppress behavior when the shocks are arranged as a dependent punisher. These two processes were studied by presenting non-dependent shock to monkeys at regular intervals, thereby producing biting attacks on a pneumatic tube. Immediate shock punishment was stimultaneously delivered for each biting attack. The attacks were found to decrease as a function of increasing punishment intensity. These results show that aggression is eliminated by direct punishment of the aggression even when the stimulus that is used as a punisher otherwise causes the aggression. PMID:4988590

  19. Lipoproteins and lipoprotein metabolism in periodontal disease

    PubMed Central

    Griffiths, Rachel; Barbour, Suzanne

    2010-01-01

    A growing body of evidence indicates that the incidence of atherosclerosis is increased in subjects with periodontitis – a chronic infection of the oral cavity. This article summarizes the evidence that suggests periodontitis shifts the lipoprotein profile to be more proatherogenic. LDL-C is elevated in periodontitis and most studies indicate that triglyceride levels are also increased. By contrast, antiatherogenic HDL tends to be low in periodontitis. Periodontal therapy tends to shift lipoprotein levels to a healthier profile and also reduces subclinical indices of atherosclerosis. In summary, periodontal disease alters lipoprotein metabolism in ways that could promote atherosclerosis and cardiovascular disease. PMID:20835400

  20. Lapped Block Image Analysis via the Method of Legendre Moments

    NASA Astrophysics Data System (ADS)

    El Fadili, Hakim; Zenkouar, Khalid; Qjidaa, Hassan

    2003-12-01

    Research investigating the use of Legendre moments for pattern recognition has been performed in recent years. This field of research remains quite open. This paper proposes a new technique based on block-based reconstruction method (BBRM) using Legendre moments compared with the global reconstruction method (GRM). For alleviating the blocking artifact involved in the processing, we propose a new approach using lapped block-based reconstruction method (LBBRM). For the problem of selecting the optimal number of moment used to represent a given image, we propose the maximum entropy principle (MEP) method. The main motivation of the proposed approaches is to allow fast and efficient reconstruction algorithm, with improvement of the reconstructed images quality. A binary handwritten musical character and multi-gray-level Lena image are used to demonstrate the performance of our algorithm.

  1. Shoulder-lap seat belts and thoracic transection.

    PubMed

    Byard, R W

    2002-06-01

    While seat belt usage significantly decreases mortality and morbidity from traffic accidents, specific injuries may also occur. Two cases are described in adults where the wearing of three point restraints (shoulder-lap belts) in a serious high-speed vehicle accident resulted in fatal injuries to both a driver and a passenger. 'Mirror image' fractures of the sternum, rib cage and clavicles, with separation of the two halves of the rib cages and underlying trauma to the hearts and thoracic aortae resulted in death in both victims. Profound life-threatening internal injuries may be caused by seat belts in the absence of significant cutaneous injury. The pattern of internal trauma can also be useful in determining whether a seat belt was worn at the time of the accident, and on which side of the vehicle the deceased was sitting.

  2. Testing composite-to-metal tubular lap joints

    SciTech Connect

    Guess, T.R.; Reedy, E.D. Jr.; Slavin, A.M.

    1993-11-01

    Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

  3. Testing composite-to-metal tubular lap joints

    NASA Astrophysics Data System (ADS)

    Guess, T. R.; Reedy, E. D., Jr.; Slavin, A. M.

    Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

  4. Large-Scale Advanced Prop-Fan (LAP) blade design

    NASA Technical Reports Server (NTRS)

    Violette, John A.; Sullivan, William E.; Turnberg, Jay E.

    1984-01-01

    This report covers the design analysis of a very thin, highly swept, propeller blade to be used in the Large-Scale Advanced Prop-Fan (LAP) test program. The report includes: design requirements and goals, a description of the blade configuration which meets requirements, a description of the analytical methods utilized/developed to demonstrate compliance with the requirements, and the results of these analyses. The methods described include: finite element modeling, predicted aerodynamic loads and their application to the blade, steady state and vibratory response analyses, blade resonant frequencies and mode shapes, bird impact analysis, and predictions of stalled and unstalled flutter phenomena. Summarized results include deflections, retention loads, stress/strength comparisons, foreign object damage resistance, resonant frequencies and critical speed margins, resonant vibratory mode shapes, calculated boundaries of stalled and unstalled flutter, and aerodynamic and acoustic performance calculations.

  5. Periodontal disease's contribution to Alzheimer's disease progression in Down syndrome.

    PubMed

    Kamer, Angela R; Fortea, Juan O; Videla, Sebastià; Mayoral, Angela; Janal, Malvin; Carmona-Iragui, Maria; Benejam, Bessy; Craig, Ronald G; Saxena, Deepak; Corby, Patricia; Glodzik, Lidia; Annam, Kumar Raghava Chowdary; Robbins, Miriam; de Leon, Mony J

    2016-01-01

    People with Down syndrome (DS) are at an increased risk for Alzheimer's disease (AD). After 60 years of age, >50% of DS subjects acquire dementia. Nevertheless, the age of onset is highly variable possibly because of both genetic and environmental factors. Genetics cannot be modified, but environmental risk factors present a potentially relevant intervention for DS persons at risk for AD. Among them, inflammation, important in AD of DS type, is potential target. Consistent with this hypothesis, chronic peripheral inflammation and infections may contribute to AD pathogenesis in DS. People with DS have an aggressive form of periodontitis characterized by rapid progression, significant bacterial and inflammatory burden, and an onset as early as 6 years of age. This review offers a hypothetical mechanistic link between periodontitis and AD in the DS population. Because periodontitis is a treatable condition, it may be a readily modifiable risk factor for AD.

  6. Periodontal disease's contribution to Alzheimer's disease progression in Down syndrome.

    PubMed

    Kamer, Angela R; Fortea, Juan O; Videla, Sebastià; Mayoral, Angela; Janal, Malvin; Carmona-Iragui, Maria; Benejam, Bessy; Craig, Ronald G; Saxena, Deepak; Corby, Patricia; Glodzik, Lidia; Annam, Kumar Raghava Chowdary; Robbins, Miriam; de Leon, Mony J

    2016-01-01

    People with Down syndrome (DS) are at an increased risk for Alzheimer's disease (AD). After 60 years of age, >50% of DS subjects acquire dementia. Nevertheless, the age of onset is highly variable possibly because of both genetic and environmental factors. Genetics cannot be modified, but environmental risk factors present a potentially relevant intervention for DS persons at risk for AD. Among them, inflammation, important in AD of DS type, is potential target. Consistent with this hypothesis, chronic peripheral inflammation and infections may contribute to AD pathogenesis in DS. People with DS have an aggressive form of periodontitis characterized by rapid progression, significant bacterial and inflammatory burden, and an onset as early as 6 years of age. This review offers a hypothetical mechanistic link between periodontitis and AD in the DS population. Because periodontitis is a treatable condition, it may be a readily modifiable risk factor for AD. PMID:27239536

  7. Surgical and nonsurgical periodontal therapy. Learned and unlearned concepts.

    PubMed

    Heitz-Mayfield, Lisa J A; Lang, Niklaus P

    2013-06-01

    This review aims to highlight concepts relating to nonsurgical and surgical periodontal therapy, which have been learned and unlearned over the past few decades. A number of treatment procedures, such as gingival curettage and aggressive removal of contaminated root cementum, have been unlearned. Advances in technology have resulted in the introduction of a range of new methods for use in nonsurgical periodontal therapy, including machine-driven instruments, lasers, antimicrobial photodynamic therapy and local antimicrobial-delivery devices. However, these methods have not been shown to offer significant benefits over and above nonsurgical debridement using hand instruments. The method of debridement is therefore largely dependent on the preferences of the operator and the patient. Recent evidence indicates that specific systemic antimicrobials may be indicated for use as adjuncts to nonsurgical debridement in patients with advanced disease. Full-mouth disinfection protocols have been proven to be a relevant treatment option. We have learned that while nonsurgical and surgical methods result in similar long-term treatment outcomes, surgical therapy results in greater probing-depth reduction and clinical attachment gain in initially deep pockets. The surgical technique chosen seems to have limited influence upon changes in clinical attachment gain. What has not changed is the importance of thorough mechanical debridement and optimal plaque control for successful nonsurgical and surgical periodontal therapy.

  8. Lamina Associated Polypeptide 1 (LAP1) Interactome and Its Functional Features

    PubMed Central

    Serrano, Joana B.; da Cruz e Silva, Odete A. B.; Rebelo, Sandra

    2016-01-01

    Lamina-associated polypeptide 1 (LAP1) is a type II transmembrane protein of the inner nuclear membrane encoded by the human gene TOR1AIP1. LAP1 is involved in maintaining the nuclear envelope structure and appears be involved in the positioning of lamins and chromatin. To date, LAP1’s precise function has not been fully elucidated but analysis of its interacting proteins will permit unraveling putative associations to specific cellular pathways and cellular processes. By assessing public databases it was possible to identify the LAP1 interactome, and this was curated. In total, 41 interactions were identified. Several functionally relevant proteins, such as TRF2, TERF2IP, RIF1, ATM, MAD2L1 and MAD2L1BP were identified and these support the putative functions proposed for LAP1. Furthermore, by making use of the Ingenuity Pathways Analysis tool and submitting the LAP1 interactors, the top two canonical pathways were “Telomerase signalling” and “Telomere Extension by Telomerase” and the top functions “Cell Morphology”, “Cellular Assembly and Organization” and “DNA Replication, Recombination, and Repair”. Once again, putative LAP1 functions are reinforced but novel functions are emerging. PMID:26784240

  9. A Strategic Approach to Aggression.

    ERIC Educational Resources Information Center

    Archer, John

    2001-01-01

    Discusses two issues raised by Underwood et al.: the distinction between indirect and relational forms of aggression, and implications of indirect aggression for definitions of aggression; and the normative view of aggression that indicates that aggressive individuals may be socially skilled. Suggests that both issues lead to the conclusion that…

  10. P-LAP/IRAP-induced cell proliferation and glucose uptake in endometrial carcinoma cells via insulin receptor signaling

    PubMed Central

    Shibata, Kiyosumi; Kajiyama, Hiroaki; Ino, Kazuhiko; Nawa, Akihiro; Nomura, Seiji; Mizutani, Shigehiko; Kikkawa, Fumitaka

    2007-01-01

    Background Hyperglycemia or hyperinsulinemia contributes to poorer endometrial cancer survival. It was shown that P-LAP/IRAP translocates to the plasma membrane in response to insulin stimulation. Recently, we demonstrated that P-LAP/IRAP is associated with a poor prognosis in endometrial adenocarcinoma patients. The aim of this study was to examine whether the malignant potential of endometrial cancer enhanced by P-LAP/IRAP is due to increased glucose uptake via the P-LAP/IRAP-mediated activation of insulin signaling. Methods We transfected P-LAP/IRAP cDNA into A-MEC cells (endometrial adenocarcinoma cell line), and A-MEC-LAP cells expressed a remarkably high level of GLUT4 proteins. Results 3H-2-deoxyglucose uptake which responds to insulin in A-MEC-LAP cells was significantly higher than that of A-MEC-pc cells. A-MEC-LAP cells exhibited a significant growth-stimulatory effect compared to A-MEC-pc cells. A-MEC-LAP cells expressed a remarkably high level of p85PI3K protein compared to A-MEC-pc cells, and showed a higher degree of AKT phosphorylation by insulin stimulation. Conclusion In summary, P-LAP/IRAP was involved in the increasing malignant potential of endometrial cancer mediated by insulin. P-LAP/IRAP was suggested to be a potential new target of molecular-targeted therapy for endometrial cancer. PMID:17233921

  11. Deformation verification and surface improvement of active stressed lap for 4  m-class primary mirror fabrication.

    PubMed

    Zhao, Hongshen; Li, Xiaojin; Fan, Bin; Zeng, Zhige

    2015-04-01

    The surface shape accuracy of the active stressed lap impacts the performance of grinding and polishing in the fabrication of large mirrors. We introduce a model of active stressed lap for the fabrication of a 4 m f/1.5 mirror based on finite element analysis (FEA), and the lap surface accuracy achieves RMS<1.8  μm in the FEA method. Using the lap surface measurement system, experimental verification is put forward, and the RMS of the measured lap surface is within 2 μm in practice. A general improvement in lap surface accuracy using the Zernike polynomial is shown. After compensating the calculation errors, the lap surface accuracy is improved by 8%-23%, and achieves RMS<1.5  μm, which is appropriate for practical grinding and polishing. PMID:25967173

  12. Electromechanical behaviour of REBCO tape lap splices under transverse compressive loading

    NASA Astrophysics Data System (ADS)

    Grether, A.; Scheuerlein, C.; Ballarino, A.; Bottura, L.

    2016-07-01

    We have studied the influence of transverse compressive stress on the resistance and critical current (I c ) of soldered REBCO tape lap splices. Internal contact resistances dominate the overall REBCO lap splice resistances. Application of transverse compressive stress up to 250 MPa during the resistance measurements does not alter the resistance and I c of the soldered REBCO splices that were studied. The resistance of unsoldered REBCO tape lap splices depends strongly on the contact pressure. At a transverse compressive stress of 100 MPa, to which Roebel cables are typically exposed in high field magnets, the crossover splice contact resistance is comparable to the internal tape resistances.

  13. Lumbar Chance fracture associated with use of the lap belt restraint in an adolescent.

    PubMed

    Walsh, A; Sheehan, E; Walsh, M G

    2003-05-01

    The use of the 2-point seat belt or lap belt in motor vehicles, particularly to restrain young rear seat passengers, remains an issue of some concern. The occurrence of lumbar spinal flexion-distraction injuries in lap belt restrained children and adolescents during road traffic accidents is a well known phenomenon, but is still occurring. High velocity paediatric Chance fractures are frequently associated with significant intra-abdominal trauma. We present the case of a Chance fracture sustained by a 15 year old girl, involved in a motor vehicle collision, while wearing a lap belt. We emphasise the need to develop safer seat belt designs for juvenile car passengers.

  14. Seat belt induced transection of the trachea in a child on the lap of an adult.

    PubMed

    Uemura, K; Yoshida, K

    2001-05-01

    As a victim of his parents' suicide, a three-year-old boy was found dead on the lap of the passenger in the left front seat of a car that dove from the wharf and crashed into the sea. He died from the transection of trachea due to shoulder belt in the absence of the signs of drowning. The seat belt paradoxically injured the child on the passenger's lap in the traffic accident. The popular custom of Japanese parents of holding their children on their laps in cars is dangerous, while another custom of killing their children upon suicide of parents or couples should be socially and legally controlled.

  15. Global-Local Finite Element Analysis of Bonded Single-Lap Joints

    NASA Technical Reports Server (NTRS)

    Kilic, Bahattin; Madenci, Erdogan; Ambur, Damodar R.

    2004-01-01

    Adhesively bonded lap joints involve dissimilar material junctions and sharp changes in geometry, possibly leading to premature failure. Although the finite element method is well suited to model the bonded lap joints, traditional finite elements are incapable of correctly resolving the stress state at junctions of dissimilar materials because of the unbounded nature of the stresses. In order to facilitate the use of bonded lap joints in future structures, this study presents a finite element technique utilizing a global (special) element coupled with traditional elements. The global element includes the singular behavior at the junction of dissimilar materials with or without traction-free surfaces.

  16. Machine imparting complex rotary motion for lapping a spherical inner diameter

    DOEpatents

    Carroll, T.A.; Yetter, H.H.

    1985-01-30

    An apparatus for imparting complex rotary motion is used to lap an inner spherical diameter surface of a workpiece. A lapping tool consists of a dome and rod mounted along the dome's vertical axis. The workpiece containing the lapping tool is held in a gimbal which uses power derived from a secondary takeoff means to impart rotary motion about a horizontal axis. The gimbal is rotated about a vertical axis by a take means while mounted at a radially outward position on a rotating arm.

  17. Machine imparting complex rotary motion for lapping a spherical inner diameter

    DOEpatents

    Carroll, Thomas A.; Yetter, Harold H.

    1986-01-01

    An apparatus for imparting complex rotary motion is used to lap an inner spherical diameter surface of a workpiece. A lapping tool consists of a dome and rod mounted along the dome's vertical axis. The workpiece containing the lapping tool is held in a gimbal which uses power derived from a secondary takeoff means to impart rotary motion about a horizontal axis. The gimbal is rotated about a vertical axis by a take means while mounted at a radially outward position on a rotating arm.

  18. The effect of diamond powder characteristics on lapping of sintered silicon carbide

    NASA Astrophysics Data System (ADS)

    Rosczyk, Benjamin; Burkam, Eric; Titov, Artem; Onyenemezu, Clement; Benea, Ion C.

    2015-10-01

    In Automotive applications, sintered Silicon Carbide has been used in applications such as seal pump faces. The surface of sintered SiC, when lapped or polished for sealing to another surface, must be free of blemishes and mechanical defects. Lapping and polishing processes therefore must be well defined and controlled assuring minimal variation and production scrap. In this study, we related the characteristics of different diamond powders (particle size distribution, particle shape and surface) to their performance in lapping of sintered silicon carbide material, expressed as removal rate and surface finish.

  19. Girls' Aggressive Behavior

    ERIC Educational Resources Information Center

    Owens, Larry; Shute, Rosalyn; Slee, Phillip

    2004-01-01

    In contrast to boys' bullying behavior which is often overt and easily visible, girls' aggression is usually indirect and covert. Less research has been conducted on the types of bullying that girls usually engage in. Using focus groups composed of teenaged girls, Dr. Owens and colleagues examine the nature of teenage girls' indirect aggression.

  20. Third Person Instigated Aggression.

    ERIC Educational Resources Information Center

    Gaebelein, Jacquelyn

    Since many acts of aggression in society are more than simply an aggressor-victim encounter, the role played by third person instigated aggression also needs examination. The purpose of this study was to develop a laboratory procedure to systematically investigate instigation. In a competitive reaction time task, high and low Machiavellian Males…

  1. Social Aggression among Girls.

    ERIC Educational Resources Information Center

    Underwood, Marion K.

    Noting recent interest in girls' social or "relational" aggression, this volume offers a balanced, scholarly analysis of scientific knowledge in this area. The book integrates current research on emotion regulation, gender, and peer relations, to examine how girls are socialized to experience and express anger and aggression from infancy through…

  2. Lessons learned and unlearned in periodontal microbiology

    PubMed Central

    Teles, Ricardo; Teles, Flavia; Frias-Lopez, Jorge; Paster, Bruce; Haffajee, Anne

    2013-01-01

    Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation initiated by specific subgingival species. In the past few decades, efforts to understand the microbiota of periodontal diseases have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this chapter we will review how our comprehension of the structure and function of the subgingival microbiota evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: 1) how the data obtained through molecular techniques has impacted our knowledge of the etiology of periodontal infections; 2) the potential role of viruses in the etiopathogenesis of periodontal diseases; 3) how concepts of microbial ecology have expanded our understanding of host microbial interactions that might lead to periodontal diseases; 4) the role of inflammation in the pathogenesis of periodontal diseases; and 5) the impact of these evolving concepts on treatment and preventive approaches to periodontal infections. We will conclude by reviewing how novel systems biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and, hopefully, lead to a better understanding of periodontal disease mechanisms. PMID:23574465

  3. Smoking and periodontal disease severity.

    PubMed

    Martinez-Canut, P; Lorca, A; Magán, R

    1995-10-01

    This study was performed to assess the influence of smoking on periodontal disease severity. Data concerning periodontal status and smoking habits were collected from 889 periodontal patients: 340 male and 549 female, 21 to 76 years of age, 47.4% being non smokers and 52.6% smokers. Periodontal parameters, recorded by the same examiner (PMC), were: gingival recession (GR), Pocket depth (PD), Probing attachment level (PAL), and mobility (M). The influence of age, sex and tobacco consumption on these periodontal parameters was statistically evaluated using an analysis of variance (ANOVA) with covariates. A non-linear effect model was also fitted by taking the natural logarithms of the response variables (GR, PD, PAL) closer to biomedical phenomena. Mobility was analyzed by a chi2-test. The effect of smoking on periodontitis showed no association with age or with sex. Smoking, age and sex were shown to be statistically significant for periodontitis, by performing both univariate (t-test for equal means) and multivariate tests. p-values for smoking and periodontitis were: GR (p=0.000), PD (p=0.000), PAL (p=0.000) and M (P=0.015). Smoking one cigarette per day, up to 10, and up to 20, increased PAL by 0.5%, 5% and 10%, respectively. The impact of tobacco is comparable to the impact resulting from the factor of age in this sample, increasing PAL by 0.7% for each year of life. Comparison between smokers of less than 10 cigarettes per day (PAL mean 3.72 mm +/-0.86) and non-smokers (PAL mean 3.84 +/- 0.89) showed no differences in PAL (p=0.216), while comparison for smokers from 11 to 20 cigarettes (PAL mean 4.36 +/- 1.23) and for more than 20 cigarettes (PAL mean 4.50 +/- 1.04) demonstrated significant differences (p=0.000). These findings suggest that: (1) tobacco increases periodontal disease severity; (2) this effect is clinically evident above consumption of a certain quantity of tobacco.

  4. A characterization of the LAP Aquarius Phantom for external LAP laser alignment and magnetic resonance geometric distortion verification for stereotactic radiation surgery patient simulation

    NASA Astrophysics Data System (ADS)

    Vergara, Daniel

    The Thesis explores additional applications of LAP's Aquarius external laser alignment verification Phantom by examining geometric accuracy of magnetic resonance images commonly used for planning intracranial stereotactic radiation surgery (ICSRS) cases. The scans were performed with MRI protocols used for ICSRS, and head and neck diagnosis, and their images fused to computerized tomographic (CT) images. The geometric distortions (GDs) were measured against the CT in all axial, sagittal, and coronal directions at different levels. Using the Aquarius Phantom, one is able to detect GD in ICSRS planning MRI acquisitions, and align the external LAP patient alignment lasers, by following the LAP QA protocol. GDs up to about 2 mm are observed at the distal regions of the longitudinal axis in the SRS treatment planning MR images. Based on the results, one may recommend the use of the Aquarius Phantom to determine if margins should be included for SRS treatment planning.

  5. Alteration of Sulphides in the Rumuruti Chondrite La Paz Icefield (LAP) 031275

    NASA Astrophysics Data System (ADS)

    Steer, E. D.; Treiman, A. H.

    2014-09-01

    Pyrrhotite in LAP 03175 (R5) has altered to a fine-grained mineral mixture. New data (optical, chemical, and Raman) suggest the mixture includes violarite and tochilinite, but not (as suggested earlier) graphite, hematite, and/or jarosite.

  6. Moving into a new era of periodontal genetic studies: relevance of large case-control samples using severe phenotypes for genome-wide association studies.

    PubMed

    Vaithilingam, R D; Safii, S H; Baharuddin, N A; Ng, C C; Cheong, S C; Bartold, P M; Schaefer, A S; Loos, B G

    2014-12-01

    Studies to elucidate the role of genetics as a risk factor for periodontal disease have gone through various phases. In the majority of cases, the initial 'hypothesis-dependent' candidate-gene polymorphism studies did not report valid genetic risk loci. Following a large-scale replication study, these initially positive results are believed to be caused by type 1 errors. However, susceptibility genes, such as CDKN2BAS (Cyclin Dependend KiNase 2B AntiSense RNA; alias ANRIL [ANtisense Rna In the Ink locus]), glycosyltransferase 6 domain containing 1 (GLT6D1) and cyclooxygenase 2 (COX2), have been reported as conclusive risk loci of periodontitis. The search for genetic risk factors accelerated with the advent of 'hypothesis-free' genome-wide association studies (GWAS). However, despite many different GWAS being performed for almost all human diseases, only three GWAS on periodontitis have been published - one reported genome-wide association of GLT6D1 with aggressive periodontitis (a severe phenotype of periodontitis), whereas the remaining two, which were performed on patients with chronic periodontitis, were not able to find significant associations. This review discusses the problems faced and the lessons learned from the search for genetic risk variants of periodontitis. Current and future strategies for identifying genetic variance in periodontitis, and the importance of planning a well-designed genetic study with large and sufficiently powered case-control samples of severe phenotypes, are also discussed. PMID:24528298

  7. Periodontal plastic surgery.

    PubMed

    Zucchelli, Giovanni; Mounssif, Ilham

    2015-06-01

    The aim of the present article is to summarize current knowledge in terms of the etiology, diagnosis, prognosis and surgical treatment of gingival recession. Whilst the main etiological factors (i.e. toothbrushing trauma and bacterial plaque) are well established, challenges still remain to be solved in the diagnostic, prognostic and classification processes of gingival recession, especially when the main reference parameter - the cemento-enamel junction - is no longer detectable on the affected tooth or when there is a slight loss of periodontal interdental attachment. Root coverage in single type gingival recession defects is a very predictable outcome following the use of various surgical techniques. The coronally advanced flap, with or without connective tissue grafting, is the technique of choice. The adjunctive use of connective tissue grafts improves the probability of achieving complete root coverage. Surgical coverage of multiple gingival recessions is also predictable with the coronally advanced flap and the coronally advanced flap plus the connective tissue graft, but no data are available indicating which, and how many, gingival recessions should be treated adjunctively with connective tissue grafting in order to limit patient morbidity and improve the esthetic outcome. None of the allograft materials currently available can be considered as a full substitute for the connective tissue graft, even if some recent results are encouraging. The need for future studies with patient-based outcomes (i.e. esthetics and morbidity) as primary objectives is emphasized in this review. PMID:25867992

  8. On the water lapping of felines and the water running of lizards: A unifying physical perspective.

    PubMed

    Aristoff, Jeffrey M; Stocker, Roman; Reis, Pedro M; Jung, Sunghwan

    2011-03-01

    We consider two biological phenomena taking place at the air-water interface: the water lapping of felines and the water running of lizards. Although seemingly disparate motions, we show that they are intimately linked by their underlying hydrodynamics and belong to a broader class of processes called Froude mechanisms. We describe how both felines and lizards exploit inertia to defeat gravity, and discuss water lapping and water running in the broader context of water exit and water entry, respectively.

  9. Composition of matrix in the CR chondrite LAP 02342

    NASA Astrophysics Data System (ADS)

    Wasson, John T.; Rubin, Alan E.

    2009-03-01

    We report evidence of interchondrule matrix heterogeneity on a scale of ˜50 μm in the well-preserved CR2 chondrite LAP 02342. Despite minor effects resulting from asteroidal aqueous alteration, the matrix in this CR chondrite seems to preserve much of the compositional record of nebular fines. We carried out electron-microprobe studies using a 3-μm-diameter beam; we analyzed 10 elements in 36- or 49-point grids on 11 ca. 50 × 50-μm rectangular areas of matrix. Each grid area has a distinct composition, inconsistent with a simple model of matrix material having a uniform composition throughout the nebular formation region of the CR chondrites. On S-Fe, Mg-Si, K-Na and K-Al scatter diagrams, the grid areas (i.e., different matrix patches) are largely separated from each other; plots of means with 95% confidence limits demonstrate that the compositions are resolvable. Five matrix areas were analyzed again in duplicate runs; excellent agreement was observed between duplicate studies. LAP 02342 experienced two forms of mild aqueous alteration - as patchy enrichments in Ca (inferred to reflect CaCO 3) and as regions in which sulfide laths are embedded within phyllosilicates. Despite this evidence of aqueous transport, the effect on the composition of matrix is not resolvable. For example, matrix points that were adjacent to points with high CaCO 3 contents show elemental concentrations similar to those in regions having only one or two points with a Ca enrichment. It appears that secondary minerals are found in areas where there are suitable precursor phases and voids into which new phases could grow unimpeded. Calcium appears to be unique in forming a phase that greatly lowers the Ca ++ content of the aqueous medium, thus enhancing the rate of diffusion. Because chondrules vary widely in bulk composition, the formation of chondrules in small sets (100 or less) could generate "smoke" and mesostasis spray with compositions unique to each set. However, if these

  10. Cost analysis of Periodontitis management in public sector specialist dental clinics

    PubMed Central

    2014-01-01

    Background The objective of this paper is to quantify the cost of periodontitis management at public sector specialist periodontal clinic settings and analyse the distribution of cost components. Methods Five specialist periodontal clinics in the Ministry of Health represented the public sector in providing clinical and cost data for this study. Newly-diagnosed periodontitis patients (N = 165) were recruited and followed up for one year of specialist periodontal care. Direct and indirect costs from the societal viewpoint were included in the cost analysis. They were measured in 2012 Ringgit Malaysia (MYR) and estimated from the societal perspective using activity-based and step-down costing methods, and substantiated by clinical pathways. Cost of dental equipment, consumables and labour (average treatment time) for each procedure was measured using activity-based costing method. Meanwhile, unit cost calculations for clinic administration, utilities and maintenance used step-down approach. Patient expenditures and absence from work were recorded via diary entries. The conversion from MYR to Euro was based on the 2012 rate (1€ = MYR4). Results A total of 2900 procedures were provided, with an average cost of MYR 2820 (€705) per patient for the study year, and MYR 376 (€94) per outpatient visit. Out of this, 90% was contributed by provider cost and 10% by patient cost; 94% for direct cost and 4% for lost productivity. Treatment of aggressive periodontitis was significantly higher than for chronic periodontitis (t-test, P = 0.003). Higher costs were expended as disease severity increased (ANOVA, P = 0.022) and for patients requiring surgeries (ANOVA, P < 0.001). Providers generally spent most on consumables while patients spent most on transportation. Conclusions Cost of providing dental treatment for periodontitis patients at public sector specialist settings were substantial and comparable with some non-communicable diseases. These findings

  11. Aggression in Pretend Play and Aggressive Behavior in the Classroom

    ERIC Educational Resources Information Center

    Fehr, Karla K.; Russ, Sandra W.

    2013-01-01

    Research Findings: Pretend play is an essential part of child development and adjustment. However, parents, teachers, and researchers debate the function of aggression in pretend play. Different models of aggression predict that the expression of aggression in play could either increase or decrease actual aggressive behavior. The current study…

  12. Periodontal status in snow leopards.

    PubMed

    Cook, R A; Stoller, N H

    1986-11-01

    Periodontal examinations were performed on ten 1- to 22-year-old snow leopards (6 males and 4 females), using dentistry methods for determining the plaque and gingival indices. All tooth surfaces were probed, and alveolar bone attachment loss was determined. After subgingival plaque removal, plaque specimens were examined for differential bacterial morphotypes. The small number of leopards evaluated precluded definitive statistical analysis. However, the progression from gingival health to gingivitis to periodontitis was similar to that seen in man. Therefore, the use of plaque index, gingival index, alveolar bone attachment loss, and differential bacterial morphotypes can be used to determine the dental health of snow leopards. PMID:3505932

  13. Fatigue strength of a single lap joint SPR-bonded

    SciTech Connect

    Di Franco, G.; Fratini, L.; Pasta, A.

    2011-05-04

    In the last years, hybrid joints, meaning with this the joints which consist in combining a traditional mechanical joint to a layer of adhesive, are gradually attracting the attention of various sectors of the construction of vehicles and transportation industries, for their better performance compared to just mechanical joints (self-piercing riveting SPR, riveting, and so on) or just to bonded joints.The paper investigates the fatigue behavior of a single lap joint self-piercing riveted (SPR) and bonded throughout fatigue tests. The considered geometric configuration allowed the use of two rivets placed longitudinally; an epoxy resin was used as adhesive. In the first part of the work static characterization of the joints was carried out through tensile tests. Then fatigue tests were made with the application of different levels of load. The fatigue curves were also obtained at the varying the distance between the two rivets in order to better assess the joint strength for a given length of overlap.

  14. Molten pool characterization of laser lap welded copper and aluminum

    NASA Astrophysics Data System (ADS)

    Xue, Zhiqing; Hu, Shengsun; Zuo, Di; Cai, Wayne; Lee, Dongkyun; Elijah, Kannatey-Asibu, Jr.

    2013-12-01

    A 3D finite volume simulation model for laser welding of a Cu-Al lap joint was developed using ANSYS FLUENT to predict the weld pool temperature distribution, velocity field, geometry, alloying element distribution and transition layer thickness—all key attributes and performance characteristics for a laser-welded joint. Melting and solidification of the weld pool was simulated with an enthalpy-porosity formulation. Laser welding experiments and metallographic examination by SEM and EDX were performed to investigate the weld pool features and validate the simulated results. A bowl-shaped temperature field and molten pool, and a unique maximum fusion zone width were observed near the Cu-Al interface. Both the numerical simulation and experimental results indicate an arch-shaped intermediate layer of Cu and Al, and a gradual transition of Cu concentration from the aluminum plate to the copper plate with high composition gradient. For the conditions used, welding with Cu on top was found to result in a better weld joint.

  15. Accuracy of NHANES periodontal examination protocols.

    PubMed

    Eke, P I; Thornton-Evans, G O; Wei, L; Borgnakke, W S; Dye, B A

    2010-11-01

    This study evaluates the accuracy of periodontitis prevalence determined by the National Health and Nutrition Examination Survey (NHANES) partial-mouth periodontal examination protocols. True periodontitis prevalence was determined in a new convenience sample of 454 adults ≥ 35 years old, by a full-mouth "gold standard" periodontal examination. This actual prevalence was compared with prevalence resulting from analysis of the data according to the protocols of NHANES III and NHANES 2001-2004, respectively. Both NHANES protocols substantially underestimated the prevalence of periodontitis by 50% or more, depending on the periodontitis case definition used, and thus performed below threshold levels for moderate-to-high levels of validity for surveillance. Adding measurements from lingual or interproximal sites to the NHANES 2001-2004 protocol did not improve the accuracy sufficiently to reach acceptable sensitivity thresholds. These findings suggest that NHANES protocols produce high levels of misclassification of periodontitis cases and thus have low validity for surveillance and research.

  16. Association between postmenopausal osteoporosis and experimental periodontitis.

    PubMed

    Luo, Kai; Ma, Souzhi; Guo, Jianbin; Huang, Yongling; Yan, Fuhua; Xiao, Yin

    2014-01-01

    To investigate the correlation between postmenopausal osteoporosis (PMO) and the pathogenesis of periodontitis, ovariectomized rats were generated and the experimental periodontitis was induced using a silk ligature. The inflammatory factors and bone metabolic markers were measured in the serum and periodontal tissues of ovariectomized rats using an automatic chemistry analyzer, enzyme-linked immunosorbent assays, and immunohistochemistry. The bone mineral density of whole body, pelvis, and spine was analyzed using dual-energy X-ray absorptiometry and image analysis. All data were analyzed using SPSS 13.0 statistical software. It was found that ovariectomy could upregulate the expression of interleukin- (IL-)6, the receptor activator of nuclear factor- κB ligand (RANKL), and osteoprotegerin (OPG) and downregulate IL-10 expression in periodontal tissues, which resulted in progressive alveolar bone loss in experimental periodontitis. This study indicates that changes of cytokines and bone turnover markers in the periodontal tissues of ovariectomized rats contribute to the damage of periodontal tissues.

  17. Minimally invasive periodontal therapy for general practitioners.

    PubMed

    Ryder, Mark I; Armitage, Gary C

    2016-06-01

    There remains a high prevalence of mild-to-moderate forms of periodontal diseases in both developed and developing countries. Although many periodontal specialty practices currently place strong emphasis on implant surgery, periodontal plastic surgery and esthetics, general dentists and hygienists have often assumed more responsibility than periodontal specialty practices for the diagnosis, treatment, assessment and maintenance, and possible referral, of their patients. To address these current trends and challenges, this volume of Periodontology 2000 presents a series of topics on the basic biological principles of periodontal disease, as well as on approaches to diagnosis, treatment planning and treatment, in what is called 'conservative' or 'noninvasive' periodontal therapy. These topics include risk assessment of the periodontal condition; reduction, elimination and/or control of etiologies and risk factors, including mechanical, antimicrobial and host-modulation approaches; considerations for evaluation of clinical outcomes based on treatment approaches; and selected topics in laser therapy, halitosis and gingival recession. PMID:27045427

  18. Apoptosis in the lens anlage of the heritable lens aplastic mouse (lap mouse).

    PubMed

    Aso, S; Tashiro, M; Baba, R; Sawaki, M; Noda, S; Fujita, M

    1998-08-01

    Adult homozygous lap mice show various eye abnormalities, such as aphakia, retinal disorganization, and dysplasia of the cornea and anterior chamber. In the fetal eye of a homozygous lap mouse, the lens placode seems to develop normally. However, the lens vesicle progresses abnormally to form a mass of cells without a cavity, and the mass vanishes soon afterward. We examined cell death in the lens anlage of this mutant. The lens anlagen of homozygous lap and normal mice from days 10 to 12 of gestation were observed by light microscopy after DNA end-labeling by immunohistochemistry and by transmission electron microscopy. By light microscopy, a slight frequency of cell death was detected in the lens anlage encircling the surface ectoderm and in the anlage or in the anlage of both homozygous lap mice and normal mice at day 10 of gestation. Cell death was seen in the lens anlage encircling the surface ectoderm in the normal mouse and sporadically in the anlage of the homozygous lap mouse at day 10.5 of gestation. Cell death was visible at the area of the lens vesicle attached to the surface ectoderm and encircling the surrounding surface ectoderm in the normal mouse, and in the lens anlage encircling the surface ectoderm and the apex areas of the lens anlage in the homozygous lap mouse at day 11 of gestation. At day 12 of gestation, almost no cell death was observed in the lens anlage of the normal mouse. However, extensive areas of cell death were still seen in the lens anlage at its apex, at the inner region, and encircling the surface ectoderm in the homozygous lap mouse. Electron microscopic observation showed that the dead cells observed in the lens anlagen by light microscopy in normal and lap mice are the result of apoptosis. In lap mice, cells with cytoplasmic condensation were observed mainly at days 10 and 10.5 of gestation. Many apoptotic bodies which had been phagocytosed by adjacent cells were seen predominantly at day 11 of gestation. At day 12 of

  19. Periodontitis and systemic lupus erythematosus.

    PubMed

    Sete, Manuela Rubim Camara; Figueredo, Carlos Marcelo da Silva; Sztajnbok, Flavio

    2016-01-01

    A large number of studies have shown a potential association between periodontal and autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus (SLE). Similar mechanisms of tissue destruction concerning periodontitis and other autoimmune diseases have stimulated the study of a possible relationship between these conditions. This study aims to review the literature about this potential association and their different pathogenic mechanisms. Considering that periodontal disease is a disease characterized by inflammation influenced by infectious factors, such as SLE, it is plausible to suggest that SLE would influence periodontal disease and vice versa. However, this issue is not yet fully elucidated and several mechanisms have been proposed to explain this association, as deregulation mainly in innate immune system, with action of phagocytic cells and proinflammatory cytokines such as IL-1β and IL-18 in both conditions' pathogenesis, leading to tissue destruction. However, studies assessing the relationship between these diseases are scarce, and more studies focused on common immunological mechanisms should be conducted to further understanding. PMID:27267530

  20. Periodontitis and systemic lupus erythematosus.

    PubMed

    Sete, Manuela Rubim Camara; Figueredo, Carlos Marcelo da Silva; Sztajnbok, Flavio

    2016-01-01

    A large number of studies have shown a potential association between periodontal and autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus (SLE). Similar mechanisms of tissue destruction concerning periodontitis and other autoimmune diseases have stimulated the study of a possible relationship between these conditions. This study aims to review the literature about this potential association and their different pathogenic mechanisms. Considering that periodontal disease is a disease characterized by inflammation influenced by infectious factors, such as SLE, it is plausible to suggest that SLE would influence periodontal disease and vice versa. However, this issue is not yet fully elucidated and several mechanisms have been proposed to explain this association, as deregulation mainly in innate immune system, with action of phagocytic cells and proinflammatory cytokines such as IL-1β and IL-18 in both conditions' pathogenesis, leading to tissue destruction. However, studies assessing the relationship between these diseases are scarce, and more studies focused on common immunological mechanisms should be conducted to further understanding.

  1. Periodontal considerations in veneer cases.

    PubMed

    Peto, David

    2015-04-01

    Porcelain veneers are a minimally invasive technique to enhance patients' smiles. A crucial component in these cases is the supporting periodontal apparatus and its interaction with the restorations. This article addresses basic concepts such as biologic width, altered eruption patterns, appropriate gingival contouring and smile design to give practitioners the tools to diagnose, evaluate and treat cases successfully and predictably.

  2. Biomaterials in periodontal osseous defects

    PubMed Central

    Lal, Nand; Dixit, Jaya

    2012-01-01

    Introduction Osseous defects in periodontal diseases require osseous grafts and guided tissue regeneration (GTR) using barrier membranes. The present study was undertaken with the objectives to clinically evaluate the osteogenic potential of hydroxyapatite (HA), cissus quadrangularis (CQ), and oxidized cellulose membrane (OCM) and compare with normal bone healing. Materials and Methods Twenty subjects with periodontitis in the age group ranging from 20 years to 40 years were selected from our outpatient department on the basis of presence of deep periodontal pockets, clinical probing depth ≥5 mm, vertical osseous defects obvious on radiograph and two- or three-walled involvement seen on surgical exposure. Infrabony defects were randomly divided into four groups on the basis of treatment to be executed, such that each group comprised 5 defects. Group I was control, II received HA, III received CQ and IV received OCM. Probing depth and attachment level were measured at regular months after surgery. Defects were re-exposed using crevicular incisions at 6 months. Results There was gradual reduction in the mean probing pocket depth in all groups, but highly significant in the site treated with HA. Gain in attachment level was higher in sites treated with HA, 3.2 mm at 6 months. Conclusion Hydroxyapatite and OCM showed good reduction in pocket depth, attachment level gain and osseous defect fill. Further study should be conducted by using a combination of HA and OCM in periodontal osseous defects with growth factors and stem cells. PMID:25756030

  3. Cementum and Periodontal Ligament Regeneration.

    PubMed

    Menicanin, Danijela; Hynes, K; Han, J; Gronthos, S; Bartold, P M

    2015-01-01

    The unique anatomy and composition of the periodontium make periodontal tissue healing and regeneration a complex process. Periodontal regeneration aims to recapitulate the crucial stages of wound healing associated with periodontal development in order to restore lost tissues to their original form and function and for regeneration to occur, healing events must progress in an ordered and programmed sequence both temporally and spatially, replicating key developmental events. A number of procedures have been employed to promote true and predictable regeneration of the periodontium. Principally, the approaches are based on the use of graft materials to compensate for the bone loss incurred as a result of periodontal disease, use of barrier membranes for guided tissue regeneration and use of bioactive molecules. More recently, the concept of tissue engineering has been integrated into research and applications of regenerative dentistry, including periodontics, to aim to manage damaged and lost oral tissues, through reconstruction and regeneration of the periodontium and alleviate the shortcomings of more conventional therapeutic options. The essential components for generating effective cellular based therapeutic strategies include a population of multi-potential progenitor cells, presence of signalling molecules/inductive morphogenic signals and a conductive extracellular matrix scaffold or appropriate delivery system. Mesenchymal stem cells are considered suitable candidates for cell-based tissue engineering strategies owing to their extensive expansion rate and potential to differentiate into cells of multiple organs and systems. Mesenchymal stem cells derived from multiple tissue sources have been investigated in pre-clinical animal studies and clinical settings for the treatment and regeneration of the periodontium.

  4. Aggression in Drosophila.

    PubMed

    Kravitz, Edward A; Fernandez, Maria de la Paz

    2015-10-01

    Aggression is used by essentially all species of animals to gain access to desired resources, including territory, food, and potential mates: Fruit flies are no exception. In Drosophila, both males and females compete in same sex fights for resources, but only males establish hierarchical relationships. Many investigators now study aggression using the fruit fly model, mainly because (a) aggression in fruit flies is a quantifiable well-defined and easily evoked behavior; (b) powerful genetic methods allow investigators to manipulate genes of interest at any place or time during embryonic, larval, pupal or adult life, and while flies are behaving; (c) the growth of the relatively new field of optogenetics makes physiological studies possible at single neuron levels despite the small sizes of neurons and other types of cells in fly brains; and (d) the rearing of fly stocks with their short generation times and limited growth space requirements can easily be performed at relatively low cost in most laboratories. This review begins with an examination of the behavior, both from a historical perspective and then from the birth of the "modern" era of studies of aggression in fruit flies including its quantitative analysis. The review continues with examinations of the roles of genes, neurotransmitters and neurohormones, peptides, nutritional and metabolic status, and surface cuticular hydrocarbons in the initiation and maintenance of aggression. It concludes with suggestions for future studies with this important model system.

  5. The Effects of Cigarette Smoke Condensate and Nicotine on Periodontal Tissue in a Periodontitis Model Mouse.

    PubMed

    Kubota, Mikiko; Yanagita, Manabu; Mori, Kenta; Hasegawa, Shiori; Yamashita, Motozo; Yamada, Satoru; Kitamura, Masahiro; Murakami, Shinya

    2016-01-01

    Cigarette smoking is a major lifestyle-related risk factor for periodontal diseases. However, the pathophysiological role of cigarette smoking in periodontal disease has yet to be fully elucidated. Here we report that the systemic administration of cigarette smoke condensate or nicotine, which is the major ingredient of cigarette smoke, augmented alveolar bone loss. Concomitantly, the number of osteoclasts in periodontal tissues increased and the expression of receptor activator of nuclear factor κB ligand was upregulated at the ligated side in mice with periodontitis. Nicotine also attenuated alveolar bone repair after ligature removal. These observations highlight the destruction of periodontal tissue by smoking and the unfavorable clinical course of periodontal disease in patients with a cigarette smoking habit. The present study demonstrates that periodontal disease models are useful for elucidating the pathogenesis of cigarette smoking-related periodontal diseases. PMID:27203240

  6. [Gender-related marker pathogens of periodontal disease in chronic periodontitis].

    PubMed

    Zorina, O A; Aymadinova, N K; Basova, A A; Shibaeva, A V; Rebrikov, D V

    2016-01-01

    By using qPCR system, women as well as men were found to have an equal periodontal pathogen colonization. However, the women are subjected to have a higher risk of chronic periodontitis onsets. Women with the chronic periodontitis usually expose an evident hypercolonization with a single pathogen. P. gingivalis is the most prevalent causative agent of the chronic periodontitis in women but not in men. In health as well as in the chronic periodontitis a complex of periodontal pathogens forms such as P. gingivalis, P. intermedia, T. forsythensis and T. denticola. T. forsythensis demonstrates the highest correlation with the chronic periodontitis onset in men. Our data allow us to prove T. forsythensis playing the key role in the forming of periodontal pathogen complex.

  7. The Effects of Cigarette Smoke Condensate and Nicotine on Periodontal Tissue in a Periodontitis Model Mouse

    PubMed Central

    Mori, Kenta; Hasegawa, Shiori; Yamashita, Motozo; Yamada, Satoru; Kitamura, Masahiro; Murakami, Shinya

    2016-01-01

    Cigarette smoking is a major lifestyle-related risk factor for periodontal diseases. However, the pathophysiological role of cigarette smoking in periodontal disease has yet to be fully elucidated. Here we report that the systemic administration of cigarette smoke condensate or nicotine, which is the major ingredient of cigarette smoke, augmented alveolar bone loss. Concomitantly, the number of osteoclasts in periodontal tissues increased and the expression of receptor activator of nuclear factor κB ligand was upregulated at the ligated side in mice with periodontitis. Nicotine also attenuated alveolar bone repair after ligature removal. These observations highlight the destruction of periodontal tissue by smoking and the unfavorable clinical course of periodontal disease in patients with a cigarette smoking habit. The present study demonstrates that periodontal disease models are useful for elucidating the pathogenesis of cigarette smoking-related periodontal diseases. PMID:27203240

  8. Large-scale Advanced Prop-fan (LAP) high speed wind tunnel test report

    NASA Technical Reports Server (NTRS)

    Campbell, William A.; Wainauski, Harold S.; Arseneaux, Peter J.

    1988-01-01

    High Speed Wind Tunnel testing of the SR-7L Large Scale Advanced Prop-Fan (LAP) is reported. The LAP is a 2.74 meter (9.0 ft) diameter, 8-bladed tractor type rated for 4475 KW (6000 SHP) at 1698 rpm. It was designated and built by Hamilton Standard under contract to the NASA Lewis Research Center. The LAP employs thin swept blades to provide efficient propulsion at flight speeds up to Mach .85. Testing was conducted in the ONERA S1-MA Atmospheric Wind Tunnel in Modane, France. The test objectives were to confirm that the LAP is free from high speed classical flutter, determine the structural and aerodynamic response to angular inflow, measure blade surface pressures (static and dynamic) and evaluate the aerodynamic performance at various blade angles, rotational speeds and Mach numbers. The measured structural and aerodynamic performance of the LAP correlated well with analytical predictions thereby providing confidence in the computer prediction codes used for the design. There were no signs of classical flutter throughout all phases of the test up to and including the 0.84 maximum Mach number achieved. Steady and unsteady blade surface pressures were successfully measured for a wide range of Mach numbers, inflow angles, rotational speeds and blade angles. No barriers were discovered that would prevent proceeding with the PTA (Prop-Fan Test Assessment) Flight Test Program scheduled for early 1987.

  9. Evaluation of pediatric use patterns and performance of lap shoulder belt systems in the center rear.

    PubMed

    Arbogast, Kristy B; Durbin, Dennis R; Kallan, Michael J; Winston, Flaura K

    2004-01-01

    Lap and shoulder belts have been required in rear outboard positions since 1989. A recent congressional mandate encouraged the requirement of a lap and shoulder belt in the center rear seat position. This study utilized Data from the Partners for Child Passenger Safety study, a large-scale child-focused crash surveillance system, to quantify changes in seating patterns for children in vehicles that already have this feature compared to those which do not and measured the safety benefit associated with the provision of a shoulder belt in the center rear seat position. The data demonstrate that the presence of a shoulder belt in the center rear seating position influences seating practices only when there is a single child occupant in the vehicle. Belted children in the center rear of vehicles equipped with a lap shoulder belt are at an 81% reduction in risk of injury than those belted in the center rear equipped with a lap only belt. The data suggest that by requiring lap shoulder belts in the center rear, benefits would be realized to belted children, specifically the 4-8 year old group.

  10. Application of the lag-after-pulsed-separation (LAPS) flow meter to different protein solutions.

    PubMed

    Sengupta, Shramik; Mahmud, Goher; Chiou, Daniel J; Ziaie, Babak; Barocas, Victor H

    2005-02-01

    A lag after pulsed separation (LAPS) meter was previously developed to measure flow rates of protein solutions. The LAPS meter operates on the time-of-flight principle. An upstream event (electrophoretic concentration of the particles in one section of the device) is detected downstream (by change in ac resistance). The time lag between the event and its detection is inversely proportional to the fluid flow rate. We demonstrate the ability of the LAPS meter to measure the flow rate of solutions containing one or more charged biomacromolecules or particles. A prototype of the LAPS meter was used to measure flow rates of solutions of model proteins [bovine serum albumin (BSA), lysozyme and hemoglobin] and mixtures of BSA and lysozyme. Flow rates of 10-50 microl min(-1)(average velocities of 0.24-1.2 mm s(-1)) were measured. When a single ac measurement was used, the results were solution-dependent, which we attribute to the interface between the protein solution and the ac electrodes. A differential mode, in which the signal from a positive and a negative dc pulse were subtracted from each other, eliminated interfacial effects and led to a single universal (solution-independent) calibration curve. The LAPS meter can be used as a non-invasive, no-moving-parts flow sensor in any microfluidic system (such as drug delivery devices or micro-reactor arrays) where one needs to measure the flow rate of a solution or a suspension containing charged species such as proteins or cells.

  11. Poor periodontal health: A cancer risk?

    PubMed Central

    Rajesh, K. S.; Thomas, Deepak; Hegde, Shashikanth; Kumar, M. S. Arun

    2013-01-01

    Evidence indicates that chronic infections and inflammation are associated with increased risk of cancer development. There has also been considerable evidence that proves the interrelationship between bacterial and viral infections and carcinogenesis. Periodontitis is a chronic oral infection thought to be caused by gram-negative anaerobic bacteria in the dental biofilm. Periodontal bacteria and viruses may act synergistically to cause periodontitis. Many studies have shown that periodontal pockets may act as reservoirs for human papilloma virus, cytomegalovirus, Epstein Barr virus, and suspected agents associated with oral cancer. Periodontitis, characterized by epithelial proliferation and migration, results in a chronic release of inflammatory cytokines, chemokines, growth factors, prostaglandins, and enzymes, all of which are associated with cancer development. This review article intends to shed light on the association between periodontal health and carcinogenesis. PMID:24554877

  12. Associations between Periodontal Microbiota and Death Rates

    PubMed Central

    Chiu, Chung-Jung; Chang, Min-Lee; Taylor, Allen

    2016-01-01

    It is conceived that specific combinations of periodontal bacteria are associated with risk for the various forms of periodontitis. We hypothesized that such specificity is also related to human cause-specific death rates. We tested this hypothesis in a representative sample of the US population followed for a mean duration of 11 years and found that two specific patterns of 21 serum antibodies against periodontal bacteria were significantly associated with increased all-cause and/or diabetes-related mortalities. These data suggested that specific combinations of periodontal bacteria, even without inducing clinically significant periodontitis, may have a significant impact on human cause-specific death rates. Our findings implied that increased disease and mortality risk could be transmittable via the transfer of oral microbiota, and that developing personalized strategies and maintaining healthy oral microbiota beyond protection against periodontitis would be important to manage the risk. PMID:27748442

  13. Periodontal pathogens in erupting third molars of periodontally healthy subjects.

    PubMed

    Rajasuo, A; Sihvonen, O J; Peltola, M; Meurman, J H

    2007-09-01

    The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Tannerella forsythensis in bacteriologic samples of 5-7-mm deep mandibular third-molar pericoronal pockets was analysed by polymerase chain reaction, to test the hypothesis that these sites would harbour the bacteria. The patients were periodontally healthy 20-year-old Finnish male conscripts. Sixteen had acute pericoronitis, 28 chronic pericoronitis, and 15 were symptom-free controls. A. actinomycetemcomitans was detected in only 7% of the samples from chronic pericoronitis cases, whereas P. gingivalis was positive in 20% of the symptom-free versus 69% (P = 0.018) of the acute and 57% (P = 0.044) of the chronic cases. The percentages for P. intermedia were 93, 94 and 93%, and for T. forsythensis 47, 63 and 57%, respectively. These results confirm that, apart from A. actinomycetemcomitans, periodontopathogens are common in third-molar sites in periodontally healthy individuals.

  14. Effect of non-surgical periodontal treatment on transferrin serum levels in patients with chronic periodontitis

    PubMed Central

    Shirmohamadi, Adileh; Chitsazi, Mohamad Taghi; Faramarzi, Masoumeh; Salari, Ashkan; Naser Alavi, Fereshteh; Pashazadeh, Nazila

    2016-01-01

    Background. Transferrin is a negative acute phase protein, which decreases during inflammation and infection. The aim of the present investigation was to evaluate changes in the transferrin serum levels subsequent to non-surgical treatment of chronic periodontal disease. Methods. Twenty patients with chronic periodontitis and 20 systemically healthy subjects without periodontal disease, who had referred to Tabriz Faculty of Dentistry, were selected. Transferrin serum levels and clinical periodontal parameters (pocket depth, clinical attachment level, gingival index, bleeding index and plaque index) were measured at baseline and 3 months after non-surgical periodontal treatment. Data were analyzed with descriptive statistical methods (means ± standard deviations). Independent samples t-test was used to compare transferrin serum levels and clinical variables between the test and control groups. Paired samples t-test was used in the test group for comparisons before and after treatment. Statistical significance was set at P < 0.05. Results. The mean transferrin serum level in patients with chronic periodontitis (213.1 ± 9.2 mg/dL) was significantly less than that in periodontally healthy subjects (307.8 ± 11.7 mg/dL). Three months after periodontal treatment, the transferrin serum level increased significantly (298.3 ± 7.6 mg/dL) and approached the levels in periodontally healthy subjects (P < 0.05). Conclusion. The decrease and increase in transferrin serum levels with periodontal disease and periodontal treatment, respectively, indicated an inverse relationship between transferrin serum levels and chronic periodontitis.

  15. Emdogain--periodontal regeneration based on biomimicry.

    PubMed

    Gestrelius, S; Lyngstadaas, S P; Hammarström, L

    2000-06-01

    Biomimicry has been introduced as a term for innovations inspired by nature [1]. Such innovations may appear in almost every part of modern society. This review on the effects of enamel matrix proteins on the formation of cementum and the development of emdogain for regeneration of periodontal tissues lost due to periodontitis shows an example of biomimicry in dentistry. Findings from clinical and laboratory investigations are summarized and the biological basis for enamel matrix-induced periodontal regeneration is discussed.

  16. Effect of gene polymorphisms on periodontal diseases

    PubMed Central

    Tarannum, Fouzia; Faizuddin, Mohamed

    2012-01-01

    Periodontal diseases are inflammatory diseases of supporting structures of the tooth. It results in the destruction of the supporting structures and most of the destructive processes involved are host derived. The processes leading to destruction and regeneration of the destroyed tissues are of great interest to both researchers and clinicians. The selective susceptibility of subjects for periodontitis has remained an enigma and wide varieties of risk factors have been implicated for the manifestation and progression of periodontitis. Genetic factors have been a new addition to the list of risk factors for periodontal diseases. With the availability of human genome sequence and the knowledge of the complement of the genes, it should be possible to identify the metabolic pathways involved in periodontal destruction and regeneration. Most forms of periodontitis represent a life-long account of interactions between the genome, behaviour, and environment. The current practical utility of genetic knowledge in periodontitis is limited. The information contained within the human genome can potentially lead to a better understanding of the control mechanisms modulating the production of inflammatory mediators as well as provides potential therapeutic targets for periodontal disease. Allelic variants at multiple gene loci probably influence periodontitis susceptibility. PMID:22754216

  17. Interaction between periodontitis and liver diseases

    PubMed Central

    Han, Pengyu; Sun, Dianxing; Yang, Jie

    2016-01-01

    Periodontitis is an oral disease that is highly prevalent worldwide, with a prevalence of 30–50% of the population in developed countries, but only ~10% present with severe forms. It is also estimated that periodontitis results in worldwide productivity losses amounting to ~54 billion USD yearly. In addition to the damage it causes to oral health, periodontitis also affects other types of disease. Numerous studies have confirmed the association between periodontitis and systemic diseases, such as diabetes, respiratory disease, osteoporosis and cardiovascular disease. Increasing evidence also indicated that periodontitis may participate in the progression of liver diseases, such as non-alcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma, as well as affecting liver transplantation. However, to the best of our knowledge, there are currently no reviews elaborating upon the possible links between periodontitis and liver diseases. Therefore, the current review summarizes the human trials and animal experiments that have been conducted to investigate the correlation between periodontitis and liver diseases. Furthermore, in the present review, certain mechanisms that have been postulated to be responsible for the role of periodontitis in liver diseases (such as bacteria, pro-inflammatory mediators and oxidative stress) are considered. The aim of the review is to introduce the hypothesis that periodontitis may be important in the progression of liver disease, thus providing dentists and physicians with an improved understanding of this issue. PMID:27588170

  18. Periodontal Diagnosis Affected by Variation in Terminology

    PubMed Central

    Martin, John A.; Grill, Ashley C.; Matthews, Abigail G.; Vena, Don; Thompson, Van P.; Craig, Ronald G.; Curro, Frederick A.

    2014-01-01

    Background The randomized case presentation (RCP) study is designed to assess the degree of diagnostic accuracy for described periodontal cases. This is to lay the basis for practitioner calibration in the Practitioners Engaged in Applied Research and Learning (PEARL) Network for future clinical studies. Methods The RCP consisted of 10 case scenarios ranging from periodontal health to gingivitis and mild, moderate, and severe periodontitis. Respondents were asked to diagnose the described cases. Survey diagnoses were compared to two existing classifications of periodontal disease status. The RCP was administered via a proprietary electronic data capture system maintained by the PEARL Data Coordinating Center. Standard analytic techniques, including frequency counts and cross-tabulations, were used for categorical data with mean and standard deviation and median values reported for continuous data elements. Results Demonstrable variations in periodontal assessment for health, gingivitis, and mild, moderate, and severe periodontitis were found among the 130 PEARL general practitioners who participated in the RCP survey. The highest agreement for diagnosis among dentists was for severe periodontitis (88%) and the lowest for gingivitis (55%). The highest percentage of variation was found in cases with health and gingivitis. Conclusions There was variation among PEARL practitioners in periodontal diagnosis that may affect treatment outcomes. Our findings add clinical support to recent publications suggesting a need for standardization of terminology in periodontitis diagnosis. PMID:22702518

  19. Lap belt iliac wing fracture: a predictor of bowel injury in children.

    PubMed

    Emery, Kathleen H

    2002-12-01

    Lap belt restraints in motor vehicle collisions have been associated with a variety of injuries, mainly bowel and lumbar spine. Cephalad positioning of the belt over the intended position across the anterior superior iliac spines (which typically occurs in younger children) is thought to be responsible for the observed bowel injuries. We report two pediatric patients, both restrained by lap belts in high-speed collisions, who suffered iliac wing fractures in addition to bowel injuries. Unexplained free peritoneal fluid was the sole CT finding in one patient (a teenage girl) who had a delay in diagnosis of bowel perforation. These cases illustrate the high frequency of bowel injury in pediatric patients with iliac wing fractures associated with lap belt use.

  20. Measurements of fuselage skin strains and displacements near a longitudinal lap joint in a pressurized aircraft

    NASA Technical Reports Server (NTRS)

    Phillips, Edward P.; Britt, Vicki O.

    1991-01-01

    Strains and displacements in a small area near a longitudinal lap joint in the fuselage skin of a B737 aircraft were measured during a pressurization cycle to a differential pressure of 6.2 psi while the aircraft was on the ground. It was found that hoop strains were higher than longitudinal strains at each location; membrane strains in the unreinforced skin were higher than in the joint; membrane strains in the hoop direction, as well as radial displacements, tended to be highest at the mid-bay location between skin reinforcements; significant bending in the hoop direction occurred in the joint and in the skin near the joint, and the bending was unsymmetrically distributed about the stringer at the middle of the joint; and radial displacements were unsymmetrically distributed across the lap joint. The interpretation of the strain gage data for locations on the bonded and riveted lap joint assumed that the joint did not contain disbonded areas.

  1. Large-scale Advanced Prop-fan (LAP) technology assessment report

    NASA Technical Reports Server (NTRS)

    Degeorge, C. L.

    1988-01-01

    The technologically significant findings and accomplishments of the Large Scale Advanced Prop-Fan (LAP) program in the areas of aerodynamics, aeroelasticity, acoustics and materials and fabrication are described. The extent to which the program goals related to these disciplines were achieved is discussed, and recommendations for additional research are presented. The LAP program consisted of the design, manufacture and testing of a near full-scale Prop-Fan or advanced turboprop capable of operating efficiently at speeds to Mach .8. An aeroelastically scaled model of the LAP was also designed and fabricated. The goal of the program was to acquire data on Prop-Fan performance that would indicate the technology readiness of Prop-Fans for practical applications in commercial and military aviation.

  2. Grain decoration in aluminum oxynitride (ALON) from polishing on bound abrasive laps

    NASA Astrophysics Data System (ADS)

    Gregg, Leslie L.; Marino, Anne E.; Hayes, Jennifer C.; Jacobs, Stephen D.

    2004-01-01

    Aluminum oxynitride (ALON) is a polycrystalline material that has proven difficult to polish due to its grain structure. Bound abrasives are an effective means for polishing ALON, and work is being done with them to obtain good surfaces, with reasonable removal rates. Laps consisting of abrasives bound in epoxy matrices were created for polishing ALON. The effects of varying abrasive type, abrasive concentration, lap shape, coolant and load were studied. Metrology procedures were developed to monitor different aspects of the grain structure and numerically evaluate grain boundary decoration. Strategies were developed to polish ALON at acceptable rates with reasonably good surface quality. Work is directed toward finding optimal bound abrasive lap formulations that can be fabricated into ring and/or contour tools for testing on CNC machining platforms.

  3. Grain decoration in aluminum oxynitride (ALON) from polishing on bound abrasive laps

    NASA Astrophysics Data System (ADS)

    Marino, Anne E.; Hayes, Jennifer; Gregg, Leslie L.; Jacobs, Stephen D.

    2003-05-01

    Aluminum oxynitride (ALON) is a material with desirable qualities for a variety of applications that has proven difficult to polish because of its grain structure. Bound abrasives may prove to be an effective means of polishing it, and work is being done with them to obtain good surfaces on ALON, with reasonable removal rates. Laps consisting of abrasives bound in epoxy matrices have been created for polishing ALON. The effects of varying abrasive type, abrasive concentration, lap shape, coolant and load are being studied. Metrology procedures are being developed to monitor different aspects of the grain structure and numerically evaluate its decoration. Strategies have been developed to polish ALON at acceptable rates with reasonably good surface quality. Work is directed toward finding optimal bound abrasive lap formulations that can be fabricated into ring and/or contour tools for testing on CNC machining platforms.

  4. EFFECT OF TOOL FEATURE ON THE JOINT STRENGTH OF DISSIMILAR FRICTION STIR LAP WELDS

    SciTech Connect

    Jana, Saumyadeep; Hovanski, Yuri; Grant, Glenn J.; Mattlin, Karl F.

    2011-04-25

    Several variations of friction stir tools were used to investigate the effects on the joint strengths of dissimilar friction stir lap welds. In the present lap weld configuration the top sheet was a 2.32 mm thick Mg (AZ 31) alloy. The bottom sheet consisted of two different steels, a (i) 0.8 mm thick electro-galvanized (EG) mild steel, or a (ii) 1.5 mm thick hot dip galvanized (HDG) high strength low alloy (HSLA) steel. Initially the tool shape was modified to accommodate the material, at which point the tool geometry was fixed. With a fixed tool geometry an additional feature was added to the pin bottom on one of the tools by incorporating a short hard insert, which would act as a stronger bottom sheet cutter. The effects of such modification on the unguided lap shear strength, and associated microstructural changes are discussed in this study.

  5. Failure strength prediction for adhesively bonded single lap joints

    NASA Astrophysics Data System (ADS)

    Rahman, Niat Mahmud

    For adhesively bonded joint, failure strength depends on many factors such as material properties (both adhesive and adherend), specimen geometries, test environments, surface preparation procedures, etc. Failure occurs inside constitutive materials or along joint interfaces. Based on location, adhesively bonded failure mode can be classified as adhesive failure mode, cohesive failure mode and adherend failure mode. Failure mode directly affects the failure strength of joint. For last eight decades, researchers have developed analytical, empirical or semi-empirical methods capable of predicting failure strength for adhesively bonded joints generating either cohesive failure or adherend failure. Applicability of most of the methods is limited to particular cases. In this research, different failure modes for single lap joints (SLJs) were generated experimentally using epoxy based paste adhesive. Based on experimental data and analytical study, simplified failure prediction methods were developed for each failure mode. For adhesive failure mode, it is observed that peel stress distributions concur along interface near crack initiation points. All SLJs for this test endured consistent surface treatments. Geometric parameters of the joints were varied to study their effect on failure strength. Peel stress distributions were calculated using finite analysis (FEA). Based on peel stress distribution near crack initiation point, a failure model is proposed. Numerous analytical, empirical and semi-empirical models are available for predicting failure strengths of SLJs generating cohesive failures. However, most of the methods in the literature failed to capture failure behavior of SLJs having thickness of adhesive layer as variable. Cohesive failure mode was generated experimentally using aluminum as adherend and epoxy adhesive considering thickness of adhesive layers as variable within SLJs. Comparative study was performed among various methods. It was observed that

  6. Aggressiveness and Disobedience

    ERIC Educational Resources Information Center

    Vaaland, Grete Sorensen; Idsoe, Thormod; Roland, Erling

    2011-01-01

    This study aims to conceptualize disobedient pupil behavior within the more general framework of antisocial behavior and to reveal how two forms of aggressiveness are related to disobedience. Disobedience, in the context of this article, covers disruptive pupil behavior or discipline problems when the pupil is aware of breaking a standard set by…

  7. Neuroimaging and Aggression.

    ERIC Educational Resources Information Center

    Mills, Shari; Raine, Adrian

    1994-01-01

    Brain imaging research allows direct assessment of structural and functional brain abnormalities, and thereby provides an improved methodology for studying neurobiological factors predisposing to violent and aggressive behavior. This paper reviews 20 brain imaging studies using four different types of neuroimaging techniques that were conducted in…

  8. Intellectual Competence and Aggression.

    ERIC Educational Resources Information Center

    Huesmann, L. Rowell; Yarmel, Patty Warnick

    Using data from a broader longitudinal study, this investigation explores within-subject and cross-generational stability of intellectual competence and the relationship of such stability to aggressive behavior. Data were gathered three times (when subjects' modal age was 8, 19, and 30 years). Initially, subjects included the entire population…

  9. Stability of Aggressive Behavior.

    ERIC Educational Resources Information Center

    Eron, Leonard D.; Huesmann, L. Rowell

    As indicated by multiple measures (including overt criminal behavior), stability of aggressive behavior was investigated across 22 years for males and females in a variety of situations. Originally, subjects included the entire population enrolled in the third grade in a semi-rural county in New York State. The sample included approximately 870…

  10. Relational Aggression among Students

    ERIC Educational Resources Information Center

    Young, Ellie L.; Nelson, David A.; Hottle, America B.; Warburton, Brittney; Young, Bryan K.

    2011-01-01

    "Relational aggression" refers to harm within relationships caused by covert bullying or manipulative behavior. Examples include isolating a youth from his or her group of friends (social exclusion), threatening to stop talking to a friend (the silent treatment), or spreading gossip and rumors by email. This type of bullying tends to be…

  11. Human Aggression and Suicide

    ERIC Educational Resources Information Center

    Brown, Gerald L.; Goodwin, Frederick K

    1986-01-01

    The central nervous system transmitter serontonin may be altered in aggressive/impulsive and suicidal behaviors in humans. These reports are largely consistent with animal data, and constitute one of the most highly replicated set of findings in biological psychiatry. Suggests that some suicidal behavior may be a special kind of aggressive…

  12. Initial periodontal screening and radiographic findings - A comparison of two methods to evaluate the periodontal situation

    PubMed Central

    2011-01-01

    Background The periodontal screening index (PSI) is an element of the initial dental examination. The PSI provides information on the periodontal situation and allows a first estimation of the treatment required. The dental panoramic tomography (DPT) indicates the proximal bone loss, thus also allowing conclusions on the periodontal situation. In this study, the results of both methods in determining the periodontal situation are compared. Methods The clinical examination covered DMF-T, QHI, and PSI scores at four proximal sites per tooth; the examining dentist was unaware of the radiographic finding. Based on the PSI scores, the findings were diagnosed as follows: score 0 - 2 "no periodontitis", score 3 and 4 "periodontitis". Independent of the locality and time of the clinical evaluation, two dentists examined the DPTs of the subjects. The results were classified as follows: no bone loss = "no periodontitis", and bone loss = "periodontitis". Results 112 male subjects (age 18 to 58, Ø 37.7 ± 8 years) were examined. Regarding the PSI, 17 subjects were diagnosed "no periodontitis" and 95 subjects "periodontitis". According to the evaluation of the DPTs, 70 subjects were diagnosed "no periodontitis" and 42 "periodontitis". A comparison of both methods revealed that the diagnosis "no periodontitis" corresponded in 17 cases and "periodontitis" in 42 cases (53%). In 47% (53 cases) the results were not congruent. The difference between both methods was statistically significant (p < 0.001; kappa = 0.194). Conclusion The present study shows that the initial assessment of the periodontal situation significantly depends on the method of evaluation. PMID:21235747

  13. Parents' Aggressive Influences and Children's Aggressive Problem Solutions with Peers

    ERIC Educational Resources Information Center

    Duman, Sarah; Margolin, Gayla

    2007-01-01

    This study examined children's aggressive and assertive solutions to hypothetical peer scenarios in relation to parents' responses to similar hypothetical social scenarios and parents' actual marital aggression. The study included 118 children ages 9 to 10 years old and their mothers and fathers. Children's aggressive solutions correlated with…

  14. Relational Aggression and Physical Aggression among Adolescent Cook Islands Students

    ERIC Educational Resources Information Center

    Page, Angela; Smith, Lisa F.

    2016-01-01

    Both physical and relational aggression are characterised by the intent to harm another. Physical aggression includes direct behaviours such as hitting or kicking; relational aggression involves behaviours designed to damage relationships, such as excluding others, spreading rumours, and delivering threats and verbal abuse. This study extended…

  15. HA95 and LAP2 beta mediate a novel chromatin-nuclear envelope interaction implicated in initiation of DNA replication.

    PubMed

    Martins, Sandra; Eikvar, Sissel; Furukawa, Kazuhiro; Collas, Philippe

    2003-01-20

    HA95 is a chromatin-associated protein that interfaces the nuclear envelope (NE) and chromatin. We report an interaction between HA95 and the inner nuclear membrane protein lamina-associated polypeptide (LAP) 2 beta, and a role of this association in initiation of DNA replication. Precipitation of GST-LAP2 beta fusion proteins and overlays of immobilized HA95 indicate that a first HA95-binding region lies within amino acids 137-242 of LAP2 beta. A second domain sufficient to bind HA95 colocalizes with the lamin B-binding domain of LAP2beta at residues 299-373. HA95-LAP2 beta interaction is not required for NE formation. However, disruption of the association of HA95 with the NH2-terminal HA95-binding domain of LAP2 beta abolishes the initiation, but not elongation, of DNA replication in purified G1 phase nuclei incubated in S-phase extract. Inhibition of replication initiation correlates with proteasome-mediated proteolysis of Cdc6, a component of the prereplication complex. Rescue of Cdc6 degradation with proteasome inhibitors restores replication. We propose that an interaction of LAP2beta, or LAP2 proteins, with HA95 is involved in the control of initiation of DNA replication. PMID:12538639

  16. Lap-belt injury with complete avulsion of the spinal cord and cauda equina.

    PubMed

    Tubbs, R Shane; Golden, Blake; Doyle, Scott; Grabb, Paul A; Oakes, W Jerry

    2006-10-01

    The authors report a child who was involved in an automobile accident. The patient was restrained by a rear seat lap belt. Radiological examination revealed an L4 Chance-type fracture and ligamentous disruption at the L4-L5 interval. During superficial dissection of the paraspinal muscles for a spinal fusion procedure, the cauda equina and the lower spinal cord (several centimeters) were visible, completely transected and herniated into the extraspinal space through a disrupted thoracolumbar fascia. The clinician should be aware of the potentially devastating results following a lap-belt injury in which a Chance fracture is produced.

  17. Non destructive evaluation of adhesively bonded carbon fiber reinforced composite lap joints with varied bond quality

    NASA Astrophysics Data System (ADS)

    Vijayakumar, R. L.; Bhat, M. R.; Murthy, C. R. L.

    2012-05-01

    Structural adhesive bonding is widely used to execute assemblies in automobile and aerospace structures. The quality and reliability of these bonded joints must be ensured during service. In this context non destructive evaluation of these bonded structures play an important role. Evaluation of adhesively bonded composite single lap shear joints has been attempted through experimental approach. Series of tests, non-destructive as well as destructive were performed on different sets of carbon fiber reinforced polymer (CFRP) composite lap joint specimens with varied bond quality. Details of the experimental investigations carried out and the outcome are presented in this paper.

  18. Reverse Discrimination and Aggressive Behavior.

    ERIC Educational Resources Information Center

    Johnson, Stephen D.

    1980-01-01

    White subjects were aggressive toward Black opponents when contest results appeared to reflect elements of reverse discrimination; but they showed less aggressive behavior toward Black opponents when they thought their loss was due to their opponents' superior ability. (RL)

  19. Gene Polymorphisms in Chronic Periodontitis

    PubMed Central

    Laine, Marja L.; Loos, Bruno G.; Crielaard, W.

    2010-01-01

    We aimed to conduct a review of the literature for gene polymorphisms associated with chronic periodontitis (CP) susceptibility. A comprehensive search of the literature in English was performed using the keywords: periodontitis, periodontal disease, combined with the words genes, mutation, or polymorphism. Candidate gene polymorphism studies with a case-control design and reported genotype frequencies in CP patients were searched and reviewed. There is growing evidence that polymorphisms in the IL1, IL6, IL10, vitamin D receptor, and CD14 genes may be associated with CP in certain populations. However, carriage rates of the rare (R)-allele of any polymorphism varied considerably among studies and most of the studies appeared under-powered and did not correct for other risk factors. Larger cohorts, well-defined phenotypes, control for other risk factors, and analysis of multiple genes and polymorphisms within the same pathway are needed to get a more comprehensive insight into the contribution of gene polymorphisms in CP. PMID:20339487

  20. Periodontal Proteomics: Wonders Never Cease!

    PubMed Central

    Grover, Harpreet Singh; Kapoor, Shalini; Saksena, Neha

    2013-01-01

    Proteins are vital parts of living organisms, as they are integral components of the physiological metabolic pathways of cells. Periodontal tissues comprise multicompartmental groups of interacting cells and matrices that provide continuous support, attachment, proprioception, and physical protection for the teeth. The proteome map, that is, complete catalogue of the matrix and cellular proteins expressed in alveolar bone, cementum, periodontal ligament, and gingiva, is to be explored for more in-depth understanding of periodontium. The ongoing research to understand the signalling pathways that allow cells to divide, differentiate, and die in controlled manner has brought us to the era of proteomics. Proteomics is defined as the study of all proteins including their relative abundance, distribution, posttranslational modifications, functions, and interactions with other macromolecules, in a given cell or organism within a given environment and at a specific stage in the cell cycle. Its application to periodontal science can be used to monitor health status, disease onset, treatment response, and outcome. Proteomics can offer answers to critical, unresolved questions such as the biological basis for the heterogeneity in gingival, alveolar bone, and cemental cell populations. PMID:24490073

  1. "Ladettes," Social Representations, and Aggression.

    ERIC Educational Resources Information Center

    Muncer, Steven; Campbell, Anne; Jervis, Victoria; Lewis, Rachel

    2001-01-01

    Examined the relationship among "laddishness" (traditionally working-class, youthful, male social behavior by young women), social representations, and self-reported aggression among English college students. Measures of aggression correlated with holding more instrumental representations of aggression. Females indicated no relationship between…

  2. Children's normative beliefs about aggression and aggressive behavior.

    PubMed

    Huesmann, L R; Guerra, N G

    1997-02-01

    Normative beliefs have been defined as self-regulating beliefs about the appropriateness of social behaviors. In 2 studies the authors revised their scale for assessing normative beliefs about aggression, found that it is reliable and valid for use with elementary school children, and investigated the longitudinal relation between normative beliefs about aggression and aggressive behavior in a large sample of elementary school children living in poor urban neighborhoods. Using data obtained in 2 waves of observations 1 year apart, the authors found that children tended to approve more of aggression as they grew older and that this increase appeared to be correlated with increases in aggressive behavior. More important, although individual differences in aggressive behavior predicted subsequent differences in normative beliefs in younger children, individual differences in aggressive behavior were predicted by preceding differences in normative beliefs in older children. PMID:9107008

  3. Aggressive drowsy cache cells

    NASA Astrophysics Data System (ADS)

    Shawkey, H. A.; El-Dib, D. A.; Abid, Z.

    2010-01-01

    An aggressive drowsy cache block management, where the cache block is forced into drowsy mode all the time except during write and read operations, is proposed. The word line (WL) is used to enable the normal supply voltage (V DD_high) to the cache line only when it is accessed for read or write whereas the drowsy supply voltage (V DD_low) is enabled to the cache cell otherwise. The proposed block management neither needs extra cycles nor extra control signals to wake the drowsy cache cell, thereby reducing the performance penalty associated with traditional drowsy caches. In fact, the proposed aggressive drowsy mode can reduce the total power consumption of the traditional drowsy mode by 13% or even more, depending on the cache access rate, access frequency and the CMOS technology used.

  4. Uncovering the molecular networks in periodontitis

    PubMed Central

    Trindade, Fábio; Oppenheim, Frank G.; Helmerhorst, Eva J.; Amado, Francisco; Gomes, Pedro S.; Vitorino, Rui

    2015-01-01

    Periodontitis is a complex immune-inflammatory disease that results from a preestablished infection in gingiva, mainly due to Gram-negative bacteria that colonize deeper in gingival sulcus and latter periodontal pocket. Host inflammatory and immune responses have both protective and destructive roles. Although cytokines, prostaglandins, and proteases struggle against microbial burden, these molecules promote connective tissue loss and alveolar bone resorption, leading to several histopathological changes, namely destruction of periodontal ligament, deepening of periodontal pocket, and bone loss, which can converge to attain tooth loss. Despite the efforts of genomics, transcriptomics, proteomics/peptidomics, and metabolomics, there is no available biomarker for periodontitis diagnosis, prognosis, and treatment evaluation, which could assist on the established clinical evaluation. Nevertheless, some genes, transcripts, proteins and metabolites have already shown a different expression in healthy subjects and in patients. Though, so far, ‘omics approaches only disclosed the host inflammatory response as a consequence of microbial invasion in periodontitis and the diagnosis in periodontitis still relies on clinical parameters, thus a molecular tool for assessing periodontitis lacks in current dental medicine paradigm. Saliva and gingival crevicular fluid have been attracting researchers due to their diagnostic potential, ease, and noninvasive nature of collection. Each one of these fluids has some advantages and disadvantages that are discussed in this review. PMID:24828325

  5. [Diabetes and periodontitis: A bidirectional relationship].

    PubMed

    Bascones-Martínez, Antonio; Muñoz-Corcuera, Marta; Bascones-Ilundain, Jaime

    2015-07-01

    Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, a defect in insulin action or a combination of both. Periodontitis is now considered a chronic localized infection of the oral cavity that can trigger inflammatory host immune responses at local and systemic levels, and can also be a source of bacteremia. It is now known that periodontitis has an influence on the pathogenesis of certain systemic diseases. The biological relationship between diabetes and periodontal disease is well documented. In the mid-90s sufficient scientific support for the association between diabetes and periodontitis was published, and periodontitis was designated as the sixth complication of diabetes. There have been studies that show an improvement in both clinical and immunological parameters of periodontitis and glycemic control in long-term diabetes after treatment of periodontal disease. In addition, scientific evidence confirms that poorer glycemic control contributes to a worse periodontal condition. The interplay between the 2 conditions highlights the importance of the need for a good communication between the internist and dentist about diabetic patients, considering always the possibility that the 2 diseases may be occurring simultaneously in order to ensure an early diagnosis of both.

  6. An update on periodontic-orthodontic interrelationships

    PubMed Central

    Dannan, Aous

    2010-01-01

    Talking about periodontic-orthodontic interrelationships is related primarily to the 1960s, where a generalized increase in salivary bacterial counts, especially Lactobacillus, had been shown after orthodontic band placement. The purpose of this article is to provide the dental practitioner with basic understanding of the interrelationship between periodontics and orthodontics by means of representing classical studies, and, to give an update on this topic by demonstrating the most recent opinions concerning periodontic-orthodontic interrelationships. Specific areas reviewed are the ability of orthodontic treatment to afford some degree of protection against periodontal breakdown, short-term and long-term effects of orthodontic treatment on the periodontium, and some mucogingival considerations. Topics considering orthodontic treatment in periodontally compromised patients were not included in this review. While past studies have shown that orthodontic treatment can positively affect the periodontal health, recent reviews indicate an absence of reliable evidence for the positive effects of orthodontic therapy on patients’ periodontal status. Periodontic-orthodontic interrelationships are still controversial issues. However, a standard language between the periodontist and the orthodontist must always be established to eliminate the existing communications barrier, and to improve the outcomes of the whole treatment. PMID:20922083

  7. Quorum sensing inhibition, relevance to periodontics.

    PubMed

    Yada, Sudheer; Kamalesh, B; Sonwane, Siddharth; Guptha, Indra; Swetha, R K

    2015-01-01

    Quorum sensing helps bacteria to communicate with each other and in coordinating their behavior. Many diseases of human beings, plants, and animals are mediated by quorum sensing. Various approaches are being tried to inhibit this communication to control the diseases caused by bacteria. Periodontal pathogens also communicate through quorum sensing and new approaches to treat periodontal disease using quorum sensing inhibition need to explored.

  8. [Aggressive fibromatoses in orthopedics].

    PubMed

    Adler, C P; Stock, D

    1986-01-01

    Aggressive fibromatoses which may develop either in soft tissue or in the bone present considerable problems for the pathologist trying to establish a diagnosis as well as for the radiologist and surgeon. In radiographs, a destruction of the soft and osseous tissue is seen which suggests a malignant tumor. Histologically a monomorphic connective tissue prevails in the biopsy showing no essential signs of malignancy. Under pathoanatomical aspects often a benign proliferation of the connective tissue is assumed. Surgically the tumor may either be removed in a too radical and mutilating way, or the excision may remain incomplete. Two cases of desmoplastic bone fibroma (aggressive fibromatosis in the ulna and in the sacrum) are described in which the complete tumor removal led to healing, whereas the incomplete excision of the tumor resulted in recurrences. Aggressive fibromatosis represents a semimalignant tumor which has a locally destructive and invasive growth tendency but does not metastasize. The various fibromatoses are defined with regard to their biological growth tendency and the therapeutic consequences are discussed.

  9. Acceleration of purine degradation by periodontal diseases.

    PubMed

    Barnes, V M; Teles, R; Trivedi, H M; Devizio, W; Xu, T; Mitchell, M W; Milburn, M V; Guo, L

    2009-09-01

    Periodontal diseases, such as gingivitis and periodontitis, are characterized by bacterial plaque accumulation around the gingival crevice and the subsequent inflammation and destruction of host tissues. To test the hypothesis that cellular metabolism is altered as a result of host-bacteria interaction, we performed an unbiased metabolomic profiling of gingival crevicular fluid (GCF) collected from healthy, gingivitis, and periodontitis sites in humans, by liquid and gas chromatography mass spectrometry. The purine degradation pathway, a major biochemical source for reactive oxygen species (ROS) production, was significantly accelerated at the disease sites. This suggests that periodontal-disease-induced oxidative stress and inflammation are mediated through this pathway. The complex host-bacterial interaction was further highlighted by depletion of anti-oxidants, degradation of host cellular components, and accumulation of bacterial products in GCF. These findings provide new mechanistic insights and a panel of comprehensive biomarkers for periodontal disease progression. PMID:19767584

  10. Acceleration of purine degradation by periodontal diseases.

    PubMed

    Barnes, V M; Teles, R; Trivedi, H M; Devizio, W; Xu, T; Mitchell, M W; Milburn, M V; Guo, L

    2009-09-01

    Periodontal diseases, such as gingivitis and periodontitis, are characterized by bacterial plaque accumulation around the gingival crevice and the subsequent inflammation and destruction of host tissues. To test the hypothesis that cellular metabolism is altered as a result of host-bacteria interaction, we performed an unbiased metabolomic profiling of gingival crevicular fluid (GCF) collected from healthy, gingivitis, and periodontitis sites in humans, by liquid and gas chromatography mass spectrometry. The purine degradation pathway, a major biochemical source for reactive oxygen species (ROS) production, was significantly accelerated at the disease sites. This suggests that periodontal-disease-induced oxidative stress and inflammation are mediated through this pathway. The complex host-bacterial interaction was further highlighted by depletion of anti-oxidants, degradation of host cellular components, and accumulation of bacterial products in GCF. These findings provide new mechanistic insights and a panel of comprehensive biomarkers for periodontal disease progression.

  11. Periodontal disease among New England elders.

    PubMed

    Fox, C H; Jette, A M; McGuire, S M; Feldman, H A; Douglass, C W

    1994-07-01

    Much of the existing oral epidemiologic literature is limited by having inadequate numbers of the oldest-old in their sample, having used rudimentary periodontal measures, or not having examined probability samples of community-dwelling elders. The New England Elders Dental Study (NEEDS) is the first study that documents the periodontal disease status of a probability sample of 554 adults aged 70 to 96 living within an entire U.S. Public Health Service region. The NEEDS study revealed substantially higher estimates of periodontal destruction among older adults than previous national studies would suggest. These results are consistent with several papers in the literature that suggest that periodontal disease rates are on the increase in older adults. In the coming decades dentistry should be prepared to meet the increasing need and demand for periodontal services in the growing older population. PMID:7608844

  12. Learning Activity Package, Biology, LAPs 20, 30, 31, 32, and 33.

    ERIC Educational Resources Information Center

    Rhoden, Bruce

    Included is a set of five teacher-prepared Learning Activity Packages (LAPs) for individualized instruction in topics in biology. The units cover the topics of genetic continuity, methods of investigation, cell biology, genetics, and animal physiology. Each unit contains a rationale for the material; a list of behavioral objectives for the unit; a…

  13. Learning Activity Package, Algebra 93-94, LAPs 12-22.

    ERIC Educational Resources Information Center

    Evans, Diane

    A set of 11 teacher-prepared Learning Activity Packages (LAPs) in beginning algebra, these units cover sets, properties of operations, operations over real numbers, open expressions, solution sets of equations and inequalities, equations and inequalities with two variables, solution sets of equations with two variables, exponents, factoring and…

  14. Progerin reduces LAP2α-telomere association in Hutchinson-Gilford progeria

    PubMed Central

    Chojnowski, Alexandre; Ong, Peh Fern; Wong, Esther SM; Lim, John SY; Mutalif, Rafidah A; Navasankari, Raju; Dutta, Bamaprasad; Yang, Henry; Liow, Yi Y; Sze, Siu K; Boudier, Thomas; Wright, Graham D; Colman, Alan; Burke, Brian; Stewart, Colin L; Dreesen, Oliver

    2015-01-01

    Hutchinson-Gilford progeria (HGPS) is a premature ageing syndrome caused by a mutation in LMNA, resulting in a truncated form of lamin A called progerin. Progerin triggers loss of the heterochromatic marker H3K27me3, and premature senescence, which is prevented by telomerase. However, the mechanism how progerin causes disease remains unclear. Here, we describe an inducible cellular system to model HGPS and find that LAP2α (lamina-associated polypeptide-α) interacts with lamin A, while its interaction with progerin is significantly reduced. Super-resolution microscopy revealed that over 50% of telomeres localize to the lamina and that LAP2α association with telomeres is impaired in HGPS. This impaired interaction is central to HGPS since increasing LAP2α levels rescues progerin-induced proliferation defects and loss of H3K27me3, whereas lowering LAP2 levels exacerbates progerin-induced defects. These findings provide novel insights into the pathophysiology underlying HGPS, and how the nuclear lamina regulates proliferation and chromatin organization. DOI: http://dx.doi.org/10.7554/eLife.07759.001 PMID:26312502

  15. Fracture analysis of multi-site cracking in fuselage lap joints

    NASA Astrophysics Data System (ADS)

    Beuth, J. L.; Hutchinson, J. W.

    1994-09-01

    A two-dimensional plane stress elastic fracture mechanics analysis of a cracked lap joint fastened by rigid pins is presented and results are applied to the problem of multi-site damage (MSD) in riveted lap joints of aircraft fuselage skins. Two problems are addressed, the problem of equal length MSD cracks and the problem of alternating length MSD cracks. For the problem of equal length cracks, two models of rivet/skin interactions are studied and the role of residual stresses due to the riveting process is explored. Stress intensity factors are obtained as a function of normalized crack length. Also, the load distribution among rivet rows and the compliance change of the joint due to MSD cracking are obtained. For the problem of alternating length cracks, attention is focussed on how load is distributed between columns of rivets and how this load shedding can alter crack tip stress intensity factors. The equal and alternating length crack analyses reveal no clear-cut mechanism to explain the relative uniformity of fatigue cracks emerging from lap joint rivet holes in actual aircraft and in mechanical lap joint tests.

  16. Progerin reduces LAP2α-telomere association in Hutchinson-Gilford progeria.

    PubMed

    Chojnowski, Alexandre; Ong, Peh Fern; Wong, Esther S M; Lim, John S Y; Mutalif, Rafidah A; Navasankari, Raju; Dutta, Bamaprasad; Yang, Henry; Liow, Yi Y; Sze, Siu K; Boudier, Thomas; Wright, Graham D; Colman, Alan; Burke, Brian; Stewart, Colin L; Dreesen, Oliver

    2015-08-27

    Hutchinson-Gilford progeria (HGPS) is a premature ageing syndrome caused by a mutation in LMNA, resulting in a truncated form of lamin A called progerin. Progerin triggers loss of the heterochromatic marker H3K27me3, and premature senescence, which is prevented by telomerase. However, the mechanism how progerin causes disease remains unclear. Here, we describe an inducible cellular system to model HGPS and find that LAP2α (lamina-associated polypeptide-α) interacts with lamin A, while its interaction with progerin is significantly reduced. Super-resolution microscopy revealed that over 50% of telomeres localize to the lamina and that LAP2α association with telomeres is impaired in HGPS. This impaired interaction is central to HGPS since increasing LAP2α levels rescues progerin-induced proliferation defects and loss of H3K27me3, whereas lowering LAP2 levels exacerbates progerin-induced defects. These findings provide novel insights into the pathophysiology underlying HGPS, and how the nuclear lamina regulates proliferation and chromatin organization.

  17. A neural-fuzzy model with confidence measure for controlled stressed-lap surface shape presentation

    NASA Astrophysics Data System (ADS)

    Chen, Minyou; Wan, Yongjian; Wu, Fan; Xie, Kaigui; Wang, Mingyu; Fan, Bin

    2009-05-01

    In computer controlled large aspheric mirror polishing process, it is crucially important to build an accurate stressed-lap surface model for shape control. It is desirable to provide a practical measure of prediction confidence to access the reliability of the resulting models. To build a reliable prediction model for representing the surface shape of stressed lap polishing process in large aperture and highly aspheric optical surface, this paper proposed a predictive model with its own confidence interval estimate based on a fuzzy neural network. The calculation of confidence interval accounts for the training data distribution and accuracy of the trained model with the given input-output data. Simulation results show that the proposed confidence interval estimation reflects the data distribution and extrapolation correctly, and works well in high-dimensional sparse data set of the detected stressed lap surface shape changes. The original data from the micro-displacement sensor matrix were used to train the neural network model. The experiment results showed that the proposed model can represent the surface shape of the stressed-lap accurately and facilitate the computer controlled optical polishing process.

  18. Design Considerations of Polishing Lap for Computer-Controlled Cylindrical Polishing Process

    NASA Technical Reports Server (NTRS)

    Khan, Gufran S.; Gubarev, Mikhail; Arnold, William; Ramsey, Brian D.

    2009-01-01

    This paper establishes a relationship between the polishing process parameters and the generation of mid spatial-frequency error. The consideration of the polishing lap design to optimize the process in order to keep residual errors to a minimum and optimization of the process (speeds, stroke, etc.) and to keep the residual mid spatial-frequency error to a minimum, is also presented.

  19. 77 FR 27746 - Notice of Submission for OMB Review; Federal Student Aid; Lender Application Process (LAP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... special allowance, as well as Federal Insured Student Loan claims payment, under the Federal Family Education Loan Program. DATES: Interested persons are invited to submit comments on or before June 11, 2012... Notice of Submission for OMB Review; Federal Student Aid; Lender Application Process (LAP) SUMMARY:...

  20. Correlates of Mood and RPE During Multi-Lap Off-Road Cycling.

    PubMed

    Viana, Bruno Ferreira; Pires, Flávio Oliveira; Inoue, Allan; Micklewright, Dominic; Santos, Tony Meireles

    2016-03-01

    This study examined the relationship between mood and rating of perceived exertion (RPE) during a simulated multiple-lap time trial (MLTT). Nineteen male cyclists performed a MLTT consisting of four 9.9 km laps, each lap with a gradient ranging from 0 to 10 %. Mood as measured by the Profile of Mood States Questionnaire (POMS) and perceived exertion as measured by the Borg CR100 scale (RPE) were obtained at the end of each lap. A categorical multiple regressive model, having median of POMS subscales as independent variables, was obtained to explain the variance in median RPE responses. Increases in POMS fatigue scores and decreases in POMS vigour scores were observed throughout the MLTT (P < 0.001). A linear increase in RPE during the MLTT was also observed (P < 0.001). POMS fatigue subscale scores accounted for 88 % of the variance in RPE during the MLTT (R(2) = 0.88, P = 0.002), and no other POMS subscale improved the final predictive model. With the exception of fatigue these results suggest that most aspects of mood do not have a discernable effect on RPE during a MLTT. The rate of increase in RPE can predict the MLTT endpoint.

  1. Learning Activity Package, Physical Science. LAP Numbers 5, 6, and 7.

    ERIC Educational Resources Information Center

    Williams, G. J.

    These three units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover the physical and chemical properties of water, dehydration of crystals, solutions, acidity, strong and weak bases, neutral properties of salts, amorphous forms of carbon, hydrocarbons, and petroleum products. Each unit contains a…

  2. Learning Activity Package, Physical Science. LAP Numbers 8, 9, 10, and 11.

    ERIC Educational Resources Information Center

    Williams, G. J.

    These four units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover nuclear reactions, alpha and beta particles, atomic radiation, medical use of nuclear energy, fission, fusion, simple machines, Newton's laws of motion, electricity, currents, electromagnetism, Oersted's experiment, sound, light,…

  3. Determination of Arsenic Poisoning and Metabolism in Hair by Synchrotron Radiation: The Case of Phar Lap

    SciTech Connect

    Kempson, Ivan M.; Henry, Dermot A.

    2010-08-26

    Fresh physical evidence about the demise of the racehorse Phar Lap (see photograph) has been gathered from the study of mane hair samples by synchrotron radiation analysis with high resolution X-ray fluorescence (XRF) and X-ray absorption near edge structure (XANES) analyses. The results are indicative of arsenic ingestion and metabolism, and show that the racing champion died from arsenic poisoning.

  4. Learning Activity Package, Chemistry I. LAP Numbers 22, 23, 24, 25, 26, 27, and 28.

    ERIC Educational Resources Information Center

    Jones, Naomi

    As a set of seven Learning Activity Packages (LAPs) for individualized instruction in chemistry, the units cover the unit system, matter, energy, atomic structures, chemical formulas, physical states of matter, solutions and suspensions, ionization, acids, bases, and salts. Each unit contains a rationale for the material; a list of behavioral…

  5. Improving Critical Thinking Skills Using Learning Model Logan Avenue Problem Solving (LAPS)-Heuristic

    ERIC Educational Resources Information Center

    Anggrianto, Desi; Churiyah, Madziatul; Arief, Mohammad

    2016-01-01

    This research was conducted in order to know the effect of Logan Avenue Problem Solving (LAPS)-Heuristic learning model towards critical thinking skills of students of class X Office Administration (APK) in SMK Negeri 1 Ngawi, East Java, Indonesia on material curve and equilibrium of demand and supply, subject Introduction to Economics and…

  6. The impact of layer thickness on the performance of additively manufactured lapping tools

    NASA Astrophysics Data System (ADS)

    Williams, Wesley B.

    2015-10-01

    Lower cost additive manufacturing (AM) machines which have emerged in recent years are capable of producing tools, jigs, and fixtures that are useful in optical fabrication. In particular, AM tooling has been shown to be useful in lapping glass workpieces. Various AM machines are distinguished by the processes, materials, build times, and build resolution they provide. This research investigates the impact of varied build resolution (specifically layer resolution) on the lapping performance of tools built using the stereolithographic assembly (SLA) process in 50 μm and 100 μm layer thicknesses with a methacrylate photopolymer resin on a high resolution desktop printer. As with previous work, the lapping tools were shown to remove workpiece material during the lapping process, but the tools themselves also experienced significant wear on the order of 2-3 times the mass loss of the glass workpieces. The tool wear rates for the 100 μm and 50 μm layer tools were comparable, but the 50 μm layer tool was 74% more effective at removing material from the glass workpiece, which is attributed to some abrasive particles being trapped in the coarser surface of the 100 um layer tooling and not being available to interact with the glass workpiece. Considering the tool wear, these additively manufactured tools are most appropriate for prototype tooling where the low cost (<$45) and quick turnaround make them attractive when compared to a machined tool.

  7. Learning Activity Package, Physical Science. LAP Numbers 1, 2, 3, and 4.

    ERIC Educational Resources Information Center

    Williams, G. J.

    These four units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover measuring techniques, operations of instruments, metric system heat, matter, energy, elements, atomic numbers, isotopes, molecules, mixtures, compounds, physical and chemical properties, liquids, solids, and gases. Each unit contains…

  8. Hypoplastic basement membrane of the lens anlage in the inheritable lens aplastic mouse (lap mouse).

    PubMed

    Aso, S; Baba, R; Noda, S; Ikuno, S; Fujita, M

    2000-04-01

    Adult homozygous lap mice show various eye abnormalities such as aphakia, retinal disorganization, and dysplasia of the cornea and anterior chamber. In the fetal eye of a homozygous lap mouse, the lens placode appears to develop normally. However, the lens vesicle develops abnormally to form a mass of cells without a cavity, and the mass vanishes soon afterward. Apoptotic cell death is associated with the disappearance of the lens anlage. We examined the basement membranes of the lens anlage of this mutant by immunohistochemical methods under light microscopy using antibodies against basement membrane components of the lens anlage, type IV collagen, fibronectin, laminin, heparan sulfate proteoglycan, and entactin and by transmission electron microscopy. Immunohistochemistry showed the distribution and intensity of antibody binding to the lens anlage to be almost the same for each these antibodies regardless of the stage of gestation or whether the anlagen were from normal BALB/c or lap mice. Thus, positive continuous reactions were observed around the exterior region of the lens anlage from day 10 of gestation for type IV collagen, fibronectin, laminin, heparan sulfate proteoglycan antibodies, and at least from day 11of gestation for entactin antibody. The basement membrane lamina densa of both normal and lap mice was shown by electron microscopy to be discontinuous at days 10 and 10.5 of gestation. However, by day 11 the lamina densa was continuous in the lens anlagen of normal mice but still discontinuous in the lap mice. By day 12 of gestation, the lamina densa had thickened markedly in normal mice, whereas in lap mice it remained discontinuous and its thinness indicated hypoplasia. These results indicate that, while all basement components examined are produced and deposited in the normal region of the lens anlage in the lap mouse, the basement membrane is, for some reason, imperfectly formed. The time at which hypoplasia of the basement membrane was observed

  9. The Characteristics of Fatigue Damage in the Fuselage Riveted Lap Splice Joint

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Willard, Scott A.

    1997-01-01

    An extensive data base has been developed to form the physical basis for new analytical methodology to predict the onset of widespread fatigue damage in the fuselage lap splice joint. The results of detailed destructive examinations have been cataloged to describe the physical nature of MSD in the lap splice joint. ne catalog includes a detailed description, e.g., crack initiation, growth rates, size, location, and fracture morphology, of fatigue damage in the fuselage lap splice joint structure. Detailed examinations were conducted on a lap splice joint panel removed from a full scale fuselage test article after completing a 60,000 cycle pressure test. The panel contained a four bay region that exhibited visible outer skin cracks and regions of crack link-up along the upper rivet row. Destructive examinations revealed undetected fatigue damage in the outer skin, inner skin, and tear strap regions. Outer skin fatigue cracks were found to initiate by fretting damage along the faying surface. The cracks grew along the faying surface to a length equivalent to two to three skin thicknesses before penetrating the outboard surface of the outer skin. Analysis of fracture surface marker bands produced during full scale testing revealed that all upper rivet row fatigue cracks contained in a dim bay region grow at similar rates; this important result suggests that fracture mechanics based methods can be used to predict the growth of outer skin fatigue cracks in lap splice structure. Results are presented showing the affects of MSD and out-of-plane pressure loads on outer skin crack link-up.

  10. Determination of the Corrosive Conditions Present within Aircraft Lap-Splice Joints

    NASA Technical Reports Server (NTRS)

    Lewis, Karen S.; Kelly, Robert G.; Piascik, Robert S.

    1999-01-01

    The complexity of airframe structure lends itself to damage resulting from crevice corrosion. Fuselage lap-splice joints are a particularly important structural detail in this regard because of the difficulty associated with detection and measurement of corrosion in these occluded regions. The objective of this work is to develop a laboratory corrosion test protocol to identify the chemistry to which lap joints are exposed and to develop a model of the corrosion within the joints. A protocol for collecting and identifying the chemistry of airframe crevice corrosion has been developed. Capillary electrophoresis (CE) is used to identify the ionic species contained in corrosion product samples removed from fuselage lap splice joints. CE analysis has been performed on over sixty corrosion product samples removed from both civilian and military aircraft. Over twenty different ions have been detected. Measurements of pH of wetted corroded surfaces indicated an alkaline occluded solution. After determining the species present and their relative concentrations, the resultant solution was reproduced in bulk and electrochemical tests were performed to determine the corrosion rate. Electrochemical analyses of the behavior of AA2024-T3 in these solutions gave corrosion rates of up to 250 microns per year (10 mpy). Additional tests have determined the relative importance of each of the detected ions in model solutions used for future predictive tests. The statistically significant ions have been used to create a second generation solution. Laboratory studies have also included exposure tests involving artificial lap joints exposed to various simulated bulk and crevice environments. The extent and morphology of the attack in artificial lap joints has been compared to studies of corroded samples from actual aircraft. Other effects, such as temperature and potential, as well as the impact of the environment on fatigue crack growth have also been studied.

  11. Periodontal disease and diabetes mellitus

    PubMed Central

    NEGRATO, Carlos Antonio; TARZIA, Olinda; JOVANOVIČ, Lois; CHINELLATO, Luiz Eduardo Montenegro

    2013-01-01

    Periodontal disease (PD) is one of the most commonly known human chronic disorders. The relationship between PD and several systemic diseases such as diabetes mellitus (DM) has been increasingly recognized over the past decades. Objective: The purpose of this review is to provide the reader with knowledge concerning the relationship between PD and DM. Many articles have been published in the english and Portuguese literature over the last 50 years examining the relationship between these two chronic diseases. Data interpretation is often confounded by varying definitions of DM, PD and different clinical criteria were applied to determine the prevalence, extent and severity of PD, levels of glycemic control and diabetes-related complications. Methods: This paper provides a broad overview of the predominant findings from research conducted using the BBO (Bibliografia Brasileira de Odontologia), MEDLINE, LILACS and PubMed for Controlled Trials databases, in english and Portuguese languages published from 1960 to October 2012. Primary research reports on investigations of relationships between DM/DM control, PD/periodontal treatment and PD/DM/diabetes-related complications identified relevant papers and meta-analyses published in this period. Results: This paper describes the relationship between PD and DM and answers the following questions: 1- The effect of DM on PD, 2- The effects of glycemic control on PD and 3- The effects of PD on glycemic control and on diabetes-related complications. Conclusions: The scientific evidence reviewed supports diabetes having an adverse effect on periodontal health and PD having an adverse effect on glycemic control and on diabetes-related complications. Further research is needed to clarify these relationships and larger, prospective, controlled trials with ethnically diverse populations are warranted to establish that treating PD can positively influence glycemic control and possibly reduce the burden of diabetes

  12. Antibiotics/antimicrobials: systemic and local administration in the therapy of mild to moderately advanced periodontitis.

    PubMed

    Jepsen, Karin; Jepsen, Søren

    2016-06-01

    This review gives an update of the current scientific evidence on the efficacy of the adjunctive use of systemic and local antibiotics/antimicrobials in the treatment of periodontitis. In particular, it addresses whether their use can improve the results of nonsurgical mechanical therapy in mild-to-moderate forms of the disease. Large numbers of randomized clinical trials and systematic reviews with meta-analyses have clearly established that adjunctive systemic antibiotics, combined with mechanical debridement, offer clinical improvements additional to those obtained with scaling and root planing alone. These effects are more pronounced in aggressive periodontitis and in initially deep pockets, whereas more limited additional improvements, of 0.3 mm for additional pocket reduction and 0.2 mm for additional clinical attachment gain, have been documented for moderately deep sites (4-6 mm) in patients with chronic periodontitis. The marginal clinical benefit in patients with moderate disease has to be balanced against possible side effects. Notably, it has to be realized that an increasing number of warnings have been articulated against the unrestricted use of antibiotics in treating periodontal diseases because of the emerging global public health issue of bacterial resistance. The effects of the adjunctive local administration of antimicrobials have also been very well documented in several systematic reviews. Overall, in persistent or recurrent localized deep sites, the application of antimicrobials by sustained-delivery devices may offer a benefit of an additional 0.4 mm in pocket depth reduction and 0.3 mm in clinical attachment level gain. In conclusion, the slight additional benefits of adjunctive antimicrobials, which were shown for moderate forms of periodontitis, have to be balanced against their side effects and therefore their prescription should be limited as much as possible. PMID:27045432

  13. RANKL Expression in Periodontal Disease: Where Does RANKL Come from?

    PubMed Central

    Wu, Wenlei; Sun, Weibin

    2014-01-01

    Periodontitis is an inflammatory disease characterized by periodontal pocket formation and alveolar bone resorption. Periodontal bone resorption is induced by osteoclasts and receptor activator of nuclear factor-κB ligand (RANKL) which is an essential and central regulator of osteoclast development and osteoclast function. Therefore, RANKL plays a critical role in periodontal bone resorption. In this review, we have summarized the sources of RANKL in periodontal disease and explored which factors may regulate RANKL expression in this disease. PMID:24719884

  14. [Periodontitis and systemic diseases: from science to clinical practice].

    PubMed

    Thomas, R Z; Loos, B G; Teeuw, W; Kunnen, A; van Winkelhoff, A J; Abbas, F

    2015-10-01

    The evidence for an association between systemic diseases and periodontitis is strongest with diabetes mellitus type 2 and cardiovascular disease. There is a moderate association of periodontitis with adverse pregnancy outcomes and rheumatoid arthritis. Periodontal treatment has, on average, a positive effect on reducing systemic infection and improving the condition of the vascular system. For diabetes patients, periodontal treatment can also have a positive effect on metabolic regulation. There is insufficient evidence that periodontal treatment prevents adverse pregnancy outcomes and rheumatoid arthritis.

  15. Periodontitis and diabetes interrelationships: role of inflammation.

    PubMed

    Iacopino, A M

    2001-12-01

    Diabetes mellitus is a systemic disease with several major complications affecting both the quality and length of life. One of these complications is periodontal disease (periodontitis). Periodontitis is much more than a localized oral infection. Recent data indicate that periodontitis may cause changes in systemic physiology. The interrelationships between periodontitis and diabetes provide an example of systemic disease predisposing to oral infection, and once that infection is established, the oral infection exacerbates systemic disease. In this case, it may also be possible for the oral infection to predispose to systemic disease. In order to understand the cellular/molecular mechanisms responsible for such a cyclical association, one must identify common physiological changes associated with diabetes and periodontitis that produce a synergy when the conditions coexist. A potential mechanistic link involves the broad axis of inflammation, specifically immune cell phenotype, serum lipid levels, and tissue homeostasis. Diabetes-induced changes in immune cell function produce an inflammatory immune cell phenotype (upregulation of proinflammatory cytokines from monocytes/polymorphonuclear leukocytes and downregulation of growth factors from macrophages). This predisposes to chronic inflammation, progressive tissue breakdown, and diminished tissue repair capacity. Periodontal tissues frequently manifest these changes because they are constantly wounded by substances emanating from bacterial biofilms. Diabetic patients are prone to elevated low density lipoprotein cholesterol and triglycerides (LDL/TRG) even when blood glucose levels are well controlled. This is significant, as recent studies demonstrate that hyperlipidemia may be one of the factors associated with diabetes-induced immune cell alterations. Recent human studies have established a relationship between high serum lipid levels and periodontitis. Some evidence now suggests that periodontitis itself may

  16. Systemic antibiotic therapy in periodontics

    PubMed Central

    Kapoor, Anoop; Malhotra, Ranjan; Grover, Vishakha; Grover, Deepak

    2012-01-01

    Systemic antibiotics in conjunction with scaling and root planing (SRP), can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of clinical attachment loss (CAL) and pocket depth change, and reduced risk of additional CAL loss. However, antibiotics are not innocuous drugs. Their use should be justified on the basis of a clearly established need and should not be substituted for adequate local treatment. The aim of this review is to discuss the rationale, proper selection, dosage and duration for antibiotic therapy so as to optimize the usefulness of drug therapy. PMID:23559912

  17. Drug addiction and periodontal diseases.

    PubMed

    Saini, Gurpreet Kaur; Gupta, N D; Prabhat, K C

    2013-09-01

    The prevalence of drug addiction is increasing globally. Drug abuse damages many parts of the body such as oral cavity, lungs, liver, brain, heart etc., Addicts suffer from physical, psychological, emotional and behavioral problems. Their nutrition is also compromised. There is certainly an impact of all these factors on the health of periodontium. Dentists should be aware of the effects of drugs while treating the drug addicts. This article correlates the studies done on the impact of abused drugs such as alcohol, tobacco, opiates, cannabis, amphetamines etc., on general and periodontal health. PMID:24174750

  18. Estimation of interleukin-18 in the gingival crevicular fluid and serum of Bengali population with periodontal health and disease

    PubMed Central

    Nair, Vineet; Bandyopadhyay, Prasanta; Kundu, Debabrata; Das, Satadal

    2016-01-01

    Context: Host's immune response elicits cytokines in response to bacterial challenge. We explore role of one such cytokine interleukin-18 (IL-18) in periodontal health and disease. Aims: IL-18 is a pro-inflammatory and tumor suppressive cytokine. Dental literatures suggest that IL-18 might have a role to play in the progression from oral health to periodontal disease. Therefore, this study was undertaken to elucidate the level and role of IL-18 in the gingival crevicular fluid (GCF) and serum of individuals with healthy gingiva, chronic gingivitis, chronic periodontitis, and aggressive periodontitis before and after periodontal therapy. Settings and Design: Eighty individuals chosen for the study were divided into healthy control group (1A), chronic gingivitis (2A), chronic periodontitis (3A), and aggressive periodontitis (4A) with twenty individuals each. Criteria for the division were the subject's gingival index, probing pocket depth, clinical attachment loss, and radiographic evidence of bone loss. Materials and Methods: The individuals underwent treatment (scaling in case of Groups 1A and 2A and scaling and root planing followed by flap surgery in Groups 3A and 4A) to form posttreatment Groups 1B, 2B, 3B, and 4B, respectively. Thus, a total of 160 GCF and 160 serum samples were collected and tested by ELISA. Statistical Analysis Used: Intergroup comparison was done by post hoc Tukey's test. Results: The mean IL-18 concentration was greatest in Group 3A (GCF 144.61 pg/μl, serum 55.12 pg/ml) followed by Group 4A (GCF 98.55 pg/μl, serum 39.06 pg/ml), Group 2A (GCF 22.27 pg/μl, serum 27.73 pg/ml) and lowest (GCF 17.94 pg/μl, serum 11.49 pg/ml) in Group 1A. Posttreatment groups (1B–4B) showed reduction in the mean IL-18 concentration in both GCF and serum. Conclusions: As the inflammation increased, there was a concomitant increase in the level of IL-18 and vice versa following periodontal therapy. PMID:27563198

  19. Ultrasonic device for measuring periodontal attachment levels

    NASA Astrophysics Data System (ADS)

    Lynch, J. E.; Hinders, M. K.

    2002-07-01

    Periodontal disease is manifested clinically by a degradation of the ligament that attaches the tooth to the bone. The most widely used diagnostic tool for assessment of periodontal diseases, measurement of periodontal attachment loss with a manual probe, may overestimate attachment loss by as much as 2 mm in untreated sites, while underestimating attachment loss by an even greater margin following treatment. Manual probing is also invasive, which causes patient discomfort. This work describes the development and testing of an ultrasonographic periodontal probe designed to replace manual probing. It uses a thin stream of water to project an ultrasonic beam into the periodontal pocket, and then measures echoes off features within the pocket. To do so, the ultrasonic beam must be narrowed from 2 (the diameter of the transducer) to 0.5 mm (the approximate width of the periodontal pocket at the gingival margin). The proper choice of transducer frequency, the proper method for controlling water flow from the probe, and a model for interpreting these echoes are also addressed. Initial results indicate that the device measures echoes from the hard tissue of the tooth surface, and that the periodontal attachment level can be inferred from these echoes.

  20. Periodontitis and Cognitive Decline in Alzheimer's Disease.

    PubMed

    Ide, Mark; Harris, Marina; Stevens, Annette; Sussams, Rebecca; Hopkins, Viv; Culliford, David; Fuller, James; Ibbett, Paul; Raybould, Rachel; Thomas, Rhodri; Puenter, Ursula; Teeling, Jessica; Perry, V Hugh; Holmes, Clive

    2016-01-01

    Periodontitis is common in the elderly and may become more common in Alzheimer's disease because of a reduced ability to take care of oral hygiene as the disease progresses. Elevated antibodies to periodontal bacteria are associated with an increased systemic pro-inflammatory state. Elsewhere raised serum pro-inflammatory cytokines have been associated with an increased rate of cognitive decline in Alzheimer's disease. We hypothesized that periodontitis would be associated with increased dementia severity and a more rapid cognitive decline in Alzheimer's disease. We aimed to determine if periodontitis in Alzheimer's disease is associated with both increased dementia severity and cognitive decline, and an increased systemic pro inflammatory state. In a six month observational cohort study 60 community dwelling participants with mild to moderate Alzheimer's Disease were cognitively assessed and a blood sample taken for systemic inflammatory markers. Dental health was assessed by a dental hygienist, blind to cognitive outcomes. All assessments were repeated at six months. The presence of periodontitis at baseline was not related to baseline cognitive state but was associated with a six fold increase in the rate of cognitive decline as assessed by the ADAS-cog over a six month follow up period. Periodontitis at baseline was associated with a relative increase in the pro-inflammatory state over the six month follow up period. Our data showed that periodontitis is associated with an increase in cognitive decline in Alzheimer's Disease, independent to baseline cognitive state, which may be mediated through effects on systemic inflammation. PMID:26963387

  1. Periodontitis and Cognitive Decline in Alzheimer's Disease.

    PubMed

    Ide, Mark; Harris, Marina; Stevens, Annette; Sussams, Rebecca; Hopkins, Viv; Culliford, David; Fuller, James; Ibbett, Paul; Raybould, Rachel; Thomas, Rhodri; Puenter, Ursula; Teeling, Jessica; Perry, V Hugh; Holmes, Clive

    2016-01-01

    Periodontitis is common in the elderly and may become more common in Alzheimer's disease because of a reduced ability to take care of oral hygiene as the disease progresses. Elevated antibodies to periodontal bacteria are associated with an increased systemic pro-inflammatory state. Elsewhere raised serum pro-inflammatory cytokines have been associated with an increased rate of cognitive decline in Alzheimer's disease. We hypothesized that periodontitis would be associated with increased dementia severity and a more rapid cognitive decline in Alzheimer's disease. We aimed to determine if periodontitis in Alzheimer's disease is associated with both increased dementia severity and cognitive decline, and an increased systemic pro inflammatory state. In a six month observational cohort study 60 community dwelling participants with mild to moderate Alzheimer's Disease were cognitively assessed and a blood sample taken for systemic inflammatory markers. Dental health was assessed by a dental hygienist, blind to cognitive outcomes. All assessments were repeated at six months. The presence of periodontitis at baseline was not related to baseline cognitive state but was associated with a six fold increase in the rate of cognitive decline as assessed by the ADAS-cog over a six month follow up period. Periodontitis at baseline was associated with a relative increase in the pro-inflammatory state over the six month follow up period. Our data showed that periodontitis is associated with an increase in cognitive decline in Alzheimer's Disease, independent to baseline cognitive state, which may be mediated through effects on systemic inflammation.

  2. [Periodontal disease in pediatric rheumatic diseases].

    PubMed

    Fabri, Gisele M C; Savioli, Cynthia; Siqueira, José T; Campos, Lucia M; Bonfá, Eloisa; Silva, Clovis A

    2014-01-01

    Gingivitis and periodontitis are immunoinflammatory periodontal diseases characterized by chronic localized infections usually associated with insidious inflammation This narrative review discusses periodontal diseases and mechanisms influencing the immune response and autoimmunity in pediatric rheumatic diseases (PRD), particularly juvenile idiopathic arthritis (JIA), childhood-onset systemic lupus erythematosus (C-SLE) and juvenile dermatomyositis (JDM). Gingivitis was more frequently observed in these diseases compared to health controls, whereas periodontitis was a rare finding. In JIA patients, gingivitis and periodontitis were related to mechanical factors, chronic arthritis with functional disability, dysregulation of the immunoinflammatory response, diet and drugs, mainly corticosteroids and cyclosporine. In C-SLE, gingivitis was associated with longer disease period, high doses of corticosteroids, B-cell hyperactivation and immunoglobulin G elevation. There are scarce data on periodontal diseases in JDM population, and a unique gingival pattern, characterized by gingival erythema, capillary dilation and bush-loop formation, was observed in active patients. In conclusion, gingivitis was the most common periodontal disease in PRD. The observed association with disease activity reinforces the need for future studies to determine if resolution of this complication will influence disease course or severity.

  3. [The relationship of periodontitis and diabetes mellitus].

    PubMed

    Kasaj, Adrian; Gortan-Kasaj, Aristea; Willerhausen, Brita; Hoffmann, Oliver; Angelov, Nikola; Zafiropoulos, Gregory-George

    2007-09-01

    Periodontitis is a chronic, dental-plaque induced inflammatory disease of the tooth-supporting tissues, resulting in a gradual loss of connective tissue attachment and alveolar bone. The interrelationship between diabetes mellitus and periodontitis has been studied for many years. At,present, there is strong evidence to suggest that the incidence and severity of periodontitis is influenced by the presence or absence of diabetes mellitus as well as by the degree of diabetes control by patients. Elevated blood glucose levels in poorly controlled diabetics result in an increase of protein glycosylation leading to amplified formation of so-called Advanced Glycation End products (AGE). AGEs are glucose products that have the ability to attract and stimulate inflammatory cells to produce inflammatory cytokines, elevating the risk of periodontal attachment and/or alveolar bone loss. Gram-negative periodontal infection significantly decreases glucose tolerance and can lead, like other types of inflammation, to an increase in the severity of diabetes. Thus, diabetes and periodontal disease form a system in which periodontitis is aggravated and metabolic control of blood glucose levels becomes more difficult. This in turn leads to mutual aggravation that results in a self-enforcing catabolic process, a vicious circle of inflammation, tissue destruction and insulin resistance. PMID:18044471

  4. Petrography of Lunar Meteorite LAP 02205, a New Low-Ti Basalt Possibly Launch Paired with NWA 032

    NASA Technical Reports Server (NTRS)

    Jolliff, B. L.; Zeigler, R. A.; Korotev, R. L.

    2004-01-01

    Lunar meteorite LAP 02205 is a 1.23 kg basalt collected during the 2002 field season in the La- Paz ice field, Antarctica [1]. We present a petrographic description including mineral modes and compositions, and the major-element composition of the bulk meteorite. LAP 02205 is an Fe-rich, moderately low-Ti mare basalt that is similar in composition, mineralogy, and mineral chemistry to the NWA 032 basaltic lunar meteorite. LAP 02205 is yet another of the moderately low- Ti basaltic meteorites that are underrepresented among Apollo and Luna samples but that appear from remote sensing to be the most common basalt type on the Moon.

  5. Effect of non-surgical periodontal treatment on transferrin serum levels in patients with chronic periodontitis.

    PubMed

    Shirmohamadi, Adileh; Chitsazi, Mohamad Taghi; Faramarzi, Masoumeh; Salari, Ashkan; Naser Alavi, Fereshteh; Pashazadeh, Nazila

    2016-01-01

    Background. Transferrin is a negative acute phase protein, which decreases during inflammation and infection. The aim of the present investigation was to evaluate changes in the transferrin serum levels subsequent to non-surgical treatment of chronic periodontal disease. Methods. Twenty patients with chronic periodontitis and 20 systemically healthy subjects without periodontal disease, who had referred to Tabriz Faculty of Dentistry, were selected. Transferrin serum levels and clinical periodontal parameters (pocket depth, clinical attachment level, gingival index, bleeding index and plaque index) were measured at baseline and 3 months after non-surgical periodontal treatment. Data were analyzed with descriptive statistical methods (means ± standard deviations). Independent samples t-test was used to compare transferrin serum levels and clinical variables between the test and control groups. Paired samples t-test was used in the test group for comparisons before and after treatment. Statistical significance was set at P < 0.05. Results. The mean transferrin serum level in patients with chronic periodontitis (213.1 ± 9.2 mg/dL) was significantly less than that in periodontally healthy subjects (307.8 ± 11.7 mg/dL). Three months after periodontal treatment, the transferrin serum level increased significantly (298.3 ± 7.6 mg/dL) and approached the levels in periodontally healthy subjects (P < 0.05). Conclusion. The decrease and increase in transferrin serum levels with periodontal disease and periodontal treatment, respectively, indicated an inverse relationship between transferrin serum levels and chronic periodontitis. PMID:27651883

  6. [Microcirculation impairment in periodontal tissues in patients with chronic generalized periodontitis combined with metabolic syndrome].

    PubMed

    Krechina, E K; Zorina, O A; Molchanov, A M; Shilov, A M

    2016-01-01

    Using the method of laser Doppler flowmetry the study of microcirculation in periodontal tissues in patients with moderate chronic generalized periodontitis and metabolic syndrome was carried out. The analysis of microcirculation values proved not only the reduction of blood flow intensity but also the decreased vasoactivity of microvessels essential to maintain normal microcirculation in periodontal tissues, as it provides active modulation of tissue blood flow and its adaptation to local metabolic needs. PMID:26925562

  7. Effect of non-surgical periodontal treatment on transferrin serum levels in patients with chronic periodontitis

    PubMed Central

    Shirmohamadi, Adileh; Chitsazi, Mohamad Taghi; Faramarzi, Masoumeh; Salari, Ashkan; Naser Alavi, Fereshteh; Pashazadeh, Nazila

    2016-01-01

    Background. Transferrin is a negative acute phase protein, which decreases during inflammation and infection. The aim of the present investigation was to evaluate changes in the transferrin serum levels subsequent to non-surgical treatment of chronic periodontal disease. Methods. Twenty patients with chronic periodontitis and 20 systemically healthy subjects without periodontal disease, who had referred to Tabriz Faculty of Dentistry, were selected. Transferrin serum levels and clinical periodontal parameters (pocket depth, clinical attachment level, gingival index, bleeding index and plaque index) were measured at baseline and 3 months after non-surgical periodontal treatment. Data were analyzed with descriptive statistical methods (means ± standard deviations). Independent samples t-test was used to compare transferrin serum levels and clinical variables between the test and control groups. Paired samples t-test was used in the test group for comparisons before and after treatment. Statistical significance was set at P < 0.05. Results. The mean transferrin serum level in patients with chronic periodontitis (213.1 ± 9.2 mg/dL) was significantly less than that in periodontally healthy subjects (307.8 ± 11.7 mg/dL). Three months after periodontal treatment, the transferrin serum level increased significantly (298.3 ± 7.6 mg/dL) and approached the levels in periodontally healthy subjects (P < 0.05). Conclusion. The decrease and increase in transferrin serum levels with periodontal disease and periodontal treatment, respectively, indicated an inverse relationship between transferrin serum levels and chronic periodontitis. PMID:27651883

  8. Neutrophil Functions in Periodontal Homeostasis

    PubMed Central

    Cortés-Vieyra, Ricarda; Rosales, Carlos

    2016-01-01

    Oral tissues are constantly exposed to damage from the mechanical effort of eating and to microorganisms, mostly bacteria. In healthy gingiva tissue remodeling and a balance between bacteria and innate immune cells are maintained. However, excess of bacteria biofilm (plaque) creates an inflammation state that recruits more immune cells, mainly neutrophils to the gingiva. Neutrophils create a barrier for bacteria to reach inside tissues. When neutrophils are insufficient, bacteria thrive causing more inflammation that has been associated with systemic effects on other conditions such as atherosclerosis, diabetes, and cancer. But paradoxically when neutrophils persist, they can also promote a chronic inflammatory state that leads to periodontitis, a condition that leads to damage of the bone-supporting tissues. In periodontitis, bone loss is a serious complication. How a neutrophil balance is needed for maintaining healthy oral tissues is the focus of this review. We present recent evidence on how alterations in neutrophil number and function can lead to inflammatory bone loss, and how some oral bacteria signal neutrophils to block their antimicrobial functions and promote an inflammatory state. Also, based on this new information, novel therapeutic approaches are discussed. PMID:27019855

  9. Girls, aggression, and emotion regulation.

    PubMed

    Conway, Anne M

    2005-04-01

    Many studies have demonstrated that boys are more aggressive than girls (see J. D. Coie & K. Dodge, 1997, for a review) and that emotion regulation difficulties are associated with problematic behaviors (N. Eisenberg & R. A. Fabes, 1999; M. Gilliom, D. S. Shaw, J. E. Beck, M. A. Schonberg, & J. L. Lukon, 2002). However, recent findings indicate that gender differences in aggressive behaviors disappear when assessments are broadened to include relational aggression--behaviors designed to harm the relationship goals of others by spreading rumors, gossiping, and eliciting peer rejection of others. Moreover, although difficulties regulating emotions have been reported for physically aggressive children, little research has examined these processes in relationally aggressive children. This article argues that investigation into the associations between emotion regulation and relational aggression is a critical direction for future research on the etiology and prevention of mental health problems in girls. PMID:15839769

  10. [The aggressive child (author's transl)].

    PubMed

    Harbauer, H

    1978-08-01

    In children a "normal" aggressiveness should be distinguished from "hostile" and "inhibited" aggression; the latter usually become apparent as heteroaggressive or autoaggressive behaviour. Autoaggression is more common with younger children. Different hypotheses about the origin of aggressiveness are discussed. In the younger child nail biting, trichotillomania, rocking, an intensified phase of contrariness and enkopresis may have components of aggressiveness. In older children and adolescents dissocial forms of development, drug taking, attempted suicid, and anorexia nervosa may be parts of aggressive behaviour. Minimal brain dysfunction, autism, and postencephalitic syndromes predominate amongst organic alterations of the brain as causes for aggressive behaviour. Particularly the Lesch-Nyhan-syndrome, but equally the Cornelia de Lange-syndrome show autoaggressive tendencies.

  11. The periodontal – endodontic continuum: A review

    PubMed Central

    Sunitha V, Raja; Emmadi, Pamela; Namasivayam, Ambalavanan; Thyegarajan, Ramakrishnan; Rajaraman, Vijayalakshmi

    2008-01-01

    Periodontal therapy deals with many aspects of the supporting structures, including the prevention and repair of lesions of the gingival sulcus. Endodontics deals primarily with disease of the pulp and periapical tissues. The success of both periodontal and endodontic therapy depends on the elimination of both disease processes, whether they exist separately or as a combined lesion. The relationship between periodontal and endodontic disease has been a subject of speculation for many years. This paper aims at presenting a comprehensive review of several aspects of perio-endo lesions. PMID:20142886

  12. Salivary Markers for Periodontal and General Diseases

    PubMed Central

    Podzimek, Stepan; Vondrackova, Lucie; Duskova, Jana; Janatova, Tatjana; Broukal, Zdenek

    2016-01-01

    The determination of biomarkers in saliva is becoming an important part of laboratory diagnostics and the prediction of not only periodontal, but also other tissue and organ diseases. Biomarkers in saliva (e.g., enzymes, protein markers, or oxidative stress markers) can be used for activity determination and for periodontal disease prognosis. Saliva also contains many markers which can predict the risk of certain diseases (e.g., diabetes mellitus, cardiovascular, oncology, endocrinology, and psychiatric diseases). The study of salivary components proteomics clearly shows the relationship of periodontal diseases and diseases of distant systems, organs, or tissues. PMID:27143814

  13. Smoking and periodontal tissues: a review.

    PubMed

    César Neto, João Batista; Rosa, Ecinele Francisca; Pannuti, Cláudio Mendes; Romito, Giuseppe Alexandre

    2012-01-01

    The impact of smoking on general health has been widely studied and is directly related to several important medical problems including cancer, low birth weight, and pulmonary and cardiovascular disease. In the past 25 years, there has also been an increasing awareness of the role of cigarette consumption in oral health problems such as periodontal disease. Smoking is considered the major risk factor in the prevalence, extent and severity of periodontal diseases. This article will discuss the available evidence and provide the reader with an overview of the impact of smoking and its cessation on the pathogenesis and treatment of periodontal diseases.

  14. Association between periodontal diseases and systemic diseases.

    PubMed

    Weidlich, Patrícia; Cimões, Renata; Pannuti, Claudio Mendes; Oppermann, Rui Vicente

    2008-01-01

    Current evidence suggests that periodontal disease may be associated with systemic diseases. This paper reviewed the published data about the relationship between periodontal disease and cardiovascular diseases, adverse pregnancy outcomes, diabetes and respiratory diseases, focusing on studies conducted in the Brazilian population. Only a few studies were found in the literature focusing on Brazilians (3 concerning cardiovascular disease, 7 about pregnancy outcomes, 9 about diabetes and one regarding pneumonia). Although the majority of them observed an association between periodontitis and systemic conditions, a causal relationship still needs to be demonstrated. Further studies, particularly interventional well-designed investigations, with larger sample sizes, need to be conducted in Brazilian populations. PMID:19838549

  15. Radiologic Assessment of the Periodontal Patient.

    PubMed

    Korostoff, Jonathan; Aratsu, Ali; Kasten, Brian; Mupparapu, Mel

    2016-01-01

    Periodontal examination involves evaluation of soft and hard tissue parameters to gauge gingival inflammatory changes and quantify attachment loss. Conventional radiographs are vital components of this process and can be used to assess the presence of calculus and other local factors to establish a diagnosis, prognosis, and periodontal treatment plan. The 2-dimensional nature of these images limits their utility. The advent of high-resolution cone beam computed tomography (CBCT) offers 3-dimensional images that might overcome these limitations. We discuss the use of conventional radiographic techniques as well as CBCT for evaluating, diagnosing, and treatment planning patients presenting for periodontal and/or implant therapy. PMID:26614950

  16. The antioxidant master glutathione and periodontal health

    PubMed Central

    Bains, Vivek Kumar; Bains, Rhythm

    2015-01-01

    Glutathione, considered to be the master antioxidant (AO), is the most-important redox regulator that controls inflammatory processes, and thus damage to the periodontium. Periodontitis patients have reduced total AO capacity in whole saliva, and lower concentrations of reduced glutathione (GSH) in serum and gingival crevicular fluid, and periodontal therapy restores the redox balance. Therapeutic considerations for the adjunctive use of glutathione in management of periodontitis, in limiting the tissue damage associated with oxidative stress, and enhancing wound healing cannot be underestimated, but need to be evaluated further through multi-centered randomized controlled trials. PMID:26604952

  17. Membranes for periodontal regeneration: From commercially available to spatially designed and functionally graded materials

    NASA Astrophysics Data System (ADS)

    Bottino, Marco Cicero

    The aging of the global population will lead to a considerable increase in the number of surgical and restorative procedures related to oral rehabilitation or periodontal regeneration. Periodontitis is one of the most aggressive pathologies that concern the integrity of the periodontal system that can lead to the destruction of the periodontium. Guided tissue and guided bone regeneration (GTR/GBR) have been used for the repair and regeneration of periodontal tissues by utilizing an occlusive membrane. The goal of this dissertation is to advance the knowledge in the area of periodontal regeneration by investigating the properties of a commercially available freeze-dried collagen-based graft (AlloDermRTM) and by designing/fabricating a functionally graded membrane (FGM) via multilayer electrospinning. The effects of different rehydration times and of a simultaneous rehydration/crosslinking procedure on the biomechanical properties and matrix stability of the commercially available membrane were investigated. The results revealed that there are significant changes on the biomechanical properties of the graft as rehydration time increases. Moreover, it was demonstrated that the simultaneous rehydration/crosslinking protocol has a synergistic effect in terms of enhancing biomechanical properties. A FGM consisting of a core-layer (CL) and two functional surface-layers (SL) was fabricated via sequential electrospinning. Hydroxyapatite nanoparticles (n-HAp) were incorporated to enhance bone formation (SL facing bone defect), and metronidazole benzoate (MET) was added to prevent bacterial colonization (SL facing the epithelial tissue). Degradation studies performed on both the CL and the FGM confirmed that the design holds promise in terms of providing the required mechanical stability to avoid membrane collapse and, therefore, enhance bone regeneration. Finally, it was demonstrated that MET incorporation into the SL that would face epithelial tissue is effective in

  18. Aggressive fibromatosis of anterior maxilla

    PubMed Central

    Shetty, Devi C; Urs, Aadithya B; Ahuja, Puneet; Sikka, Seema

    2011-01-01

    Aggressive fibromatosis is a comparitively rare tumor with unpredictable growth and varying local recurrence rates. It does not develop distant metastases but locally it shows an aggressive and infiltrative behavior. Clinically, aggressive fibromatosis manifests as a painless, firm, often rapidly enlarging mass, fixed to underlying bone or soft tissue. It is never encapsulated. Histologically, it is rich in collagen and fibroblastic cells that are devoid of hyperchromatic or atypical nuclei, but with more variable cellularity in different tumor sections. PMID:21731285

  19. Periodontal Regenerative Therapy in Patient with Chronic Periodontitis and Type 2 Diabetes Mellitus: A Case Report.

    PubMed

    Seshima, Fumi; Nishina, Makiko; Namba, Takashi; Saito, Atsushi

    2016-01-01

    We report a case of generalized chronic periodontitis and type 2 diabetes mellitus requiring periodontal treatment including regenerative therapy. The patient was a 66-year-old man who presented with the chief complaint of gingival inflammation and mobile teeth in the molar region. He had been being treated for type 2 diabetes mellitus since 1999. His glycated hemoglobin (HbA1c) level was 7.8%. An initial examination revealed sites with a probing depth of ≥7 mm in the molar region, and radiography revealed angular bone defects in this area. Based on a clinical diagnosis of generalized chronic periodontitis, the patient underwent initial periodontal therapy. An improvement was observed in periodontal conditions on reevaluation, and his HbA1c level showed a reduction to 6.9%. Periodontal regenerative therapy with enamel matrix derivative was then performed on #16, 26, and 27. Following another reevaluation, a removable partial denture was fabricated for #47 and the patient placed on supportive periodontal therapy (SPT). To date, periodontal conditions have remained stable and the patient's HbA1c level has increased to 7.5% during SPT. The results show the importance of collaboration between dentist and physician in managing periodontal and diabetic conditions in such patients.

  20. Review of the use of physical restraints and lap belts with wheelchair users.

    PubMed

    Chaves, Eliana S; Cooper, Rory A; Collins, Diane M; Karmarkar, Amol; Cooper, Rosemarie

    2007-01-01

    Wheelchair-related physical restraints, lap belts, and other alternatives are intended to provide safe and adequate seating and mobility for individuals using wheelchairs. Physical restraints and lap belts are also helpful for positioning people in their wheelchairs to reduce the risk of injury during wheelchair tips and falls. However, when used improperly or in ways other than intended, injury or even death can result. Although widely prescribed, little evidence is available to direct professionals on the appropriate use of these restraints and lap belts and for whom these restraints are indicated. The purpose of this study was to conduct a review of available literature from 1966-2006 to identify the risks and benefits associated with lap belts while seated in wheelchairs. Twenty-five studies that met the inclusion criteria were reviewed. Nine studies reported the frequency of asphyxial deaths caused by physical restraints, nine studies reported the long-term complication and indirect adverse effects of physical restraints and lap-belt use, and seven studies reported the benefits of physical restraints and lap belts with individuals using wheelchairs. Despite the weak evidence, the results suggest a considerable number of deaths from asphyxia caused by the use of physical restraints occurred each year in the U.S. The majority of the deaths occurred in nursing homes, followed by hospitals, and then the home of the person. Most deaths occurred while persons were restrained in wheelchairs or beds. Based on that, caution needs to be exercised when using restraints or positioning belts. In addition, other seating and environment alternatives should be explored prior to using restraints or positioning belts, such as power wheelchair seating options. Positioning belts may reduce risk of falls from wheelchairs and should be given careful consideration, but caution should be exercised if the individual cannot open the latch independently. Also, the duration of use of the

  1. Supportive periodontal therapy and periodontal biotype as prognostic factors in implants placed in patients with a history of periodontitis

    PubMed Central

    Vallejo-Aisa, Francisco J.; Estefanía-Fresco, Ruth

    2013-01-01

    Objectives: To evaluate bone loss around implants placed in patients with a history of treated chronic periodontitis and who did or did not attend supportive periodontal therapy, after one year in function. Furthermore, the influence of periodontal biotype and level of plaque was also evaluated. Material and Methods: Forty-nine patients participated voluntarily in the study. All subjects had a history of chronic periodontitis, which had been previously treated. After the active treatment, 27 patients attended supportive periodontal therapy (SPT) and the rest did not (No SPT). The O’Leary plaque index and periodontal biotype were recorded for each subject and 246 Astra Tech® OsseospeedTM implants were radiographically analysed (123 placed in SPT patients and 123 in No SPT patients) at the time of loading and one year later, measuring marginal bone loss with the program Dental Studio NX 6.0®. The statistical analysis was performed with Windows SPSS, applying Pearson’s correlation index and the Kruskal-Wallis and U-Mann Whitney non-parametric tests. Results: Six patients were found to have periimplantitis and sixteen mucositis. The survival rate was 99.59% (100% SPT and 99.18% No SPT). Mean bone loss was 0.39 mm (range [-0.71 - 8.05]). Among SPT patients, 95% of the implants had losses less than or equal to the mean (mean bone loss of 0.16 mm) compared to 53.7% for the No SPT group (mean bone loss of 0.62 mm). A statistically significant relationship was demonstrated between bone loss around the implant and the patient’s periodontal biotype and plaque index. Conclusions: The marginal bone loss around implants in patients with treated chronic periodontitis is minimal if they are in a controlled SPT programme and there is individual control of plaque index. Moreover, the presence of a thin periodontal biotype represents a risk factor for additional bone loss. Key words:Peri-implantitis, chronic periodontitis, bacterial plaque, periodontal biotype. PMID:23722147

  2. The Trimeric Model: A New Model of Periodontal Treatment Planning

    PubMed Central

    Tarakji, Bassel

    2014-01-01

    Treatment of periodontal disease is a complex and multidisciplinary procedure, requiring periodontal, surgical, restorative, and orthodontic treatment modalities. Several authors attempted to formulate models for periodontal treatment that orders the treatment steps in a logical and easy to remember manner. In this article, we discuss two models of periodontal treatment planning from two of the most well-known textbook in the specialty of periodontics internationally. Then modify them to arrive at a new model of periodontal treatment planning, The Trimeric Model. Adding restorative and orthodontic interrelationships with periodontal treatment allows us to expand this model into the Extended Trimeric Model of periodontal treatment planning. These models will provide a logical framework and a clear order of the treatment of periodontal disease for general practitioners and periodontists alike. PMID:25177662

  3. Rethinking Aggression: A Typological Examination of the Functions of Aggression.

    ERIC Educational Resources Information Center

    Little, Todd D.; Brauner, Jessica; Jones, Stephanie M.; Nock, Matthew K.; Hawley, Patricia H.

    2003-01-01

    Compared five subgroups of aggressive children and adolescents on several adjustment correlates. Found that the reactive group and the group high on both instrumental and reactive reasons for aggression showed consistent maladaptive patterns across the adjustment correlates. The instrumental and typical groups (moderate on instrumental and…

  4. Calcium Causes Multimerization of the Large Adhesin LapF and Modulates Biofilm Formation by Pseudomonas putida

    PubMed Central

    Martínez-Gil, Marta; Romero, Diego; Kolter, Roberto

    2012-01-01

    LapF is a large secreted protein involved in microcolony formation and biofilm maturation in Pseudomonas putida. Its C-terminal domain shows the characteristics of proteins secreted through a type I secretion system and includes a predicted calcium binding motif. We provide experimental evidence of specific binding of Ca2+ to the purified C-terminal domain of LapF (CLapF). Calcium promotes the formation of large aggregates, which disappear in the presence of the calcium chelator EGTA. Immunolocalization of LapF also shows the tendency of this protein to accumulate in vivo in certain extracellular regions. These findings, along with results showing that calcium influences biofilm formation, lead us to propose a model in which P. putida cells interact with each other via LapF in a calcium-dependent manner during the development of biofilms. PMID:23042991

  5. Metabolic syndrome, periodontal infection, and dental caries.

    PubMed

    Timonen, P; Niskanen, M; Suominen-Taipale, L; Jula, A; Knuuttila, M; Ylöstalo, P

    2010-10-01

    Only a few studies have examined the association of metabolic syndrome with periodontal infection and dental caries. The aim in this study was to examine the association of metabolic syndrome with periodontal infection and dental caries using the European Group for the Study of Insulin Resistance (EGIR) definition and its separate components. This study population consisted of dentate, non-diabetic individuals aged 30 to 64 years (N = 2050) who had never smoked. Relative risks (RR) were estimated with Poisson regression models. Metabolic syndrome was associated with teeth with deepened periodontal pockets 4 mm deep or deeper [adjusted RR 1.19 (95% CI 1.01-1.42)], with pockets 6 mm deep or deeper [adjusted RR 1.50 (95% CI 0.96-2.36)], and carious teeth [adjusted RR 1.25 (95% CI 0.93-1.70)]. The results suggest that metabolic syndrome or some of its components are associated weakly with periodontal infection.

  6. Clinical periodontics with the argon laser

    NASA Astrophysics Data System (ADS)

    Finkbeiner, R. L.

    1995-04-01

    The argon laser has proven to be a valuable tool for the thermodynamic debridement of the periodontal lesion, incisions and tissue fusion. Illustrations of clinical applications and discussion of laser parameters will be provided.

  7. Defective neutrophil chemotaxis in juvenile periodontitis.

    PubMed Central

    Clark, R A; Page, R C; Wilde, G

    1977-01-01

    Neutrophil chemotaxis was evaluated in nine patients with juvenile periodontitis, with normal subjects and patients with the adult form of periodontitis as controls. Defective chemotactic responses were observed in neutrophils from seven of nine juvenile patients, and a reduced level of complement-derived chemotactic activity was demonstrated in serum from four patients. These determinations were normal in all the patients with adult periodontitis. Serum from five of the juvenile patients contained a heat-stable, non-dialyzable factor that markedly inhibited the chemotaxis of normal neutrophils. Thus the characteristic tissue destruction seen in juvenile periodontitis may be, at least in part, a consequence of a failure of host defense mechanisms. PMID:591063

  8. Association between Periodontitis and Alzheimer's Disease

    PubMed Central

    Abbayya, Keshava; Puthanakar, Nagraj Y; Naduwinmani, Sanjay; Chidambar, Y S

    2015-01-01

    Alzheimer's disease (AD) is a neurodegenerative disease which significantly increases with age. Its onset can be either early or late. AD is characterized by the salient inflammatory features, microglial activation, and increased levels of proinflammatory cytokines which contribute to the inflammatory status of the central nervous system (CNS). Whereas, periodontitis is a common oral infection associated with the gram negative anaerobic bacteria. Periodontitis can be marked as a “low-grade systemic disease” by release of proinflammatory cytokines into systemic circulation and elevation of C-reactive protein (CRP). Inflammation is known to play a pivotal role in both the disease process serving as a connecting link between periodontitis and AD. The present review throws a light on possible enigmatic link between AD and periodontitis. This review is designed by collecting data from PubMed database using key words like “Alzheimer's disease”, “inflammation”, “periodontitis”, and “proinflammatory cytokines”. PMID:26199919

  9. Optical coherence tomography for diagnosing periodontal disease

    NASA Astrophysics Data System (ADS)

    Colston, Bill W., Jr.; Everett, Matthew J.; Da Silva, Luiz B.; Otis, Linda L.; Nathel, Howard

    1997-05-01

    We have, in this preliminary study, investigated the use of optical coherence tomography for diagnosis of periodontal disease. We took in vitro OCT images of the dental and periodontal tissues from a young pig and compared them to histological sections. These images distinguish tooth and soft tissue relationships that are important in diagnosing and assessing periodontal disease. We have imaged the attachment of gingiva to the tooth surface and located the cemento-enamel junction. This junction is an important reference point for defining attachment level in the diagnosis of periodontal disease. the boundary between enamel and dentin is also visible for most of the length of the anatomical crown, allowing quantitation of enamel thickness and character.

  10. Oxidative Stress and Periodontal Disease in Obesity.

    PubMed

    Dursun, Erhan; Akaln, Ferda Alev; Genc, Tolga; Cinar, Nese; Erel, Ozcan; Yildiz, Bulent Okan

    2016-03-01

    Periodontal disease is a chronic inflammatory disease of the jaws and is more prevalent in obesity. Local and systemic oxidative stress may be an early link between periodontal disease and obesity. The primary aim of this study was to detect whether increased periodontal disease susceptibility in obese individuals is associated with local and systemic oxidative stress. Accordingly; we analyzed periodontal status and systemic (serum) and local (gingival crevicular fluid [GCF]) oxidative status markers in young obese women in comparison with age-matched lean women.Twenty obese and 20 lean women participated. Periodontal condition was determined by clinical periodontal indices including probing depth, clinical attachment level, gingival index, gingival bleeding index, and plaque index. Anthropometric, hormonal, and metabolic measurements were also performed. Blood and GCF sampling was performed at the same time after an overnight fasting. Serum and GCF total antioxidant capacity (TAOC), and total oxidant status (TOS) levels were determined, and oxidative stress index (OSI) was calculated.Clinical periodontal analyses showed higher gingival index and gingival bleeding index in the obese group (P = 0.001 for both) with no significant difference in probing depth, clinical attachment level, and plaque index between the obese and the lean women. Oxidant status analyses revealed lower GCF and serum TAOC, and higher GCF and serum OSI values in the obese women (P < 0.05 for all). GCF TOS was higher in the obese women (P < 0.05), whereas there was a nonsignificant trend for higher serum TOS in obese women (P = 0.074). GCF TAOC values showed a negative correlation with body mass index, whereas GCF OSI was positively correlated with fasting insulin and low-density lipoprotein-cholesterol levels (P < 0.05 for all). Clinical periodontal indices showed significant correlations with body mass index, insulin, and lipid levels, and also oxidant status markers

  11. Oxidative Stress and Periodontal Disease in Obesity

    PubMed Central

    Dursun, Erhan; Akalın, Ferda Alev; Genc, Tolga; Cinar, Nese; Erel, Ozcan; Yildiz, Bulent Okan

    2016-01-01

    Abstract Periodontal disease is a chronic inflammatory disease of the jaws and is more prevalent in obesity. Local and systemic oxidative stress may be an early link between periodontal disease and obesity. The primary aim of this study was to detect whether increased periodontal disease susceptibility in obese individuals is associated with local and systemic oxidative stress. Accordingly; we analyzed periodontal status and systemic (serum) and local (gingival crevicular fluid [GCF]) oxidative status markers in young obese women in comparison with age-matched lean women. Twenty obese and 20 lean women participated. Periodontal condition was determined by clinical periodontal indices including probing depth, clinical attachment level, gingival index, gingival bleeding index, and plaque index. Anthropometric, hormonal, and metabolic measurements were also performed. Blood and GCF sampling was performed at the same time after an overnight fasting. Serum and GCF total antioxidant capacity (TAOC), and total oxidant status (TOS) levels were determined, and oxidative stress index (OSI) was calculated. Clinical periodontal analyses showed higher gingival index and gingival bleeding index in the obese group (P = 0.001 for both) with no significant difference in probing depth, clinical attachment level, and plaque index between the obese and the lean women. Oxidant status analyses revealed lower GCF and serum TAOC, and higher GCF and serum OSI values in the obese women (P < 0.05 for all). GCF TOS was higher in the obese women (P < 0.05), whereas there was a nonsignificant trend for higher serum TOS in obese women (P = 0.074). GCF TAOC values showed a negative correlation with body mass index, whereas GCF OSI was positively correlated with fasting insulin and low-density lipoprotein-cholesterol levels (P < 0.05 for all). Clinical periodontal indices showed significant correlations with body mass index, insulin, and lipid levels, and also oxidant status

  12. THE IMPACT OF AGGRESSION IN THE CLASSROOM.

    ERIC Educational Resources Information Center

    MCNEIL, ELTON B.; AND OTHERS

    IN THIS INVESTIGATION, AGGRESSION WAS MEASURED FROM FOUR PERSPECTIVES--(1) THE PERCEPTION THAT THE SUBJECT HAD OF HIS AGGRESSION, (2) HIS SATISFACTION, AS HE VIEWED IT, WITH HIS OWN AGGRESSION, (3) THE PERCEPTION THAT THE TEACHER HAD OF THE SUBJECT'S AGGRESSIVENESS, AND (4) THE PERCEPTION OF THE SUBJECT'S AGGRESSIVENESS HELD BY HIS CLASSMATES. IN…

  13. The Effects of Pornography on Aggressive Behavior.

    ERIC Educational Resources Information Center

    Stacy, Lauri L.

    This document reviews existing empirical research on the effect of pornography on aggressive behavior. Two types of pornography are distinguished: aggressive pornography and non-aggressive pornography. Conclusions drawn from the research review are presented, including: (1) aggressive pornograpy consistently increases aggressive attitudes and…

  14. Lumbar compression fractures secondary to lap-belt use in children.

    PubMed

    Sturm, P F; Glass, R B; Sivit, C J; Eichelberger, M R

    1995-01-01

    The correlation between flexion-distraction injuries and lap-belt use has been well documented. Over a 10-year period, we identified seven children admitted to Children's National Medical Center, Washington, DC, with compression fractures of the lumbar spine secondary to lap-belt use. Four were rear seat passengers, and three were in the front seat. The average age was 7 years. Four of the seven (57%) suffered associated abdominal injuries. One died of an associated head injury. We hypothesize that the mechanism of injury in these cases was similar to that in flexion-distraction injuries. The increased elasticity in the posterior ligamentous complex in children may be responsible for the occurrence of these compression fractures rather than the expected flexion-distraction-type injuries.

  15. Material characterization of structural adhesives in the lap shear mode. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Schenck, S. C.; Sancaktar, E.

    1983-01-01

    A general method for characterizing structural adhesives in the bonded lap shear mode is proposed. Two approaches in the form of semi-empirical and theoretical approaches are used. The semi-empirical approach includes Ludwik's and Zhurkov's equations to describe respectively, the failure stresses in the constant strain rate and constant stress loading modes with the inclusion of the temperature effects. The theoretical approach is used to describe adhesive shear stress-strain behavior with the use of viscoelastic or nonlinear elastic constitutive equations. Three different model adhesives are used in the simple lap shear mode with titanium adherends. These adhesives (one of which was developed at NASA Langley Research Center) are currently considered by NASA for possible aerospace applications. Use of different model adhesives helps in assessment of the generality of the method.

  16. Ground based experiments on the growth and characterization of L-Arginine Phosphate (LAP) crystals

    NASA Technical Reports Server (NTRS)

    Rao, S. M.; Cao, C.; Batra, A. K.; Lal, R. B.; Mookherji, T. K.

    1991-01-01

    L-Arginine Phosphate (LAP) is a new nonlinear optical material with higher efficiency for harmonic generation compared to KDP. Crystals of LAP were grown in the laboratory from supersaturated solutions by temperature lowering technique. Investigations revealed the presence of large dislocation densities inside the crystals which are observed to produce refractive index changes causing damage at high laser powers. This is a result of the convection during crystal growth from supersaturated solutions. It is proposed to grow these crystals in a diffusion controlled growth condition under microgravity environment and compare the crystals grown in space with those grown on ground. Physical properties of the solutions needed for modelling of crystal growth are also presented.

  17. A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

    NASA Technical Reports Server (NTRS)

    Harris, C. E.; Piascik, R. S.; Newman, J. C., Jr.

    2000-01-01

    An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

  18. Investigation of defect rate of lap laser welding of stainless steel railway vehicles car body

    NASA Astrophysics Data System (ADS)

    Wang, Hongxiao

    2015-02-01

    In order to resolve the disadvantages such as poor appearance quality, poor tightness, low efficiency of resistance spot welding of stainless steel rail vehicles, partial penetration lap laser welding process was investigated widely. But due to the limitation of processing technology, there will be local incomplete fusion in the lap laser welding seam. Defect rate is the ratio of the local incomplete fusion length to the weld seam length. The tensile shear strength under different defect rate and its effect on the car body static strength are not clear. It is necessary to find the biggest defect rate by numerical analysis of effects of different defect rates on the laser welding stainless steel rail vehicle body structure strength ,and tests of laser welding shear tensile strength.

  19. Periodontal implications of orthodontic treatment in adults with reduced or normal periodontal tissues versus those of adolescents.

    PubMed

    Boyd, R L; Leggott, P J; Quinn, R S; Eakle, W S; Chambers, D

    1989-09-01

    This longitudinal study monitored periodontal status in 20 adults and 20 adolescents undergoing fixed orthodontic treatment. Ten adults had generalized periodontitis and received periodontal treatment, including periodontal surgery, before orthodontic treatment. They also received periodontal maintenance at 3-month intervals during orthodontic treatment. The other 10 adults had normal periodontal tissues. Neither these latter adults nor the adolescents received periodontal maintenance during orthodontic treatment. Periodontal status was determined (1) at six standard sites before fixed appliances were placed (baseline), (2) at 1, 3, 6, 9, 12, and 18 months after appliances had been placed, and (3) 1, 3, 6, and 12 months after appliances had been removed. At each of these visits, these sites were assessed for plaque index, gingival index, bleeding tendency, and pocket depth. Loss of attachment between baseline and 3 months after appliances were removed and tooth loss were also determined. Complete data were obtained for 15 adolescents and 14 adults. During orthodontic treatment the adolescent group showed significantly more (p less than 0.05) periodontal inflammation and supragingival plaque than the adults; after appliances were removed, this pattern was no longer statistically significant. For loss of attachment, there were no significant differences among adolescents, adults with normal periodontal tissues, or adults with reduced but healthy periodontal tissues who had undergone treatment for periodontal disease. For tooth loss, three nonstudy site teeth with pockets deeper than 6 mm and/or furcation involvements were lost because of periodontal abscesses in the adult group treated for periodontal disease. PMID:2773862

  20. Quorum Sensing Inhibition, Relevance to Periodontics

    PubMed Central

    Yada, Sudheer; Kamalesh, B; Sonwane, Siddharth; Guptha, Indra; Swetha, R K

    2015-01-01

    Quorum sensing helps bacteria to communicate with each other and in coordinating their behavior. Many diseases of human beings, plants, and animals are mediated by quorum sensing. Various approaches are being tried to inhibit this communication to control the diseases caused by bacteria. Periodontal pathogens also communicate through quorum sensing and new approaches to treat periodontal disease using quorum sensing inhibition need to explored. PMID:25709373

  1. Newly Identified Pathogens Associated with Periodontitis

    PubMed Central

    Pérez-Chaparro, P.J.; Gonçalves, C.; Figueiredo, L.C.; Faveri, M.; Lobão, E.; Tamashiro, N.; Duarte, P.; Feres, M.

    2014-01-01

    There is substantial evidence supporting the role of certain oral bacteria species in the onset and progression of periodontitis. Nevertheless, results of independent-culture diagnostic methods introduced about a decade ago have pointed to the existence of new periodontal pathogens. However, the data of these studies have not been evaluated together, which may generate some misunderstanding on the actual role of these microorganisms in the etiology of periodontitis. The aim of this systematic review was to determine the current weight of evidence for newly identified periodontal pathogens based on the results of “association” studies. This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE, EMBASE, and Cochrane databases were searched up to September 2013 for studies (1) comparing microbial data of subgingival plaque samples collected from subjects with periodontitis and periodontal health and (2) evaluating at least 1 microorganism other than the already-known periodontal pathogens. From 1,450 papers identified, 41 studies were eligible. The data were extracted and registered in predefined piloted forms. The results suggested that there is moderate evidence in the literature to support the association of 17 species or phylotypes from the phyla Bacteroidetes, Candidatus Saccharibacteria, Firmicutes, Proteobacteria, Spirochaetes, and Synergistetes. The phylum Candidatus Saccharibacteria and the Archaea domain also seem to have an association with disease. These data point out the importance of previously unidentified species in the etiology of periodontitis and might guide future investigations on the actual role of these suspected new pathogens in the onset and progression of this infection. PMID:25074492

  2. Enamel matrix protein derivatives: role in periodontal regeneration

    PubMed Central

    Rathva, Vandana J

    2011-01-01

    The role of regenerative periodontal therapy is the reconstitution of lost periodontal structures, ie, new formation of root cementum, periodontal ligament, and alveolar bone. The outcome of basic research has pointed to the important role of enamel matrix protein derivative (EMD) in periodontal wound healing. Histologic results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of this paper is to review the existing literature on EMD. PMID:23674918

  3. A study of sandwich T-joints and composite lap joints

    NASA Astrophysics Data System (ADS)

    Turaga, Umamaheswar V. R. S.

    In this study, new efficient designs for adhesive sandwich T-joint and single-lap joint were proposed and investigated. In the proposed new sandwich T-joint, called U-channel joint, the load transfer path at the web-flange interface was modified to include a U-shaped aluminum channel which provides strong path for load transfer. Experimental results show that the new design has 62% more strength than the conventional circular fillet joint. The new U-channel joint was tested in tension, compression and bending to investigate its characteristics. It is found to have good performance in bending also, even though in compression it performs same as the circular fillet joint. An extensive parametric study was carried out to investigate the effect of parameters like flange skin stiffener, foam density, foam thickness in the web, and aluminum attachments. A fracture mechanics criterion based on the strain energy release rate was used to explain the failure modes, apart from the stress analysis explanation. The failure loads of the joints in compression were predicted using a maximum principal stress failure criterion based on the sandwich beam theory. A new single lap joint with attachments was proposed in the second phase of the research. The design was verified using both aluminum and composite materials. The new design was found to have 59% more strength than the single-lap joint. A parametric study was performed to find out the influence of the angle of attachment, thickness of attachment and the length of attachment. By careful consideration of design parameters, the joint can be optimized. Finally, the failure loads of the single lap joints with and without attachments were predicted using different failure criteria.

  4. Low frequency ultrasonic nondestructive inspection of aluminum/adhesive fuselage lap splices

    SciTech Connect

    Patton, T.

    1994-01-04

    This thesis is a collection of research efforts in ultrasonics, conducted at the Center for Aviation Systems Reliability located at Iowa State University, as part of the Federal Aviation Administration`s ``Aging Aircraft Program.`` The research was directed toward the development of an ultrasonic prototype to inspect the aluminum/adhesive fuselage lap splices found on 1970`s vintage Boeing passenger aircraft. The ultrasonic prototype consists of a normal incidence, low frequency inspection technique, and a scanning adapter that allows focused immersion transducers to be operated in a direct contact manner in any inspection orientation, including upside-down. The inspection technique uses a computer-controlled data acquisition system to produce a C-scan image of a radio frequency (RF) waveform created by a low frequency, broadband, focused beam transducer, driven with a spike voltage pulser. C-scans produced by this technique are color representations of the received signal`s peak-to-peak amplitude (voltage) taken over an (x, y) grid. Low frequency, in this context, refers to a wavelength that is greater than the lap splice`s layer thicknesses. With the low frequency technique, interface echoes of the lap splice are not resolved and gating of the signal is unnecessary; this in itself makes the technique simple to implement and saves considerable time in data acquisition. Along with the advantages in data acquisition, the low frequency technique is relatively insensitive to minor surface curvature and to ultrasonic interference effects caused by adhesive bondline thickness variations in the lap splice.

  5. Evaluation of the fuselage lap joint fatigue and terminating action repair

    NASA Technical Reports Server (NTRS)

    Samavedam, Gopal; Thomson, Douglas; Jeong, David Y.

    1994-01-01

    Terminating action is a remedial repair which entails the replacement of shear head countersunk rivets with universal head rivets which have a larger shank diameter. The procedure was developed to eliminate the risk of widespread fatigue damage (WFD) in the upper rivet row of a fuselage lap joint. A test and evaluation program has been conducted by Foster-Miller, Inc. (FMI) to evaluate the terminating action repair of the upper rivet row of a commercial aircraft fuselage lap splice. Two full scale fatigue tests were conducted on fuselage panels using the growth of fatigue cracks in the lap joint. The second test was performed to evaluate the effectiveness of the terminating action repair. In both tests, cyclic pressurization loading was applied to the panels while crack propagation was recorded at all rivet locations at regular intervals to generate detailed data on conditions of fatigue crack initiation, ligament link-up, and fuselage fracture. This program demonstrated that the terminating action repair substantially increases the fatigue life of a fuselage panel structure and effectively eliminates the occurrence of cracking in the upper rivet row of the lap joint. While high cycle crack growth was recorded in the middle rivet row during the second test, failure was not imminent when the test was terminated after cycling to well beyond the service life. The program also demonstrated that the initiation, propagation, and linkup of WFD in full-scale fuselage structures can be simulated and quantitatively studied in the laboratory. This paper presents an overview of the testing program and provides a detailed discussion of the data analysis and results. Crack distribution and propagation rates and directions as well as frequency of cracking are presented for both tests. The progression of damage to linkup of adjacent cracks and to eventual overall panel failure is discussed. In addition, an assessment of the effectiveness of the terminating action repair and the

  6. Lap time variation and executive function in older adults: the Baltimore Longitudinal Study of Aging

    PubMed Central

    Tian, Qu; Simonsick, Eleanor M.; Resnick, Susan M.; Shardell, Michelle D.; Ferrucci, Luigi; Studenski, Stephanie A.

    2015-01-01

    Background: poor cognitive and motor performance predicts neurological dysfunction. Variable performance may be a subclinical indicator of emerging neurological problems. Objective: examine the cross-sectional association between a clinically accessible measure of variable walking and executive function. Methods: older adults aged 60 or older from the Baltimore Longitudinal Study of Aging (n = 811) with data on the 400-m walk test and cognition. Based on ten 40-m laps, we calculated mean lap time (MLT) and variation in time across ten 40-m laps (lap time variation, LTV). Executive function tests assessed attention and short-term memory (digit span forward and backward), psychomotor speed [Trail Making Test (TMT) part A] and multicomponent tasks requiring cognitive flexibility [TMT part B, part B-A (Delta TMT) and digit symbol substitution test (DSST)]. Multivariate linear regression analysis examined the cross-sectional association between LTV and executive function, adjusted for MLT, age, sex and education, as well as the LTV × MLT interaction. Results: the LTV was univariately associated with all executive function tests except digit span (P < 0.001); after adjustment, the association with TMT part A remained (standardised β = 0.142, P = 0.002). There was an interaction between MLT and LTV; among fast walkers, greater LTV was associated with a greater Delta TMT (β for LTV × MLT = −1.121, P = 0.016) after adjustment. Conclusion: at any walking speed, greater LTV is associated with psychomotor slowing. Among persons with faster walking speed, variation is associated with worse performance on a complex measure of cognitive flexibility. A simple measure of variability in walking time is independently associated with psychomotor slowing. PMID:26082177

  7. A Single-Lap Joint Adhesive Bonding Optimization Method Using Gradient and Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Smeltzer, Stanley S., III; Finckenor, Jeffrey L.

    1999-01-01

    A natural process for any engineer, scientist, educator, etc. is to seek the most efficient method for accomplishing a given task. In the case of structural design, an area that has a significant impact on the structural efficiency is joint design. Unless the structure is machined from a solid block of material, the individual components which compose the overall structure must be joined together. The method for joining a structure varies depending on the applied loads, material, assembly and disassembly requirements, service life, environment, etc. Using both metallic and fiber reinforced plastic materials limits the user to two methods or a combination of these methods for joining the components into one structure. The first is mechanical fastening and the second is adhesive bonding. Mechanical fastening is by far the most popular joining technique; however, in terms of structural efficiency, adhesive bonding provides a superior joint since the load is distributed uniformly across the joint. The purpose of this paper is to develop a method for optimizing single-lap joint adhesive bonded structures using both gradient and genetic algorithms and comparing the solution process for each method. The goal of the single-lap joint optimization is to find the most efficient structure that meets the imposed requirements while still remaining as lightweight, economical, and reliable as possible. For the single-lap joint, an optimum joint is determined by minimizing the weight of the overall joint based on constraints from adhesive strengths as well as empirically derived rules. The analytical solution of the sin-le-lap joint is determined using the classical Goland-Reissner technique for case 2 type adhesive joints. Joint weight minimization is achieved using a commercially available routine, Design Optimization Tool (DOT), for the gradient solution while an author developed method is used for the genetic algorithm solution. Results illustrate the critical design variables

  8. Spatial distribution of low energy plasma at comet 67P from Rosetta RPC-LAP measurements

    NASA Astrophysics Data System (ADS)

    Edberg, Niklas J. T.; Eriksson, Anders I.; Odelstad, Elias; Vigren, Erik; Henri, Pierre; Lebreton, Jean-Pierre; Mandt, Kathleen; Nilsson, Hans; Carr, Chris; Cupido, Emanuele; Vallat, Claire; Altwegg, Kathrin

    2015-04-01

    We present in situ measurements of the low energy plasma environment around comet 67P from the two Langmuir probes (LAP) on the Rosetta spacecraft, which form part of the Rosetta plasma consortium (RPC). RPC-LAP has operated almost continuously as Rosetta has orbited the comet at close distance (10-30 km) at low velocity (about 1 m/s) since August 2014. Using the RPC-LAP measurements we have produced global maps of the low energy plasma in the vicinity of 67P. Initial estimates indicate that the plasma density has reached values of several 100 cm^-3 and that the electron temperature has typically been in the range 5-10 eV, when the comet was beyond 2.5 AU from the sun. Photoionisation is the dominating process for producing the plasma around the comet while charge-exchange and impact ionisation may also contribute. The plasma environment has been found to be strongly coupled to the local neutral gas density, which in turn is coupled to which area on the comet is facing the sun. The northern summer neck-area of the comet outgasses more than other areas and above this region are the highest densities observed. In the southern winter and above the two main lobes of the comet body, the plasma density is lower. The plasma density is hence not determined by the solar wind, but by the outgassing from the comet. The 12.4-hour rotation period of the comet together with the varying latitude of the slow-moving Rosetta provide strong modulation of the RPC-LAP measurements. Besides orbiting the comet, Rosetta will also perform flybys of the comet in early 2015 when Rosetta will move to distances of several hundred kilometres from the nucleus. These flybys provide a cut-through view of the near-comet plasma environment, which will possibly give some insight to the solar-wind interaction with the cometary coma.

  9. Early evolution of comet 67P studied with the RPC-LAP onboard Rosetta

    NASA Astrophysics Data System (ADS)

    Miloch, Wojciech; Edberg, Niklas J. T.; Eriksson, Anders I.; Yang, Lei; Paulsson, Joakim J. P.; Wedlund, Cyril Simon; Odelstad, Elias

    2016-07-01

    The Rosetta mission provides the in-situ measurements of a comet that are closest to a comet's aphelion ever made. The Rosetta Plasma Consortium (RPC) is a set of five instruments on board the spacecraft that specialise in the measurements of the plasma environment of comet 67P. One of the instruments is RPC-LAP, which consists of two Langmuir Probes and can measure the density, temperature, and flow speed of the plasma in the vicinity of the comet. At the early stage of the Rosetta mission, when the spacecraft is far from the nucleus of comet 67P, the ion part of the current-voltage characteristics of RPC-LAP1 is dominated by the photoemission current which surpasses the currents from the dilute solar wind plasma. As Rosetta starts orbiting around the nucleus in September 2014, LAP1 picks up signatures of local plasma density enhancements corresponding to variations of water-group ions observed in the vicinity of the comet. With the help of current-voltage characteristics and the spacecraft potential, we identify and characterise in space and time the entering of this coma-dominated plasma. In particular we determine the transition for entering the ion dominated region characterised by the 6-hour variations in the local plasma density due to the comet rotation. This transition manifests as a steep gradient in the density with respect to the distance to the comet nucleus. We discuss these RPC-LAP results together with the corresponding measurements by other instruments to provide a comprehensive picture of the transition.

  10. Psychological Research on Human Aggressiveness

    ERIC Educational Resources Information Center

    Hamburg, D. A.; Brodie, H. K. H.

    1973-01-01

    Discusses research relating to the effects of hormones, neurophysiology, and the environment on animal and human aggression. Indicates that the interactions of biological, psychological and social processes in the development of human aggressiveness should constitute one of the principal frontiers for science in the next two decades. (JR)

  11. Aggression and Violence in Youth.

    ERIC Educational Resources Information Center

    William Gladden Foundation, York, PA.

    This booklet was written to provide an understanding of aggression and violence in youth. Its purpose is to help parents, professionals, and other concerned citizens prevent or reduce these potentially dangerous behaviors. The introduction notes that many experts agree that aggression and violence are on the rise in America. The first section of…

  12. [Periodontal disease and preterm birth].

    PubMed

    Malinova, M

    2013-01-01

    Preterm birth (PB) is a primary public health challenge in both developed and underdeveloped nations. Despite improvements in obstetric care, rates of preterm birth have not decreased during the last 10 years. The etiological role of maternal infection, either in the genital tract or elsewhere, on preterm delivery remains unclear. Periodontal disease (PD) is one of the most common chronic infectious diseases. This type of infection is caused primarily by Gram-negative anaerobic, and microaerophilic bacteria that colonize the subgingival area and produce significant amounts of proinflammatory cytokines, mainly interleukin 1 beta and interleukin 6, prostaglandin E2, and Tumor necrosis factor alpha. PD may therefore influence PB through an indirect mechanism involving inflammatory mediators or through a direct bacterial assault on the amnion. PMID:24294762

  13. Biochemical markers of the periodontal ligament.

    PubMed

    Castro, Cecilia Estela; Koss, Myriam Adriana; López, María Elena

    2003-01-01

    For many years the diagnosis of Periodontal Disease has been based on clinical and radiographic methods. Other more recent methods have the objective of studying the inflammatory response of the host. That way, immunologic and biological methods determine the free mediators in the periodontal infection. The components of the gingivo-crevicular liquid or fluid are used to identify or to diagnose the active disease, to anticipate the risk of acquiring the disease and to determine its progress. For it to be clinically useful important changes should be registered the way a specific site turns active or that a previously disease affected site improves its conditions as a result of periodontal therapy. The response of the neutrophillic granulocytes play an important role in the detection of Periodontal Disease. The unspecific defense system in the gingivo-crevicular fluid can be determined through cytokines and/or interleukines that serve to identify sites at risk on the patient. In Periodontal Disease, the cytokines are not only defense mediators of the gingival sulcus fluid, but are also an indicator of tissue destruction. The liberation of high levels of lysosomal enzymes by neutrophils, proteolytic enzymes as the collagenases, or intercytoplasmatic enzymes as dehydrogenase lactate and aspartate amino transferase can equally help monitor the progress of the Periodontal Disease. PMID:14595256

  14. Multiphasic Scaffolds for Periodontal Tissue Engineering

    PubMed Central

    Ivanovski, S.; Vaquette, C.; Gronthos, S.; Hutmacher, D.W.; Bartold, P.M.

    2014-01-01

    For a successful clinical outcome, periodontal regeneration requires the coordinated response of multiple soft and hard tissues (periodontal ligament, gingiva, cementum, and bone) during the wound-healing process. Tissue-engineered constructs for regeneration of the periodontium must be of a complex 3-dimensional shape and adequate size and demonstrate biomechanical stability over time. A critical requirement is the ability to promote the formation of functional periodontal attachment between regenerated alveolar bone, and newly formed cementum on the root surface. This review outlines the current advances in multiphasic scaffold fabrication and how these scaffolds can be combined with cell- and growth factor–based approaches to form tissue-engineered constructs capable of recapitulating the complex temporal and spatial wound-healing events that will lead to predictable periodontal regeneration. This can be achieved through a variety of approaches, with promising strategies characterized by the use of scaffolds that can deliver and stabilize cells capable of cementogenesis onto the root surface, provide biomechanical cues that encourage perpendicular alignment of periodontal fibers to the root surface, and provide osteogenic cues and appropriate space to facilitate bone regeneration. Progress on the development of multiphasic constructs for periodontal tissue engineering is in the early stages of development, and these constructs need to be tested in large animal models and, ultimately, human clinical trials. PMID:25139362

  15. Periodontal disease in an Amish population.

    PubMed

    Bagramian, R A; Farghaly, M M; Lopatin, D; Sowers, M; Syed, S A; Pomerville, J L

    1993-04-01

    Epidemiological studies of periodontal disease have attempted to focus on defined groups in which the variables thought to be responsible for disease could be controlled or more easily identified. This study documents periodontal disease parameters in a unique population of Amish farmers. A total of 371 Amish were contacted and 282 were examined in their homes giving a participation rate of 76%. Ages ranged from 18 to 79 years. Overall means for periodontal conditions were 1.54 mm for attachment loss, 2.63 mm for pocket depth, 0.17 for calculus, 0.63 for plaque and 0.61 for gingivitis. One dental examiner conducted all examinations. Prevalence of periodontal disease tended to be higher among males and increased with age. The majority of Amish examined had little evidence of destructive periodontal disease; about 3.4% of teeth examined had attachment loss of 6 mm or more. These findings indicate a modest level of periodontal disease among the Amish. It is of interest that this population does not generally seek routine dental care. Preliminary analyses of health behavior data collected indicate a lack of regular oral hygiene practices. It appears that the Amish may have protective factors which affect their level of disease. PMID:8473537

  16. Biochemical markers of the periodontal ligament.

    PubMed

    Castro, Cecilia Estela; Koss, Myriam Adriana; López, María Elena

    2003-01-01

    For many years the diagnosis of Periodontal Disease has been based on clinical and radiographic methods. Other more recent methods have the objective of studying the inflammatory response of the host. That way, immunologic and biological methods determine the free mediators in the periodontal infection. The components of the gingivo-crevicular liquid or fluid are used to identify or to diagnose the active disease, to anticipate the risk of acquiring the disease and to determine its progress. For it to be clinically useful important changes should be registered the way a specific site turns active or that a previously disease affected site improves its conditions as a result of periodontal therapy. The response of the neutrophillic granulocytes play an important role in the detection of Periodontal Disease. The unspecific defense system in the gingivo-crevicular fluid can be determined through cytokines and/or interleukines that serve to identify sites at risk on the patient. In Periodontal Disease, the cytokines are not only defense mediators of the gingival sulcus fluid, but are also an indicator of tissue destruction. The liberation of high levels of lysosomal enzymes by neutrophils, proteolytic enzymes as the collagenases, or intercytoplasmatic enzymes as dehydrogenase lactate and aspartate amino transferase can equally help monitor the progress of the Periodontal Disease.

  17. Regulator of Calcineurin 1 in Periodontal Disease

    PubMed Central

    Peters, Ulrike; Solominidou, Eleni; Korkmaz, Yüksel; Rüttermann, Stefan; Klocke, Astrid; Flemmig, Thomas Frank; Beikler, Thomas

    2016-01-01

    Nuclear factor of activated T-cells (NFAT) and NF-kB pathway associated processes are involved in the pathogenesis of various inflammatory disorders, for example, periodontal disease. The activation of these pathways is controlled by the regulator of calcineurin 1 (RCAN1). The aim of this study was to elucidate the role of RCAN1 in periodontal disease. Healthy and inflamed periodontal tissues were analyzed by immunohistochemistry and immunofluorescence using specific rabbit polyclonal anti-RCAN1 antibodies. For expression analysis human umbilical vein endothelial cells (HUVEC) were used. HUVEC were incubated for 2 h with Vascular Endothelial Growth Factor (VEGF) or with wild type and laboratory strains of Porphyromonas gingivalis (P. gingivalis). Expression analysis of rcan1 and cox2 was done by real time PCR using specific primers for rcan1.4 and cox2. The expression of rcan1 was found to be significantly suppressed in endothelial cells of chronically inflamed periodontal tissues compared to healthy controls. Rcan1 and cox2 were significantly induced by VEGF and wild type and laboratory P. gingivalis strains. Interestingly, the magnitude of the rcan1 and cox2 induction was strain dependent. The results of this study indicate that RCAN1 is suppressed in endothelial cells of chronically inflamed periodontal tissues. During an acute infection, however, rcan1 seems to be upregulated in endothelial cells, indicating a modulating role in immune homeostasis of periodontal tissues. PMID:27403036

  18. Enamel Pearls Implications on Periodontal Disease

    PubMed Central

    Zenóbio, Elton Gonçalves; Vieira, Thaís Ribeiral; Bustamante, Roberta Paula Colen; Gomes, Hayder Egg; Shibli, Jamil Awad; Soares, Rodrigo Villamarin

    2015-01-01

    Dental anatomy is quite complex and diverse factors must be taken into account in its analysis. Teeth with anatomical variations present an increase in the rate of severity periodontal tissue destruction and therefore a higher risk of developing periodontal disease. In this context, this paper reviews the literature regarding enamel pearls and their implications in the development of severe localized periodontal disease as well as in the prognosis of periodontal therapy. Radiographic examination of a patient complaining of pain in the right side of the mandible revealed the presence of a radiopaque structure around the cervical region of lower right first premolar. Periodontal examination revealed extensive bone loss since probing depths ranged from 7.0 mm to 9.0 mm and additionally intense bleeding and suppuration. Surgical exploration detected the presence of an enamel pearl, which was removed. Assessment of the remaining supporting tissues led to the extraction of tooth 44. Local factors such as enamel pearls can lead to inadequate removal of the subgingival biofilm, thus favoring the establishment and progression of periodontal diseases. PMID:26491574

  19. Enamel Pearls Implications on Periodontal Disease.

    PubMed

    Zenóbio, Elton Gonçalves; Vieira, Thaís Ribeiral; Bustamante, Roberta Paula Colen; Gomes, Hayder Egg; Shibli, Jamil Awad; Soares, Rodrigo Villamarin

    2015-01-01

    Dental anatomy is quite complex and diverse factors must be taken into account in its analysis. Teeth with anatomical variations present an increase in the rate of severity periodontal tissue destruction and therefore a higher risk of developing periodontal disease. In this context, this paper reviews the literature regarding enamel pearls and their implications in the development of severe localized periodontal disease as well as in the prognosis of periodontal therapy. Radiographic examination of a patient complaining of pain in the right side of the mandible revealed the presence of a radiopaque structure around the cervical region of lower right first premolar. Periodontal examination revealed extensive bone loss since probing depths ranged from 7.0 mm to 9.0 mm and additionally intense bleeding and suppuration. Surgical exploration detected the presence of an enamel pearl, which was removed. Assessment of the remaining supporting tissues led to the extraction of tooth 44. Local factors such as enamel pearls can lead to inadequate removal of the subgingival biofilm, thus favoring the establishment and progression of periodontal diseases.

  20. Diagnosis of Periodontal Diseases by Biomarkers

    NASA Astrophysics Data System (ADS)

    Kido, Jun-Ichi; Hino, Mami; Bando, Mika; Hiroshima, Yuka

    Many middle aged and old persons take periodontal diseases that mainly cause teeth loss and result in some systemic diseases. The prevention of periodontal diseases is very important for oral and systemic health, but the present diagnostic examination is not fully objective and suitable. To diagnose periodontal diseases exactly, some biomarkers shown inflammation, tissue degradation and bone resorption, in gingival crevicular fluid (GCF) and saliva are known. We demonstrated that GCF levels of calprotectin, inflammation-related protein, and carboxy-terminal propeptide of type I procollagen, bone metabolism-related protein, were associated with clinical condition of periodontal diseases, and suggested that these proteins may be useful biomarkers for periodontal diseases. Recently, determinations of genes and proteins by using microdevices are studied for diagnosis of some diseases. We detected calprotectin protein by chemiluminescent immunoassay on a microchip and showed the possibility of specific and quantitative detection of calprotectin in a very small amount of GCF. To determine plural markers in GCF by using microdevices contributes to develop accurate, objective diagnostic system of periodontal diseases.

  1. Intraclass correlations of periodontal measurements.

    PubMed

    Haffajee, A D; Socransky, S S; Goodson, J M; Lindhe, J

    1985-03-01

    Components of variance and intraclass correlation coefficients were computed for changes in attachment level, pocket depth, gingival and plaque index scores for 5 groups of treated periodontal disease patients and 1 group of untreated subjects with periodontal disease. The intraclass correlation coefficients for attachment level change ranged from 0.011 to 0.165 (median 0.067), while intraclass correlation coefficients for pocket depth changes ranged from -0.009 to 0.178 (median 0.071). These intraclass correlation coefficients were much lower than those computed for changes in measurements of plaque which ranged from 0.086 to 0.568 (median 0.268) or gingival inflammation which ranged from 0.119 to 0.522 (median 0.264). Intraclass correlation coefficients at baseline for pocket depths ranged from 0.000 to 0.199 (median 0.053), for plaque accumulation from 0.121 to 0.531 (median 0.222) and for gingival inflammation from 0.229 to 0.596 (median 0.391). The differences in the intraclass correlation coefficients between pocket depth and attachment level on the one hand and plaque accumulation or gingival inflammation on the other could not be explained on the basis of differences in the measurement scale employed, since collapsing measurement scales had little effect on the intraclass correlation coefficients. The observed larger intraclass correlation coefficients for changes in plaque and gingival indices suggest a larger rôle for host contribution to these measurements. In contrast, the data suggest that the major but by no means the sole factor determining the variability of attachment level or pocket depth changes is the nature of the local factors.

  2. Probabilistic seismic performance assessment of lap-spliced RC columns retrofitted by steel wrapping jackets

    NASA Astrophysics Data System (ADS)

    Choi, Eunsoo; Youn, Heejung; Cho, Baik-Soon

    2016-06-01

    In this study, the seismic fragility curves of two reinforced concrete (RC) columns that were lap-spliced at the bottom and retrofitted with steel wrapping jackets were generated. Their seismic performance was probabilistically assessed in comparison to that of lap-spliced or continuous reinforcement RC columns. This study used two types of steel wrapping jackets, a full jacket and a split jacket. Analytical models of the four types of columns were developed based on the experimental results of the columns using OpenSEES, which is effective in conducting nonlinear time history analyses. A suite of ten artificial ground motions, modified from recorded ground motions, was used to perform nonlinear time history analyses of the analytical models with scaling of the peak ground acceleration from 0.1 g to 1.0 g in increments of 0.1 g. The steel wrapping jackets did not increase the medians for yield (slight damage state) of the lap-spiced column and did not exceed the corresponding median of the continuous reinforcement column. However, the two steel jackets increased the medians for failure by 1.872 and 2.017 times, respectively, and exceeded the corresponding median of the continuous reinforcement column by 11.8% and 20.5%, respectively.

  3. Enhancing pulsed eddy current for inspection of P-3 Orion lap-joint structures

    NASA Astrophysics Data System (ADS)

    Butt, D. M.; Underhill, P. R.; Krause, T. W.

    2016-02-01

    During flight, aircraft are subjected to cyclic loading. In the Lockheed P-3 Orion airframe, this cyclic loading can lead to development of fatigue cracks at steel fastener locations in the top and second layers of aluminum wing skin lap-joints. An inspection method that is capable of detecting these cracks, without fastener removal, is desirable as this can minimize aircraft downtime, while subsequently reducing the risk of collateral damage. The ability to detect second layer cracks has been demonstrated using a Pulsed Eddy Current (PEC) probe design that utilizes the ferrous fastener as a flux conduit. This allows for deeper penetration of flux into the lap-joint second layer and consequently, sensitivity to the presence of cracks. Differential pick-up coil pairs are used to sense the eddy current response due to the presence of a crack. The differential signal obtained from pick-up coils on opposing sides of the fastener is analyzed using a Modified Principal Components Analysis (MPCA). This is followed by a cluster analysis of the resulting MPCA scores to separate fastener locations with cracks from those without. Probe design features, data acquisition system parameters and signal post-processing can each have a strong impact on crack detection. Physical probe configurations and signal analysis processes, used to enhance the PEC system for detection of cracks in P-3 Orion lap-joint structures, are investigated and an enhanced probe design is identified.

  4. Large-scale Advanced Prop-fan (LAP) static rotor test report

    NASA Technical Reports Server (NTRS)

    Degeorge, Charles L.; Turnberg, Jay E.; Wainauski, Harry S.

    1987-01-01

    Discussed is Static Rotor Testing of the SR-7L Large Scale Advanced Prop-Fan (LAP). The LAP is an advanced 9 foot diameter, 8 bladed propeller designed and built by Hamilton Standard under contract to the NASA Lewis Research Center. The Prop-Fan employs thin swept blades to provide efficient propulsion at flight speeds up to Mach .85. Static Testing was conducted on a 10,000 HP whirl rig at Wright Patterson Air Force Base. The test objectives were to investigate the Prop-Fan static aerodynamic and structural dynamic performance, determine the blade steady state stressers and deflections and to measure steady and unsteady pressures on the SR-7L blade surface. The measured performance of the LAP correlated well with analytical predictions at blade pitch angles below 30 deg. A stall buffet phenomenon was observed at blade pitch angles above 30 deg. This phenomenon manifested itself by elevated blade vibratory stress levels and lower than expected thrust produced and power absorbed by the Prop-Fan for a given speed and blade angle.

  5. Periodontitis and coronary artery disease: a questioned association between periodontal and vascular plaques

    PubMed Central

    Thomopoulos, Costas; Tsioufis, Costas; Soldatos, Nikos; Kasiakogias, Alexandros; Stefanadis, Christodoulos

    2011-01-01

    Periodontitis is a bacterially-induced, localized chronic inflammatory disease destroying both the connective tissue and the supporting bone of the teeth. In the general population, severe forms of the disease demonstrate a prevalence of almost 5%, whereas initial epidemiological evidence suggests an association between periodontitis and coronary artery disease (CAD). Both the infectious nature of periodontitis and the yet etiologically unconfirmed infectious hypothesis of CAD, question their potential association. Ephemeral bacteremia, systemic inflammation and immune-pathological reactions constitute a triad of mechanisms supporting a cross-talk between periodontal and vascular damage. To which extent each of these periodontitis-mediated components contribute to vascular damage still remains uncertain. More than twenty years from the initial epidemiological association, the positive weight of evidence remains still alive but rather debated, because of both the presence of many uncontrolled confounding factors and the different assessment of periodontal disease. From the clinical point of view, advising periodontal prevention or treatment targeting on the prevention of CAD it is unjustified. By contrast, oral hygiene including periodontal health might contribute to the overall well-being and healthy lifestyle and hence as might at least partially contribute to cardiovascular prevention. PMID:22254188

  6. Identification of the anatomical elements used in periodontal diagnosis on 40 MHz periodontal ultrasonography.

    PubMed

    Chifor, Radu; Badea, Mîndra Eugenia; Hedeşiu, Mihaela; Chifor, Ioana

    2015-01-01

    Gingival inflammation is highly prevalent among adult populations in all regions of the world. High rates of chronic periodontitis have been reported worldwide. The methods for assessing the gingival inflammation and periodontal disease would need more precision and less user-dependence. The aim of this study consists in identifying the information for diagnosis and staging of periodontal disease using 40 MHz periodontal ultrasonography. Our in vivo study has been made on 49 teeth of 10 patients with marginal periodontal disease. Standard clinical and radiological periodontal examinations were performed. Afterwards the results were compared with the information obtained from images recorded with Ultrasonix SonoTouch used at 40 MHz. On the ultrasound images, were performed very accurate measurements between the cortical bone and the cement-enamel junction or the root wall compared with the measurements made on intraoral digital radiographs. Those measurements could be used to diagnose the bone resorption. In order to monitor the gingival inflammation could be recorded the width of the attached gingival mucosa and the height of the gingival margin on ultrasound images. 40 MHz periodontal ultrasonography is a reliable imagistic method for identifying the necessary anatomical elements in order to make an accurate periodontal diagnosis for the examined area.

  7. Association between susceptible genotypes to periodontitis and clinical outcomes of periodontal regenerative therapy: A systematic review

    PubMed Central

    Koidou, Vasiliki-Petros

    2016-01-01

    Background The aim of this review is to systematically investigate the effect of a susceptible genotype to periodontitis with the clinical outcomes of periodontal regeneration. Material and Methods Based on a focused question, an electronic search identified 155 unique citations. Three journals (Journal of Periodontology, Journal of Clinical Periodontology and Journal of Periodontal Research), references of relevant studies and review articles were hand-searched. Two independent reviewers implementing eligibility inclusion criteria selected the studies. Results Of the 155, four studies fulfilled the inclusion criteria. All studies were published between 2000 and 2004 and the samples’ size was 40 to 86 patients. Polymorphisms of Interleukin-1 (IL-1) gene were included in all. Three out of four studies failed to identify an association between susceptible genotypes to periodontitis and clinical outcomes of periodontal regeneration, while one found an association. The heterogeneity and small number of studies included prevented the conduct of a meta-analysis. No studies were identified evaluating the effect of other genotypes and as a result only IL-1 genotype studies were included. Conclusions Within the limits of the present review, no direct conclusion for the effect of a susceptible IL-1 genotype status to the clinical outcome after periodontal regeneration could be drawn. The need of more qualitative studies to explore a possible association emerges. Key words:Periodontitis, genotype, periodontal therapy, regeneration, susceptibility, systematic review. PMID:26946210

  8. Fibrinogen Degradation Products and Periodontitis: Deciphering the Connection

    PubMed Central

    2015-01-01

    Introduction Fibrinogen degradation products (e.g. D-dimer) arise from digested fibrin clots and fibrinogen. Elevated concentrations accompany activation of coagulation and fibrinolysis and indicate chronic inflammatory diseases. D-Dimer tests are a quick, noninvasive method to rule out abnormal clotting. Periodontitis strongly affects the haemostatic system and evokes a procoagulant state. Correlation of chronic periodontitis with early indicators of disease (biomarkers) might be useful. Aim The aim of the study was to examine whether the plasma D-dimer concentration reflects the progression of chronic periodontitis and the beneficial effect of periodontal therapy. Materials and Methods Forty randomly selected subjects were divided into four groups, Group I: 10 healthy subjects, Group II: 10 with mild periodontitis, Group III: 10 with moderate periodontitis, Group IV: 10 with severe periodontitis. After thorough dental and periodontal examination, 3 mL of venous blood was collected for measurement of fibrinogen degradation products. Results The patients with moderate and chronic periodontitis exhibited high concentrations of D-dimer (mean value 434.98–535.52 mcg/mL), whereas subjects with mild or no periodontitis exhibited values of 329.78–211.29 mcg/mL. Concentrations of D-dimer were significantly reduced after therapy of all classes of periodontitis. Conclusion Periodontal treatment can reduce amount of D-dimer in the plasma. A higher than normal concentration is observed in chronic periodontitis. PMID:26816985

  9. Detection and diagnosis of periodontal conditions amenable to prevention

    PubMed Central

    2015-01-01

    Gingivitis and chronic periodontitis are highly prevalent chronic inflammatory diseases. Gingivitis affects the majority of people, and advanced periodontitis is estimated to affect 5-15% of adults. The detection and diagnosis of these common diseases is a fundamentally important component of oral health care. All patients should undergo periodontal assessment as part of routine oral examination. Periodontal screening using methods such as the Basic Periodontal Examination/Community Periodontal Index or Periodontal Screening Record should be performed for all new patients, and also on a regular basis as part of ongoing oral health care. If periodontitis is identified, full periodontal assessment is required, involving recording of full mouth probing and bleeding data, together with assessment of other relevant parameters such as plaque levels, furcation involvement, recession and tooth mobility. Radiographic assessment of alveolar bone levels is driven by the clinical situation, and is required to assess bone destruction in patients with periodontitis. Risk assessment (such as assessing diabetes status and smoking) and risk management (such as promoting smoking cessation) should form a central component of periodontal therapy. This article provides guidance to the oral health care team regarding methods and frequencies of appropriate clinical and radiographic examinations to assess periodontal status, to enable appropriate detection and diagnosis of periodontal conditions. PMID:26390822

  10. Detection and diagnosis of periodontal conditions amenable to prevention.

    PubMed

    Preshaw, Philip M

    2015-01-01

    Gingivitis and chronic periodontitis are highly prevalent chronic inflammatory diseases. Gingivitis affects the majority of people, and advanced periodontitis is estimated to affect 5-15% of adults. The detection and diagnosis of these common diseases is a fundamentally important component of oral health care. All patients should undergo periodontal assessment as part of routine oral examination. Periodontal screening using methods such as the Basic Periodontal Examination/Community Periodontal Index or Periodontal Screening Record should be performed for all new patients, and also on a regular basis as part of ongoing oral health care. If periodontitis is identified, full periodontal assessment is required, involving recording of full mouth probing and bleeding data, together with assessment of other relevant parameters such as plaque levels, furcation involvement, recession and tooth mobility. Radiographic assessment of alveolar bone levels is driven by the clinical situation, and is required to assess bone destruction in patients with periodontitis. Risk assessment (such as assessing diabetes status and smoking) and risk management (such as promoting smoking cessation) should form a central component of periodontal therapy. This article provides guidance to the oral health care team regarding methods and frequencies of appropriate clinical and radiographic examinations to assess periodontal status, to enable appropriate detection and diagnosis of periodontal conditions. PMID:26390822

  11. Instrumental and Social Outcome Expectations of High-Aggressive and Low-Aggressive Boys.

    ERIC Educational Resources Information Center

    Cillessen, Antonius H. N.; Hubbard, Julie A.

    This study examined high-aggressive and low-aggressive boys' ratings of the effectiveness of aggressive and assertive strategies for solving social problems involving hypothetical peers and actual peers. Subjects were 66 third-grade boys (11 groups of 6 boys each for a total of 22 high-aggressive, 22 low-aggressive, and 22 average aggressive boys)…

  12. Aggressive Erotica and Violence against Women.

    ERIC Educational Resources Information Center

    Donnerstein, Edward

    1980-01-01

    Examines the effects of aggressive-erotic stimuli on male aggression toward females. Male subjects' deliveries of electric shocks to males or females after viewing either a neutral, erotic, or aggressive-erotic film were measured. (Author/SS)

  13. Involvement in internet aggression during early adolescence.

    PubMed

    Werner, Nicole E; Bumpus, Matthew F; Rock, Daquarii

    2010-06-01

    The current study examined concurrent and longitudinal predictors of early adolescents' involvement in Internet aggression. Cross-sectional results (N = 330; 57% female) showed that the likelihood of reporting Internet aggression was higher among youth who spent more time using Internet-based technologies to communicate with friends and who were themselves targets of Internet aggression. Offline relational aggression and beliefs supportive of relational and physical aggression also predicted concurrent involvement in Internet aggression. We used longitudinal data (N = 150; 51% female) to distinguish between youth who were aggressive in traditional contexts only (i.e., school) from those who were aggressive both online and offline. These results indicated that youth who were aggressive both online and offline were older at the initial assessment, were targets of Internet aggression, and held beliefs more supportive of relational aggression than youth who were aggressive offline only. Implications and directions for future research are discussed.

  14. Investigation of hemorheological parameters in periodontal diseases.

    PubMed

    Seringec, Nurten; Guncu, Guliz; Arihan, Okan; Avcu, Nihal; Dikmenoglu, Neslihan

    2015-01-01

    Periodontal diseases are frequently associated with cardiovascular diseases (CVD). On the other hand, occurrence of CVD has also been related with increased blood viscosity. This study was planned to investigate four main hemorheological parameters contributing to blood viscosity - hematocrit, erythrocyte deformability, erythrocyte aggregation and plasma viscosity - and also some biochemical parameters (hs-CRP, fibrinogen, globulin etc.) in patients with periodontal disease. We hypothesized that poor periodontal health would be associated with deterioration of hemorheological properties. According to periodontal health status, subjects were divided into three groups as control (healthy), with plaque induced gingivitis and with chronic periodontitis. All groups included 15 males who had not received periodontal therapy in the last six months before the study, were non-smokers, had no systemic diseases and were not on any medication. Erythrocyte deformability and erythrocyte aggregation were measured with laser-assisted optical rotational cell analyzer (LORCA). Plasma viscosity was measured by a cone-plate viscometer. Data were analyzed with Kruskal-Wallis, Mann-Whitney U Test and Spearman Correlation Coefficient. Plasma viscosity (1.36 ± 0.01 mPa.s in the control group and 1.43 ± 0.02 mPa.s in the chronic periodontitis group, P <  0.01), erythrocyte aggregation tendency (aggregation index, amplitude and t½ were 58.82 ± 1.78% , 20.22 ± 0.40 au, 2.80 ± 0.25 s respectively in the control group, and 67.05 ± 1.47% , 22.19 ± 0.50 au, 1.84 ± 0.15 s in the chronic periodontitis group, P <  0.01), hs-CRP, fibrinogen and globulin levels were significantly higher, whereas HDL level was significantly lower in the chronic periodontitis group (P <  0.05) compared to the control group. All of these conditions may contribute to cardiovascular morbidity and mortality observed in people with periodontal disease, via increasing blood viscosity. PMID:25261434

  15. Relationship between invasion of the periodontium by periodontal pathogens and periodontal disease: a systematic review.

    PubMed

    Mendes, Luzia; Azevedo, Nuno Filipe; Felino, António; Pinto, Miguel Gonçalves

    2015-01-01

    Bacterial invasion of the periodontal tissues has been suggested as a relevant step in the etiopathogenesis of periodontal disease. However, its exact importance remains to be defined. The present systematic review assessed the scientific evidence concerning the relationship between the quality or quantity of periodontal microbiota in periodontal tissues and development of periodontal disease. The databases Medline-PubMed, Cochrane-CENTRAL, ISI Web of Knowledge and SCOPUS were searched, up to January 2014. Studies that reported evaluation of periodontal pathogens invasion on human tissues were selected. The screening of 440 title/abstracts elected 26 papers for full-text reading. Twenty three papers were subsequently excluded because of insufficient data or a study protocol not related to the objectives of this systematic review. All included studies were case-control studies that evaluated intracellular or adherent bacteria to epithelial cells from periodontal pockets versus healthy sulci. Study protocols presented heterogeneity regarding case and control definitions and methodological approaches for microbial identification. No consistent significant differences were found related to the presence/absence or proportion of specific periopathogens across the studies, as only one study found statistically significant differences regarding the presence of A. actinomycetemcomitans (p = 0.043), T. forsythia (P < 0.001), P. intermedia (P < 0.001), C. ochracea (P < 0.001) and C. rectus (P = 0.003) in epithelial cells from periodontal pockets vs. healthy sulci. All studies reported a larger unspecific bacterial load in or on the epithelial cells taken from a diseased site compared to a healthy sulcus. The current available data is of low to moderate quality and inconsistent mainly due to study design, poor reporting and methodological diversity. As so, there is insufficient evidence to support or exclude the invasion by periodontal pathogens as a key step in the

  16. Relationship between invasion of the periodontium by periodontal pathogens and periodontal disease: a systematic review

    PubMed Central

    Mendes, Luzia; Azevedo, Nuno Filipe; Felino, António; Pinto, Miguel Gonçalves

    2015-01-01

    Bacterial invasion of the periodontal tissues has been suggested as a relevant step in the etiopathogenesis of periodontal disease. However, its exact importance remains to be defined. The present systematic review assessed the scientific evidence concerning the relationship between the quality or quantity of periodontal microbiota in periodontal tissues and development of periodontal disease. The databases Medline-PubMed, Cochrane-CENTRAL, ISI Web of Knowledge and SCOPUS were searched, up to January 2014. Studies that reported evaluation of periodontal pathogens invasion on human tissues were selected. The screening of 440 title/abstracts elected 26 papers for full-text reading. Twenty three papers were subsequently excluded because of insufficient data or a study protocol not related to the objectives of this systematic review. All included studies were case-control studies that evaluated intracellular or adherent bacteria to epithelial cells from periodontal pockets versus healthy sulci. Study protocols presented heterogeneity regarding case and control definitions and methodological approaches for microbial identification. No consistent significant differences were found related to the presence/absence or proportion of specific periopathogens across the studies, as only one study found statistically significant differences regarding the presence of A. actinomycetemcomitans (p = 0.043), T. forsythia (P < 0.001), P. intermedia (P < 0.001), C. ochracea (P < 0.001) and C. rectus (P = 0.003) in epithelial cells from periodontal pockets vs. healthy sulci. All studies reported a larger unspecific bacterial load in or on the epithelial cells taken from a diseased site compared to a healthy sulcus. The current available data is of low to moderate quality and inconsistent mainly due to study design, poor reporting and methodological diversity. As so, there is insufficient evidence to support or exclude the invasion by periodontal pathogens as a key step in the

  17. Aggression Can be Contagious: Longitudinal Associations between Proactive Aggression and Reactive Aggression Among Young Twins

    PubMed Central

    Dickson, Daniel J.; Richmond, Ashley; Brendgen, Mara; Vitaro, Frank; Laursen, Brett; Dionne, Ginette; Boivin, Michel

    2015-01-01

    The present study examined sibling influence over reactive and proactive aggression in a sample of 452 same-sex twins (113 male dyads, 113 female dyads). Between and within siblings influence processes were examined as a function of relative levels of parental coercion and hostility to test the hypothesis that aggression contagion between twins occurs only among dyads who experience parental coerciveness. Teacher reports of reactive and proactive aggression were collected for each twin in kindergarten (M = 6.04 years; SD = 0.27) and in first grade (M = 7.08 years; SD = 0.27). Families were divided into relatively low, average, and relatively high parental coercion-hostility groups on the basis of maternal reports collected when the children were 5 years old. In families with relatively high levels of parental coercion-hostility, there was evidence of between-sibling influence, such that one twin’s reactive aggression at age 6 predicted increases in the other twin’s reactive aggression from ages 6 to 7, and one twin’s proactive aggression at age 6 predicted increases in the other twin’s proactive aggression from ages 6 to 7. There was also evidence of within-sibling influence such that a child’s level of reactive aggression at age 6 predicted increases in the same child’s proactive aggression at age 7, regardless of parental coercion-hostility. The findings provide new information about the etiology of reactive and proactive aggression and individual differences in their developmental interplay. PMID:25683448

  18. The Role of Nutrition in Periodontal Health: An Update.

    PubMed

    Najeeb, Shariq; Zafar, Muhammad Sohail; Khurshid, Zohaib; Zohaib, Sana; Almas, Khalid

    2016-01-01

    Periodontal health is influenced by a number of factors such as oral hygiene, genetic and epigenetic factors, systemic health, and nutrition. Many studies have observed that a balanced diet has an essential role in maintaining periodontal health. Additionally, the influences of nutritional supplements and dietary components have been known to affect healing after periodontal surgery. Studies have attempted to find a correlation between tooth loss, periodontal health, and nutrition. Moreover, bone formation and periodontal regeneration are also affected by numerous vitamins, minerals, and trace elements. The aim of this review is to critically appraise the currently available data on diet and maintenance of periodontal health and periodontal healing. The effects of nutritional intervention studies to improve the quality of life and well-being of patients with periodontal disease have been discussed. PMID:27589794

  19. The Role of Nutrition in Periodontal Health: An Update

    PubMed Central

    Najeeb, Shariq; Zafar, Muhammad Sohail; Khurshid, Zohaib; Zohaib, Sana; Almas, Khalid

    2016-01-01

    Periodontal health is influenced by a number of factors such as oral hygiene, genetic and epigenetic factors, systemic health, and nutrition. Many studies have observed that a balanced diet has an essential role in maintaining periodontal health. Additionally, the influences of nutritional supplements and dietary components have been known to affect healing after periodontal surgery. Studies have attempted to find a correlation between tooth loss, periodontal health, and nutrition. Moreover, bone formation and periodontal regeneration are also affected by numerous vitamins, minerals, and trace elements. The aim of this review is to critically appraise the currently available data on diet and maintenance of periodontal health and periodontal healing. The effects of nutritional intervention studies to improve the quality of life and well-being of patients with periodontal disease have been discussed. PMID:27589794

  20. Rheumatoid factor (RF) distribution in periodontal disease.

    PubMed

    Thé, J; Ebersole, J L

    1991-05-01

    This study investigated the occurrence of an autoantibody, IgM rheumatoid factor, that may result from the chronic inflammation noted in periodontal disease and rheumatoid arthritis. In order to detect IgM-RF, a biotin-avidin ELISA was developed. This assay was found to be sensitive and accurate by testing a rheumatoid arthritis population. The characteristics of this rheumatoid arthritis group were further determined, such that the total serum immunoglobulin concentrations were slightly elevated although within the normal range for IgM, IgG, and IgA; IgG antibody levels were elevated against oral microorganisms of the genus Capnocytophaga, while elevated IgM antibody levels were noted to Bacteroides species. In a population of 260 subjects of which 171 were periodontal disease patients, 16 of 171 (9.4%) were seropositive for IgM-RF, of which the predominant disease types were advanced destructive periodontitis and adult periodontitis. For comparison, a random population of seronegative periodontal disease patients was constructed that was matched for sex and approximate age to the seropositive group. The total immunoglobulin levels of the two groups were not significantly different and the means of both were slightly lower than the rheumatoid arthritis group. When the antibody profiles of the two periodontal disease populations were compared it became evident that the RF-positive group showed IgM and IgG antibody that was significantly elevated to Capnocytophaga species and F. nucleatum. Therefore, the chronic inflammation associated with periodontitis appears to increase significantly the formation of IgM-RF; however, there does appear to be a relationship between IgM-RF and elevated antibody to selected oral microorganisms. PMID:1890163

  1. Periodontal Disease and its Association with Angiographically Verified Coronary Artery Disease

    PubMed Central

    Miovski, Zoran; Strozzi, Maja; Puhar, Ivan; Badovinac, Ana; Božić, Darko; Plančak, Darije

    2015-01-01

    Purpose The aim of this research was to investigate the association of chronic and aggressive periodontitis with the severity of coronary artery disease which was angiographically verified. Material and methods Subjects were selected among the hospitalized patients at the University Hospital Centre Zagreb who had coronary angiography done because of the chest pain. Thorough clinical examination included periodontal indices and clinical and socio-demographic characteristics of participants. Subjects were divided in two test groups, acute coronary syndrome (ACS) and stable coronary artery disease (CAD), and the control group with no significant CAD. Data were analyzed using Kruskal-Wallis and Pearson’s Chi-Square test. Results From 106 subjects, 66 (62.3%) were hospitalized for ACS, 22 (20.7%) had stable CAD and only 18 (17.0%) had no significant CAD. Only 26 (24.5%) out of 106 patients were never smokers (p<0.05). Chronic periodontitis was the most common finding with 68.2% in ACS group and 54.5% in stable CAD group, while healthy patients without periodontitis (72.6%) were dominant in the control group (p<0.001). Stable CAD group had the highest mean probing depth (PD) 3.92±1.16, gingival recession (GR) 1.34±0.78, clinical attachment level (CAL) 4.60±1.41 and bleeding on probing (BOP) 45.98±26.19 values, whereas ACS group had mean PD value of 3.77±0.91, GR 1.11±0.66, CAL 4.32±1.08 and BOP 41.30±22.09, and no significant CAD group had mean PD value of 3.27±0.97, GR 0.69±0.37, CAL 3.62±1.04 and BOP 26.39±13.92 (p<0.05). Conclusion Periodontitis was shown to be associated with angiographically verified coronary artery disease. Physical inactivity, poor oral hygiene and periodontal inflammation were observed in patients with ACS and stable CAD.

  2. Predicting workplace aggression and violence.

    PubMed

    Barling, Julian; Dupré, Kathryne E; Kelloway, E Kevin

    2009-01-01

    Consistent with the relative recency of research on workplace aggression and the considerable media attention given to high-profile incidents, numerous myths about the nature of workplace aggression have emerged. In this review, we examine these myths from an evidence-based perspective, bringing greater clarity to our understanding of the predictors of workplace aggression. We conclude by pointing to the need for more research focusing on construct validity and prevention issues as well as for methodologies that minimize the likelihood of mono-method bias and that strengthen the ability to make causal inferences.

  3. Relationship between the Pathogenic Representatives of Periodontal Pockets Microbiocenosis in Patients with Periodontitis with Varying Degrees of Severity

    PubMed Central

    Zorina, O.A.; Kulakov, A.A.; Boriskina, O.A.; Rebrikov, D.V.

    2011-01-01

    Periodontitis is a common disease that is considered to be a manifestation of the distortion of the ratio between the normal and conditionally pathogenic microflora of periodontal pockets. In this study, the ratio between the six most important periodontal pathogens and the total microflora of the periodontal pocket in healthy individuals and patients with varying severity of periodontitis was ascertained by quantitative real-time PCR. It was ascertained that the relative content ofPorphyromonas gingivalis,Prevotella intermedia, andTannerella forsythensis(Bacteroides forsythus) persistently develops in the total microflora of the periodontal pocket upon progressing periodontitis; this value is higher than that in the control group by more than two orders of magnitude upon a severe degree of chronic generalized periodontitis. PMID:22649688

  4. Oral Chlamydia trachomatis in Patients with Established Periodontitis

    PubMed Central

    Reed, Susan G.; Lopatin, Dennis E.; Foxman, Betsy; Burt, Brian A.

    2009-01-01

    Periodontitis is considered a consequence of a pathogenic microbial infection at the periodontal site and host susceptibility factors. Periodontal research supports the association of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, and Bacteroides forsythus, and periodontitis; however causality has not been demonstrated. In pursuit of the etiology of periodontitis, we hypothesized that the intracellular bacteria, Chlamydia trachomatis, may play a role. As a first step, a cross-sectional study of dental school clinic patients with established periodontitis were assessed for the presence of C. trachomatis in the oral cavity, and in particular from the lining epithelium of periodontal sites. C. trachomatis was detected using a direct fluorescent monoclonal antibody (DFA) in oral specimens from 7% (6/87) of the patients. Four patients tested positive in specimens from the lining epithelium of diseased periodontal sites, one patient tested positive in healthy periodontal sites, and one patient tested positive in the general mucosal specimen. In conclusion, this study provides preliminary evidence of C. trachomatis in the periodontal sites. Planned studies include the use of a more precise periodontal epithelial cell collection device, the newer nucleic acid amplification techniques to detect C. trachomatis, and additional populations to determine the association of C. trachomatis and periodontitis. PMID:11218493

  5. Gender differences in reactive and proactive aggression.

    PubMed

    Connor, Daniel F; Steingard, Ronald J; Anderson, Jennifer J; Melloni, Richard H

    2003-01-01

    The purpose of our investigation was to study gender differences in proactive and reactive aggression in a sample of 323 clinically referred children and adolescents (68 females and 255 males). Proactive aggression and reactive aggression were assessed using the Proactive/Reactive Aggression Scale. Demographic, historical, family, diagnostic, and treatment variables were entered into stepwise regression analyses to determine correlates of proactive and reactive aggression in males and females. Results reveal high rates of aggression in both males and females in the sample. Self reported drug use, expressed hostility, and experiences of maladaptive parenting were correlated with proactive aggression for both genders. Hyperactive/impulsive behaviors were correlated with male reactive aggression. An early age of traumatic stress and a low verbal IQ were correlated with female proactive aggression. Gender differences in correlates of proactive and reactive aggression may provide possible targets for research, prevention, and treatment efforts focused on reducing maladaptive aggression in clinically referred youth. PMID:12723901

  6. The Structure and Enzyme Characteristics of a Recombinant Leucine Aminopeptidase rLap1 from Aspergillus sojae and Its Application in Debittering.

    PubMed

    Huang, Wei-Qian; Zhong, Li-Fen; Meng, Zhi-Zhong; You, Zi-Juan; Li, Jia-Zhou; Luo, Xiao-Chun

    2015-09-01

    A leucine aminopeptidase Lap1 was cloned from Aspergillus sojae GIM3.30. The truncated Lap1 without a signal peptide was over-expressed in P. pastoris, and the enzymatic characteristics of recombinant Lap1 (rLap1) were tested. The rLap1 was about 36.7 kDa with an optimal pH 8.0 and optimal temperature 50 °C for substrate Leu-p-nitroanilide and it sustained 50 % activity after 1 h incubation at 50 °C. The activity of rLap1 was significantly inhibited by EDTA, whereas Co(2+), Mn(2+), and Ca(2+) ions, but not Zn(2+) ions, restored its activity. rLap1 showed the highest activity against Arg-pNA and then Leu-, Lys-, Met-, and Phe-pNA. The 3D structure of rLap1 showed it had a conserved functional charge/dipole complex and a hydrogen bond network of Zn2-D179-S228-Q177-D229-S158 around its active center. An acidic Asp residue was found at the bottom of the substrate binding pocket, which explains its preference for basic N-terminal amino acid substrates such as Arg and Lys. rLap1 improved the degree of hydrolysis of casein and soy protein hydrolysates and also decreased their bitterness, indicating its potential utility in food production.

  7. Spatiotemporally Controlled Microchannels of Periodontal Mimic Scaffolds

    PubMed Central

    Park, C.H.; Kim, K.H.; Rios, H.F.; Lee, Y.M.; Giannobile, W.V.; Seol, Y.J.

    2014-01-01

    Physiologic bioengineering of the oral, dental, and craniofacial complex requires optimized geometric organizations of fibrous connective tissues. A computer-designed, fiber-guiding scaffold has been developed to promote tooth-supporting periodontal tissue regeneration and functional restoration despite limited printing resolution for the manufacture of submicron-scaled features. Here, we demonstrate the use of directional freeze-casting techniques to control pore directional angulations and create mimicked topographies to alveolar crest, horizontal, oblique, and apical fibers of natural periodontal ligaments. For the differing anatomic positions, the gelatin displayed varying patterns of ice growth, determined via internal pore architectures. Regardless of the freezing coordinates, the longitudinal pore arrangements resulted in submicron-scaled diameters (~50 µm), along with corresponding high biomaterial porosity (~90%). Furthermore, the horizontal + coronal ((x→−y→) freezing orientation facilitated the creation of similar structures to major fibers in the periodontal ligament interface. This periodontal tissue-mimicking microenvironment is a potential tissue platform for the generation of naturally oriented ligamentous tissues consistent with periodontal ligament neogenesis. PMID:25216511

  8. Epigenetic Modifications of Histones in Periodontal Disease.

    PubMed

    Martins, M D; Jiao, Y; Larsson, L; Almeida, L O; Garaicoa-Pazmino, C; Le, J M; Squarize, C H; Inohara, N; Giannobile, W V; Castilho, R M

    2016-02-01

    Periodontitis is a chronic infectious disease driven by dysbiosis, an imbalance between commensal bacteria and the host organism. Periodontitis is a leading cause of tooth loss in adults and occurs in about 50% of the US population. In addition to the clinical challenges associated with treating periodontitis, the progression and chronic nature of this disease seriously affect human health. Emerging evidence suggests that periodontitis is associated with mechanisms beyond bacteria-induced protein and tissue degradation. Here, we hypothesize that bacteria are able to induce epigenetic modifications in oral epithelial cells mediated by histone modifications. In this study, we found that dysbiosis in vivo led to epigenetic modifications, including acetylation of histones and downregulation of DNA methyltransferase 1. In addition, in vitro exposure of oral epithelial cells to lipopolysaccharides resulted in histone modifications, activation of transcriptional coactivators, such as p300/CBP, and accumulation of nuclear factor-κB (NF-κB). Given that oral epithelial cells are the first line of defense for the periodontium against bacteria, we also evaluated whether activation of pathogen recognition receptors induced histone modifications. We found that activation of the Toll-like receptors 1, 2, and 4 and the nucleotide-binding oligomerization domain protein 1 induced histone acetylation in oral epithelial cells. Our findings corroborate the emerging concept that epigenetic modifications play a role in the development of periodontitis. PMID:26496800

  9. Treatment modalities and evaluation models for periodontitis

    PubMed Central

    Tariq, Mohammad; Iqbal, Zeenat; Ali, Javed; Baboota, Sanjula; Talegaonkar, Sushama; Ahmad, Zulfiqar; Sahni, Jasjeet K

    2012-01-01

    Periodontitis is the most common localized dental inflammatory disease related with several pathological conditions like inflammation of gums (gingivitis), degeneration of periodontal ligament, dental cementum and alveolar bone loss. In this perspective, the various preventive and treatment modalities, including oral hygiene, gingival irrigations, mechanical instrumentation, full mouth disinfection, host modulation and antimicrobial therapy, which are used either as adjunctive treatments or as stand-alone therapies in the non-surgical management of periodontal infections, have been discussed. Intra-pocket, sustained release systems have emerged as a novel paradigm for the future research. In this article, special consideration is given to different locally delivered anti-microbial and anti inflammatory medications which are either commercially available or are currently under consideration for Food and Drug Administration (FDA) approval. The various in vitro dissolution models and microbiological strain investigated to impersonate the infected and inflamed periodontal cavity and to predict the in vivo performance of treatment modalities have also been thrashed out. Animal models that have been employed to explore the pathology at the different stages of periodontitis and to evaluate its treatment modalities are enlightened in this proposed review. PMID:23373002

  10. Histopathological lesions associated with equine periodontal disease.

    PubMed

    Cox, Alistair; Dixon, Padraic; Smith, Sionagh

    2012-12-01

    Equine periodontal disease (EPD) is a common and painful condition, the aetiology and pathology of which are poorly understood. To characterise the histopathological lesions associated with EPD, the skulls of 22 horses were assessed grossly for the presence of periodontal disease, and a standard set of interdental tissues taken from each for histopathological examination. Histological features of EPD included ulceration and neutrophilic inflammation of the gingival epithelium. Mononuclear and eosinophilic inflammation of the gingival lamina propria and submucosa was commonly present irrespective of the presence or degree of periodontal disease. Gingival hyperplasia was present to some degree in all horses, and was only weakly associated with the degree of periodontal disease. In all horses dental plaque was present at the majority of sites examined and was often associated with histological evidence of peripheral cemental erosion. Bacteria (including spirochaetes in four horses) were identified in gingival samples by Gram and silver impregnation techniques and were significantly associated with the presence of periodontal disease. This is the first study to describe histological features of EPD, and the first to identify associated spirochaetes in some cases. Histological features were variable, and there was considerable overlap of some features between the normal and diseased gingiva. Further investigation into the potential role of bacteria in the pathogenesis and progression of EPD is warranted.

  11. Human periodontal ligament cell sheets can regenerate periodontal ligament tissue in an athymic rat model.

    PubMed

    Hasegawa, Masateru; Yamato, Masayuki; Kikuchi, Akihiko; Okano, Teruo; Ishikawa, Isao

    2005-01-01

    Conventional periodontal regeneration methods remain insufficient to attain complete and reliable clinical regeneration of periodontal tissues. We have developed a new method of cell transplantation using cell sheet engineering and have applied it to this problem. The purpose of this study was to investigate the characteristics of human periodontal ligament (HPDL) cell sheets retrieved from culture on unique temperature-responsive culture dishes, and to examine whether these cell sheets can regenerate periodontal tissues. The HPDL cell sheets were examined histologically and biochemically, and also were transplanted into a mesial dehiscence model in athymic rats. HPDL cells were harvested from culture dishes as a contiguous cell sheet with abundant extracellular matrix and retained intact integrins that are susceptible to trypsin-EDTA treatment. In the animal study, periodontal ligament-like tissues that include an acellular cementum-like layer and fibrils anchoring into this layer were identified in all the athymic rats transplanted with HPDL cell sheets. This fibril anchoring highly resembles native periodontal ligament fibers; such regeneration was not observed in nontransplanted controls. These results suggest that this technique, based on the concept of cell sheet engineering, can be useful for periodontal tissue regeneration. PMID:15869425

  12. Quantifying Aggressive Behavior in Zebrafish.

    PubMed

    Teles, Magda C; Oliveira, Rui F

    2016-01-01

    Aggression is a complex behavior that influences social relationships and can be seen as adaptive or maladaptive depending on the context and intensity of expression. A model organism suitable for genetic dissection of the underlying neural mechanisms of aggressive behavior is still needed. Zebrafish has already proven to be a powerful vertebrate model organism for the study of normal and pathological brain function. Despite the fact that zebrafish is a gregarious species that forms shoals, when allowed to interact in pairs, both males and females express aggressive behavior and establish dominance hierarchies. Here, we describe two protocols that can be used to quantify aggressive behavior in zebrafish, using two different paradigms: (1) staged fights between real opponents and (2) mirror-elicited fights. We also discuss the methodology for the behavior analysis, the expected results for both paradigms, and the advantages and disadvantages of each paradigm in face of the specific goals of the study. PMID:27464816

  13. Effect of nonsurgical periodontal treatment in patients with periodontitis and rheumatoid arthritis: A systematic review

    PubMed Central

    Silvestre-Rangil, Javier; Bagan, Leticia; Bagan, Jose V.

    2016-01-01

    Background Periodontitis has been regarded as a potential risk factor for rheumatoid arthritis (RA). A systematic review is made to determine whether nonsurgical periodontal treatment in patients with RA offers benefits in terms of the clinical activity and inflammatory markers of the disease. Material and Methods A search was made of the Medline-PubMed, Cochrane, Embase and Scopus databases to identify studies on the relationship between the two disease processes, and especially on the effects of nonsurgical treatment in patients of this kind. The search was based on the following keywords: rheumatoid arthritis AND periodontitis (MeSH), rheumatoid arthritis AND periodontal treatment. Results Eight articles on the nonsurgical treatment of patients with periodontitis and RA were finally included in the study. All of them evaluated clinical (DAS28) and laboratory test activity (ESR, CRP, IL-6, TNFα) before and after treatment. A clear decrease in DAS28 score and ESR was recorded, while other parameters such as CRP, IL-6 and TNFα showed a non significant tendency to decrease as a result of treatment. Conclusions Nonsurgical treatment improved the periodontal condition of patients with periodontitis and RA, with beneficial effects upon the clinical and laboratory test parameters (DAS28 and ESR), while other inflammatory markers showed a marked tendency to decrease. However, all the studies included in the review involved small samples sizes and follow-up periods of no more than 6 months. Larger and particularly longitudinal studies are therefore needed to more firmly establish possible significant relations between the two disease processes. Key words:Periodontitis, rheumatoid arthritis, periodontal treatment. PMID:26946202

  14. Comparative cytotoxicity of periodontal bacteria

    SciTech Connect

    Stevens, R.H.; Hammond, B.F.

    1988-11-01

    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species.

  15. Quorum Sensing of Periodontal Pathogens

    PubMed Central

    Plančak, Darije; Musić, Larisa

    2015-01-01

    The term ‘quorum sensing’ describes intercellular bacterial communication which regulates bacterial gene expression according to population cell density. Bacteria produce and secrete small molecules, named autoinducers, into the intercellular space. The concentration of these molecules increases as a function of population cell density. Once the concentration of the stimulatory threshold is reached, alteration in gene expression occurs. Gram-positive and Gram-negative bacteria possess different types of quorum sensing systems. Canonical LuxI/R-type/acyl homoserine lactone mediated quorum sensing system is the best studied quorum sensing circuit and is described in Gram-negative bacteria which employ it for inter-species communication mostly. Gram-positive bacteria possess a peptide-mediated quorum sensing system. Bacteria can communicate within their own species (intra-species) but also between species (inter-species), for which they employ an autoinducer-2 quorum sensing system which is called the universal language of the bacteria. Periodontal pathogenic bacteria possess AI-2 quorum sensing systems. It is known that they use it for regulation of biofilm formation, iron uptake, stress response and virulence factor expression. A better understanding of bacterial communication mechanisms will allow the targeting of quorum sensing with quorum sensing inhibitors to prevent and control disease.

  16. Quorum Sensing of Periodontal Pathogens.

    PubMed

    Plančak, Darije; Musić, Larisa; Puhar, Ivan

    2015-09-01

    The term 'quorum sensing' describes intercellular bacterial communication which regulates bacterial gene expression according to population cell density. Bacteria produce and secrete small molecules, named autoinducers, into the intercellular space. The concentration of these molecules increases as a function of population cell density. Once the concentration of the stimulatory threshold is reached, alteration in gene expression occurs. Gram-positive and Gram-negative bacteria possess different types of quorum sensing systems. Canonical LuxI/R-type/acyl homoserine lactone mediated quorum sensing system is the best studied quorum sensing circuit and is described in Gram-negative bacteria which employ it for inter-species communication mostly. Gram-positive bacteria possess a peptide-mediated quorum sensing system. Bacteria can communicate within their own species (intra-species) but also between species (inter-species), for which they employ an autoinducer-2 quorum sensing system which is called the universal language of the bacteria. Periodontal pathogenic bacteria possess AI-2 quorum sensing systems. It is known that they use it for regulation of biofilm formation, iron uptake, stress response and virulence factor expression. A better understanding of bacterial communication mechanisms will allow the targeting of quorum sensing with quorum sensing inhibitors to prevent and control disease. PMID:27688408

  17. Quorum Sensing of Periodontal Pathogens

    PubMed Central

    Plančak, Darije; Musić, Larisa

    2015-01-01

    The term ‘quorum sensing’ describes intercellular bacterial communication which regulates bacterial gene expression according to population cell density. Bacteria produce and secrete small molecules, named autoinducers, into the intercellular space. The concentration of these molecules increases as a function of population cell density. Once the concentration of the stimulatory threshold is reached, alteration in gene expression occurs. Gram-positive and Gram-negative bacteria possess different types of quorum sensing systems. Canonical LuxI/R-type/acyl homoserine lactone mediated quorum sensing system is the best studied quorum sensing circuit and is described in Gram-negative bacteria which employ it for inter-species communication mostly. Gram-positive bacteria possess a peptide-mediated quorum sensing system. Bacteria can communicate within their own species (intra-species) but also between species (inter-species), for which they employ an autoinducer-2 quorum sensing system which is called the universal language of the bacteria. Periodontal pathogenic bacteria possess AI-2 quorum sensing systems. It is known that they use it for regulation of biofilm formation, iron uptake, stress response and virulence factor expression. A better understanding of bacterial communication mechanisms will allow the targeting of quorum sensing with quorum sensing inhibitors to prevent and control disease. PMID:27688408

  18. Quorum Sensing of Periodontal Pathogens.

    PubMed

    Plančak, Darije; Musić, Larisa; Puhar, Ivan

    2015-09-01

    The term 'quorum sensing' describes intercellular bacterial communication which regulates bacterial gene expression according to population cell density. Bacteria produce and secrete small molecules, named autoinducers, into the intercellular space. The concentration of these molecules increases as a function of population cell density. Once the concentration of the stimulatory threshold is reached, alteration in gene expression occurs. Gram-positive and Gram-negative bacteria possess different types of quorum sensing systems. Canonical LuxI/R-type/acyl homoserine lactone mediated quorum sensing system is the best studied quorum sensing circuit and is described in Gram-negative bacteria which employ it for inter-species communication mostly. Gram-positive bacteria possess a peptide-mediated quorum sensing system. Bacteria can communicate within their own species (intra-species) but also between species (inter-species), for which they employ an autoinducer-2 quorum sensing system which is called the universal language of the bacteria. Periodontal pathogenic bacteria possess AI-2 quorum sensing systems. It is known that they use it for regulation of biofilm formation, iron uptake, stress response and virulence factor expression. A better understanding of bacterial communication mechanisms will allow the targeting of quorum sensing with quorum sensing inhibitors to prevent and control disease.

  19. Efect of periodontal disease and non surgical periodontal treatment on C-reactive protein. Evaluation of type 1 diabetic patients

    PubMed Central

    Llambés, Fernando; Hernández-Mijares, Antonio; Guiha, Rami; Bautista, Daniel; Caffesse, Raúl

    2012-01-01

    Objectives: The purpose of this study was to analyze how anti-infectious periodontal treatment affects C reactive protein (CRP) values in patients with type 1 diabetes, and correlate baseline CRP levels with periodontal disease severity. Study Design: A cohort of fifty three subjects with type 1 diabetes and moderate to severe periodontitis were recruited. Periodontal parameters were measured, and blood samples were obtained to evaluate high-sensitivity C-reactive protein (hs-CRP). Group 1 was treated with scaling, root planning, and systemic administration of doxycycline. Group 2 received only scaling and root planning. Results: Hs-CRP was reduced after periodontal treatment in group 1 (-0.22 mg/l) and 2 (-0.21 mg/l ) but this reduction was not statistically significant, even in the patients with the best response to periodontal treatment. However, significant correlation appeared between hs-CRP and mean probing pocket depth (PPD) (p=0, 01) and mean clinical attachment level (CAL) (p=0,03). Conclusions: Non-surgical periodontal treatment couldn’t reduce hs-CRP values, however, it was found an association between advanced periodontitis and elevated blood hs-CRP levels in patients with type 1 diabetes. It can be speculated that periodontal disease increases production of pro-inflammatory mediators in patients with type 1 diabetes, but other producing sources of these pro-inflammatory substances may exist. Key words:Periodontal disease, periodontitis, diabetes mellitus type 1, periodontal therapy, C reactive protein. PMID:22322513

  20. Music, Substance Use, and Aggression

    PubMed Central

    Chen, Meng-Jinn; Miller, Brenda A.; Grube, Joel W.; Waiters, Elizabeth D.

    2016-01-01

    Objective This study investigated whether young people’s substance use and aggressive behaviors are related to their listening to music containing messages of substance use and violence. Method Data were collected using self-administered questionnaires and from a sample of community college students aged 15-25 (N = 1056; 43% male). A structural equation modeling method was used to simultaneously assess the associations between listening to various genres of music, alcohol use, illicit drug use, and aggressive behaviors, taking into account respondents’ age, gender, race/ethnicity, and level of sensation seeking. Results Listening to rap music was significantly and positively associated with alcohol use, problematic alcohol use, illicit drug use, and aggressive behaviors when all other variables were controlled. Additionally, alcohol and illicit drug use were positively associated with listening to musical genres of techno and reggae. Control variables such as sensation seeking, age, gender and race/ethnicity were significantly related to substance use and aggressive behaviors. Conclusion The findings suggest that young people’s substance use and aggressive behaviors may be related to their frequent exposure to music containing references to substance use and violence. Conversely, music listening preference may reflect some personal predispositions or lifestyle preferences. Alternatively, substance use, aggression and music preference are independent constructs, but share common “third factors.” PMID:16608146

  1. Normative beliefs about aggression and cyber aggression among young adults: a longitudinal investigation.

    PubMed

    Wright, Michelle F; Li, Yan

    2013-01-01

    This longitudinal study examined normative beliefs about aggression (e.g., face-to-face, cyber) in relation to the engagement in cyber aggression 6 months later among 126 (69 women) young adults. Participants completed electronically administered measures assessing their normative beliefs, face-to-face and cyber aggression at Time 1, and cyber aggression 6 months later (Time 2). We found that men reported more cyber relational and verbal aggression when compared to women. After controlling for each other, Time 1 face-to-face relational aggression was positively related to Time 2 cyber relational aggression, whereas Time 1 face-to-face verbal aggression was positively related to Time 2 cyber verbal aggression. Normative beliefs regarding cyber aggression was positively related to both forms of cyber aggression 6 months later, after controlling for normative beliefs about face-to-face aggression. Furthermore, a significant two-way interaction between Time 1 cyber relational aggression and normative beliefs about cyber relational aggression was found. Follow-up analysis showed that Time 1 cyber relational aggression was more strongly related to Time 2 cyber relational aggression when young adults held higher normative beliefs about cyber relational aggression. A similar two-way interaction was found for cyber verbal aggression such that the association between Time 1 and Time 2 cyber verbal aggression was stronger at higher levels of normative beliefs about cyber verbal aggression. Results are discussed in terms of the social cognitive and behavioral mechanisms associated with the engagement of cyber aggression.

  2. Normative beliefs about aggression and cyber aggression among young adults: a longitudinal investigation.

    PubMed

    Wright, Michelle F; Li, Yan

    2013-01-01

    This longitudinal study examined normative beliefs about aggression (e.g., face-to-face, cyber) in relation to the engagement in cyber aggression 6 months later among 126 (69 women) young adults. Participants completed electronically administered measures assessing their normative beliefs, face-to-face and cyber aggression at Time 1, and cyber aggression 6 months later (Time 2). We found that men reported more cyber relational and verbal aggression when compared to women. After controlling for each other, Time 1 face-to-face relational aggression was positively related to Time 2 cyber relational aggression, whereas Time 1 face-to-face verbal aggression was positively related to Time 2 cyber verbal aggression. Normative beliefs regarding cyber aggression was positively related to both forms of cyber aggression 6 months later, after controlling for normative beliefs about face-to-face aggression. Furthermore, a significant two-way interaction between Time 1 cyber relational aggression and normative beliefs about cyber relational aggression was found. Follow-up analysis showed that Time 1 cyber relational aggression was more strongly related to Time 2 cyber relational aggression when young adults held higher normative beliefs about cyber relational aggression. A similar two-way interaction was found for cyber verbal aggression such that the association between Time 1 and Time 2 cyber verbal aggression was stronger at higher levels of normative beliefs about cyber verbal aggression. Results are discussed in terms of the social cognitive and behavioral mechanisms associated with the engagement of cyber aggression. PMID:23440595

  3. Safety knowledge of users and non-users of the lap belt on two-point motorized belt systems.

    PubMed

    Lehto, M R; James, D S

    1997-11-01

    A field study of 1146 drivers and passengers of vehicles equipped with motorized passive belts was conducted in shopping malls and other locations in the states of Arizona and Indiana. The Indiana data was collected the summer of 1994 and the Arizona data the summer of 1995. Shoulder belt use by drivers and passengers was 93.4% in Indiana and 87.8% in Arizona. Lap belt use was 65% in Indiana and 69.9% in Arizona. Over 99% of drivers in both states knew that a manually fastened lap belt was provided along with the motorized shoulder belt. Most drivers agreed that they are supposed to wear the lap belt (96.3% in Indiana and 94.3% in Arizona) and said that the vehicle they were driving provided a warning signal when the lap belt was not fastened (75.7% in Indiana and 79.4% in Arizona). Most drivers were also aware of warning labels telling them to use their lap belt (63.9% in Indiana and 68.2% in Arizona).

  4. Probiotics in periodontal health and disease

    PubMed Central

    Chatterjee, Anirban; Bhattacharya, Hirak; Kandwal, Abhishek

    2011-01-01

    Macfarlane Burnett stated in 1962 that “By the late twentieth century, we can anticipate the virtual elimination of infectious diseases as a significant factor in social life”. Probiotics have become of interest to researchers in recent times. Time has come to shift the paradigm of treatment from specific bacteria elimination to altering bacterial ecology by probiotics. The development of resistance to a range of antibiotics by some important pathogens has raised the possibility of a return to the pre-antibiotic dark ages. Here, probiotics provide an effective alternative way, which is economical and natural to combat periodontal disease. Thus, a mere change in diet by including probiotic foods may halt, retard, or even significantly delay the pathogenesis of periodontal diseases, promoting a healthy lifestyle to fight periodontal infections. PMID:21772717

  5. Platelet Rich Fibrin in Periodontal Regeneration

    PubMed Central

    Arunachalam, Muthukumaraswamy; Pulikkotil, Shaju J.; Sonia, Nath

    2016-01-01

    Periodontitis is a chronic bacterial infection resulting in destruction of the supporting structures of the teeth. Regeneration of the lost tissues has faced difficulties primarily due to the lack of support during the intricate healing processes. A surgical additive which can ‘jump start’ the healing process to a more predictable regenerative process is always on the wish list of any periodontist. Platelet-rich fibrin (PRF) is a second generation platelet concentrate that has been considered to be an important, easy to obtain, predictable surgical additive for periodontal regeneration. This autologous scaffold provides the much needed bio-chemical mediators which has the potential for enhancing reconstruction of the periodontium. This review article tries to understand as to why PRF would be an important link to reach predictable periodontal regeneration. PMID:27386002

  6. Platelet Rich Fibrin in Periodontal Regeneration.

    PubMed

    Arunachalam, Muthukumaraswamy; Pulikkotil, Shaju J; Sonia, Nath

    2016-01-01

    Periodontitis is a chronic bacterial infection resulting in destruction of the supporting structures of the teeth. Regeneration of the lost tissues has faced difficulties primarily due to the lack of support during the intricate healing processes. A surgical additive which can 'jump start' the healing process to a more predictable regenerative process is always on the wish list of any periodontist. Platelet-rich fibrin (PRF) is a second generation platelet concentrate that has been considered to be an important, easy to obtain, predictable surgical additive for periodontal regeneration. This autologous scaffold provides the much needed bio-chemical mediators which has the potential for enhancing reconstruction of the periodontium. This review article tries to understand as to why PRF would be an important link to reach predictable periodontal regeneration. PMID:27386002

  7. Do Teachers Misbehave? Aggression in School Teams

    ERIC Educational Resources Information Center

    Ben Sasson, Dvora; Somech, Anit

    2015-01-01

    Purpose: Despite growing research on school aggression, significant gaps remain in the authors' knowledge of team aggression, since most studies have mainly explored aggression on the part of students. The purpose of this paper is to focus on understanding the phenomenon of workplace aggression in school teams. Specifically, the purpose of the…

  8. Adolescents' Social Reasoning about Relational Aggression

    ERIC Educational Resources Information Center

    Goldstein, Sara E.; Tisak, Marie S.

    2010-01-01

    We examined early adolescents' reasoning about relational aggression, and the links that their reasoning has to their own relationally aggressive behavior. Thinking about relational aggression was compared to thinking about physical aggression, conventional violations, and personal behavior. In individual interviews, adolescents (N = 103) rated…

  9. Application of ozone in the treatment of periodontal disease

    PubMed Central

    Srikanth, Adusumilli; Sathish, Manthena; Sri Harsha, Anumolu Venkatanaga

    2013-01-01

    Gingivitis and periodontitis are most common inflammatory diseases of supporting tissues of teeth. Role of microbial etiology and host response in progression of gingival and periodontal diseases has been well established. Because of the beneficial biological effects of ozone, due to its antimicrobial and immunostimulating effect, it is well indicated in the treatment of gingival and periodontal diseases. The objective of this article is to provide a general review about clinical applications of ozone in treatment of periodontal diseases and to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. PMID:23946585

  10. [Periodontitis and systemic diseases: from science to clinical practice].

    PubMed

    Thomas, R Z; Loos, B G; Teeuw, W; Kunnen, A; van Winkelhoff, A J; Abbas, F

    2015-10-01

    The evidence for an association between systemic diseases and periodontitis is strongest with diabetes mellitus type 2 and cardiovascular disease. There is a moderate association of periodontitis with adverse pregnancy outcomes and rheumatoid arthritis. Periodontal treatment has, on average, a positive effect on reducing systemic infection and improving the condition of the vascular system. For diabetes patients, periodontal treatment can also have a positive effect on metabolic regulation. There is insufficient evidence that periodontal treatment prevents adverse pregnancy outcomes and rheumatoid arthritis. PMID:26465017

  11. Using quantum dots to tag subsurface damage in lapped and polished glass samples

    SciTech Connect

    Williams, Wesley B.; Mullany, Brigid A.; Parker, Wesley C.; Moyer, Patrick J.; Randles, Mark H.

    2009-09-20

    Grinding, lapping, and polishing are finishing processes used to achieve critical surface parameters in a variety of precision optical and electronic components. As these processes remove material from the surface through mechanical and chemical interactions, they may induce a damaged layer of cracks, voids, and stressed material below the surface. This subsurface damage (SSD) can degrade the performance of a final product by creating optical aberrations due to diffraction, premature failure in oscillating components, and a reduction in the laser induced damage threshold of high energy optics. As these defects lie beneath the surface, they are difficult to detect, and while many methods are available to detect SSD, they can have notable limitations regarding sample size and type, preparation time, or can be destructive in nature. The authors tested a nondestructive method for assessing SSD that consisted of tagging the abrasive slurries used in lapping and polishing with quantum dots (nano-sized fluorescent particles). Subsequent detection of fluorescence on the processed surface is hypothesized to indicate SSD. Quantum dots that were introduced to glass surfaces during the lapping process were retained through subsequent polishing and cleaning processes. The quantum dots were successfully imaged by both wide field and confocal fluorescence microscopy techniques. The detected fluorescence highlighted features that were not observable with optical or interferometric microscopy. Atomic force microscopy and additional confocal microscope analysis indicate that the dots are firmly embedded in the surface but do not appear to travel deep into fractures beneath the surface. Etching of the samples exhibiting fluorescence confirmed that SSD existed. SSD-free samples exposed to quantum dots did not retain the dots in their surfaces, even when polished in the presence of quantum dots.

  12. TRMM and GPM: Radar Observations and Simulations with the Local Analysis and Prediction System (LAPS)

    NASA Astrophysics Data System (ADS)

    Albers, S. C.; Holub, K.; Xie, Y.

    2015-12-01

    The Local Analysis and Prediction System (LAPS), developed at NOAAs Earth System Research Laboratory is used for data assimilation, nowcasting, and model initialization/post-processing.It is a portable system and typically runs with a high resolution and rapid updateBlends a wide variety of in-situ and remotely sensed data sets (e.g. METARs, mesonets, radar, satellite)‏Here we test the assimilation of PMM radar data, using reflectivity obtained from the TRMM satellite, as a preparation for GPM. A case study for July 26 2013 with a small region of convection occurring over Florida. The 3-D LAPS domain is on a 1km grid and is producing analyses and forecasts.TRMM radar data was remapped to mimic the appearance of reflectivity in a ground-based radar over Florida.Three assimilation experiments are being performed using non-radar observations plus: TRMM radar, ground-based radar, and neither source of radar. We are comparing both analyses (initial condition) and forecasts where the WRF modelis initialized with the LAPS analysis. When evaluating the results we consider some big picture aspects in thatthe GPM Core Observatory radar coverage is limited in space and time and potentially less operational model benefit.To address this 4DVAR can help increase impact (particularly in a global model), since it spreads observations in time and space.The spreading in time also helps compensate for latency of the real-time data stream.We can also use GPM (core satellite) radar paired with microwave imager data to calibrate microwave data from other GPM constellation satellites. We thus can leverage more frequent satellite microwave passes compared with radar to assess hydrometeor climatological covariance between various species, fill in ice phase information.These relationships, leveraged from related climate research, help to provide constraints for our planned variational analysis improvements.

  13. A comparative study of the hydroxy acids from the Murchison, GRA 95229 and LAP 02342 meteorites

    NASA Astrophysics Data System (ADS)

    Pizzarello, Sandra; Wang, Yi; Chaban, Galina M.

    2010-11-01

    The hydroxy acid suites extracted from the Murchison (MN), GRA 95229 (GRA) and LAP 02342 (LAP) meteorites have been investigated for their molecular, chiral and isotopic composition. Substantial amounts of the compounds have been detected in all three meteorites, with a total abundance that is lower than that of the amino acids in the same stones. Overall, their molecular distributions mirror closely that of the corresponding amino acids and most evidently so for the LAP meteorite. A surprising L-lactic acid enantiomeric excess was found present in all three stones, which cannot be easily accounted by terrestrial contamination; all other compounds of the three hydroxy acid suites were found racemic. The branched-chain five carbon and the diastereomer six-carbon hydroxy acids were also studied vis-a-vis the corresponding amino acids and calculated ab initio thermodynamic data, with the comparison allowing the suggestion that meteoritic hydroxyacid at these chain lengths formed under thermodynamic control and, possibly, at a later stage than the corresponding amino acids. 13C and D isotopic enrichments were detected for many of the meteoritic hydroxy acids and found to vary between molecular species with trends that also appear to correlate to those of amino acids; the highest δD value (+3450‰) was displayed by GRA 2-OH-2-methylbutyric acid. The data suggest that, while the amino- and hydroxy acids likely relate to common presolar precursor, their final distribution in meteorites was determined to large extent by the overall composition of the environments that saw their formation, with ammonia being the determining factor in their final abundance ratios.

  14. Periodontal innate immune mechanisms relevant to obesity.

    PubMed

    Amar, S; Leeman, S

    2013-10-01

    Obesity affects over 35% of the adult population of the USA, and obesity-related illnesses have emerged as the leading cause of preventable death worldwide, according to the World Health Organization. Obesity's secondary morbidities include increased risk of cardiovascular disease, type II diabetes, and cancer, in addition to increased occurrence and severity of infections. Sedentary lifestyle and weight gain caused by consumption of a high-fat diet contribute to the development of obesity, with individuals having a body mass index (BMI) score > 30 being considered obese. Genetic models of obesity (ob/ob mice, db/db mice, and fa/fa rats) have been insufficient to study human obesity because of the overall lack of genetic causes for obesity in human populations. To date, the diet-induced obese (DIO) mouse model best serves research studies relevant to human health. Periodontal disease presents with a wide range of clinical variability and severity. Research in the past decade has shed substantial light on both the initiating infectious agents and host immunological responses in periodontal disease. Up to 46% of the general population harbors the microorganism(s) associated with periodontal disease, although many are able to limit the progression of periodontal disease or even clear the organism(s) if infected. In the last decade, several epidemiological studies have found an association between obesity and increased incidence of periodontal disease. This review focuses on exploring the immunological consequences of obesity that exacerbate effects of infection by pathogens, with focus on infection by the periodontal bacterium Porphyromonas gingivalis as a running example. PMID:23911141

  15. Genetic influences in caries and periodontal diseases.

    PubMed

    Hassell, T M; Harris, E L

    1995-01-01

    Deciphering the relative roles of heredity and environmental factors ("nature vs. nurture") in the pathogenesis of dental caries and diseases of the periodontium has occupied clinical and basic researchers for decades. Success in the endeavor has come more easily in the case of caries; the complex interactions that occur between host-response mechanisms and putative microbiologic pathogens in periodontal disease have made elucidation of genetic factors in disease susceptibility more difficult. In addition, during the 30-year period between 1958 and 1987, only meager resources were targeted toward the "nature" side of the nature/nurture dipole in periodontology. In this article, we present a brief history of the development of genetic epistemology, then describe the three main research mechanisms by which questions about the hereditary component of diseases in humans can be addressed. A critical discussion of the evidence for a hereditary component in caries susceptibility is next presented, also from a historical perspective. The evolution of knowledge concerning possible genetic ("endogenous", "idiotypic") factors in the pathogenesis of inflammatory periodontal disease is initiated with an analysis of some foreign-language (primarily German) literature that is likely to be unfamiliar to the reader. We identify a turning point at about 1960, when the periodontal research community turned away from genetics in favor of microbiology research. During the past five years, investigators have re-initiated the search for the hereditary component in susceptibility to common adult periodontal disease; this small but growing body of literature is reviewed. Recent applications of in vitro methods for genetic analyses in periodontal research are presented, with an eye toward a future in which persons who are at risk--genetically predisposed--to periodontal disease may be identified and targeted for interventive strategies. Critical is the realization that genes and environment

  16. Genetic influences in caries and periodontal diseases.

    PubMed

    Hassell, T M; Harris, E L

    1995-01-01

    Deciphering the relative roles of heredity and environmental factors ("nature vs. nurture") in the pathogenesis of dental caries and diseases of the periodontium has occupied clinical and basic researchers for decades. Success in the endeavor has come more easily in the case of caries; the complex interactions that occur between host-response mechanisms and putative microbiologic pathogens in periodontal disease have made elucidation of genetic factors in disease susceptibility more difficult. In addition, during the 30-year period between 1958 and 1987, only meager resources were targeted toward the "nature" side of the nature/nurture dipole in periodontology. In this article, we present a brief history of the development of genetic epistemology, then describe the three main research mechanisms by which questions about the hereditary component of diseases in humans can be addressed. A critical discussion of the evidence for a hereditary component in caries susceptibility is next presented, also from a historical perspective. The evolution of knowledge concerning possible genetic ("endogenous", "idiotypic") factors in the pathogenesis of inflammatory periodontal disease is initiated with an analysis of some foreign-language (primarily German) literature that is likely to be unfamiliar to the reader. We identify a turning point at about 1960, when the periodontal research community turned away from genetics in favor of microbiology research. During the past five years, investigators have re-initiated the search for the hereditary component in susceptibility to common adult periodontal disease; this small but growing body of literature is reviewed. Recent applications of in vitro methods for genetic analyses in periodontal research are presented, with an eye toward a future in which persons who are at risk--genetically predisposed--to periodontal disease may be identified and targeted for interventive strategies. Critical is the realization that genes and environment

  17. Host response mechanisms in periodontal diseases

    PubMed Central

    SILVA, Nora; ABUSLEME, Loreto; BRAVO, Denisse; DUTZAN, Nicolás; GARCIA-SESNICH, Jocelyn; VERNAL, Rolando; HERNÁNDEZ, Marcela; GAMONAL, Jorge

    2015-01-01

    Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4+ T-cells (T-helper cells). Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs) and bone-resorbing osteoclasts (OCLs). This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as a stage that

  18. Periodontal innate immune mechanisms relevant to obesity.

    PubMed

    Amar, S; Leeman, S

    2013-10-01

    Obesity affects over 35% of the adult population of the USA, and obesity-related illnesses have emerged as the leading cause of preventable death worldwide, according to the World Health Organization. Obesity's secondary morbidities include increased risk of cardiovascular disease, type II diabetes, and cancer, in addition to increased occurrence and severity of infections. Sedentary lifestyle and weight gain caused by consumption of a high-fat diet contribute to the development of obesity, with individuals having a body mass index (BMI) score > 30 being considered obese. Genetic models of obesity (ob/ob mice, db/db mice, and fa/fa rats) have been insufficient to study human obesity because of the overall lack of genetic causes for obesity in human populations. To date, the diet-induced obese (DIO) mouse model best serves research studies relevant to human health. Periodontal disease presents with a wide range of clinical variability and severity. Research in the past decade has shed substantial light on both the initiating infectious agents and host immunological responses in periodontal disease. Up to 46% of the general population harbors the microorganism(s) associated with periodontal disease, although many are able to limit the progression of periodontal disease or even clear the organism(s) if infected. In the last decade, several epidemiological studies have found an association between obesity and increased incidence of periodontal disease. This review focuses on exploring the immunological consequences of obesity that exacerbate effects of infection by pathogens, with focus on infection by the periodontal bacterium Porphyromonas gingivalis as a running example.

  19. Juvenile aggressive cemento-ossifying fibroma of the sinonasal tract: case report.

    PubMed

    Bist, Sampan Singh; Varshney, Saurabh; Kumar, Rakesh; Bhagat, Sanjeev; Gupta, Nitin

    2011-11-01

    Cemento-ossifying fibroma (COF) is a rare nonodontogenic tumor of the periodontal membrane that arises from the mesodermal germ layer. Clinically, these lesions are usually asymptomatic, slowly growing, and well circumscribed. However, they have demonstrated an aggressive course of development in a very small number of cases, particularly in younger patients. Surgical management via wide local excision is necessary because COF is notorious for recurrence, particularly lesions in the paranasal sinuses. We describe a case of juvenile aggressive COF of the sinonasal tract in a 12-year-old boy. This tumor presented with various overlapping clinical, radiologic, and pathologic features, which led to initial confusion and a diagnostic dilemma. We also discuss the radiologic interpretation of COF, which can be helpful in making the diagnosis and in selecting the appropriate surgical approach in a growing child.

  20. Bolted Double-Lap Composite Joints Under Mechanical and Thermal Loading

    NASA Technical Reports Server (NTRS)

    Kradinov, V.; Barut, A.; Madenci, E.; Walker, Sandra P. (Technical Monitor)

    2000-01-01

    This study concerns the determination of the contact stresses and contact region around bolt holes and the bolt load distribution in single- and double-lap joints of composite laminates with arbitrarily located bolts under general mechanical loading conditions and uniform temperature change. The unknown contact stress distribution and contact region between the bolt and laminates and the interaction among the bolts require the bolt load distribution, as well as the contact stresses, to be as part of the solution. The present method is based on the complex potential theory and the variational formulation in order to account for bolt stiffness, bolt-hole clearance, and finite geometry of the composite laminates.

  1. On the determination of diffusion lengths by means of angle-lapped p-n junctions

    NASA Technical Reports Server (NTRS)

    Von Roos, O.

    1979-01-01

    A standard procedure for determining the minority carrier diffusion length by means of SEM consists of scanning an angle-lapped surface of a p-n junction and measuring the resulting short circuit current as a function of beam position. The present paper points out that the usual expression linking the short circuit current induced by the electron beam to the angle between the semiconductor surface and the junction plane is incorrect. The correct expression is discussed and it is noted that, for angles less than 10 deg, the new and the old expression are practically indistinguishable.

  2. Lap belt complex. Recognition & assessment of seatbelt injuries in pediatric trauma patients.

    PubMed

    Jordan, B

    2001-05-01

    That seatbelts save lives is irrefutable. Every health-care professional should advocate parents use proper restraint systems for their children. Resource guides are available from local, state and national organizations regarding proper restraint usage for the pediatric population. However, children restrained with lap belts are at risk of sustaining an occult injury. You must quickly stabilize the ABCs, immobilize the spine and get the patient en route to a trauma center while you perform a solid baseline assessment. The trauma team needs information on kinetics, type of restraints used, assessment findings and treatment rendered so they can accurately assess subtle changes in the patient's condition and initiate proper treatment.

  3. Traumatic disruption of the abdominal wall: lap-belt injuries in children.

    PubMed

    Moremen, Jacob R; Nakayama, Don K; Ashley, Dennis W; Astin, Matthew; Nolan, Tracy L

    2013-04-01

    Traumatic abdominal wall hernia (TAWH) from high speed mechanism is a unique finding in adult trauma, and exceedingly rare in pediatrics. The majority of reports are of low-speed "handlebar" hernias associated with direct injury by bicycle handlebars. We report a series of three pediatric patients in motor vehicle collisions (MVC) who experienced TAWH by lap-belt and associated intra-abdominal injuries necessitating immediate operative intervention. Different operative approaches were used in each case to manage the varying types of disruptions. This adds to the pediatric literature the largest series of its kind.

  4. Nonsurgical mechanical treatment strategies for periodontal disease.

    PubMed

    Apatzidou, Danae A; Kinane, Denis F

    2010-01-01

    The comparison of the efficacy of surgical and nonsurgical procedures revealed that scaling and root planing alone or in combination with flap procedures are effective methods for the treatment of chronic periodontitis. Also, the consistent message is that in treating deep pockets, open-flap debridement results in greater probing pocket depth reduction and clinical attachment gain than nonsurgical modalities. Nonsurgical modalities in shallower pockets consistently involve less post-therapy recession and are clearly recognized as being more conservative. Research is still needed on the clinical benefit of the granulation tissue removal that is a feature of periodontal surgical therapy and, to a lesser extent, occurs through indirect trauma in nonsurgical therapy.

  5. Periodontal Probe Improves Exams, Alleviates Pain

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Dentists, comedian Bill Cosby memorably mused, tell you not to pick your teeth with any sharp metal object. Then you sit in their chair, and the first thing they grab is an iron hook!" Conventional periodontal probing is indeed invasive, uncomfortable for the patient, and the results can vary greatly between dentists and even for repeated measurements by the same dentist. It is a necessary procedure, though, as periodontal disease is the most common dental disease, involving the loss of teeth by the gradual destruction of ligaments that hold teeth in their sockets in the jawbone. The disease usually results from an increased concentration of bacteria in the pocket, or sulcus, between the gums and teeth. These bacteria produce acids and other byproducts, which enlarge the sulcus by eroding the gums and the periodontal ligaments. The sulcus normally has a depth of 1 to 2 millimeters, but in patients with early stages of periodontal disease, it has a depth of 3 to 5 millimeters. By measuring the depth of the sulcus, periodontists can have a good assessment of the disease s progress. Presently, there are no reliable clinical indicators of periodontal disease activity, and the best available diagnostic aid, periodontal probing, can only measure what has already been lost. A method for detecting small increments of periodontal ligament breakdown would permit earlier diagnosis and intervention with less costly and time-consuming therapy, while overcoming the problems associated with conventional probing. The painful, conventional method for probing may be destined for the archives of dental history, thanks to the development of ultrasound probing technologies. The roots of ultrasound probes are in an ultrasound-based time-of-flight technique routinely used to measure material thickness and length in the Nondestructive Evaluation Sciences Laboratory at Langley Research Center. The primary applications of that technology have been for corrosion detection and bolt tension

  6. Association of Synergistetes and Cyclodipeptides with Periodontitis.

    PubMed

    Marchesan, J T; Morelli, T; Moss, K; Barros, S P; Ward, M; Jenkins, W; Aspiras, M B; Offenbacher, S

    2015-10-01

    The purpose of this study was to evaluate the microbial community (MC) composition as it relates to salivary metabolites and periodontal clinical parameters in a 21-d biofilm-overgrowth model. Subjects (N = 168) were enrolled equally into 5 categories of periodontal status per the biofilm-gingival interface classification. Microbial species within subgingival plaque samples were identified by human microbiome identification microarray. Whole saliva was analyzed by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry for metabolite identification. Phylum was grouped into MCs according to principal component analysis. Generalized linear and regression models were used to examine the association among MC, species, periodontal clinical parameters, and salivary metabolome. Multiple comparisons were adjusted with the false discovery rate. The study population was distributed into 8 distinct MC profiles, designated MC-1 to MC-8. MC-2 explained 14% of the variance and was dominated by Synergistetes and Spirochaetes. It was the only community structure significantly associated with high probing depth (P = 0.02) and high bleeding on probing (P = 0.008). MC-2 was correlated with traditional periodontal pathogens and several newly identified putative periodontal pathogens: Fretibacterium fastidiosum, Fretibacterium sp. OT360/OT362, Filifactor alocis, Treponema lecithinolyticum, Eubacterium saphenum, Desulfobulbus sp./OT041, and Mogibacterium timidum. Synergistetes phylum was strongly associated with 2 novel metabolites-cyclo (-leu-pro) and cyclo (-phe-pro)-at 21 d of biofilm overgrowth (P = 0.02). In subjects with severe periodontitis (P2 and P3), cyclo (-leu-pro) and cyclo (-phe-pro) were significantly associated with increased changes in probing depth at 21 d of biofilm overgrowth (P ≤ 0.05). The analysis identified a MC dominated by Synergistetes, with classic and putative newly identified pathogens/pathobionts associated with clinical disease

  7. Periodontal considerations of the removable partial overdenture.

    PubMed

    Gomes, B C; Renner, R P

    1990-10-01

    1. An overdenture, whether complete or partial, is an excellent mode of treatment in the mutilated dentition for the preservation of the residual ridge. 2. Selection of patients for an overdenture should be based on past history of dental neglect, the status of the teeth and their periodontium, including present oral hygiene status, and patient motivation. The patients with a history of dental neglect, poor oral hygiene, and lack of motivation in having the teeth and the periodontium restored to health as well as strict compliance to a home-care regimen and recall schedule are not good candidates for treatment with an overdenture. 3. The choice of teeth or roots to serve as overdenture abutments must include their periodontal evaluation, which should consist of a detailed periodontal examination, diagnosis, prognosis, and treatment when this is indicated, including chemical protection (fluoride gel) and an oral hygiene regimen tailored to individual needs. 4. The knowledge and expertise in the selection and implementation of appropriate periodontal treatment modalities is of paramount importance in restoring optimum periodontal health to the overdenture abutments before overdenture fabrication. 5. The maintenance phase of the overdenture abutments as well as of the existing natural teeth is of critical importance in the preservation of health of these abutments and teeth. This maintenance phase should consist of periodic recalls based on individual needs; a detailed periodontal evaluation, including patient's motivation and status of oral hygiene and denture hygiene; and detection of caries. If necessary, appropriate periodontal and/or restorative therapy should be performed, and oral hygiene measures reinforced. This will ensure longevity of both abutment teeth or roots and of the existing natural teeth resulting in a long-term success of an overdenture. 6. Because there is evidence of high incidence of periodontal disease and dental caries in overdenture wearers

  8. Association between Human Body Composition and Periodontal Disease.

    PubMed

    Salekzamani, Yagoub; Shirmohammadi, Adileh; Rahbar, Mohammad; Shakouri, Seyed-Kazem; Nayebi, Farough

    2011-01-01

    Obesity in humans might increase the risk of periodontitis. The aim of the present study was to examine the relationship between body composition of males and their periodontal status. AS total of 150 males (aged 30-60) were selected: 31 were periodontally healthy, 45 had gingivitis, 39 had initial periodontitis, and 35 suffered from established periodontitis. BMI (body mass index), WC (waist circumference), and body composition parameters (consisting of body water, body fat, and skeletal muscle and bone mass) were measured. After adjusting for age, history of diabetes, smoking, physical activity status, and socioeconomic status, statistically significant correlations were found between periodontitis and BMI, WC, and body composition. There was only a statistically significant difference between the periodontal health and established periodontitis; that is, periodontal disease in mild forms (gingivitis) and initial periodontitis do not influence these variables (BMI, WC, and body composition parameters) and only the severe form of the disease influences the variables. These data suggest that there is a considerable association between severe forms of periodontal disease in males and their body composition, but this preliminary finding needs to be confirmed in more extensive studies. PMID:22111011

  9. Contribution of Nanotechnology to Improved Treatment of Periodontal Disease.

    PubMed

    Zupancic, Spela; Kocbek, Petra; Baumgartner, Sasa; Kristl, Julijana

    2015-01-01

    Periodontal disease is chronic inflammation of periodontal tissues resulting in formation of periodontal pockets, periodontal attachment loss and progressive destruction of the ligament and alveolar bone. This review gives an update on periodontal disease pathogenesis, which is important for the development of novel methods and delivery systems for its treatment. The available treatment approaches, including removal of dental plaque, modulation of the host inflammatory response, and regeneration of periodontal tissue, are reviewed and their drawbacks discussed. Furthermore the latest achievements involving development of nanomedicines, which represent a new approach to better treatment of periodontal disease, are highlighted. They enable local drug delivery to particular tissues, cells, or subcellular compartments in periodontal pockets, either to biofilm pathogens or host cells, as well as control the release of incorporated drugs, usually antibiotic or anti-inflammatory. Specific examples of the nanocarriers or nanomaterials such as liposomes, lipid and polymeric nanoparticles, nanocrystals, dendrimers, and nanofibers under development for the treatment of periodontal disease are also clearly reviewed. Nanofibers are of special interest as nanodelivery systems and scaffolds for the regeneration of periodontal tissue. Finally, the future outlook of novel therapeutic approaches involving nanodelivery systems in the treatment of periodontal disease is provided. PMID:26027560

  10. Contribution of Nanotechnology to Improved Treatment of Periodontal Disease.

    PubMed

    Zupancic, Spela; Kocbek, Petra; Baumgartner, Sasa; Kristl, Julijana

    2015-01-01

    Periodontal disease is chronic inflammation of periodontal tissues resulting in formation of periodontal pockets, periodontal attachment loss and progressive destruction of the ligament and alveolar bone. This review gives an update on periodontal disease pathogenesis, which is important for the development of novel methods and delivery systems for its treatment. The available treatment approaches, including removal of dental plaque, modulation of the host inflammatory response, and regeneration of periodontal tissue, are reviewed and their drawbacks discussed. Furthermore the latest achievements involving development of nanomedicines, which represent a new approach to better treatment of periodontal disease, are highlighted. They enable local drug delivery to particular tissues, cells, or subcellular compartments in periodontal pockets, either to biofilm pathogens or host cells, as well as control the release of incorporated drugs, usually antibiotic or anti-inflammatory. Specific examples of the nanocarriers or nanomaterials such as liposomes, lipid and polymeric nanoparticles, nanocrystals, dendrimers, and nanofibers under development for the treatment of periodontal disease are also clearly reviewed. Nanofibers are of special interest as nanodelivery systems and scaffolds for the regeneration of periodontal tissue. Finally, the future outlook of novel therapeutic approaches involving nanodelivery systems in the treatment of periodontal disease is provided.

  11. Matrix Metalloproteinase-3 -1171 5A/6A Polymorphism (rs35068180) is Associated with Risk of Periodontitis.

    PubMed

    Ding, Cheng; Chen, Xing; Zhang, Peng-tao; Huang, Jin-ping; Xu, Yan; Chen, Ning; Zhong, Liang-jun

    2015-01-01

    Matrix metalloproteinase-3 (MMP3) plays a key role in tissue degradation in periodontitis. The relationship between the MMP3 -1171 5A/6A polymorphism (rs35068180) and periodontitis has been widely studied. However, existing studies have yielded contradictory results. We therefore conducted a meta-analysis to comprehensively investigate these inconclusive findings. Several electronic databases were searched for eligible articles. Seven case-control studies from 6 articles were searched without any language restrictions. Pooled estimates indicated that MMP3 -1171 5A/6A polymorphism is associated with a decreased risk of periodontitis (allelic genetic model: OR = 0.70, 95% CI: 0.62-0.80, P(heterogeneity) = 0.315; heterozygous model: OR = 0.50, 95% CI: 0.39-0.65, P(heterogeneity) = 0.221; homozygous model: OR = 0.42, 95% CI: 0.25-0.69, P(heterogeneity) = 0.265; dominant model: OR = 0.49, 95% CI: 0.38-0.62, P(heterogeneity) = 0.238, respectively). Similar results were also found in chronic periodontitis (CP), Asian, Asian&CP, and non-smokers subgroups. Moreover, MMP3 rs35068180 polymorphism might be associated with a lower risk of aggressive periodontitis (AgP) in Asians (allelic genetic model: OR = 0.66, 95% CI: 0.48-0.91, P(heterogeneity) = 0.945), and CP in Caucasians and Brazilians. In conclusion, this meta-analysis demonstrates that MMP3 -1171 5A/6A polymorphism may be associated with decreased risk of both CP and AgP in Asians. Large independent studies to replicate these results are necessary to validate these associations in other populations. PMID:26123623

  12. Matrix Metalloproteinase-3 -1171 5A/6A Polymorphism (rs35068180) is Associated with Risk of Periodontitis.

    PubMed

    Ding, Cheng; Chen, Xing; Zhang, Peng-tao; Huang, Jin-ping; Xu, Yan; Chen, Ning; Zhong, Liang-jun

    2015-06-30

    Matrix metalloproteinase-3 (MMP3) plays a key role in tissue degradation in periodontitis. The relationship between the MMP3 -1171 5A/6A polymorphism (rs35068180) and periodontitis has been widely studied. However, existing studies have yielded contradictory results. We therefore conducted a meta-analysis to comprehensively investigate these inconclusive findings. Several electronic databases were searched for eligible articles. Seven case-control studies from 6 articles were searched without any language restrictions. Pooled estimates indicated that MMP3 -1171 5A/6A polymorphism is associated with a decreased risk of periodontitis (allelic genetic model: OR = 0.70, 95% CI: 0.62-0.80, P(heterogeneity) = 0.315; heterozygous model: OR = 0.50, 95% CI: 0.39-0.65, P(heterogeneity) = 0.221; homozygous model: OR = 0.42, 95% CI: 0.25-0.69, P(heterogeneity) = 0.265; dominant model: OR = 0.49, 95% CI: 0.38-0.62, P(heterogeneity) = 0.238, respectively). Similar results were also found in chronic periodontitis (CP), Asian, Asian&CP, and non-smokers subgroups. Moreover, MMP3 rs35068180 polymorphism might be associated with a lower risk of aggressive periodontitis (AgP) in Asians (allelic genetic model: OR = 0.66, 95% CI: 0.48-0.91, P(heterogeneity) = 0.945), and CP in Caucasians and Brazilians. In conclusion, this meta-analysis demonstrates that MMP3 -1171 5A/6A polymorphism may be associated with decreased risk of both CP and AgP in Asians. Large independent studies to replicate these results are necessary to validate these associations in other populations.

  13. Kindergarten Children's Genetic Vulnerabilities Interact with Friends' Aggression to Promote Children's Own Aggression

    ERIC Educational Resources Information Center

    van Lier, Pol; Boivin, Michel; Dionne, Ginette; Vitaro, Frank; Brendgen, Mara; Koot, Hans; Tremblay, Richard E.; Perusse, Daniel

    2007-01-01

    Objective: To examine whether kindergarten children's genetic liability to physically aggress moderates the contribution of friends' aggression to their aggressive behaviors. Method: Teacher and peer reports of aggression were available for 359 6-year-old twin pairs (145 MZ, 212 DZ) as well as teacher and peer reports of aggression of the two best…

  14. Endovascular management of lap belt-related abdominal aortic injury in a 9-year-old child.

    PubMed

    Papazoglou, Konstantinos O; Karkos, Christos D; Kalogirou, Thomas E; Giagtzidis, Ioakeim T

    2015-02-01

    Blunt abdominal aortic trauma is a rare occurrence in children with only a few patients having been reported in the literature. Most such cases have been described in the context of lap belt injuries. We report a 9-year-old boy who suffered lap belt trauma to the abdomen during a high-speed road traffic accident resulting to the well-recognized pattern of blunt abdominal injury, that is, the triad of intestinal perforation, fractures of the lumbar spine, and abdominal aortic injury. The latter presented with lower limb ischemia due to dissection of the infrarenal aorta and right common iliac artery. Revascularization was achieved by endovascular means using 2 self-expanding stents in the infrarenal aorta and the right common iliac artery. This case is one of the few reports of lap belt-related acute traumatic abdominal aortic dissection in a young child and highlights the feasibility of endovascular management in the pediatric population. PMID:25463338

  15. Acute cervical spinal cord injury secondary to air bag deployment without proper use of lap or shoulder harnesses.

    PubMed

    Hart, R A; Mayberry, J C; Herzberg, A M

    2000-02-01

    The authors present a case report of a patient with cervical central spinal cord syndrome caused by a hyperextension injury after a motor vehicle collision in which the air bag deployed in the absence of shoulder or lap belt harnesses. The potential for cervical spine and spinal cord hyperextension injuries in passengers positioned in front of air bags without proper use of shoulder or lap belt harnesses is discussed. Cervical central spinal cord quadriplegia occurred with cervical spondylosis and kyphosis that was managed by early three-level cervical corpectomy in a 58-year-old patient. Early improvement in the patient's neurological status occurred but was incomplete at the time of this report. Cervical hyperextension injuries are possible in passengers positioned in the front seat of cars with air bags when shoulder or lap belt harnesses are not used properly. Previous biomechanical studies have documented the potential for these types of injuries.

  16. Endovascular management of lap belt-related abdominal aortic injury in a 9-year-old child.

    PubMed

    Papazoglou, Konstantinos O; Karkos, Christos D; Kalogirou, Thomas E; Giagtzidis, Ioakeim T

    2015-02-01

    Blunt abdominal aortic trauma is a rare occurrence in children with only a few patients having been reported in the literature. Most such cases have been described in the context of lap belt injuries. We report a 9-year-old boy who suffered lap belt trauma to the abdomen during a high-speed road traffic accident resulting to the well-recognized pattern of blunt abdominal injury, that is, the triad of intestinal perforation, fractures of the lumbar spine, and abdominal aortic injury. The latter presented with lower limb ischemia due to dissection of the infrarenal aorta and right common iliac artery. Revascularization was achieved by endovascular means using 2 self-expanding stents in the infrarenal aorta and the right common iliac artery. This case is one of the few reports of lap belt-related acute traumatic abdominal aortic dissection in a young child and highlights the feasibility of endovascular management in the pediatric population.

  17. Interfacial and Mechanical Behavior of AA5456 Filling Friction-Stir-Welded Lap Joints Using Similar and Dissimilar Pins

    NASA Astrophysics Data System (ADS)

    Behmand, Saleh Alaei; Mirsalehi, Seyyed Ehsan; Omidvar, Hamid; Safarkhanian, Mohammad Ali

    2016-10-01

    In this article, filling friction stir welding (FFSW) of the remaining exit holes of AA5456 alloy friction-stir-welded lap joints was studied. For this purpose, the influences of different rotating speeds, holding times, and pin materials, AA5456 and AA2024, on the metallurgical structure and joint strength were investigated. The observations showed that defect-free lap joints are successfully obtainable by this method using similar and dissimilar consumable pins. The results indicated that the higher rotating speed and holding time adversely affect the weld performance. The best result was achieved for 30 seconds holding time, 500 rpm rotating speed, and AA2024 consumable pin. In this condition, a lap shear strength of 10 pct higher than that of the nonfilled joint, equivalent to about 94 pct of the original defect-free FSW joint, was obtained, whereas the GTAW filled joint showed only approximately 87 pct of the continuous FSW joint strength.

  18. Interfacial and Mechanical Behavior of AA5456 Filling Friction-Stir-Welded Lap Joints Using Similar and Dissimilar Pins

    NASA Astrophysics Data System (ADS)

    Behmand, Saleh Alaei; Mirsalehi, Seyyed Ehsan; Omidvar, Hamid; Safarkhanian, Mohammad Ali

    2016-06-01

    In this article, filling friction stir welding (FFSW) of the remaining exit holes of AA5456 alloy friction-stir-welded lap joints was studied. For this purpose, the influences of different rotating speeds, holding times, and pin materials, AA5456 and AA2024, on the metallurgical structure and joint strength were investigated. The observations showed that defect-free lap joints are successfully obtainable by this method using similar and dissimilar consumable pins. The results indicated that the higher rotating speed and holding time adversely affect the weld performance. The best result was achieved for 30 seconds holding time, 500 rpm rotating speed, and AA2024 consumable pin. In this condition, a lap shear strength of 10 pct higher than that of the nonfilled joint, equivalent to about 94 pct of the original defect-free FSW joint, was obtained, whereas the GTAW filled joint showed only approximately 87 pct of the continuous FSW joint strength.

  19. Influence of nanotopography on periodontal ligament stem cell functions and cell sheet based periodontal regeneration.

    PubMed

    Gao, Hui; Li, Bei; Zhao, Lingzhou; Jin, Yan

    2015-01-01

    Periodontal regeneration is an important part of regenerative medicine, with great clinical significance; however, the effects of nanotopography on the functions of periodontal ligament (PDL) stem cells (PDLSCs) and on PDLSC sheet based periodontal regeneration have never been explored. Titania nanotubes (NTs) layered on titanium (Ti) provide a good platform to study this. In the current study, the influence of NTs of different tube size on the functions of PDLSCs was observed. Afterward, an ectopic implantation model using a Ti/cell sheets/hydroxyapatite (HA) complex was applied to study the effect of the NTs on cell sheet based periodontal regeneration. The NTs were able to enhance the initial PDLSC adhesion and spread, as well as collagen secretion. With the Ti/cell sheets/HA complex model, it was demonstrated that the PDLSC sheets were capable of regenerating the PDL tissue, when combined with bone marrow mesenchymal stem cell (BMSC) sheets and HA, without the need for extra soluble chemical cues. Simultaneously, the NTs improved the periodontal regeneration result of the ectopically implanted Ti/cell sheets/HA complex, giving rise to functionally aligned collagen fiber bundles. Specifically, much denser collagen fibers, with abundant blood vessels as well as cementum-like tissue on the Ti surface, which well-resembled the structure of natural PDL, were observed in the NT5 and NT10 sample groups. Our study provides the first evidence that the nanotopographical cues obviously influence the functions of PDLSCs and improve the PDLSC sheet based periodontal regeneration size dependently, which provides new insight to the periodontal regeneration. The Ti/cell sheets/HA complex may constitute a good model to predict the effect of biomaterials on periodontal regeneration. PMID:26150714

  20. Influence of nanotopography on periodontal ligament stem cell functions and cell sheet based periodontal regeneration

    PubMed Central

    Gao, Hui; Li, Bei; Zhao, Lingzhou; Jin, Yan

    2015-01-01

    Periodontal regeneration is an important part of regenerative medicine, with great clinical significance; however, the effects of nanotopography on the functions of periodontal ligament (PDL) stem cells (PDLSCs) and on PDLSC sheet based periodontal regeneration have never been explored. Titania nanotubes (NTs) layered on titanium (Ti) provide a good platform to study this. In the current study, the influence of NTs of different tube size on the functions of PDLSCs was observed. Afterward, an ectopic implantation model using a Ti/cell sheets/hydroxyapatite (HA) complex was applied to study the effect of the NTs on cell sheet based periodontal regeneration. The NTs were able to enhance the initial PDLSC adhesion and spread, as well as collagen secretion. With the Ti/cell sheets/HA complex model, it was demonstrated that the PDLSC sheets were capable of regenerating the PDL tissue, when combined with bone marrow mesenchymal stem cell (BMSC) sheets and HA, without the need for extra soluble chemical cues. Simultaneously, the NTs improved the periodontal regeneration result of the ectopically implanted Ti/cell sheets/HA complex, giving rise to functionally aligned collagen fiber bundles. Specifically, much denser collagen fibers, with abundant blood vessels as well as cementum-like tissue on the Ti surface, which well-resembled the structure of natural PDL, were observed in the NT5 and NT10 sample groups. Our study provides the first evidence that the nanotopographical cues obviously influence the functions of PDLSCs and improve the PDLSC sheet based periodontal regeneration size dependently, which provides new insight to the periodontal regeneration. The Ti/cell sheets/HA complex may constitute a good model to predict the effect of biomaterials on periodontal regeneration. PMID:26150714

  1. Platelet gel biotechnology applied to regenerative surgery of intrabony defects in patients with refractory generalized aggressive peridontitis. Case report.

    PubMed

    Mauro, S; Orlando, L; Panzoni, R; Orlando, P F

    2003-01-01

    Platelet gel biotechnology, a method which has all the components of "tissue engineering" techniques, potentiates the already known healing process of guided tissue regeneration procedures (GTR) by multiplying the number of molecules that activate the healing response and by grafting in the host site various cell types, among which stem cells. Here are reported cases of patients affected by refractory generalized aggressive periodontitis treated with the association GTR and platelet gel biotechnology to verify if the contribution of the gel would produce superior results than those obtained by surgery alone which had been previously applied to the same sites with negative results. Three patients in therapy from 4 to 11 years, already subjected to surgery (GTR) and antibiotic therapy, were reoperated with the adjunct of autologous platelet gel. At a distance of 15.2 months (range 11-17 months) the operated sites showed a reduction in probing pocket depth of 3.4 mm (range 2.8-4.8 mm) and a gain in clinical attachment level of 3.1 mm (range 3-3.5 mm). The association of platelet gel biotechnology with GTR in the surgical treatment of intrabony defects of refractory generalized aggressive periodontitis patients seems to produce results similar to those reported for patients with chronic adult periodontitis. The observations at 15.2 months indicate that there is a stability over time of the results in those sites where previous surgical therapy had shown relapse.

  2. Relationship between Acute Phase of Chronic Periodontitis and Meteorological Factors in the Maintenance Phase of Periodontal Treatment: A Pilot Study

    PubMed Central

    Takeuchi, Noriko; Ekuni, Daisuke; Tomofuji, Takaaki; Morita, Manabu

    2015-01-01

    The acute phase of chronic periodontitis may occur even in patients during supportive periodontal therapy. However, the details are not fully understood. Since the natural environment, including meteorology affects human health, we hypothesized that weather conditions may affect occurrence of acute phase of chronic periodontitis. The aim of this study was to investigate the relationship between weather conditions and acute phase of chronic periodontitis in patients under supportive periodontal therapy. Patients who were diagnosed with acute phase of chronic periodontitis under supportive periodontal therapy during 2011–2013 were selected for this study. We performed oral examinations and collected questionnaires and meteorological data. Of 369 patients who experienced acute phase of chronic periodontitis, 153 had acute phase of chronic periodontitis without direct-triggered episodes. When using the autoregressive integrated moving average model of time-series analysis, the independent covariant of maximum hourly range of barometric pressure, maximum hourly range of temperature, and maximum daily wind speed were significantly associated with occurrence of acute phase of chronic periodontitis (p < 0.05), and 3.1% of the variations in these occurrence over the study period were explained by these factors. Meteorological variables may predict occurrence of acute phase of chronic periodontitis. PMID:26251916

  3. Relationship between Acute Phase of Chronic Periodontitis and Meteorological Factors in the Maintenance Phase of Periodontal Treatment: A Pilot Study.

    PubMed

    Takeuchi, Noriko; Ekuni, Daisuke; Tomofuji, Takaaki; Morita, Manabu

    2015-08-01

    The acute phase of chronic periodontitis may occur even in patients during supportive periodontal therapy. However, the details are not fully understood. Since the natural environment, including meteorology affects human health, we hypothesized that weather conditions may affect occurrence of acute phase of chronic periodontitis. The aim of this study was to investigate the relationship between weather conditions and acute phase of chronic periodontitis in patients under supportive periodontal therapy. Patients who were diagnosed with acute phase of chronic periodontitis under supportive periodontal therapy during 2011-2013 were selected for this study. We performed oral examinations and collected questionnaires and meteorological data. Of 369 patients who experienced acute phase of chronic periodontitis, 153 had acute phase of chronic periodontitis without direct-triggered episodes. When using the autoregressive integrated moving average model of time-series analysis, the independent covariant of maximum hourly range of barometric pressure, maximum hourly range of temperature, and maximum daily wind speed were significantly associated with occurrence of acute phase of chronic periodontitis (p < 0.05), and 3.1% of the variations in these occurrence over the study period were explained by these factors. Meteorological variables may predict occurrence of acute phase of chronic periodontitis. PMID:26251916

  4. L-Cysteine and L-AP4 microinjections in the rat caudal ventrolateral medulla decrease arterial blood pressure.

    PubMed

    Takemoto, Yumi

    2014-12-01

    The thiol amino acid L-cysteine increases arterial blood pressure (ABP) when injected into the cerebrospinal fluid space in conscious rats, indicating a pressor response to centrally acting L-cysteine. A prior synaptic membrane binding assay suggests that L-cysteine has a strong affinity for the L-2-amino-4-phosphonobutyric acid (L-AP4) binding site. The central action of L-cysteine may be vial-AP4 sensitive receptors. The present study investigated cardiovascular responses to L-cysteine and L-ap4 microinjected into the autonomic area of the caudal ventrolateral medulla (CVLM) where inhibitory neurons regulate ABP via pre-sympathetic vasomotor neurons. Both the injection of L-cysteine and L-AP4 in the CVLM sites identified with L-glutamate produced the same depressor and bradycardic responses in urethane-anesthetized rats. Neither a prior antagonist microinjection of MK801 for the N-methyl-D-aspartate (NMDA) receptor nor CNQX for the non-NMDA receptor attenuated the responses to L-cysteine, but the combination of the two receptor blocking with an additional prior injection abolished the response. In contrast, either receptor blockade alone abolished the response to L-AP4, indicating distinct mechanisms between responses to L-cysteine and L-AP4 in the CVLM. The results indicate that the CVLM is a central active site for L-cysteine's cardiovascular response. Central L-cysteine's action could be independent of the L-AP4 sensitive receptors. Cardiovascular regulation may involve endogenous L-cysteine in the CVLM. Further multidisciplinary examinations are required to elaborate on L-cysteine's functional roles in the CVLM.

  5. Periodontitis promotes the proliferation and suppresses the differentiation potential of human periodontal ligament stem cells.

    PubMed

    Zheng, Wei; Wang, Shi; Wang, Jianguo; Jin, Fang

    2015-10-01

    The aim of the present study was to investigate the periodontitis-associated changes in the number, proliferation and differentiation potential of human periodontal ligament stem cells (PDLSCs). Cultures of human periodontal ligament cells (PDLCs) were established from healthy donors and donors with periodontitis. The numbers of stem cell were characterized using flow cytometry. PDLSCs were isolated from the PDLCs by immunomagnetic bead selection. Colony‑forming abilities, osteogenic and adipogenic potential, gene expression of cementoblast phenotype, alkaline phosphatase activity and in vivo differentiation capacities were then evaluated. Periodontitis caused an increase in the proliferation of PDLSCs and a decrease in the commitment to the osteoblast lineage. This is reflected by changes in the expression of osteoblast markers. When transplanted into immunocompromised mice, PDLSCs from the healthy donors exhibited the capacity to produce cementum PDL‑like structures, whereas, the inflammatory PDLSCs transplants predominantly formed connective tissues. In conclusion, the data from the present study suggest that periodontitis affects the proliferation and differentiation potential of human PDLSCs in vitro and in vivo.

  6. Endodontic-periodontal microsurgery for combined endodontic-periodontal lesions: An overview.

    PubMed

    Sharma, Ritu; Hegde, Vivek; Siddharth, M; Hegde, Rashmi; Manchanda, Gunsha; Agarwal, Pratul

    2014-11-01

    Endodontic and periodontal microsurgery has surpassed the success rates for traditional endodontic and periodontal surgical procedures. Excellent healing results are being attributed to both the techniques, when employed, for isolated endodontic or periodontal defects. Combined endodontic-periodontal lesions have been referred to as a true challenge, requiring not only endodontic microsurgical management but also concurrent bone grafting and membrane barriers techniques. The prevention of epithelial downgrowth and regeneration of periodontal cementum, fiber, and bone seals the fate of these cases. Achieving primary closure with submergence of grafts has a positive effect on GTR outcome. New techniques of periodontal microsurgery, such as minimally invasive papilla preserving flaps with passive internal mattress suturing, have managed to obtain 90% primary flap closure over grafted sites. Root surface treatment and conditioning has also shown to be beneficial for GTR. Endodontic microsurgery for the combined lesion has not integrated these advances yet. These advances, along with a recently suggested treatment strategy, are ushering in the level next in management of the combined lesions. This article offers an overview of the combined lesion, the disease, its classification, treatment strategy, regenerative tools, microsurgical recommendations, and outcome studies.

  7. Endodontic-periodontal microsurgery for combined endodontic-periodontal lesions: An overview

    PubMed Central

    Sharma, Ritu; Hegde, Vivek; Siddharth, M; Hegde, Rashmi; Manchanda, Gunsha; Agarwal, Pratul

    2014-01-01

    Endodontic and periodontal microsurgery has surpassed the success rates for traditional endodontic and periodontal surgical procedures. Excellent healing results are being attributed to both the techniques, when employed, for isolated endodontic or periodontal defects. Combined endodontic-periodontal lesions have been referred to as a true challenge, requiring not only endodontic microsurgical management but also concurrent bone grafting and membrane barriers techniques. The prevention of epithelial downgrowth and regeneration of periodontal cementum, fiber, and bone seals the fate of these cases. Achieving primary closure with submergence of grafts has a positive effect on GTR outcome. New techniques of periodontal microsurgery, such as minimally invasive papilla preserving flaps with passive internal mattress suturing, have managed to obtain 90% primary flap closure over grafted sites. Root surface treatment and conditioning has also shown to be beneficial for GTR. Endodontic microsurgery for the combined lesion has not integrated these advances yet. These advances, along with a recently suggested treatment strategy, are ushering in the level next in management of the combined lesions. This article offers an overview of the combined lesion, the disease, its classification, treatment strategy, regenerative tools, microsurgical recommendations, and outcome studies. PMID:25506135

  8. Contributions of kinematics and viscoelastic lap deformation on the suface figure during full aperture polishing of fused silica

    SciTech Connect

    Suratwala, T I; Steele, R A; Feit, M D

    2007-10-09

    A typical optical fabrication process involves a series of basic process steps including: (1) shaping, (2) grinding, (3) polishing, and sometimes (4) sub-aperture tool finishing. With significant innovation and development over the years in both the front end (shaping using CNC machines) and the back end (sup-aperture tool polishing), these processes have become much more deterministic. However, the intermediate stages (full aperture grinding/polishing) in the process, which can be very time consuming, still have much reliance on the optician's insight to get to the desired surface figure. Such processes are not presently very deterministic (i.e. require multiple iterations to get desired figure). The ability to deterministically finish an optical surface using a full aperture grinding/polishing will aid optical glass fabricators to achieve desired figure in a more repeatable, less iterative, and more economical manner. Developing a scientific understanding of the material removal rate is a critical step in accomplishing this. In the present study, the surface figure and material removal rate of a fused silica workpiece is measured as a function of polishing time using Ceria based slurry on a polyurethane pad or pitch lap under a variety of kinematic conditions (motion of the workpiece and lap) and loading configurations. The measured results have been applied to expand the Preston model of material removal (utilizing chemical, mechanical and tribological effects). The results show that under uniform loading, the surface figure is dominated by kinematics which can be predicted by calculating the relative velocity (between the workpiece and the lap) with time and position on the workpiece. However, in the case where the kinematics predict a time-averaged removal function over the workpiece that is uniform, we find experimentally that the surface deviates significantly from uniform removal. We show that this non-uniform removal is caused by the non-uniform stress

  9. Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

    SciTech Connect

    Okafor, A. C.; Natarajan, S.

    2007-03-21

    Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

  10. Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

    NASA Astrophysics Data System (ADS)

    Okafor, A. C.; Natarajan, S.

    2007-03-01

    Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

  11. Monitoring of fatigue damage in composite lap-joints using guided waves and FBG sensors

    NASA Astrophysics Data System (ADS)

    Karpenko, Oleksii; Khomenko, Anton; Koricho, Ermias; Haq, Mahmoodul; Udpa, Lalita

    2016-02-01

    Adhesive bonding is being increasingly employed in many applications as it offers possibility of light-weighting and efficient multi-material joining along with reduction in time and cost of manufacturing. However, failure initiation and progression in critical components like joints, specifically in fatigue loading is not well understood, which necessitates reliable NDE and SHM techniques to ensure structural integrity. In this work, concurrent guided wave (GW) and fiber Bragg grating (FBG) sensor measurements were used to monitor fatigue damage in adhesively bonded composite lap-joints. In the present set-up, one FBG sensor was strategically embedded in the adhesive bond-line of a lap-joint, while two other FBGs were bonded on the surface of the adherends. Full spectral responses of FBG sensors were collected and compared at specific intervals of fatigue loading. In parallel, guided waves were actuated and sensed using PZT wafers mounted on the composite adherends. Experimental results demonstrated that time-of-flight (ToF) of the fundamental modes transmitted through the bond-line and spectral response of FBG sensors were sensitive to fatigue loading and damage. Combination of guided wave and FBG measurements provided the desired redundancy and synergy in the data to evaluate the degradation in bond-line properties. Measurements taken in the presence of continuously applied load replicated the in-situ/service conditions. The approach shows promise in understanding the behavior of bonded joints subjected to complex loading.

  12. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives.

    PubMed

    Kozowyk, P R B; Langejans, G H J; Poulis, J A

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives.

  13. Digital signal processing using lapped transforms with variable parameter windows and orthonormal bases

    NASA Astrophysics Data System (ADS)

    Raduenz, Brian D.

    1992-12-01

    A number of new concepts and tools for the analysis of signals using variable overlapped windows and orthonormal bases are developed and evaluated. Windowing, often employed as a spectral estimation technique, can result in irreparable distortions in the transformed signal. By placing conditions on the window and incorporating it into the orthonormal representation, any signal distortion resulting from the transformation can be eliminated or cancelled in reconstruction. This concept is critical to the theory discussed. As part of this evaluation, a tensor product based general N-point fast Fourier transform algorithm was implemented in the DOD standard language, Ada. The most prevalent criticism of Ada is slow execution time. This code is shown to be comparable in execution time performance to the corresponding FORTRAN code. Also, a new paradigm is presented for solving the finite length data problem associated with filter banks and lapped transforms. This result could have significant importance in many Air Force applications, such as processing images in which the objects of interest are near the borders. Additionally, a limited number of experiments were performed with the coding of speech. The results indicate the lapped transform evaluated has potential as a low bit rate speech coder.

  14. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives

    PubMed Central

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives. PMID:26983080

  15. Large-Scale Advanced Prop-Fan (LAP) pitch change actuator and control design report

    NASA Technical Reports Server (NTRS)

    Schwartz, R. A.; Carvalho, P.; Cutler, M. J.

    1986-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel consumption. Studies have shown that the high inherent efficiency previously demonstrated by low speed turboprop propulsion systems may now be extended to today's higher speed aircraft if advanced high-speed propeller blades having thin airfoils and aerodynamic sweep are utilized. Hamilton Standard has designed a 9-foot diameter single-rotation Large-Scale Advanced Prop-Fan (LAP) which will be tested on a static test stand, in a high speed wind tunnel and on a research aircraft. The major objective of this testing is to establish the structural integrity of large-scale Prop-Fans of advanced construction in addition to the evaluation of aerodynamic performance and aeroacoustic design. This report describes the operation, design features and actual hardware of the (LAP) Prop-Fan pitch control system. The pitch control system which controls blade angle and propeller speed consists of two separate assemblies. The first is the control unit which provides the hydraulic supply, speed governing and feather function for the system. The second unit is the hydro-mechanical pitch change actuator which directly changes blade angle (pitch) as scheduled by the control.

  16. Using LAPS/STMAS as a real time surface analysis tool

    NASA Astrophysics Data System (ADS)

    Moré, Jordi; Farguell, Àngel; Altava, Vicent

    2016-04-01

    A data assimilation system based on the LAPS/STMAS software is tested for a full year (2012) to provide hourly surface analyses at high resolution (3 km) in a complex terrain area centered over Catalonia. In particular, surface observations of more than 150 automatic weather stations (AWS) of the Meteorological Service of Catalonia (SMC) are combined with the operational outputs of WRF-ARW model at 3 km available at SMC. The hourly analyses obtained are verified against independent observations in order to evaluate the system as a real time tool in a small meteorological office. Additionally, an special study is carried out focusing on temperature at 2 m by means of introducing some code modifications in the LAPS/STMAS software. These tests are compared together with a simple multiregression technique exclusively based on observational data (AWS). The comparison shows that the best results are obtained for STMAS when introducing an error weight that depends on the station topography representativeness, instead of just considering a common instrumental error for all the stations. Nevertheless, the multiregression technique still provides more accurate results on temperature and reveals that additional work has to be done in order to improve the system.

  17. Friction Stir Lap Welding of Magnesium Alloy to Steel: A Preliminary Investigation

    SciTech Connect

    Jana, Saumyadeep; Hovanski, Yuri; Grant, Glenn J.

    2010-12-01

    An initial study was made to evaluate the feasibility of joining Magnesium alloy AZ31 sheet to galvanized steel sheet in lap configuration using friction stir welding (FSW). Two different automotive sheet steels were used for comparative evaluation of the dissimilar joining potential; a 0.8mm thick, electro galvanized (EG) mild steel, and a 1.5mm thick hot dipped galvanized (HDG) high-strength, low-alloy steel (HSLA). These steels were joined to 2.33mm thick AZ31B magnesium sheet. A single FSW tool design was used for both dissimilar welds, and process parameters were kept the same. Average peak load for the AZ31-1.5 mm steel weld joint in lap shear mode was found to be 6.3 ± 1.0 kN. For the AZ31-0.8 mm steel weld, joint strength was 5.1 ± 1.5 kN. Microstructural investigation indicates melting of the Zn coating at the interface and subsequent alloying with the Mg sheet resulting in formation of solidified Zn-Mg alloy layer at AZ31/steel interface.

  18. Microstructure and Properties of Lap Joint Between Aluminum Alloy and Galvanized Steel by CMT

    NASA Astrophysics Data System (ADS)

    Niu, Song; Chen, Su; Dong, Honggang; Zhao, Dongsheng; Zhang, Xiaosheng; Guo, Xin; Wang, Guoqiang

    2016-05-01

    Lap joining of 1-mm-thick Novelist AC 170 PX aluminum alloy to 1.2-mm-thick ST06 Z galvanized steel sheets for automotive applications was conducted by cold metal transfer advanced welding process with ER4043 and ER4047 filler wires. Under the optimized welding parameters with ER4043 filler wire, the tensile shear strength of joint was 189 MPa, reaching 89% of the aluminum alloy base metal. Microstructure and elemental distribution were characterized by optical metalloscope and electron probe microanalysis. The lap joints with ER4043 filler wire had smaller wetting angle and longer bonded line length with better wettability than with ER4047 filler wire during welding with same parameters. The needle-like Al-Fe-Si intermetallic compounds (IMCs) were spalled into the weld and brought negative effect to the tensile strength of joints. With increasing welding current, the needle-like IMCs grew longer and spread further into the weld, which would deteriorate the tensile shear strength.

  19. (40)Ar/(39)Ar Age of Hornblende-Bearing R Chondrite LAP 04840

    NASA Technical Reports Server (NTRS)

    Righter, K.; Cosca, M.

    2015-01-01

    Chondrites have a complex chronology due to several variables affecting and operating on chondritic parent bodies such as radiogenic heating, pressure and temperature variation with depth, aqueous alteration, and shock or impact heating. Unbrecciated chondrites can record ages from 4.56 to 4.4 Ga that represent cooling in small parent bodies. Some brecciated chondrites exhibit younger ages (much less than 4 to 4.4 Ga) that may reflect the age of brecciation, disturbance, or shock and impact events (much less than 4 Ga). A unique R chondrite was recently found in the LaPaz Icefield of Antarctica - LAP 04840. This chondrite contains approximately 15% hornblende and trace amounts of biotite, making it the first of its kind. Studies have revealed an equigranular texture, mineral equilibria yielding equilibration near 650-700 C and 250-500 bars, hornblende that is dominantly OH-bearing (very little Cl or F), and high D/H ratios. To help gain a better understanding of the origin of this unique sample, we have measured the (40)Ar/(39)Ar age (LAP 04840 split 39).

  20. Joining aluminum to titanium alloy by friction stir lap welding with cutting pin

    SciTech Connect

    Wei, Yanni; Li, Jinglong; Xiong, Jiangtao; Huang, Fu; Zhang, Fusheng; Raza, Syed Hamid

    2012-09-15

    Aluminum 1060 and titanium alloy Ti-6Al-4V plates were lap joined by friction stir welding. A cutting pin of rotary burr made of tungsten carbide was employed. The microstructures of the joining interface were observed by scanning electron microscopy. Joint strength was evaluated by a tensile shear test. During the welding process, the surface layer of the titanium plate was cut off by the pin, and intensively mixed with aluminum situated on the titanium plate. The microstructures analysis showed that a visible swirl-like mixed region existed at the interface. In this region, the Al metal, Ti metal and the mixed layer of them were all presented. The ultimate tensile shear strength of joint reached 100% of 1060Al that underwent thermal cycle provided by the shoulder. - Highlights: Black-Right-Pointing-Pointer FSW with cutting pin was successfully employed to form Al/Ti lap joint. Black-Right-Pointing-Pointer Swirl-like structures formed due to mechanical mixing were found at the interface. Black-Right-Pointing-Pointer High-strength joints fractured at Al suffered thermal cycle were produced.

  1. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    NASA Astrophysics Data System (ADS)

    Ghazali, Habibah; Ye, Lin; Zhang, Ming-Qiu

    2016-03-01

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.

  2. High Voltage Breakdown, Partial Discharge and Aging in Lapped Tape Insulated Cold Dielectric Model Cables

    NASA Astrophysics Data System (ADS)

    Sauers, I.; James, D. R.; Pace, M. O.; Ellis, A. R.; Muller, A. C.

    2004-06-01

    High temperature superconducting (HTS) power cables generally follow either of two generic designs, cold dielectric and warm dielectric. In the cold dielectric design, lapped tape insulation and liquid nitrogen are used in combination to provide the electrical insulation between the conductor and the ground shield of an HTS cable. Lapped tape insulated model cables have been tested at high voltage, including AC breakdown, negative impulse breakdown, partial discharge, and long term aging under AC stress. Tapes tested include Cryoflex™ (a proprietary tape developed by Southwire) and PPLP® (a commercial semi synthetic tape). Two high voltage cryostats have been built for short and long term aging studies that permit testing of model cables under the combined conditions of high electric stress, cryogenic temperature and elevated pressures up to 15 bar. For the aging studies, a log-log plot of electric stress versus time-to-breakdown has yielded an estimate of cable lifetime. Since aging at cryogenic temperatures is not expected to have a thermal cause, dielectric wear in HTS cables reduces to partial discharge as the primary aging mechanism. Phase and amplitude resolved partial discharge data of model cables in liquid nitrogen will be presented.

  3. A fracture mechanics analysis of adhesive failure in a single lap shear joint.

    NASA Technical Reports Server (NTRS)

    Devries, K. L.; Williams, M. L.; Chang, M. D.

    1972-01-01

    Discussion of adhesive fracture of single lap shear joints in terms of a maximum stress criterion and an energy balance. The Goland and Reissner (1944) analysis is used to determine the stress distribution in the adhesive assembly, and the results obtained are introduced into an energy balance to determine the initiation of adhesive fracture. In the stress analysis the loads at the edges of the joint are first determined. This is a problem in which the deformation of the joint sheets must be taken into account and is solved by using the finite-deflection theory of cylindrically bent plates. Then the stress in the joint due to applied loads is determined. This problem is formulated as one in plane strain consisting of two rectangular sheets of equal thickness and unit width. With the aid of this stress analysis and the stresses obtained from the conditions of equilibrium the contributions to the energy change with crack length are calculated. The analysis performed is then compared with a maximum stress criterion for a lap joint.

  4. Design for size and weight reduction of lap-winding type three-phase variable inductor

    NASA Astrophysics Data System (ADS)

    Nakamura, Kenji; Honma, Koya; Ohinata, Takashi; Arimatsu, Kenji; Ichinokura, Osamu

    2015-05-01

    Variable inductors have a simple structure that consists of only magnetic core and primary dc and secondary ac windings, but can control effective inductance of the secondary ac winding by the primary dc current due to magnetic saturation effect. Hence, the variable inductors can be applied as a var compensator in electric power systems. In a previous paper, a lap-winding type three-phase variable inductor, which has the primary dc and secondary ac windings concentrically arranged on the same leg, was presented. It has a good controllability and low distortion current. This paper describes size and weight reduction of the lap-winding type three-phase variable inductor by focusing on the leg width. First, an initial design method of the leg width considering the influence of the dc-biased magnetization is presented. Next, a detailed design of the leg width for the size and weight reduction of the proposed variable inductor is described. Finally, characteristics of the size- and weight-reduced variable inductor were compared to those of the previous variable inductor. It is demonstrated that the core diameter is reduced by about 6% and the weight is decreased by about 50% in comparison with the previous variable inductor.

  5. The development of laser-plasma interaction program LAP3D on thousands of processors

    SciTech Connect

    Hu, Xiaoyan Hao, Liang; Liu, Zhanjun; Zheng, Chunyang; Li, Bin Guo, Hong

    2015-08-15

    Modeling laser-plasma interaction (LPI) processes in real-size experiments scale is recognized as a challenging task. For explorering the influence of various instabilities in LPI processes, a three-dimensional laser and plasma code (LAP3D) has been developed, which includes filamentation, stimulated Brillouin backscattering (SBS), stimulated Raman backscattering (SRS), non-local heat transport and plasmas flow computation modules. In this program, a second-order upwind scheme is applied to solve the plasma equations which are represented by an Euler fluid model. Operator splitting method is used for solving the equations of the light wave propagation, where the Fast Fourier translation (FFT) is applied to compute the diffraction operator and the coordinate translations is used to solve the acoustic wave equation. The coupled terms of the different physics processes are computed by the second-order interpolations algorithm. In order to simulate the LPI processes in massively parallel computers well, several parallel techniques are used, such as the coupled parallel algorithm of FFT and fluid numerical computation, the load balance algorithm, and the data transfer algorithm. Now the phenomena of filamentation, SBS and SRS have been studied in low-density plasma successfully with LAP3D. Scalability of the program is demonstrated with a parallel efficiency above 50% on about ten thousand of processors.

  6. Multitechnique monitoring of fatigue damage in adhesively bonded composite lap-joints

    NASA Astrophysics Data System (ADS)

    Karpenko, Oleksii; Koricho, Ermias; Khomenko, Anton; Dib, Gerges; Haq, Mahmoodul; Udpa, Lalita

    2015-03-01

    The requirement for reduced structural weight has driven the development of adhesively bonded joints. However, a major issue preventing their full acceptance is the initiation of premature failure in the form of a disbond between adherends, mainly due to fatigue, manufacturing flaws or impact damage. This work presents the integrated approach for in-situ monitoring of degradation of the adhesive bond in the GFRP composite lap-joint using ultrasonic guided waves and dynamic measurements from strategically embedded FBG sensors. Guided waves are actuated with surface mounted piezoelectric elements and mode tuning is used to provide high sensitivity to the degradation of the adhesive layer parameters. Composite lap-joints are subjected to fatigue loading, and data from piezoceramic transducers are collected at regular intervals to evaluate the progression of damage. Results demonstrate that quasi-static loading affects guided wave measurements considerably, but FBG sensors can be used to monitor the applied load levels and residual strains in the adhesive bond. The proposed technique shows promise for determining the post-damage stiffness of adhesively bonded joints.

  7. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives.

    PubMed

    Kozowyk, P R B; Langejans, G H J; Poulis, J A

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives. PMID:26983080

  8. Recurrent idiopathic gingival fibromatosis with generalized aggressive periodontitis: A rare case report

    PubMed Central

    Jadhav, Ashwini Sudhakar; Marathe, Swati Pramodan

    2015-01-01

    Gingival fibromatosis is an enlargement of the gingival tissue, which may be localized or generalized, characterized by hypertrophy and proliferation of the connective tissue, predominantly Type I collagen, with occasional presence of an increased number of cells, supposedly fibroblasts. Gingival fibromatosis occurs more commonly as a side- effect of systemic drugs, such as phenytoin, cyclosporine, nifedipine, or due to hereditary factors. However, in some cases, it is idiopathic. We report one such case in 30 -year- old - female who presented with a complaint of swelling of gums since 2 months. This case appears to be of special interest because of the recurrent nature of gingival enlargement along with excessive osseous destruction. PMID:25810601

  9. Effectiveness of ozone against periodontal pathogenic microorganisms.

    PubMed

    Huth, Karin C; Quirling, Martina; Lenzke, Stefanie; Paschos, Ekaterini; Kamereck, Klaus; Brand, Korbinian; Hickel, Reinhard; Ilie, Nicoleta

    2011-06-01

    Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

  10. Pathogenesis of Apical Periodontitis: a Literature Review

    PubMed Central

    Lodiene, Greta; Maciulskiene, Vita

    2011-01-01

    ABSTRACT Objectives This review article discusses the host response in apical periodontitis with the main focus on cytokines, produced under this pathological condition and contributing to the degradation of periradicular tissues. The pace of research in this field has greatly accelerated in the last decade. Here we provide an analysis of studies published in this area during this period. Material and methods Literature was selected through a search of PubMed electronic database. The keywords used for search were pathogenesis of apical periodontitis cytokines, periapical granuloma cytokines, inflammatory infiltrate apical periodontitis. The search was restricted to English language articles, published from 1999 to December 2010. Additionally, a manual search in the cytokine production, cytokine functions and periapical tissue destruction in the journals and books was performed. Results In total, 97 literature sources were obtained and reviewed. The topics covered in this article include cellular composition of an inflammatory infiltrate in the periapical lesions, mechanisms of the formation of the innate and specific immune response. Studies which investigated cytokine secretion and functions were identified and cellular and molecular interactions in the course of apical periodontitis described. Conclusions The abundance and interactions of various inflammatory and anti-inflammatory molecules can influence and alter the state and progression of the disease. Therefore, periapical inflammatory response offers a model, suited for the study of many facets of pathogenesis, biocompatibility of different materials to periapical tissues and development of novel treatment methods, based on the regulation of cytokines expression PMID:24421998

  11. Intentional replantation for periodontally involved hopeless teeth.

    PubMed

    Demiralp, Burak; Nohutçu, Rahime Meral; Tepe, Durul Işik; Eratalay, Kenan

    2003-02-01

    The aim of this study was to evaluate the clinical and radiographic results of intentional replantation of periodontally involved teeth after conditioning of root surfaces with tetracycline-HCl. Thirteen patients (seven female, six male; age range: 35-52 years) with 15 periodontally involved hopeless teeth were included in this study. During the replantation procedure, the affected teeth were gently extracted, then the granulation tissues, calculus, remaining periodontal ligament and necrotic cementum on the root surfaces were removed. Tetracycline-HCl, at a concentration of 100 mg ml(-1), was applied for 5 min to the root surfaces. The teeth were then replaced into the socket and splinted. Patients were clinically and radiographically evaluated at baseline (time of surgery) and 6 months after the surgery. The following measurements were recorded: probing depth (PD), gingival recession (R), the amount of bone loss (BL) and bone gain (BG). Results indicated a reduction in PD and in the amount of bone loss and healthy gingiva. Mean PD was decreased from 5.25 to 2.36 mm, gingival recession was increased from 3.73 to 4.0 mm, and BL was reduced from 73.20 to 56.86%. At the end of 6 months, no root resorption or ankylosis was observed radiographically. Even during the short period of evaluation, it may be suggested that intentional replantation can be an alternative approach to extraction in cases where advanced periodontal destruction is present and no other treatments could be considered.

  12. Assessing risk factors for periodontitis using regression

    NASA Astrophysics Data System (ADS)

    Lobo Pereira, J. A.; Ferreira, Maria Cristina; Oliveira, Teresa

    2013-10-01

    Multivariate statistical analysis is indispensable to assess the associations and interactions between different factors and the risk of periodontitis. Among others, regression analysis is a statistical technique widely used in healthcare to investigate and model the relationship between variables. In our work we study the impact of socio-demographic, medical and behavioral factors on periodontal health. Using regression, linear and logistic models, we can assess the relevance, as risk factors for periodontitis disease, of the following independent variables (IVs): Age, Gender, Diabetic Status, Education, Smoking status and Plaque Index. The multiple linear regression analysis model was built to evaluate the influence of IVs on mean Attachment Loss (AL). Thus, the regression coefficients along with respective p-values will be obtained as well as the respective p-values from the significance tests. The classification of a case (individual) adopted in the logistic model was the extent of the destruction of periodontal tissues defined by an Attachment Loss greater than or equal to 4 mm in 25% (AL≥4mm/≥25%) of sites surveyed. The association measures include the Odds Ratios together with the correspondent 95% confidence intervals.

  13. Crevicular Fluid Biomarkers and Periodontal Disease Progression

    PubMed Central

    Oh, Min; Braun, Thomas M.; Ramseier, Christoph A.; Sugai, Jim V.; Giannobile, William V.

    2014-01-01

    Aim Assess the ability of a panel of gingival crevicular fluid (GCF) biomarkers as predictors of periodontal disease progression (PDP). Materials and Methods 100 individuals participated in a 12-month longitudinal investigation and categorized into 4 groups according to their periodontal status. GCF, clinical parameters, and saliva were collected bi-monthly. Sub-gingival plaque and serum were collected bi-annually. For 6 months, no periodontal treatment was provided. At 6-months, patients received periodontal therapy and continued participation from 6-12 months. GCF samples were analyzed by ELISA for MMP-8, MMP-9, OPG, CRP and IL-1β. Differences in median levels of GCF biomarkers were compared between stable and progressing participants using Wilcoxon Rank Sum test (p=0.05). Clustering algorithm was used to evaluate the ability of oral biomarkers to classify patients as either stable or progressing. Results Eighty-three individuals completed the 6-month monitoring phase. With the exception of GCF C-reactive protein, all biomarkers were significantly higher in the PDP group compared to stable patients. Clustering analysis showed highest sensitivity levels when biofilm pathogens and GCF biomarkers were combined with clinical measures, 74% (95% CI = 61,86). Conclusions Signature of GCF fluid-derived biomarkers combined with pathogens and clinical measures provides a sensitive measure for discrimination of PDP (ClinicalTrials.gov NCT00277745). PMID:24303954

  14. Surgical Procedures in Predoctoral Periodontics Programs.

    ERIC Educational Resources Information Center

    Radentz, William H.; Caffesse, Raul G.

    1991-01-01

    A survey of 58 dental school periodontics departments revealed the frequency of predoctoral dental students performing surgery, the frequency of specific procedures, the degree of participation or performance of students, incidence of preclinical surgical laboratories in the curricula, and materials and anesthesia used. A wide range in…

  15. Underestimation of periodontitis in NHANES surveys.

    PubMed

    Albandar, Jasim M

    2011-03-01

    The study design of national surveys of periodontal disease often uses partial-mouth examination protocols to rationalize the need for resources so that the collection of data from a large number of subjects can be achieved within the available means without significantly sacrificing precision and validity. Studies show that surveys that use partial examination protocols underestimate the prevalence of periodontitis, and the amount of underestimation varies depending on the number and type of sites examined, the case-definition of periodontal disease, tooth loss, and prevalence and severity of the disease. If a survey uses a partial-mouth examination it is recommended that the amount of underestimation be assessed in the same sample. This could be achieved by performing a full-mouth examination on a randomly selected subsample. Inflation factors should be calculated and used to adjust for the underestimation in disease prevalence because of the use of partial examination. Based on the NHANES III (1988 to 1994) data and adjusting for the bias caused by the examination protocol, it is estimated that approximately half of the United States population aged ≥30 years has periodontitis. PMID:21214340

  16. Periodontitis and rheumatoid arthritis: a review.

    PubMed

    Bartold, P M; Marshall, R I; Haynes, D R

    2005-11-01

    Periodontitis and rheumatoid arthritis (RA) appear to share many pathologic features. In this review, the common pathologic mechanisms of these two common chronic conditions are explored. Emerging evidence now suggests a strong relationship between the extent and severity of periodontal disease and RA. While this relationship is unlikely to be causal, it is clear that individuals with advanced RA are more likely to experience more significant periodontal problems compared to their non-RA counterparts, and vice versa. A case is made that these two diseases could be very closely related through common underlying dysfunction of fundamental inflammatory mechanisms. The nature of such dysfunction is still unknown. Nonetheless, there is accruing evidence to support the notion that both conditions manifest as a result of an imbalance between proinflammatory and anti-inflammatory cytokines. As a result, new treatment strategies are expected to emerge for both diseases that may target the inhibition of proinflammatory cytokines and destructive proteases. The clinical implications of the current data dictate that patients with RA should be carefully screened for their periodontal status. PMID:16277578

  17. Mechanisms of Bone Resorption in Periodontitis

    PubMed Central

    Hienz, Stefan A.; Paliwal, Sweta

    2015-01-01

    Alveolar bone loss is a hallmark of periodontitis progression and its prevention is a key clinical challenge in periodontal disease treatment. Bone destruction is mediated by the host immune and inflammatory response to the microbial challenge. However, the mechanisms by which the local immune response against periodontopathic bacteria disturbs the homeostatic balance of bone formation and resorption in favour of bone loss remain to be established. The osteoclast, the principal bone resorptive cell, differentiates from monocyte/macrophage precursors under the regulation of the critical cytokines macrophage colony-stimulating factor, RANK ligand, and osteoprotegerin. TNF-α, IL-1, and PGE2 also promote osteoclast activity, particularly in states of inflammatory osteolysis such as those found in periodontitis. The pathogenic processes of destructive inflammatory periodontal diseases are instigated by subgingival plaque microflora and factors such as lipopolysaccharides derived from specific pathogens. These are propagated by host inflammatory and immune cell influences, and the activation of T and B cells initiates the adaptive immune response via regulation of the Th1-Th2-Th17 regulatory axis. In summary, Th1-type T lymphocytes, B cell macrophages, and neutrophils promote bone loss through upregulated production of proinflammatory mediators and activation of the RANK-L expression pathways. PMID:26065002

  18. Endo-periodontal lesion--endodontic approach.

    PubMed

    Jivoinovici, R; Suciu, I; Dimitriu, B; Perlea, P; Bartok, R; Malita, M; Ionescu, C

    2014-01-01

    Endo-perio lesions might be interdependent because of the vascular and anatomic connections between the pulp and the periodontium. The aim of this study is to emphasise that primary endodontic lesion heals after a proper instrumentation, disinfection and sealing of the endodontic space. The primary endodontic lesion with a secondary periodontal involvement first requires an endodontic therapy and, in the second stage, a periodontal therapy. The prognosis is good, with an adequate root canal treatment; it depends on the severity of the periodontal disease, appropriate healing time and the response to the treatment. A correct diagnosis is sometimes difficult; an accurate identification of the etiologic factors is important for an adequate treatment. Primary perio-endo lesion may heal after a proper disinfection and sealing of the endodontic system, the one-year follow-up radiograph showing bonny repair. Invasive periodontal procedures should be avoided at that moment. The microorganisms and by-products from the infected root canal may cross accessory and furcal canals and determine sinus tract and loss of attachment. In both clinical cases presented in this article, successful healing was obtained after a proper disinfection and sealing of the endodontic system.

  19. Links between atherosclerotic and periodontal disease.

    PubMed

    Chistiakov, Dimitry A; Orekhov, Alexander N; Bobryshev, Yuri V

    2016-02-01

    Periodontal disease (PD) and cardiovascular disease (CVD) are highly prevalent in the modern community. Both pathologies are chronic inflammatory disorders, which are influenced by multiple risk factors. In part, these factors such as age, smoking, and diabetes overlap between PD and CVD. Epidemiological studies suggest that PD is strongly associated with increased CVD risk. Biochemical and physiological analyses involving in vitro experiments, animal models, and clinical studies provided evidence for the substantial impact of periodontal pathogens, their virulence factors, and bacterial endotoxins on all general pathogenic CVD mechanisms such as endothelial dysfunction, systemic inflammation, oxidative stress, foam cell formation, lipid accumulation, vascular remodeling, and atherothrombosis. Interventional studies showed moderate beneficial effects of PD treatment on reducing systemic inflammation and endothelial dysfunction. However, no interventional studies were performed to assess whether periodontal therapy can primarily prevent CVD. In summary, current data suggest for a strong contributory role of periodontal infection to CVD but cannot provide sufficient evidence for a role of PD as a cause for cardiovascular pathology. PMID:26777261

  20. A Study on the Relationship between Reflux Esophagitis and Periodontitis.

    PubMed

    Adachi, Kyoichi; Mishiro, Tomoko; Tanaka, Shino; Yoshikawa, Hiroo; Kinoshita, Yoshikazu

    2016-01-01

    Objective Metabolic syndrome and dental erosion have been demonstrated to correlate with gastroesophageal acid reflux disease (GERD), while periodontitis has been reported to have a positive relationship with metabolic syndrome. However, no correlation between periodontitis and GERD has yet been reported. We therefore investigated the relationship between periodontitis and GERD. Methods The subjects consisted of 280 individuals who visited the Health Center for a detailed medical checkup examination. Each underwent upper endoscopy and periodontitis examinations, with the latter performed by measuring the concentrations of lactate dehydrogenase and hemoglobin in saliva. The subjects were divided into those with positive and negative periodontitis findings, and the prevalence rates of endoscopically proven reflux esophagitis, dyslipidemia, hypertension, and hyperglycemia were compared. Results The number of subjects positive for periodontitis was 93, while 187 had negative findings. The prevalence of reflux esophagitis was not different between the positive and negative groups (8.6% vs. 8.0%). In addition, a multiple logistic regression analysis did not identify a positive relationship between the presence of periodontitis and reflux esophagitis. On the other hand, dyslipidemia and hypertension were more frequently observed in the subjects that were positive for periodontitis. Conclusion We did not find an association between periodontitis and reflux esophagitis in the present study. On the other hand, the presence of periodontitis was found to correlate with hypertension and dyslipidemia. PMID:27629943