bluuebunny/crossref_metadata_2025 huggingface dataset:
Static‐volumetric display using rotational‐slicing approach for rendering 3‐D images
Authors: Refai Hakki H.
Published: October 2010

Abstract— This work is related to static volumetric crystals which scintillate light when two laser beams are intersected within the crystal. The geometry in this crystal is optimized for linear slices. Most volumetric displays are based on rotational surfaces, which generate the images, while the projected images are sliced in a rotational sweep mode. To date, the majority of 3‐D graphic engines based on static‐volume displays have not been fully developed. To use an advanced 3‐D graphic engine designed for a swept‐volume display (SVD) with a static‐volume display, the display must emulate the operation of a SVD based on a rotational‐slicing approach. The CSpace® 3‐D display has the capability to render 3‐D images using the rotational‐slicing approach. This paper presents the development of a rotational‐slicing approach designed to emulate the operation of a SVD within the image volume of a static‐volume display. The display software has been modified to divide the 3‐D image into 46 slices, each passing through the image center and rotated at a fixed angle from the previous slice. Reconstructed 3‐D images were demonstrated using a rotational‐slicing approach. Suggestions are provided for future implementations that could aid in the elimination of elongations and distortions, which occur within specified slices.
Characteristics of surface‐conduction electron emitters made by ion‐exchange technology
Authors: Zhang Xiuling , Wang Wenjiang , Zhang Jintao , Wu Shengli
Published: October 2010

Abstract— The principle and preparation method of the ion‐exchange technology used in surface‐conduction electron emitters is introduced in this paper. Surface‐conduction electron emitters through the use of ion‐exchange technology were developed. The relationships between device current and emission current on device voltage has been determined. The electronic emission characteristic of surface‐conduction electron emitters were also determined. The results indicate that the relationship between emission current and device voltage is non‐linear. A device‐voltage range between 20 and 27 V results in the best emission efficiency.
Evaluation method of electro‐optical transfer function for display devices
Authors: Lee DonGyou , Hong HyungKi , Lim Moojong , Shin Hyunho
Published: October 2010

Abstract— Various gamma‐evaluation methods are investigated and newly suggested in order to establish a standard gamma metrology. First, test patterns are suggested and compared for display technologies that dynamically adjust gray levels such as global‐dimming LCDs and PDPs. Second, two gamma‐determination methods are compared and their accuracy determination methods are suggested. Third, two new models for gamma‐distortion phenomena are suggested. Finally, the monotonic characteristics of EOTF are investigated. For the most part of this study, a new international standard named ICDM‐DMS is suggested.
Measuring visual fatigue and visual discomfort associated with 3‐D displays
Authors: Lambooij Marc , Fortuin Marten , Ijsselsteijn Wijnand , Evans Bruce , Heynderickx Ingrid
Published: October 2010

Abstract— This research identifies methods for signs of visual complaints associated with stereoscopic displays. Two potential causes for contradictory results concerning these signs in previous research are hypothesized: (1) not all clinical tests are equally appropriate and (2) there is a natural variation in susceptibility amongst people with normal vision. An optometric screening differentiated participants with moderate binocular status (MBS) from those with good binocular status (GBS). In a 2 × 2 within‐subjects design (2‐D vs. 3‐D and MBS vs. GBS), a questionnaire and eight optometric tests (i.e., binocular acuity, aligning prism, fixation disparity, heterophoria, convergent and divergent fusional reserves, vergence facility, and accommodation response) were each administered before and immediately after a reading task. Results revealed that only participants with MBS in 3‐D conditions showed clinically meaningful changes in fusion range, experienced more visual discomfort, and performed worse on the reading task. Acombination of fusion range measurements and self‐report is appropriate for evaluating visual complaints of stereoscopic stills, and people with a MBS are more susceptible to visual complaints associated with stereoscopic displays. A simple measurement tool, i.e., the ratio of reading performance between 2‐D and 3‐D, to categorize people based on their binocular status is proposed.
Eye‐safety analysis of current laser‐based scanned‐beam projection systems
Authors: Buckley Edward
Published: October 2010

Abstract— Scanned‐beam projection systems have attracted much interest recently, with claimed advantages including power efficiency and potential miniaturization consistent with embedding in mobile devices. However, the laser‐safety classification and concomitant performance implications, which are arguably the most important issues pertaining to this technology, remain widely misunderstood. In this paper, Class 1 and 2 laser‐safety radiometric image power limits for scanned‐beam systems are derived with reference to the IEC 60825‐1 standard. By calculating the equivalent photometric measure of luminous flux, it is possible to show that the brightness limits for scanned‐beam projection systems using current technology are approximately 1 and 1 7 lm for Class 1 and 2 safety classifications, respectively.
A fast‐switching OCB‐mode LCD for high‐quality display applications
Authors: Ishinabe Takahiro , Wako Kazuhiro , Uchida Tatsuo
Published: October 2010

Abstract— Optically compensated bend (OCB) mode is a promising technology, due to its wide range of viewing angles without gray‐scale inversion or color shift, fast response, high contrast ratio, and wide temperature range. This paper summarizes the fundamental characteristics of OCB mode and discusses the development of field‐sequential‐color displays and 3‐D displays for future high‐quality display applications.
Spectroscopic analysis of the non‐circular external electrode fluorescent lamp for large‐sized LCD backlight applications
Authors: Ko Jae‐Hyeon
Published: October 2010

Abstract— The spectroscopic analysis of the external electrode fluorescent lamp (EEFL) having non‐circular cross sections was carried out in order to obtain insight into the discharge condition confined in this unusual discharge space. The emitting spectra of EEFLs with and without phosphor layers were investigated as a function of the measurement position and/or time. It was found that the argon (Ar) emission was intense when the lamp was turned on and decreased rapidly as the Hg emission lines got stronger. The intensities of visible lines from mercury atoms were measured as a function of position along the direction perpendicular to the channel axis. It was found that the positive column does not spread in the entire discharge space but was contracted at the center of the channel. This result was discussed in relation to the ionization process occurring in the low‐pressure discharge lamps. In addition, the correlation between the cross‐sectional shape and the backlight efficiency was investigated, from which optimized shape parameters could be derived.
Synthesis and characterization of novel blue azo‐dye derivatives containing acrylate group for dye‐based color filters
Authors: Kim Song Hak , Jang Chun Keun , Jeong Sung Hoon , Jaung Jae Yun
Published: October 2010

Abstract—Even though dyes have a fine resolution and good chromaticities, they are not widely used as coloring materials for color filters (CFs) due to their low thermal stability and chemical resistance. A series of azo‐dye derivatives, which consist of two cross‐linkable acrylate or methacrylate groups to improve thermal and chemical properties, have been synthesized and used to fabricate color filters. The spectral properties and chemical/thermal stabilities of the fabricated CFs were investigated by comparing dye‐based CFs, without a complicated dispersion process, but with pigment‐based CFs using dispersed pigment. Also, more properties including the development test and surface morphologies lithographic properties were studied. The synthesized azo dyes were characterized by elemental analysis, UV‐visible spectra, IR, mass, and1H‐NMR spectra.
Improved Clinical Decision Making Using the Evidence‐Based Approach
Authors: Newman Michael G.
Published: October 2010

Clinical experience, technical ability, and intuition are indispensable but no longer sufficient as the sole skills necessary to provide the best outcomes from periodontal and implant treatment. This article describes the evidence‐based approach, a comprehensive and rigorous literature evaluation process applied by scientists and clinicians. The methodology was used by the participants in The American Academy of Periodontology World Workshop to assess the evidentiary status of periodontal and implant treatment. The major goal of using the evidence‐based approach was to improve treatment decisions by increasing the strength of the inference that practitioners can derive from the base of knowledge contained within the literature.
Regulatory Issues Unique to Clinical Trials on Periodontal Diagnostic Methods and Devices
Authors: Gutman Steven I. , Tylenda Carolyn A.
Published: October 2010

A wide variety of in vitro diagnostic products have been proposed for use in patients with periodontal disease. The Food and Drug Administration (FDA) review focuses on three important issues. First, the product must exhibit acceptable analytical performance (accuracy, precision, analytical sensitivity, and analytical specificity). Second, the effectiveness of the device must be clearly defined. The studies required to establish this will depend largely on the proposed intended use of the product. At a minimum, clinical or diagnostic sensitivity and specificity should be established. Finally, the product must meet the labeling requirements for in vitro devices. These requirements outlined in CFR 809.10(b) are comprehensive and cover 15 key elements including information about the principles of the analytical method; handling of instruments, reagents, and patient samples; test limitations; and test performance. Applicants developing products for any in vitro diagnostic device are encouraged to review the labeling regulations along with other divisional and office guidance material to help in defining the submission requirements. The FDA is willing to meet and work with companies prior to and during preclinical and clinical trials to assist in the development of appropriate study protocols. Ann Periodontol 1997;2:108‐112.
An Overview of Food and Drug Administration Regulation of Drugs, Biologies, and Devices to Be Used for Management of Periodontal Diseases
Authors: Tylenda Carolyn A. , Weintraub Michael
Published: October 2010

The Food and Drug Administration (FDA) has been actively involved in assuring the safety and effectiveness of medical products since 1906. The FDA was granted increased authority to regulate drugs in 1938 and devices in 1976. The regulatory requirements for marketing in the United States vary according to the type of product and the degree of risk associated with it. One route to the market is through the premarket notification [510(k)] process in which devices are evaluated according to their substantial equivalence to devices marketed prior to May 28, 1976. Many devices specifically intended to treat periodontal conditions have progressed through the 510(k) process based on their substantial equivalence to predicate devices. In some cases manufacturers have needed to provide clinical data in the form of Investigational Device Exemptions (IDE) to support an equivalence determination. Certain devices with indications for use in periodontal evaluation or therapy, specifically, those determined by FDA to be not substantially equivalent to legally marketed devices, require Premarket Approval Applications (PMA). For new drug products, clinical trials are carried out under an approved Investigational New Drug Application (IND). Application for approval for marketing is requested through a New Drug Application. Data from clinical trials conducted outside the United States may be considered by the FDA in support of the safety and effectiveness of the product. The FDA is continually developing and updating guidance documents and guidelines to assist manufacturers in gaining clearance/ approval to market new products. Ann Periodontol 1997;2:11–17.
Principles of Evaluation of the Diagnostic Value of Subgingival Bacteria
Authors: Zambon Joseph J.
Published: October 2010

This paper describes steps in the process of evaluating subgingival bacteria assays for the diagnosis of periodontal disease. The first step examines the infectious etiology of periodontal disease in pointing to specific oral bacteria as periodontal pathogens. Second is characterization of the laboratory test to detect and quantitate these pathogens as to sensitivity, specificity, and positive and negative predictive value. Third is the role of the laboratory test in the diagnosis of the different forms of periodontal disease which is related to the current clinical rather than microbiological definition of these diseases. The fourth and most important step is an analysis of the significance of subgingival bacterial tests in clinical decision‐making. Ann Periodontol 1997;2:138–148.
Overview of Clinical Trials on Periodontal Regeneration
Authors: Caton Jack G.
Published: October 2010

Periodontal regeneration means healing after periodontal surgery that results in the restoration of the tooth‐supporting tissues; namely, cementum, alveolar bone, and periodontal ligament. The response of the periodontium to conventional periodontal flap surgery is primarily repair. Regenerative flap procedures involve modifications intended to alter variables in the normal wound healing response to shift the outcome from repair to regeneration. Technical manipulations, devices, pharmacological agents, and biologicals have been used to obtain regeneration. Evaluation of periodontal therapy is done by clinical and histological assessments. Human clinical trials depend on probing, re‐entry, and radiographic measurements which cannot distinguish between periodontal repair and regeneration. Histological studies are difficult in humans because they require the retrieval of tissue blocks containing the teeth and their surrounding tissues, and for this reason these studies have largely been done in animal models; however, the use of animal models creates problems of interpretation when applying the information to the human. There are other fundamental problems related to assessment of new methods of periodontal regeneration. Ideally, periodontal regeneration is attempted after resolving the periodontitis that produced the loss of periodontal support. Does the type of periodontal disease affect the outcome? If it does, then separate clinical trials would be indicated to manage defects produced by different diseases. Furthermore, certain types of periodontal defects apparently respond better than others (for example, intrabony defects versus suprabony defects). Does each type of defect require a separate trial? Do subjects respond differently and, if so, how should this be factored into selection of the study population and sample size? There appear to be more questions than answers concerning the design of clinical trials for periodontal regeneration. This is not surprising since regeneration has been possible for only a few years, is apparently unpredictable, and the origin and nature of the new tissue are poorly understood. These factors make it important that the design of clinical trials be openly and thoroughly discussed so that practical solutions are forthcoming. Ann Periodontol 1997;2:215–222.
Regulatory Issues Relating to Therapies for Periodontal Regeneration
Authors: Singleton D. Gregory , Torres‐Cabassa Angel
Published: October 2010

The Food and Drug Administration (FDA) has regulated medical devices since May 1976, when the Medical Device Amendments were enacted. The clinical trial requirements for the marketing of periodontal regeneration devices have been dependent, in part, on the degree of their similarity to devices marketed prior to the legislative enactment date in terms of materials, indication statements, and labeling claims. Nonresorbable barriers were allowed to be marketed based on their equivalence to devices marketed prior to the enactment date based on biocompatability and clinical trial data under the premarket notification requirements section of the law. Bone filling materials such as hydroxyapatite were first marketed based on the finding of equivalence to predicate devices. Newer technologies such as bioabsorbable barriers have also been reviewed under the premarket notification provisions of the law, but manufacturers have been required to provide more extensive safety and effectiveness data to establish equivalence to pre‐Amendments devices. Data to answer questions related to the potential toxicity of breakdown products, period of absorption, and ultimate clinical effectiveness needed to be answered prior to marketing. New devices that incorporate technologies that are not substantially equivalent to predicate devices must proceed through the premarket approval route to marketing. For new devices considered a potential significant risk to the patient population, clinical trials are conducted via the investigational device exemption (IDE) requirements that specify the means by which trials will proceed in order to protect the rights of patients. New devices of organic origin, such as bone morphogenic protein, have followed the premarket approval route with IDE requirements instituted as a condition for their path to the marketplace. Issues associated with immediate and long‐term contact including potential toxicity, tumorigenicity, and sensitization need to be addressed with appropriate animal models. Ann Periodontol 1997;2: 223–228.
Specific Issues in Clinical Trials on the Use of Barrier Membranes in Periodontal Regeneration
Authors: Garrett Steven
Published: October 2010

There are presently a number of different barriers available for use clinically in guided tissue regeneration (GTR) procedures. A number of trials using these techniques and comparing different types of barrier membranes are being published in the scientific literature. This review discusses issues related to clinical trials on the use of barrier membranes in periodontal regeneration. Outcome measures, both clinical and histological, are discussed in relation to results following GTR procedures. The difference between regeneration and repair is reviewed as well as methods of clinical and histologic assessment of both these outcomes. Data regarding the impact of patient variables and tooth or defect variables on outcomes are presented and suggestions for study designs are made based on these variables. Aspects of assessing for an appropriate sample size in superiority and equivalency trials using GTR techniques are presented as well as interpretation of results following these trials and their clinical significance. Ann Periodontol 1997;2:240–258.
Overview of Clinical Trials on Endosseous Implants
Authors: Fritz Michael E.
Published: October 2010

Early history of clinical trials on endosseous implants revolved around anecdotal reports on predominantly blade implants in the U.S. The first criteria to define success or failure were established at the National Institutes of Health (NIH)‐Harvard Conference in 1978. This was followed by the multi‐center trials from the Branemark group which described round, metallic implants. At the 1988 NIH Conference, questions dealt with the following: 1) the effectiveness of dental implants for the long‐term; 2) indications and contra‐indications of various types of implants; 3) requirements for management of dental implants; 4) health risks of dental implants; and 5) future directions in research. In the ensuing 7 years since the second NIH Conference, most of the data generated have been from non‐controlled case reports, which describe a 90% success rate in 5 years or more with many types of endosteal systems in both partially and fully edentulous patients. Therefore, it can be said that there is evidence that dental implants are effective for the long‐term. The other questions posed at the 1988 NIH Conference have not been as well described and have led to many controversies and future research areas. Two areas which will have a special future impact are 1) the establishment of a standard of care and risk‐benefit ratio for implants and 2) the use of various factors to accelerate bone formation to allow greater access to dental implants by patients. Ann Periodontol 1997;2: 270–283.
The Nature of Periodontal Diseases
Authors: Socransky Sigmund S. , Haffajee Anne D.
Published: October 2010

Periodontal diseases are infections. They have a number of properties in common with infections in other parts of the body, but have unique features resulting from the passage of the tooth through the soft tissue integument into the oral cavity. The tooth provides a solid, non‐shedding surface for the colonization of potentially pathogenic bacterial species as well as a wide range of hostcompatible species. Periodontal pathogens frequently colonize the periodontal area for prolonged periods of time prior to disease initiation. Disease is caused by a finite set of bacterial species leading to the development of multiple periodontal diseases. Disease occurs at individual periodontal sites and leaves an historical record of the damage to the periodontium in the form of periodontal attachment or bone loss. This feature provides difficulty in investigation since it is often unclear whether the infectious process is presently occurring or is a reflection of past destruction. Control of periodontal diseases is most effectively performed by eliminating or suppressing the organisms that cause them and establishing a host compatible microbiota. When tissue damage has been extensive, regenerative or replacement procedures should be instituted after the infection has been controlled. Ann Periodontol 1997;2:3–10.
Voluntary Programs: ADA Seal Program and International Implications
Authors: Meyer Daniel M.
Published: October 2010

For about 130 years the American Dental Association (ADA) has aided the profession and the public in selecting safe and effective dental products. Since 1930, dental products have been evaluated through the ADA Seal program. In accordance with the ADA's Bylaws, the Council on Scientific Affairs assesses information evaluating the safety, efficacy, appropriate use, and promotional claims of dental products. In doing so, the Council may award the ADA's Seal of Acceptance. In collaboration with interested parties, expert consultants, and Council members, the ADA produces guidelines suggesting appropriate methodologies and submission data to assist manufacturers in voluntarily earning the Seal of Acceptance. To dole, numerous professional and consumer products have been evaluated, and about 1,300 of these products bear the Association's Seal of Acceptance. When a product is awarded the Seal it means that adequate data have been submitted and reviewed and, based on available information, the product meets ADA guidelines of safety and effectiveness. Dental health care professionals and consumers who use products that have the Seal can be confident that a product's properties and performance are consistent with current professional standards and manufac turers' claims. The ADA Seal program serves to help dentists and manufacturers meet their ethical obligations to the public by promoting safe and effective health care products. Ann Periodontol 1997;2:31–41.
Clinical Trials on Placement of Implants in Existing Bone
Authors: Weber Hans‐Peter , Fiorellini Joseph P. , Jeffcoat Marjorie C.
Published: October 2010

The use of dental implants has become a predictable and frequently used treatment modality in partially and fully edentulous patients. In 1987, the United States Food and Drug Administration (FDA) classified dental implants as class III medical devices. In 1989, a proposed rule was published by the FDA calling for a Premarket Approval Application (PMA) for dental implants. A PMA requires the demonstration of safety and effectiveness through clinical trials. Although the effective date for Premarket Approvals and detailed information on study requirements have not been announced, many implant manufacturers have already initiated multi‐center clinical trials. Despite these initiatives, several aspects regarding appropriate study designs, outcome criteria, and success or failure analysis still need clarification. Trials should be designed to minimize bias and variability. The cornerstone of the experimental design is set by the study objective. It will determine which of many possible clinical trial parameters are essential to enable the presentation of data to a regulatory body on which basis the safety and effectiveness of a device can be judged. With the multiplicity of patient characteristics, implant types, supported prostheses, study designs, evaluation parameters, and statistical analyses, it is a difficult task to design an optimal trial. It is the purpose of this paper to propose designs and components for implant clinical trials with various objectives. Ann Periodontol 1997;2:315–328.
The Research Team, Calibration, and Quality Assurance in Clinical Trials in Periodontics
Authors: Polson Alan M.
Published: October 2010

The present report provides an overview of practical issues related to training, calibrating, and monitoring the individuals involved in conducting a clinical trial. These aspects are considered in relation to a theoretical multi‐center clinical trial designed to test the safety and efficacy of a new periodontal treatment. Many factors need to be controlled in order to reduce inherent variability and provide standardization across the study population and study centers in a large‐scale multi‐center clinical trial. Components incorporated to control these factors include identification and recruitment of study centers, pre‐study training and organization of the teams at the different research centers, quality assurance procedures and monitoring of the study for compliance with protocol and safety requirements, and management of databases. Details are given regarding the use of pre‐study survey questionnaires to assess research center capabilities, methods for training and calibrating examiners and therapists and methods for integrating these aspects prior to actual study commencement, and quality assurance after the study has begun. The review considers the critical practical details regarding all of these aspects of study organization and execution. Ann Periodontol 1997;2:75–82.
Randomized Clinical Trials in Periodontology: Ethical Considerations
Authors: Levine Robert J. , Dennison David K.
Published: October 2010

Ethical justification for starting a clinical trial requires at the outset an accurate statement of “no difference” regarding the two or more agents to be compared. This may be expressed as “theoretical equipoise” (no data to support the superiority of one of the agents) or, preferably, as “clinical equipoise” (there are insufficient data to resolve controversy among experts as to which is superior). This presents a problem when a placebo control is proposed, particularly when the outcome measure entails irreversible loss of function; preliminary data often suggest the superiority of the “active agent.” Informed consent should ordinarily include the fact that treatment assignments will be accomplished by a process of randomization and, in the case of double‐blind designs, that neither the subject nor the investigator will know the subject's treatment assignment until the end of the trial. In general, clinical trials should be monitored by data and safety monitoring boards that have access to unblinded data; they should be guided by stopping rules that should be agreed upon by all concerned before the trial is begun. Women and minorities must be included unless there is strong justification for their exclusion. Care must be taken to balance the competing objectives of validity (the results will be correct), generalizability (the results will be broadly applicable), and efficiency (the study will not be unduly expensive). Ann Periodontol 1997;2: 83–94.
Overview of Clinical Trials of Periodontal Diagnosis Methods and Devices
Authors: Mandel Irwin D.
Published: October 2010

Changing views of the pathogenesis and progression of the periodontal diseases and new modalities for treatment have stimulated a plethora of physical, biochemical, microbiologic, and Immunologie diagnostic procedures, tests, and devices. Clinical trials address needs for: 1) screening tests and risk assessment for disease susceptibility; 2) identification of active and progressive disease sites; 3) making therapeutic decisions; 4) monitoring therapy; 5) establishing a maintenance schedule; and 6) prognosis assessment. Needs and priorities of general, specialty, and public health practitioners differ. Validation of tests proceeds in a hierarchy of study designs from cross sectional and case control studies to retrospective and prospective longitudinal multi‐center trials. For broad‐scale application, randomized controlled trials (and eventual meta‐analysis) will be required. Design issues are those common to all clinical trials in periodontics plus special considerations depending on type of test and its intended use. For diagnostic tests, recommended surrogate endpoints are attachment and alveolar bone levels – the traditional “gold standards.” Validation of diagnostic tests is best accomplished by generation of 2 × 2 contingency tables to calculate sensitivity and specificity, positive and negative predictive values, relative and absolute risks, and odds ratios. Each has a place – depending on the clinical situation and needs of the clinician. Ann Periodontol 1997;2:98–107.
Dental Plaque, Platelets, and Cardiovascular Diseases
Authors: Herzberg Mark C. , Meyer Maurice W.
Published: October 2010

Cardiovascular diseases, including atherosclerosis and myocardial ischemia, occur as a result of a complex set of genetic and environmental factors. During periodontitis, dental plaque microorganisms may disseminate through the blood to infect the vascular endothelium and contribute to the occurrence of atherosclerosis and risk of myocardial ischemia and infarction. Myocardial ischemia and infarction are often preceded by acute thromboembolic events. In an in vitro model of thrombosis, certain dental plaque bacteria induce platelets to aggregate. Aggregation of platelets is induced by the platelet aggregation‐associated protein [PAAP] expressed on plaque bacteria, including Streptococcus sanguis and Porphyromonas gingivalis. Intravenous infusion of S. sanguis into rabbits has been shown previously to cause changes in the electrocardiogram (ECG), heart rate, blood pressure, and cardiac contractility. These changes are consistent with the occurrence of myocardial infarction. The ECG changes are now shown to begin within 30 seconds after infusion of PAAP+ S. sanguis, followed by alterations in blood pressure and respiratory rate. These changes occurred intermittently over a 30‐minute period and changed within one heartbeat to a normal pattern and suddenly back to abnormal. Intermittent ECG abnormalities were seen in 13 of 15 rabbits, including left axis deviation, ST‐segment depression, preventricular contractions, alternans, and bigemnia. Dose‐dependent thrombocytopenia, accumulation of 111Indium‐labeled platelets in the lungs, and tachypnea also occurred. No changes occurred with the PAAP− strain. The data indicated that PAAP+ S. sanguis interacts with circulating platelets, inducing thromboemboli to cause the pulmonary and cardiac abnormalities. During periodontitis, therefore, PAAP+ S. sanguis and P. gingivalis bacteremia may contribute to the chance of acute thromboembolic events. Ann Periodontol 1998;3:151–160.
The Relationship Between Dental Disease and Cerebral Vascular Accident in Elderly United States Veterans
Authors: Loesche Walter J. , Schork Anthony , Terpenning Margaret S. , Chen Yin‐Miao , Kerr Connie , Dominguez B. Liza
Published: October 2010

We report here information obtained from a cross‐sectional study of 401 veterans, who were at least 60 years of age, which showed that several dental/oral conditions can be significantly associated with the diagnosis of a cerebral vascular accident (CVA), when included in a multivariate logistic regression model with and without many of the known risk factors for a CVA. The dental findings relative to the prevalence of dental caries and periodontal disease were not distinctly different between the subjects with and without a CVA in the bivariate analysis. A higher stimulated salivary flow was negatively associated with a CVA in the multivariate models. The plaque index and oral hygiene habits relating to brushing, flossing, and frequency of having teeth cleaned by a dentist/hygienist were significantly associated with a CVA in the bivariate analysis. Among these oral hygiene parameters, “needing help in brushing one's teeth” and the reported annual visit to the dentist/hygienist for teeth cleaning remained significant in the multivariate models involving the dependent‐living subjects. The need for help in brushing one's teeth could reflect the fact that many subjects had reduced manual dexterity as a result of the CVA and required this extra care. However, the finding that those dependent‐living individuals who reported that they did not have their teeth cleaned at least once a year were 4.76 times more likely to have had a CVA, suggests that a pattern of oral neglect might be associated with developing a CVA. The implications of this in terms of an intervention strategy for CVA warrants further consideration. However, caution is recommended because the data were obtained from a convenience sampling of older veterans and may not be generalizable to other populations. Ann Periodontol 1998;3:161–174.
Possible Explanations for the Tooth Loss and Cardiovascular Disease Relationship
Authors: Joshipura Kaumudi J. , Douglass Chester W. , Willett Walter C.
Published: October 2010

Several studies have shown relationships between periodontal disease and cardiovascular disease (CVD). A few studies have also shown that tooth loss may be associated with increased risk of coronary heart disease and stroke. We have reviewed the relevant literature to assess possible explanations for the reported associations between tooth loss and CVD. In particular, we considered whether the reported association between tooth loss and CVD could be explained by antecedent periodontal disease, antecedent caries, the extraction process, dietary changes following tooth loss, or confounding or bias from other sources. Since access to care and attitudes to health care may influence the decision to extract teeth, as well as cardiovascular disease risk, one needs to be cautious about confounding from behaviorally related factors. Available evidence suggests that further studies are needed to rule out that confounding is a possible explanation for the tooth loss and CVD relationship, that prior periodontal disease may not completely explain the tooth loss–CVD relationship, and that the role of diet needs to be further explored. Ann Periodontol 1998;3:175–183.
The East London Study of Maternal Chronic Periodontal Disease and Preterm Low Birth Weight Infants: Study Design and Prevalence Data
Authors: Davenport Elizabeth S. , Williams Catherine E.C.S. , Sterne Jonathan A.C. , Sivapathasundram Vythilingam , Fearne Janice M. , Curtis Michael A.
Published: October 2010

The influence of subject‐based and environmental factors on the balance between the subgingival microbial challenge and the host response in periodontal diseases illustrates the intimate link between oral and systemic health. From this stems the hypothesis that the persistent Gram‐negative challenge and associated inflammatory sequelae in periodontal disease may have consequences extending beyond the periodontal tissues themselves. This paper addresses the design of a case‐control study to examine the relationship between preterm low birth weight (PLBW) and maternal periodontal disease. We present preliminary data on the prevalence of these 2 conditions in a group of mothers at the Royal Hospitals Trust, London, U.K. Cases are defined as mothers delivering an infant weighing less than 2,500g before 37 weeks' gestation and controls as mothers delivering an infant of more than 2,500g after 38 weeks. We estimated that a study involving 800 mothers (1:3 case:control) should have sufficient power to detect an association with a minimum odds ratio of 3 at the 5% significance level. Demographic details of 177 subjects demonstrated that they were representative of the local population, and the prevalence of PLBW was within the expected range. However, the extent and severity of periodontal disease were higher than predicted and may have reflected elevations in gingival inflammation associated with pregnancy. The final outcome of the study should help determine the need for further interventionist studies to demonstrate a causal relationship between periodontal disease and PLBW, as well as provide information on the prevalence of periodontal diseases in this study population. Ann Periodontol 1998;3:213–221.
Potential Pathogenic Mechanisms of Periodontitis‐Associated Pregnancy Complications
Authors: Offenbacher S. , Jared H.L. , O'Reilly P.G. , Wells S.R. , Salvi G.E. , Lawrence H.P. , Socransky S.S. , Beck J.D.
Published: October 2010

During normal pregnancy, maternal hormones and locally acting cytokines play a key role in regulating the onset of labor, cervical ripening, uterine contraction, and delivery. Maternal infections during pregnancy have been demonstrated to perturb this normal cytokine and hormone‐regulated gestation, sometimes resulting in preterm labor, preterm premature rupture of membranes, and preterm low birth weight (PLBW), i.e., < 2,500 g and < 37 weeks of gestation. Our research focus has been to determine whether periodontal infections can provide sufficient challenge to the mother to trigger PLBW. New experiments from 48 case‐control subjects have measured gingival crevicular fluid (GCF) levels of PGE2 and IL‐1β to determine whether mediator levels were related to current pregnancy outcome. In addition, the levels of 4 periodontal pathogens were measured by using microbe‐specific DNA probes. Results indicate that GCF–PGE2 levels are significantly higher in PLBW mothers, as compared with normal birth weight (NBW) controls (131.4 ± 21.8 vs. 62.6 ± 10.3 [mean ± SE ng/mL], respectively, at P = 0.02). Furthermore, within primiparous PLBW mothers, there was a significant inverse association between birth weight (as well as gestational age) and GCF–PGE2 levels at P = 0.023. These data suggest a dose‐response relationship for increasing GCF–PGE2 as a marker of current periodontal disease activity and decreasing birth weight. Microbial data indicate that 4 organisms associated with mature plaque and progressing periodontitis—Bacteroides forsythus, Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Treponema denticola—were detected at higher levels in PLBW mothers, as compared to NBW controls. These data suggest that biochemical measures of maternal periodontal status and oral microbiol burden are associated with current PLBW. Ann Periodontol 1998;3:233—250.
Associations Between Oral Conditions and Respiratory Disease in a National Sample Survey Population
Authors: Scannapieco F.A. , Papandonatos G.D. , Dunford R.G.
Published: October 2010

Respiratory infectious diseases such as bacterial pneumonia and bronchitis are common and costly, especially in institutionalized and elderly inpatients. Respiratory infection is thought to rely in part on the aspiration of oropharyngeal flora into the lower respiratory tract and failure of host defense mechanisms to eliminate the contaminating bacteria, which then multiply to cause infection. It has been suggested that dental plaque may act as a reservoir of respiratory pathogens, especially in patients with periodontal disease. However, the impact of poor oral health on oral respiratory pathogen colonization and lung infection is uncertain, especially in ambulatory, non‐institutionalized populations. To begin to assess potential associations between respiratory diseases and oral health, data from the National Health and Nutrition Examination Survey I (NHANES I) were analyzed. This database contains information on the general health status of 23,808 individuals. Of these, 386 individuals reported a suspected respiratory condition that was further assessed by a physician. These subjects were categorized as having a confirmed chronic respiratory disease (chronic bronchitis or emphysema) or an acute respiratory disease (influenza, pneumonia, acute bronchitis). They were compared to those not having a respiratory disease. Initial non‐parametric analysis noted that individuals with a confirmed chronic respiratory disease (n = 41) had significantly greater oral hygiene index scores than subjects without respiratory disease (n = 193; P = 0.0441). Logistic regression analysis of data from these subjects, which considered age, race, gender, smoking status, and simplified oral hygiene index (OHI), suggested that subjects having the median OHI value were 1.3 times more likely to have a chronic respiratory disease relative to those with an OHI of 0. Similarly, subjects with the maximum OHI value were 4.5 times more likely to have a chronic respiratory disease than those with an OHI of 0. No evidence was found to support an association between poor oral health with acute respiratory diseases. Also, no association was noted between the periodontal index and any respiratory disease. These results suggest OHI to have a residual effect on chronic respiratory disease of both practical and statistical significance. Ann Periodontol 1998;3:251–256.
Anaerobic Bacteremia and Fungemia in Patients Undergoing Endodontic Therapy: An Overview
Authors: Debelian Gilberto Jirair , Olsen Ingar , Tronstad Leif
Published: October 2010

Oral focal infection, a concept neglected for several decades, is a subject of controversy. Recent progress in classification and identification of oral microorganisms has renewed interest in focal infection. The aim of this study was to use phenotypic and genetic methods to trace microorganisms released into the bloodstream during and after endodontic treatment back to their presumed source—the root canal. Microbiological samples were taken from the root canals of 26 patients with asymptomatic apical periodontitis of single‐rooted teeth. The blood of the patients was drawn during and 10 minutes after endodontic therapy. Microorganisms in blood were collected after anaerobic lysis filtration and cultured anaerobically on blood agar plates. The phenotypic methods used for characterization and tracing of microorganisms in blood and root canals were: biochemical and antimicrobial susceptibility tests, SDS‐PAGE of whole‐cell soluble proteins, and gas chromatography of cellular fatty acids. Phenotypic data were verified by DNA restriction patterns and corresponding ribotypes of the root canal and blood isolates by using a computer‐assisted system for gel analysis. All root canals contained anaerobic bacteria. The frequency of bacteremia varied from 31% to 54%. The microorganisms from the root canal and blood presented identical phenotypic and genetic characteristics within the patients examined. These characteristics differed between patients. The present study demonstrated that endodontic treatment can be the cause of anaerobic bacteremia and fungemia. The phenotypic and genetic methods used appeared valuable for tracing microorganisms in the blood back to their origin. Ann Periodontol 1998;3:281–287.
Epidemiological and Clinical Aspects of Periodontal Diseases in Diabetics
Authors: Soskolne W. Aubrey
Published: October 2010

The association between diabetes mellitus and periodontal disease has long been discussed, with conflicting conclusions. On the one hand, numerous reports indicate a high prevalence of periodontal disease in diabetics compared to healthy controls, while others fail to show such a relationship. Clarification of this dilemma has been occurring as the diagnostic criteria for periodontal disease destruction improve and the number and size of the populations surveyed grow. This review is based on a selective review of the literature from the present decade. To date, based mainly on an extensive study of the Pima Indians who have an extremely high incidence of non–insulin‐dependent diabetes mellitus (NIDDM), it seems to be clear that patients with NIDDM have a higher prevalence and severity of periodontal disease destruction than non‐diabetics in the same population. However, it must be borne in mind that these data are for a special population. Studies on patients with insulin‐dependent diabetes mellitus (IDDM) indicate results similar to those found in studies on NIDDM. There is an increase in prevalence and severity of periodontitis compared to controls. For both IDDM and NIDDM, there does not appear to be any correlation between the prevalence or the severity of periodontal disease and the duration of diabetes. Well‐controlled diabetic patients as measured by blood glycated hemoglobin levels have less severe periodontal disease than poorly controlled diabetics. The principles of treatment of periodontitis in diabetics are the same as those for non‐diabetic patients and are consistent with our approach to all high‐risk patients who have already developed periodontal disease. The major efforts should be directed at the prevention of periodontitis in patients at risk of developing diabetes. Another important clinical question relates to the influence of periodontal disease on the control of the diabetic state. Here again the literature is unclear; however, a recent development suggests that effective control of periodontal infection in patients with diabetes reduces the level of advanced glycosylation end products in the serum. If future studies can confirm this effect, then periodontal infection control must be considered an integral part of diabetic control. Ann Periodontol 1998;3:3–12.