Ray C. Williams

The potential impact of periodontal disease on general health : a consensus view

ABSTRACT Background: Evidence for a link between periodontal disease and several systemic diseases is growing rapidly. The infectious and inflammatory burden of chronic periodontitis is thought to have an important systemic impact. Current evidence suggests that periodontitis is associated with an increased likelihood of coronary heart disease and may influence the severity of diabetes. Scope: This paper represents a UK and Ireland cross-specialty consensus review, undertaken by a group of physicians and dentists. The consensus group reviewed published evidence (PubMed search for review and original articles), focusing on the past 5 years, on the contributory role of periodontal disease to overall health. In particular, evidence relating to a role for periodontal disease in cardiovascular disease and in diabetes was considered. Findings: Initial studies of large epidemiological data sets have sought to find links between periodontitis and systemic disease outcomes, but a causal relationship still needs to be demonstrated between periodontal disease, cardiovascular disease and diabetes through prospective studies. There is a need for prospective studies assessing the association between periodontal disease and patients at particular risk of cardiovascular events which will allow assessment of both cardiovascular disease clinical endpoints and surrogate markers of cardiovascular risk. Of note, periodontal disease is also often more severe in subjects with diabetes mellitus, a group at already increased risk for cardiovascular events. Conclusions: While further research is needed to define the population-attributable risk of periodontal disease to both cardiovascular diseases and to diabetes control and progression, health education to encourage better oral health should be considered as part of current healthy lifestyle messages designed to reduce the increasing health burden of obesity, cardiovascular disease and diabetes.

Nonsteroidal Antiinflammatory Drugs as Inhibitors of Periodontal Disease Progression

Recent interest in the control and modulation of periodontal disease has focused on the potential benefits of blocking the host response mechanisms involved in the progression of the disease. In addition to recent advances in the identification and control of etiologic bacteria, investigators have indicated promising results using nonsteroidal antiinflammatory drugs (NSAIDs) as inhibitors of the inflammatory destruction in periodontal disease. This article examines research efforts over the last 20 years describing the role of prostaglandins in periodontal disease and the effect of NSAIDs on the progression of gingival inflammation and alveolar bone loss.

Contrast enhancement as an aid to interpretation in digital subtraction radiography

An initial study was performed to demonstrate the feasibility of pseudocolor contrast enhancement technique in digital subtraction radiography (DSR). DSR is an electronic image processing technique that has been shown to be of greater diagnostic value in the detection of small periodontal bone lesions than conventional radiography. Pseudocolor enhancement involves selectively assigning a unique color to each shade of gray present in a black-and-white subtracted image. Two image enhancement techniques were developed and tested in a phantom system consisting of extracted teeth set in blocks of plaster mixed with sawdust to simulate trabecular bone. It was found that experimentally induced periodontal lesions were more readily detected by the average clinician in both types of enhanced subtraction images than unenhanced subtractions. Furthermore, both enhancement techniques were of significantly greater diagnostic value for lesions smaller than 1.0 mm (p less than 0.001). The technique that colored an isolated area of interest was significantly more diagnostic at all depths tested (p less than 0.001 at 0.5 and 1.0 mm, and p less than 0.05 at 0.5 mm). Contrast enhancement may be a significant aid to the average clinician for the interpretation of DSR and the detection of small periodontal defects.

Understanding and managing periodontal diseases: a notable past, a promising future.

Throughout the 20th century, an understanding of the role of causative bacteria and the susceptible host in the initiation and progression of periodontal disease(s) has emerged from the research efforts of scientists and clinicians worldwide. Over time, specific bacterial types, such as Porphyromonas gingivalis, were discovered and shown to be important in the cause of periodontal disease. At the same time, inflammatory mediators, such as prostaglandins and interleukins, and enzymes, such as matrix metalloproteinases, were discovered and found to be important participants in the destruction of periodontal tissues. Acquired and inherited environmental risk factors began to emerge that could explain, in part, the susceptibility of individuals to periodontal disease. The discovery of antibiotics, beginning with sulfanilamide, penicillin, and streptomycin, led to additional strategies for managing periodontal disease. With the discovery of the mechanism of action of aspirin, scientists began to develop new strategies for treating diseases that focused on controlling inflammation. Thus, host-modulating therapies emerged for the management of periodontal disease through the control of inflammation. At the end of the 20th century, an old concept in medicine and dentistry reappeared: that the infection and inflammation of periodontal disease in the mouth could reach distant sites via the bloodstream. Apparently oral disease could, in fact, contribute to systemic diseases, such as atherosclerosis, diabetes, and adverse outcomes in pregnancy. This concept of the oral health-general health connection is now supported by sound and rational evidence-based observations. Clearly, the 21st century has arrived with a new understanding of the nature of periodontal diseases based on a notable era of discovery. There is a promising future for preventing and treating this common and troubling condition that affects not just the mouth but also the whole body.

Nuclear medicine techniques for the detection of active alveolar bone loss.

The use of bone-seeking radiopharmaceutical uptake (BSRU) as an indicator of periodontal disease activity was assessed in untreated beagles with naturally occurring periodontal disease, and in beagles treated with the non-steroidal anti-inflammatory drug, flurbiprofen. In untreated beagles, a single uptake measurement was indicative of the rate of bone loss subsequently determined by sequential radiographs. Beagles treated with flurbiprofen demonstrated a significant decrease in rate of bone loss and a corresponding decrease in BSRU. Transfer of this technology to untreated human subjects with moderate to severe periodontal disease also showed a positive correlation between a single measurement of BSRU and the rate of bone loss determined from sequential radiographs. Analysis of these data shows that a single BSRU examination may be indicative of periodontal disease activity.

Detection of Periodontal Disease Activity with a Scintillation Camera

The goal of this study was to assess the ability of a scintillation camera method to detect areas of active bone loss due to periodontitis. Technetium 99m methylene diphosphonate was used as the bone-seeking radiopharmaceutical. Bone-seeking radiopharmaceutical uptake (BSRU) was imaged and quantified in alveolar bone regions of interest with a scintillation camera and a computer. Analysis of the sequential radiographs over six months constituted the basis for determination of sites of active disease. The study was composed of two parts. First, 18 subjects, nine with adult periodontitis and nine controls, were enrolled in a cross-sectional study to determine whether the quantitative scintillation camera methodology detected differences in BSRU in periodontitis vs. periodontally healthy patients. Second, the nine patients with periodontitis were studied longitudinally in order to determine whether the BSRU examination was indicative of bone loss subsequently measured radiographically. In the cross-sectional study, the mean uptake ratio for the periodontitis group was significantly higher than that for the control group (1.63 ± 0.06 and 1.42 ± 0.04, respectively, p<0.01, t test). From the longitudinal study, the mean patient scintillation image uptake ratios were highly correlated with the mean bone loss determined from serial radiographs (p<0.01). The accuracy, sensitivity, and specificity of the quantitative gamma camera method for detecting site(s) of active bone loss within the region of interest were assessed relative to the longitudinal radiographic data. The accuracy, sensitivity, and specificity were 85%, 90%, and 79%, respectively. Alveolar bone scintigraphy with a gamma camera and computer may provide a simple and valid technique for the immediate indication of areas of periodontal disease activity.

Commentary: Knowledge That Shaped the Field of Periodontology: The American Academy of Periodontology Centennial Commentaries

M any date the beginning of formal universities from the University of Bologna in 1088. Although the European university model with a focus on science and research emerged later in the 19th century, original observations in the sciences were presented to members of learned scientific societies of Europe much earlier. These learned societies became the primary vehicle for discussion and transmission of new knowledge, and in the mid-1600s the proceedings of scientific societies, such as the Philosophical Transactions of the Royal Society of London, began publication. The American Academy of Periodontology (AAP) was founded in 1914 and held its first annual meeting in Washington, DC, with 17 members present. As we celebrate the 100th anniversary of the AAP, the official publication of this learned society, the Journal of Periodontology, will honor many of the great peer-reviewed papers that shaped the field during a magnificent century of evolution in knowledge about periodontal diseases and how we manage them. We have listed on the following pages 150+ peerreviewed papers that are among the top papers that influenced the development of our knowledge and practice. The list includes themost widely cited papers in periodontology and implantology and additional classic papers derived froma consensus of the reading lists from graduate programs in periodontology that were kind enough to participate. In our desire to highlight critical scientific contributions to periodontology irrespective of where they were published, our list was drawn from all scientifically respected peerreviewed journals. We regret any omissions and welcome letters to the editor that describe the impact of specific papers we have inadvertently omitted. We are aware that all specialists in the field must have a deep knowledge of the anatomy and physiology of the periodontal tissues. And so, beyond that basic knowledge, we have observed that the topcited papers cluster into a set of 11 key themes that appear to have shaped the field. We have asked scholars who were intimately involved in each theme to write a commentary to briefly highlight key knowledge that underlies the theme. Some of the authors will highlight specific papers that critically changed our thinking. Beginning in February, we will publish a commentary each month in 2014 on one of the themes. In addition to the 11 themes, we have asked Dr. Robert Genco to provide his perspective on how science in general has influenced periodontology, and we have asked Drs. Michael McGuire and Thomas Wilson Jr. to provide perspective on how the evolving knowledge has changed the practice of periodontics and what we may expect in the future. With the opening of the University of Berlin in 1810, the concepts of the science and research university, as described by Wilhelm von Humboldt, began to change universities throughout the world. Von Humboldt argued that, ‘‘Everything depends on holding to the principle of considering knowledge as something not yet found, never completely to be discovered, and searching relentlessly for it as such.’’1 We honor those dedicated researchers and clinicians who created the new knowledge and translated it to patient care, and who thereby shaped the evolution of periodontology in the past 100 years. At the same time, we constantly remind ourselves that as with all science-based disciplines, periodontology will never be at a point of perfect knowledge. We must teach our students how to evaluate new evidence and remind ourselves that we are able to deliver outstanding prevention and treatment of periodontitis today and will do even better in the future only because of those who produced new knowledge in the past—much of which was initially met with skepticism and annoyance. Congratulations to the American Academy of Periodontology on its 100th anniversary and to all who understood that the strength and future of periodontology are built on the foundations of

Commentary: The Literature That Shaped Modern Periodontology

The following reading list includes published peerreviewed papers that helped to shape the modern practice of periodontics and current knowledge in periodontology. The reading list was developed using two approaches: 1) the top-cited papers in all aspects of periodontology were identified using Google Scholar (http://scholar.google.com; searched November 2, 2013), and 2) reading lists were requested from all US graduate programs and from those lists submitted, papers that were common to most of the lists were selected as ‘‘consensus’’ papers of importance. There are undoubtedly some omissions. It is important to note that the number of citations for a specific paper is greatly influenced by the date of the paper’s publication. For example, some important papers in the early years of periodontology may not have been highly cited because there were many fewer papers published at that time and therefore fewer opportunities to cite the paper. Similarly, some papers may have influenced clinical management of patients but did not lead to additional published work that might cite the earlier findings. The papers appear to cluster into 11 themes, or unifying principles, that describe knowledge in the field. Some papers fit within multiple themes. Each theme will be the basis for a commentary to be published in 2014 to highlight how selected papers within that area influenced our current knowledge and practice.

The Impact of Oral Health on General Health: Educating Professionals and Patients

Purpose of ReviewThis review provides a brief summary of what science has postulated about the oral cavity and its relationship to the rest of the body. This article then looks at the emerging body of evidence for a definitive statement on the impact of oral health and disease on overall health and disease. It concludes by examining ways to educate oral healthcare providers (OHCPs) (i.e., dentists and dental hygienists) and their role in educating patients and the public about the interrelationships of oral and overall health and challenges associated with this.Recent FindingsSince 1989, there have been major advances in understanding the role of periodontal infection and inflammation in contributing to the risk for systemic diseases. As the evidence emerges for an oral-systemic link, new strategies for educating dentistry, medicine, other non-dental healthcare professions, and the public about this link are also emerging.SummaryHopefully, a new awareness and understanding of the significance of oral health in sustaining general health lead to a new emphasis for prevention and treatment of periodontal disease.

New technologies for the diagnosis of periodontal disease

Historically the initial onset of periodontal disease in an individual was considered slow but continuously progressive over time. It was inferred that an individual would experience progressive destruction of the attachment structures until edentulous. However, several studies in the early 1970s contested the traditional concept of continuous disease progression. These studies suggested that periodontal disease progressed by recurrent acute episodes. In specific individuals, the loss of attachment was faster than the concept of slowly progressing disease. There were also sites in patients that progressed slower (or not at all) than anticipated on the basis of radiographic and clinical history of previous disease progression. These findings clearly indicated the need to explore the nature of periodontal disease progression and to institute a major effort into innovative methods to diagnose periodontal diseases. Dentists and researchers could more effectively prevent and treat periodontal disease and relate pertinent research findings to specific disease initiation and progression.