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Inside Dentistry
Nov/Dec 2005
Volume 1, Issue 2

The Oral-Systemic Link: How Much Do We Know?

Allison M. DiMatteo, BA, MPS

Ten years ago, a shot was fired that was heard around the dental world. What was previously an intuitive hypothesis had now been substantiated with research-based proof. An association was found to exist between oral infection and systemic diseases, particularly heart disease and stroke, diabetes, and preterm low birth-weight babies, among others. Ties were also made to pneumonia, respiratory diseases, and osteoporosis. Some argue that, as a result, dentists truly now have the opportunity to elevate their roles in their patients’ care from that of “tooth technician” to “oral health physician.”

“We knew that the systemic link was there, and we used to talk about it, but we never had the evidence,” explains Dr. Louis Rose, DDS, MD, a clinical professor at the University of Pennsylvania School of Dental Medicine and a professor of surgery in the Division of Dental Medicine at Drexel University College of Medicine. “Now we have evidence to support what we thought.”

By expert accounts and based on a steadily building foundation of research, the association between oral infection and systemic disease is very real and warrants special attention for our at-risk patients. The more enlightened understanding of oral diseases has clearly demonstrated that many of them have multiple environmental, behavioral, and systemic risk factors for disease initiation and progression.1,2 The implication is that dental professionals could find themselves as the first line of defense for their patients in addressing some of the problems that were typically the domain of the physician, including—but not limited to—the clinical management of treatments for patients with diabetes and heart disease and actively promoting cessation techniques for those patients who smoke.

“Of significance is the fact that the role of the dentist has evolved over the years from being focused on the repair of damage within the oral cavity to more proactive activities, such as prevention of disease,” said Dr. Foti Panagakos, DMD, PhD, Associate Director of Clinical Dental Research in the Research and Development Division of Colgate-Palmolive Company. “If we can do something for our patients that will not only improve their oral health but also improve their systemic health, then we should participate in that care, not just rely on the primary care physician to be the person focusing on systemic care.”

Catalyzing the evolution of the dentist’s role in a patient’s overall healthcare is what the research has actually demonstrated. According to Dr. Ray Williams, DMD, Professor and Chair of the Department of Periodontology at the University of North Carolina School of Dentistry, what is now supported in the scientific literature about the association between oral infection and systemic disease can be summarized in 3 key points.

1. The association between oral infection and systemic disease is no longer a subtle hypothesis. “The data are quite impressive that there is a strong association between oral health and systemic health,” Williams says.

2. The basic research being conducted is beginning to explain the biologic plausibility of why this association exists. As a result, the dental and medical professions are gaining an understanding of how oral bacteria, their products, and resulting inflammation within the oral cavity actually contribute to and/or affect systemic conditions.

3. Dental researchers are beginning to see compelling evidence that if oral disease is treated, then the likelihood of systemic events occurring or being more severe is reduced. “What’s perhaps most exciting is that assuring oral health appears to have a very beneficial effect on systemic health,” Williams notes.

Here’s an Inside look at what you need to know to piece together the link between oral disease and systemic health.

Fundamentals of the Oral-Systemic Question

Much has been published and summarized on the subject of periodontal disease and its relationship to oral-systemic health. The topic was discussed at length during a 2003 conference in Atlanta conducted by the Centers for Disease Control and Prevention about the Public Health Implications of Chronic Periodontal Infections in Adults. There, Dr. Roy Page, DDS, Director of Periodontics for the University of Washington School of Dentistry, provided an introduction to periodontal diseases, their clinical presentations, etiology, and pathogenesis.3

Infection in the periodontium (i.e., gingival tissue, bone, and supporting tissue) primarily by gram-negative anaerobic bacteria (e.g., Porphyromonas gingivalis) can initiate a series of inflammatory and immunologic changes that ultimately lead to destructive effects.3,4 For example, as biofilms containing these pathogenic bacteria form on tooth surfaces and extend between the surface of the tooth root and gingiva, the resulting destructive inflammation ultimately creates periodontal pockets.3

Lipopolysaccharide, antigenic bacterial components, and other bacteria can access the inflamed tissue through these pockets, enter the bloodstream, and become disseminated systemically.3,5 It is the systemic dissemination of gram-negative anaerobic bacteria and their components present in subgingival biofilms, as well as inflammatory mediators that reach high levels in the diseased periodontal tissues, that are the basis for the association between oral disease and “several potentially deadly systemic diseases and conditions.”3,5

Page elaborates that bacteria and their components stimulate a dense infiltrate of inflammatory cells—including neutrophillic granulocytes, macrophages, and lymphoid cells—that activate the production and release of large quantities of proinflammatory cytokines and prostanoids.3 These especially include interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF-alpha), prostaglandin E2 (PGE2), and matrix metalloproteinases.3

In a review by Amar and Han,5 the authors succinctly and clearly recognize that the scientific evidence has increased in support of periodontal disease exacerbating certain systemic conditions. This conclusion is based on research that found significantly higher levels of circulating bacterial proinflammatory components (e.g., endotoxins) in people with severe periodontal disease compared to those with healthy gingiva.5 From studies on the systemic effects of proinflammatory cytokine levels possibly elevated by periodontitis, researchers began to hypothesize that periodontitis-induced elevations of IL-1 and TNF-alpha may contribute to the development of systemic diseases.5

How We Know the Link Is Real

There appears to have always been a hypothesis that a connection exists between oral and systemic disease. For example, the American Heart Association has long recommended antibiotic coverage for certain patients with heart defects during periodontal treatment, according to Dr. Kenneth A. Krebs, DMD, President of the American Academy of Periodontology (AAP). What’s more, he recalls being taught more than 30 years ago in dental school about the relationship between diabetes, periodontal disease, and inflammation as it pertained to slow healing.

But for the enlightenment that has ensued during at least the past 10 years, credit can be given to countless researchers for elucidating the relationship between periodontal disease and systemic disease. As a result of these endeavors, 3 mechanisms or pathways associating oral infections to secondary systemic effects have been proposed, including: metastatic spread of infection from the oral cavity as a result of transient bacteremia; metastatic injury from the effects of circulating oral microbial toxins; and metastatic inflammation caused by immunological injury induced by oral microorganisms.6

Although it is beyond the scope of this report to detail all of the essential research investigations that have contributed to our current understanding of this association, there are several that are considered landmarks. Beginning around 1997, the studies published by Genco et al from the State University of New York at Buffalo School of Dental Medicine—including work with the San Felipe and Santo Domingo communities of the Pueblo Indians in Santa Fe, NM—found that reducing gum infections with antibiotics also improved diabetes control, as well as that a 2-way relationship exists between periodontal disease and diabetes mellitus.7,8,9

Paramount to understanding the association between periodontal infection and diabetes is the fact that type 2 diabetes may involve the innate immune system and result from a chronic, low-level inflammatory process.5 Oral infection may be among the possible inflammatory triggers that lead to increased cytokine production, acute-phase protein synthesis, and subsequent insulin-resistance that results in type 2 diabetes.5

In terms of the connection between periodontal disease and its related bacteria to cardiovascular disease, stroke, infective endocarditis, and other heart conditions, the literature reported an association between dental health and acute myocardial infarction in 1989 with Mattila et al’s contribution in the British Medical Journal.10 Other heart related associations were addressed with reports by Mattila et al11 and DeStefano et al12 in 1993; Joshipura et al13 and Beck et al14 in 1996; and Grau et al15 and Genco et al16 in 1997. Numerous other citations are also among the literature.

In this arena, the association is thought to arise from the oral pathogens of periodontal disease intermittently reaching the bloodstream and inducing systemic inflammatory reactants and immune effectors against these bacteria.5 The chronic and intense local inflammatory response has been proposed to contribute to circulating mediators of inflammation that could initiate or exacerbate the inflammatory components of atherosclerosis.5 Further, periodontal pathogenic organisms have been implicated in cardiovascular disease based on their role in blood platelet aggregation, activation of the acute-phase response, and systemic production of proinflammatory mediators, among other mechanisms.5

Additionally, Offenbacher et al’s research and literature contributions from 1996 through 1998 are also considered among the driving forces in this area. In particular, his and his colleague’s endeavors have increased the broader healthcare profession’s knowledge of the association between oral disease and pregnancy complications.17,18,19

Amar and Han note that alterations in the levels of proinflammatory cytokines that result from the normal host response to an infection may be the key mechanisms by which infection (e.g., periodontal) is linked to preterm low birth-weight babies.5 They note that TNF-alpha and interleuken-6 (IL-6) have been shown to be increased in periodontitis and to cross human fetal membranes.5 This, the authors suggest, explains the plausibility that infections such as periodontitis that are remote from the genitourinary tract could still influence the fetal-placental unit.5

Research published in 2002 in the Journal of the American Geriatrics Society demonstrated that regular tooth and gum cleanings may help prevent pneumonia. In a study conducted in Japan among residents of 11 nursing homes, it was found that those residents whose teeth were regularly cleaned experienced fewer cases of pneumonia and were less likely to die from the infection.20 Those who were not given additional dental care were almost twice as likely to contract pneumonia and die from the infection. However, prior literature (e.g., Scannapieco FA, et al in 1996 and 199821,22), also proposed associations between oral conditions and pneumonia and respiratory disease.

Here, oral pathogens are thought to be aspirated into the lower airway, particularly in patients with severe periodontitis.5 Additionally, researchers believe anaerobic oral bacteria release biologically active products that may induce airway mucosa to stimulate inflammatory cytokine release from epithelial cells.5 Other mechanisms for the relationship between oral disease and respiratory disease are also proposed.

What We Now Know

It’s no longer a hypothesis. Periodontal bacteria can enter the bloodstream and travel to major organs, where it can begin new infections. The research suggests that this process may:23

a. Contribute to the development of heart disease, the nation’s leading cause of death
b. Increase the risk of stroke
c. Increase a woman’s risk of having a preterm low birth-weight baby
d. Pose a serious threat to people whose health is already compromised by diabetes, respiratory diseases, or osteoporosis

As a result of the collective research completed to date, the oral healthcare profession now knows that when looking at oral infection as a risk factor for stroke, people diagnosed with acute cerebrovascular ischemia have been more likely to have an oral infection when compared to those in the control group.23 And, researchers know that people with periodontal disease are almost twice as likely to suffer from coronary artery disease than those without periodontal disease.23

According to the AAP, the research base now suggests that pregnant women who have periodontal disease may be 7 times more likely to have a baby that is born too early and too small.23 Further, Offenbacher’s work concluded that 18.2% of preterm low birth-weight infants may result from periodontal disease.19 Therefore, the AAP recommends that women considering pregnancy undergo a complete periodontal examination.23 In terms of complications, if a pregnant woman with periodontal disease is treated, the incidence of her having a preterm low birth-weight infant is reduced by 82%, notes Williams.

And, as previously cited, when periodontal health is assured in diabetic patients, better glycemic control can be realized. “Diabetics have great difficulty controlling their blood sugar,” said Krebs, who has seen many patients at his office with diabetes, extensive periodontal problems, and poor glycemic control. “For numerous patients, once we get the periodontal infection under control, they are able to obtain better glycemic control of their diabetes.”

Implications for Dental Practitioners

According to Dr. Matthew Doyle, PhD, Director of Global Research and Product Development, as well as Clinical Operations and Professional and Scientific Relations at Procter and Gamble, dentists may be accountable in the future regarding early diagnosis for some of the conditions for which an oral-systemic association is now recognized. However, exactly what the potential legal ramifications could be to dentists for not properly diagnosing and treating oral diseases and/or identifying potential systemic risk factors is not clear at this time.

Additionally, dental and medical insurance companies will need “to be convinced that if oral disease is treated, it will have a positive impact on the systemic or physical health of the patient,” Rose noted. Further validation of the oral-systemic link could be the impetus for what some say is a long overdue unification of heretofore segregated healthcare administration.

In light of the oral-systemic association, Dr. Evanthia Lalla, DDS, MS, an Associate Professor of Dentistry at Columbia University School of Dental and Oral Surgery, emphasizes that dental clinicians can play a significant part in promoting the general health of their patients. Therefore, it is important for dentists to help patients understand that theirs is the role of healthcare provider, not just dentistry provider (See Putting What Is Known Into Practice, p. 40).

“When we provide better care, we also enhance therapeutic outcomes,” Lalla explains. “We—as dentists—are sometimes so focused on individual teeth and the mouth that we forget that they are part of a person who needs to be systemically managed. We can do our part in that.”

To this end, it may now be up to the dentist to educate patients on the meaning and significance of the presence of a bacterial infection and/or inflammation in their mouths. Rose acknowledges that dentists sometimes feel uncomfortable about providing their patients with comparisons, such as a bacterial infection in the mouth is no different than a urinary tract infection; it needs to be treated. But, he urges, it’s not enough to tell patients that they have inflammation. “You must tell them that they have an infection.”

Rose does caution against overstating the point and implying a cause-and-effect relationship. Although more research-based information is showing such a connection in certain areas, “you can’t tell patients that if they don’t floss, they’ll die,” he emphasizes.

Concurrently, communication and collaboration with colleagues in the medical profession to ensure proper and thorough patient care may become part of the treatment protocol.

“Especially when treating the patient with diabetes,” explains Lalla, “establishing a relationship and communication with the patient’s physician can provide dentists with a lot of information, particularly in terms of understanding his or her disease.” The rest of their treatment, she says, will come naturally. In fact, most often there is no need to do anything different, or incorporate a new technique, per se. Rather, all that’s required is a greater understanding of the disease and the individual.


To reiterate the point: the role of dentists will evolve such that they continue to be more proactive in managing oral disease and educating patients about the systemic associations, says Panagakos. This evolution will be fueled as the relationship between oral and systemic disease becomes more clearly defined—and as more knowledge is gained regarding the effects of periodontal treatment on systemic disease (See Increasing the Oral-Systemic Knowledge Base, p. 46).

This well-spring of new knowledge will likely bring with it a tide of recommendations for the general practitioner (See Putting What Is Known Into Practice, p. 40) in terms of how they incorporate a systemic approach into patient oral healthcare. “Dental health professionals—both the practicing dentist and the dental hygienist—are going to be at the forefront of this emerging oral-systemic area,” Doyle predicts. Therefore, with so much information currently existing (See References & Resources for More Information) and soon-to-be forthcoming regarding various systemic diseases and the implications that oral health can have on them, practicing dentists will need to stay abreast of the relevant literature in order to assume that pivotal role.

Combined, it will all serve to elevate the importance of oral care in the scheme of overall health and well-being, placing general dental practitioners in the position to more effectively facilitate health assessment and public health promotion. According to those we interviewed, that’s a very exciting and provocative proposition.

1 Kunzel C, Lalla E, Albert D, et al. On the primary care frontlines: The role of the general practitioner in smoking-cessation activities and diabetes management. JADA. 2005;136:1144-53.

2 U.S. Department of Health and Human Services. Oral Health in America: A Report of the Surgeon General. Rockville, MD: 2000.

3 Page R. Introduction to periodontal diseases: Clinical presentations, etiology, and pathogenesis. Public Health Implications of Chronic Periodontal Infections in Adults. Conference April 8-9, 2003, Atlanta, GA. Centers for Disease Control and Prevention.

4 Oral Opportunistic Infections: Links to Systemic Diseases.

5 Amar S, Han X. The impact of periodontal infection on systemic diseases. Med Sci Monit. 2003;9(12):RA291-9.

6 Li X, Kolltveit KM, Tronstad L, et al. Systemic diseases caused by oral infection. Clin Microbiol Rev. 2000;13(4):547-58.

7 Genco RJ, Glurich V, Haraszthy J, et al. Overview of risk factors for periodontal disease and implications for diabetes and cardiovascular disease. Compend Contin Educ Dent. 1998;19:40-5.

8 Grossi SG, Genco RJ. Periodontal disease and diabetes mellitus: a two-way relationship. Ann. Periodontol. 1998;3:51-61.

9 Grossi SG, Skrepcinski FB, DeCaro T, et al. Treatment of periodontal disease in diabetics reduces glycerated hemoglobin. J Periodontol. 1997;68:713-9.

10 Mattila KJ, Nieminen MS, Valtonen VV, et al. Association between dental health and acute myocardial infarction. Br. Med. J. 1989;298:779-81.

11 Mattila KJ, Valle MS, Nieminen MS, et al. Dental infections and coronary atherosclerosis. Atherosclerosis. 1993;103:205-11.

12 DeStefanno F, Anda RF, Kahn HS, et al. Dental disease and risk of coronary heart disease and mortality. Br. Med. J. 1993;306:688-91.

13 Joshipura KJ, Rimm EB, Douglass CW, et al. Poor oral health and coronary heart disease. J. Dent. Res. 1996;75:1631-6.

14 Beck JD, Garcia RI, Heiss G, et al. Periodontal disease and cardiovascular disease. J. Periodontol. 1996;67:1123-37.

15 Grau AJ, Buggle F, Ziegler C, et al. Association between acute cerebrovascular ischemia and chronic and recurrent infection. Stroke. 1997;28:1724-9.

16 Genco R, Chadda S, Grossi S, et al. J. Dent. Res. 1997;Special Issue 76:408. Abstract #3158.

17 Offenbacher S, Katz V, Fertik G. Periodontal infection as a possible risk factor for preterm low birth weight. J. Periodontol. 1996;67:1103-13.

18 Offenbacher S, Jared HL, O'Reilly PG, et al. Potential pathogenic mechanisms of periodontitis associated pregnancy complications. Ann. Periodontol. 1998;3:233-50.

19 Offenbacher S, Beck JD, Lieff S, et al. Roles of periodontitis in systemic health: spontaneous preterm birth. J. Dent. Educ. 1998;62;852-8.

20 Journal of the American Geriatrics Society. 2002;50:430-3.

21 Scannapieco FA, Mylotte JM. Relationships between periodontal disease and bacterial pneumonia. J. Periodontol. 1996;67:1114-22.

22 Scannapieco FA, Papandonatos GD, Dunford RG. Associations between oral conditions and respiratory disease in a national sample survey population. Ann. Periodontol. 1998;3: 251-6.

23 American Academy of Periodontology.


The Inside Look FROM...

The staff and publishers of Inside Dentistry gratefully acknowledge the time, insight, and candid comments shared by our interviewees, without which this inside look at the association between oral and systemic diseases would not have been possible. The following individuals—all well-respected in the dental industry and the academic and research arenas—made invaluable contributions to this presentation.


Kenneth A. Krebs, DMD
American Academy of Periodontology

Gerard Kugel, DMD, MS, PhD
Associate Dean for Research
Tufts University School of Dental Medicine

Evanthia Lalla, DDS, MS
Associate Professor
Columbia University School of Dental and Oral Surgery

Louis Rose, DDS, MD
Clinical Professor
University of Pennsylvania School of Dental Medicine
Professor of Surgery, Division of Dental Medicine
Drexel University College of Medicine

Ray Williams, DMD
Professor and Chair
Department of Periodontology
University of North Carolina School of Dentistry

Matthew Doyle, PhD
Global Research and Product Development
Clinical Operations and Professional and Scientific Relations
Procter and Gamble

Fotinos S. Panagakos, DMD, PhD
Associate Director
Clinical Dental Research
Research and Development Division
Colgate-Palmolive Company


Putting What Is Known Into Practice
Now that the association between oral infection and systemic disease is better understood, dental practitioners have an exciting opportunity to clinically manage their patients and broaden the scope of care they provide. And there’s no time like the present to incorporate new approaches to patient evaluations, examinations, and treatment planning.

“In doing so,” explains Dr. Ray Williams, DMD, Professor and Chair of the Department of Periodontology at the University of North Carolina School of Dentistry, “practitioners would not only be more effectively treating periodontal disease but, hopefully, more effectively reducing or minimizing the role of periodontal disease on systemic conditions.”

The Medical History
To this end, obtaining a complete medical history of the patient is critical, explains Dr. Kenneth A. Krebs, DMD, President of the American Academy of Periodontology, “particularly in light of the increased linkage between periodontal disease and some systemic factors.”

For example, Dr. Louis Rose, DDS, MD, a clinical professor at the University of Pennsylvania School of Dental Medicine and a professor of surgery in the Division of Dental Medicine at Drexel University College of Medicine, notes that dental practitioners “are really obligated to pursue in detail the medical history of a patient who presents with heart disease or diabetes to determine the degree of the disease and whether it is controlled or uncontrolled.”

Similarly, Dr. Foti Panagakos, DMD, PhD, Associate Director of Clinical Dental Research in the Research and Development Division of Colgate-Palmolive Company, advocates that dental practitioners not only obtain their patient’s medical history at the initial appointment, but also update it on a regular basis. This will require dental clinicians to discuss with the patient anything they find during the medical history review that may be a sign of something systemic. Additionally, if the patient were compromised by cardiovascular disease, he said, then the dentist would want to know that he or she is getting regular blood work completed, what the results are, what the cholesterol level is, etc.

The Examination
Patient examinations should include all oral structures (i.e., both hard and soft tissues, the tongue, and associated periodontal structures). Many also recommend a full periodontal probing, as well as a screening for oral cancers and check of the patient’s neck, throat, and lymph nodes.

If there are conditions such as cardiovascular disease or diabetes present, and the patient demonstrates gingival inflammation associated with periodontal disease, it may be necessary to refer the patient to a periodontist for treatment, says Krebs.

It’s important to note, however, that just because a patient presents with oral inflammation, it doesn’t mean that he or she will develop heart disease or another systemic disease, cautions Panagakos. There are many other components to the process that should be considered.

“Oral infection is only 1 piece of that, but it’s the piece that dental practitioners could have an impact on,” he said.

According to Dr. Matthew Doyle, PhD, Director of Global Research and Product Development, as well as Clinical Operations and Professional and Scientific Relations at Procter and Gamble, there are diagnostic techniques being developed that will enable early identification of a wide variety of systemic conditions—not just oral infection. He explained that because of the mouth’s biofluids—and its accessibility—dental practitioners will be able to assess patient health status from a diagnostic perspective. Such assessment may involve taking samples of saliva and crevicular fluid.

“A battery of health status assessments can be made using some of these molecular markers, and I think this is going to become part of the toolbox for the oral health professional as well,” he explained.

Patient Education & Clinical Management
Following the examination, communication with patients is essential to ensure their understanding of their condition and its implications. Panagakos notes that whatever is found in the oral cavity should be explained to the patient by stating that the condition identified in the mouth has been shown to have an association with cardiovascular disease, as an example. In this way, patients can be educated about their condition and motivated to try to enhance their oral home-care habits in order to improve their oral health. Rose recommends finding out what medications the patient is taking and advising the patient of the need to treat the oral infection.

Dr. Evanthia Lalla, DDS, MS, an Associate Professor of Dentistry at Columbia University School of Dental and Oral Surgery, suggests that when treating patients with diagnosed diabetes, dentists can help reinforce how important better management of both their diabetes and any oral infection is for them. This is particularly relevant in light of the known association between periodontal disease and diabetes.

Treatment Considerations
Panagakos explained that while dentistry has its standard therapies for treating oral disease, the profession is beginning to augment those treatments (i.e., mechanical, surgical types) with a team of therapeutic approaches. For example, clinicians are using topically applied products—either over-the-counter or prescription—or systemically administered therapeutics. Other agents are placed subgingivally to manage the infection and/or the inflammatory response.

“That area is really developing,” he explained. “There are antibiotics that are used as adjuncts, and we are seeing therapeutics that are being developed to manage the inflammatory response in other systemic diseases—such as Crohn’s or Rheumatoid arthritis—that someday might find their way into use specifically for managing oral inflammation.”

Additionally, Dr. Lalla notes that, in the case of diabetic patients, they should be considered as medically compromised. Although not necessarily requiring specific treatments, the manner in which they are treated may be different. For example, because such patients are more prone to severe periodontal disease, they may be scheduled for more frequent maintenance visits. Whereas an otherwise uncompromised patient may be able to withstand aggressive therapies, the diabetic patient may not, she explained.

“We won’t be doing something differently in the sense of a specific therapy,” Lalla said. “But we do need to be prepared to tailor treatment to the specific individual.”

A Check-List for Clinical Management
To integrate the oral-systemic mindset into the clinical management of your patients, those we spoke to advocate the following:

  • Consider yourself part of your patient’s overall healthcare team.
  • Evaluate the whole patient, not just the oral cavity, by taking a detailed medical history, reviewing it thoroughly, and updating it regularly.
  • Perform a complete and thorough oral examination (i.e., hard and soft tissues, all associated structures, periodontal probing, tongue, etc.).
  • Intervene early. If oral infection is identified and/or the patient presents with risk factors for periodontal disease (i.e., smoking, family history, poor oral hygiene) or other systemic conditions for which an association with oral disease is now known (e.g., diabetes, cardiovascular disease, osteoporosis, etc.), take steps to clinically manage the patient toward better oral and systemic health (i.e., smoking cessation programs, routine oral cleanings, etc.).
  • Educate the patient about the importance of oral health maintenance.
  • Establish prevention and treatment strategies that are tailor-made for the individual patient.


Increasing the Oral-Systemic Knowledge Base
Most industry experts agree that the definitive study on the link between oral and systemic diseases is not yet taking place. The high-quality research necessary is costly and would span a number of years before the data could be reviewed and analyzed. Further, because such an investigation would need to be a prospective study with a large number of patients involved, only 1 disease category at a time could likely be explored, whether cardiovascular, respiratory, or other systemic conditions.

“For a study of this size and magnitude, I am not sure 1 entity would be able to support and undertake it independently from others,” commented Dr. Foti Panagakos, DMD, PhD, Associate Director of Clinical Dental Research for the Research and Development Division of Colgate-Palmolive Company. “I see support for such large-scale initiatives coming from a collaboration between government, foundations, and industry.”

However, industry is supporting research in this area, asserts Dr. Matthew Doyle, PhD, Director of Global Research and Product Development, as well as Clinical Operations and Professional and Scientific Relations at Procter and Gamble. “Each of the oral care manufacturers has some level of activity or participation in this area,” he said.

And, on a national level, initiatives are underway to supplement the body of knowledge currently available and broaden both the medical and dental professions’ understanding of the link between oral and systemic diseases. According to Dr. Ray Williams, DMD, Professor and Chair of the Department of Periodontology at the University of North Carolina School of Dentistry, among them is the PAVE Study (Periodontitis and Cardiovascular Events), sponsored by the National Institute of Dental and Craniofacial Research (NIDCR). This multi-center investigation aims to determine if treating periodontal infections will lead to fewer heart problems in patients at risk for cardiovascular disease. The research is based on growing evidence of a strong association between infection and atherosclerosis, as well as a specific link between periodontal infection and heart disease.

The PAVE Study is a pilot randomized clinical trial to test the feasibility of selecting and refining a periodontal infection treatment and examining the effect of that treatment on future heart events. Five investigational centers—the State University of New York at Buffalo (lead and overall coordinating center), the University of North Carolina, Boston University, Kaiser Permanente/Oregon Health Science University, and University of Maryland—and a data coordinating center at the University of North Carolina are involved. A team of cardiologists, periodontists, epidemiologists, infectious disease specialists, biostatisticians, and others has been assembled to accomplish the research objectives.1

According to Dr. Louis Rose, DDS, MD, a clinical professor at the University of Pennsylvania School of Dental Medicine and a professor of surgery in the Division of Dental Medicine at Drexel University College of Medicine, the research definitely supports the fact that dental practitioners and researchers need to communicate with their medical colleagues in order to properly treat patients. He says more needs to be done to publish relevant oral-systemic research findings in medical journals and share this information in medical lectures.

In this regard, inroads have already been made. According to Doyle, who is a member of the National Advisory Research Council at the National Institutes of Health (NIH) and NIDCR, the NIH worked very closely with the Office of the Surgeon General in developing the landmark Oral Health in America: A Report of the Surgeon General. In the report, the link between oral and systemic health was cited as one of the important public health issues of our time.

“Little by little, this [collaborative understanding among medical and dental professionals] is happening,” Rose explains. “Physicians are becoming aware of this relationship. They wanted to see the research, and now we’re showing it to them, which is important.”

1 Periodontitis and Cardiovascular Events or "PAVE".


Where Can We Do More?
Dentistry’s growing evidence supports an increased primary and preventive care role for dentists. However, results of a recent survey published in the August 2005 issue of the Journal of the American Dental Association (JADA) suggest that some members of the profession still have not overcome their own attitudes toward their role in actively managing patients who smoke and patients who have diabetes.1

The survey was designed to assess dentists’ active involvement with in-office smoking cessation activities and management of the patient with type 1 and type 2 diabetes. The researchers found that the majority of general dental practitioners reported having a lack of knowledge about those areas.1 Additionally, respondents viewed such activities as “peripheral” to their role and disagreed that colleagues and/or patients expected them to perform such activities.1 More general dental practitioners performed both activities on an assessment/advisement basis than on an active management basis.1

Dr. Evanthia Lalla, DDS, MS, an Associate Professor of Dentistry at Columbia University School of Dental and Oral Surgery and a co-author of the JADA article, said helping dental professionals change their role in managing these 2 aspects of oral-systemic health requires not only increasing knowledge, but also overcoming attitudes.

“One of the things we tried to do with this survey was not only look at what practitioners were doing, but also why they were doing it,” Lalla explained. “If you think that what you’re doing is appreciated by your patients and your colleagues, that’s important and you’ll change your role.”

Paramount to changing attitudes, she said, is making dentists aware that they truly are healthcare providers; that by improving clinical outcomes—by helping a patient quit smoking or better managing his or her diabetes—they are promoting the general health of their patients. “We have to forget about being isolated to the mouth, because we now know that the mouth mirrors the body,” she said.

Furthering continuing education and awareness efforts in the area of oral-systemic disease associations may help change that. Additionally, Lalla admits that part of what may be required throughout the profession is a change in the curriculum at dental schools to focus more on the patient systemically, not just on teeth and restorations.

“This all might take much more time than we think,” she admits, “but I think that’s where the profession is and should be going.”

Dr. Gerard Kugel, DMD, MS, PhD, Associate Dean for Research at Tufts University School of Dental Medicine, shares similar feelings. In particular, he asserts that an oral medicine course in the dental school curriculum that makes the oral-systemic association relevant to students can help the future generations of the profession more astutely view the oral cavity as a window to the body.

“First, dental schools should make oral medicine lectures more relevant to students by targeting the oral cavity as an opportunity to help diagnose and manage diabetes and other systemic conditions,” Kugel said. “Secondly, as practitioners, we are very accustomed to charging for the procedures and services we provide. Incorporating an oral-systemic approach isn’t always something you can bill for.”

However, such fees can be worked into the overall, comprehensive visit. That’s something that could involve taking blood pressure, possibly prescribing medications to control periodontal infection and/or assist patients in managing their smoking cessation efforts, and actively encouraging and educating patients about the proven long-term health benefits associated with caring for their teeth and gums. Performing hard- and soft-tissue examinations, in addition to a head and neck exam that includes the lymph nodes, now makes the dentist the patient’s first line of defense against disease. Both Lalla and Kugel point out that, in many cases, patients will see their dentists more frequently than they see their physician.

Lalla and her co-authors’ article sums it up best. Dentists are poised to play an increasingly preventive and primary care role in their patients’ health. As such, they can be afforded opportunities to expand the boundaries of dental practice, improve therapeutic outcomes, and promote patients’ overall health.1

“If we take a slightly more aggressive approach at looking at the oral-systemic disease associations,” said Kugel, “we not only gain more respect in the medical community, but we can also begin to think of ourselves as physicians—not technicians—of the oral cavity.”

1 Kunzel C, Lalla E, Albert D, et al. On the primary care frontlines: The role of the general practitioner in smoking-cessation activities and diabetes management. JADA. 2005;136:1144-53.




Without question, dentists are well-equipped and skilled to address conditions in the oral cavity. However, some note that with the changing paradigm of what it means to provide comprehensive oral care may come a need for additional information and education.

In early 2006, the American Academy of Periodontology (AAP) will make available treatment referral guidelines. According to Dr. Kenneth A. Krebs, DMD, President of AAP, these highly-requested guidelines will assist general dental practitioners in assessing a patient’s level of disease and determining when it is appropriate to refer patients to a periodontist.

Additionally, Krebs encourages attendance at any of the numerous lectures about the link between oral and systemic diseases that are scheduled for the AAP and American Dental Association (ADA) annual meetings, respectively. “There are numerous courses available, and more information is coming to the forefront in journals,” he added.

What the oral healthcare profession is witnessing today is an evolution, notes Dr. Foti Panagakos, DMD, PhD, Associate Director of Clinical Dental Research in the Research and Development Division of Colgate-Palmolive Company. The subject of oral-systemic relationships, he says, is receiving prominent attention from professional associations—including the ADA, the AAP, and the Academy of General Dentistry (AGD).

“As a result, practitioners are able to access the information they need to develop a comfort level in this area that will translate into application within the realm of their practice,” Panagakos said.

Among the many resources available offering information about the association between oral and systemic diseases are those listed below. Additionally, the citations referenced throughout the accompanying article represent just some of the comprehensive sources available regarding the research that’s taken place thus far.

American Academy of Periodontology

Centers for Disease Control and Prevention

National Institute of Dental and Craniofacial Research

National Institutes of Health

PubMed—the National Library of Medicine


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