AGD - Academy of General Dentistry

Todd Smith, DDS, MSD, and Carolyn Cooper, chairside dental assistant, perform ultrasonic scaling on a patient.

Every breath 29-year-old Native American Mr. B. took made him feel as though he were inside an oven. He dropped his empty soda can into the recycle bin outside the doors of the Phoenix Indian Medical Center (PIMC) so as not to reveal his indulgence. The doctor forbade candy and colas. Since he had been diagnosed with Type 2 diabetes and high blood pressure, Mr. B could not enjoy his favorite Native American foods. His teeth were giving him trouble, and his physician at the hospital told him, “Dental care is pretty important, given your medical issues.”

At the clinic, PIMC periodontist Todd Smith, DDS, MSD, was ready for him. Not only did Mr. B. have a systemic disease associated with periodontitis, but Dr. Smith decided to monitor him longitudinally to help study the link between oral disease and overall health. Keeping records that chronicle Mr. B.’s disease, intervention, and outcome was important to Dr. Smith, a Diplomat of the American Academy of Periodontology (AAP).

This is a true story, and while the patient’s name and a few details have been changed, his care provides a classic case study of how dentistry’s foot soldiers are making an effort to move beyond the oral cavity.

To recap what most dentists already know, chronic periodontitis is associated with certain diseases and conditions that seriously impact overall health and vice versa. The strongest evidence when it comes to a risk factor of any kind is that diabetes is a risk factor for periodontitis. Four risk factors for systemic disease or medical conditions linked to periodontitis have been identified: Type 2 diabetes, cardiovascular and coronary heart disease, adverse pregnancy outcomes, and bacterial pneumonia. The pathological processes largely implicated in chronic oral infections’ association with overall body diseases are the result of inflammatory cytokines (inflammatory response process) that increase the production of white blood cells and possibly change blood vessel linings and increase clotting; in effect, these cytokines turn the body against itself. It has been theorized that even distant organs can become inflamed. Whether the evidence shows a causal relationship between oral disease and these systemic diseases (or the former predicts onset or worsening of the latter) is a source of controversy.

While the research concerning the existence of strong risk factor links (or even causation) between oral and systemic health is coming together at a glacial pace, many dental organizations, product manufacturers, and the insurance industry are discussing the issue. If anything, oral health professionals will hear more about the link between oral and overall health in coming years as groups are uniting to promote the agreed-upon convention that periodontitis is a suspected risk or cause for systemic disease or its complications.

The AAP and Oral Health America’s National Periodontal Coalition, as well as public health agencies, are looking past the oral cavity. The Indian Health Service (IHS), serving Native American Indian and Alaskan native people, is giving “screening” a new meaning.

In 1998, PIMC Dental began a program to improve the periodontal health of patients with diabetes; as of January 2008, 3,045 patients had been enrolled and treated through this program. Patients with gingivitis or moderate periodontitis are treated with standard nonsurgical periodontal therapy, including coronal scale and polish, scaling and root planing (where indicated), oral hygiene instruction, and recall. Diabetic patients with moderate to advanced periodontitis are treated more aggressively, with what the IHS calls the Diabetic Periodontal Protocol. This protocol was developed from the findings of a periodontal treatment study (Journal of Periodontology, August 1997) on the Gila River Indian Community in Sacaton, Ariz. Dental patient care coordinators actively reach out to those with diabetes to encourage them to seek oral care. Prevalence of diabetes is highest in Native American and Alaskan Native populations. According to the National Institutes of Health, the Pima Indians on the Gila River area of Arizona (a population of around 11,000) may be the smallest community in the country to have its own dialysis center—half of this population has diabetes, with patients diagnosed on average at age 36. Furthermore, the IHS is doing something to teach its patients and the physicians about the systemic links to periodontitis. The “Periodontal Disease Quick Screening Tool” is a poster that hangs in medical clinics; it includes photos designed to educate patients and alert medical staff to the need to screen the oral cavity and refer patients to dentists.

Dr. Smith says, “I often see improvement in blood sugar control in our patients with moderate to severe periodontitis who are treated with the [Diabetic Periodontal] Protocol, possibly as a result of reducing or eliminating the intraoral gram-negative anaerobic infection, which decreases local as well as systemic inflammation. This has been reported in the literature, particularly in the past 15 years or so. Though there are many other factors at play in terms of metabolic control—obesity, diet, exercise, acute infection, genetics, and so forth—it does appear that periodontal infection can aggravate diabetic control and increase diabetic complications.” Such complications can include heart disease and diabetic kidney disease.

“I strongly feel that medical providers should refer all patients with diabetes for regular dental care, and dentists should expedite referrals back to their provider when diabetic symptoms or complications get worse,” Dr. Smith says. As an all-in-one superstore might offer a tire rotation, groceries, and clothing, the idea of seamless health care—which has yet to be worked out in Veterans Medical Centers—is being worked out in the IHS. PIMC, in particular, has dental and medical facilities housed in one building.

And Dr. Smith doesn’t shy away from doing a finger-stick blood test in the dental chair. “Before I do an extraction, I want to know patients’ blood sugar, to know if I should put them on an antibiotic.”

Chris Halliday, DDS, MPH, RADM, Chief Dental Officer of the U.S. Public Health Service and Indian Health Service in Rockville, Md., explains why he thinks the MD-DDS relationship bonds need to be stronger. He says, “Physicians often see pediatric patients with rampant decay before dentists do, while dentists often see patients who have indicators of systemic diseases before the patient has had a medical check-up. We need to strengthen the communication between the dental and medical professionals.” Dr. Halliday feels that dentists should review the research on oral-systemic studies and should not hesitate to call medical researchers for clarification.

The Academy of General Dentistry (AGD), the American Dental Association (ADA), and the AAP long have been interested in oral-related studies, including oral-systemic research, but the American Medical Association (AMA) has not offered much on the subject since “Oral and Systemic Health: Exploring the Connection,” a 2006 joint press conference held with the ADA.

In an editorial in the Journal of Oral Maxillofacial Surgery (August 2007), Dr. L.A. Assael points out that a study (Journal of the American Dental Association, February 1999) of 678 aging nuns found that excellent oral health was associated with high levels of cognition and lifespan. Alternatively, a 2005 study of 109 pairs of identical twins found that an inflammatory burden early in life, such as chronic periodontitis, increased the risk for Alzheimer’s disease onset fourfold. Furthermore, Dr. Assael writes, the public may be more aware of the link between oral and systemic health than the dental profession realizes, as surveys have yet to tackle this. However, when dentists advocate for health of the oral cavity with this in mind, says Dr. Assael, “they are unfortunately deemed by the public and politicians to be self-serving.”

At “From Basic Science to Clinical Practice and Policy: A Medical-Dental Dialogue on the Relationship Between Periodontal Disease and Systemic Health,” a New York Academy of Sciences (NYAS) event held Jan. 18, 2008, physicians and dentists discussed periodontal research, treatment, and policy changes in medical-dental education. Mary Lee Conicella, DMD, FAGD, national director of clinical operations, Aetna Dental, Hartford, Conn., attended the NYAS course (which Aetna sponsored) and said that the speakers were “dentists and physicians involved in the ongoing research.” She remarked about its uniqueness, saying, “in most professional circles, these two groups get their CE separately,” and here dentists and physicians were “learning symbiotically.”

The event provided a venue for dentists and physicians to discuss the data and the ways in which the professions can collaborate on patient care. “This was a great opportunity for both professions to gain exposure to the current research because the major studies sometimes do not reach each others’ literature,” says Dr. Conicella.

But the medical profession still appears to be hesitant to enter into a very close relationship with dentistry. Still fresh on the medical profession’s mind might be the cooling off, or at least backing away from, the “Prevention of Infective Endocarditis: Guidelines from the American Heart Association” (1997); the 2008 revised guidelines show major changes, indicating that the risk of dental procedures causing infective endocarditis is extremely low and that only highly specific situations require antibiotic prophylaxis by dentists. According to the British Dental Journal (March 2008), antimicrobial prophylaxis for dental procedures in those at risk for infective endocarditis no longer is the standard recommended procedure. Subsequent studies and evaluations of the data that prompted the international cardiology associations to take steps to prevent deadly risks from dental procedures determined that the reasoning was “unsupported and unproven by science.”

The American Diabetes Association is the only major medical association identified with an oral health symposium. This is because enough research has shown that infection anywhere in a diabetic’s body (including the mouth) puts that person at risk for infection/inflammation throughout the body, fever, and life-threatening events.

Debora Matthews, DDS, MsC, head of the Division of Periodontics and full professor in the department of Dental Clinical Sciences at Dalhousie University in Halifax, Canada, and author for and editorial board member of the journals Evidence-Based Dental Practice and Evidence-Based Dentistry (EBD), says, “Reading summary articles by authors with experience and critiquing scientific literature can be a tremendous time-saver for a general dentist or physician.” Dr. Matthews says to ensure that a study effectively answers questions about causality of or risk for a disease, it must “establish temporality (the suspected risk factor is present before the disease manifests), specificity (the risk factor is specific to that disease), and show a dose response gradient (the greater the amount or time of exposure to a suspected risk factor, the more severe the disease).”

Evie Lalla, DDS, MS, associate professor of dental medicine in the division of periodontics at Columbia University College of Dental Medicine in New York, wants to see medical and dental care providers collaborate closely for the best management of their common patients. Specifically in the case of diabetes, she would like dentists to start assisting medicine in identifying undiagnosed individuals. This is a serious public health concern, as currently approximately one third of the people with diabetes remain undiagnosed and therefore untreated.

Based on a recent study at Columbia (Journal of Periodontal Research, 2007), Dr. Lalla suggests that if a patient’s medical history includes a family member with diabetes and self-reported high cholesterol and blood pressure, and the dentist detects periodontal destruction, it’s likely that the patient has diabetes and does not know. In such instances, dentists need to take action. When identifying at-risk patients, dentists need to inform these patients and refer them to a physician for diagnostic testing and appropriate follow-up treatment.

Textbooks such as Modern Epidemiology deserve a look by those wanting to understand the oral-systemic data. Even seasoned researchers keep abreast of the best ways of handling “confounding” (confusion of the effects) evidence and “effect modification” (problem with the effect) in study design by skimming new statistics and epidemiology textbooks for updates. Evidence-based reviews of randomized controlled clinical trials tend to comment on study methodology, which allows readers to know whether the design of the investigation was tightly constructed.

Philippe Hujoel, LTH, MSD, PhD, is a professor in the Department of Dental Public Health Sciences and the Department of Epidemiology at the University of Washington in Seattle. He summarizes his view of the body of literature on the oral-systemic link: “If one tries to link destructive periodontal disease to heart disease, diabetes, or other chronic diseases, destructive periodontal disease will spuriously appear as a cause of these diseases. It is only when one adjusts in a comprehensive fashion for tobacco and eating habits that one can truly find out if indeed destructive periodontal disease ‘causes’ other health problems…. Few studies have done this. Most do not report results among never-smokers, which is critical if one wants to find out true relationships, and even fewer take into account unhealthy eating habits.”

Finnish researcher Pekka Ylöstalo, DDS, MSocSci, agrees with Dr. Hujoel, saying that her assessments (Journal of Clinical Peridontology, 2006) caused her to conclude that “many oral epidemiologists do not fully understand the importance of handling confounders of data analysis.”

Robert Genco, DDS, PhD, a State University of New York at Buffalo Distinguished Professor, a Harvard visiting professor, and former editor/editor-in-chief of the Journal of Periodontology, noted that most studies attempt to control for confounders. While it may not be adequate in some studies, never-smokers have been assessed in some studies (European Journal of Epidemiology, October 2007). Dr. Genco notes, “One of those studies was recent and did in fact show a relationship between periodontal disease and heart disease in never-smokers.”

While researchers debate whether adjustment for confounding by smoking in other studies is adequate or inadequate, Dr. Genco believes, “Most epidemiologic studies are published in excellent peer-reviewed journals with reviewers requiring adequate handling of confounders.”

The major insurance players all have dangled sweetened dental benefits to members who have certain systemic conditions. According to Dr. Conicella, this trend in the industry began after an Aetna/Columbia University study illustrated that early treatment of periodontitis lowered the resultant cost of treating these members’ overall diseases. Not only is periodontal therapy (regardless of whether it has been solidly proven as an effective intervention to reduce complication risks of systemic disease) associated with lower costs, it also doesn’t cost a lot to offer it to the narrowly eligible members. Meanwhile, members relish the thought that they “qualify” for a “free extra benefit level,” making it a win-win situation.

In 2006, CIGNA Dental launched its “Oral Health Integration Program,” with new initiatives that expanded on its previously launched CIGNA Dental Oral Health Maternity Program and Dental Oral Health Diabetes and Cardiovascular Programs. In 2007, Aetna began offering a “Dental/Medical Integration (DMI)” program for pregnant and at-risk members with diabetes and cardiovascular disease (CVD) at no extra cost to the policy holders. The enhanced DMI benefits include an extra cleaning and full coverage for certain periodontal services. This new payout was deemed a good deal for the patient and the company as a result of collaborative research with Columbia University College of Dental Medicine. A study from BMC Health Services Research (2006) reports that medical costs for three systemic diseases (diabetes, coronary artery disease, and cerebrovascular disease) were lowered when individuals identified with at least one of these systemic diseases sought earlier dental care.

Using claims data from 2003, Blue Cross Blue Shield of Massachusetts (BCBSMA) learned that when its members with diabetes received dental prophylaxis and/or nonsurgical periodontal therapy, they had medical costs $144 per member per month (pmpm) lower than those who did not seek dental care. In addition, members with coronary artery disease had medical costs $238 pmpm lower than those who did not seek dental care annually. BCBSMA Vice President Joseph Errante, DDS, of Boston, reported that the company’s outreach calls and letters to targeted members increased the members’ compliance with seeking dental care by 32 percent in 2006 and by 38 percent in 2007.

According to the American Diabetes Association (2008), annual medical costs for diabetics are estimated at $11,744 per person, compared with $2,560 per person for nondiabetics. Heeding the data, which showed that lowering the gycosylated hemoglobin (HgA1c) (glucose control) by one point lowers diabetic complication risks by 40 percent, Delta Dental of Michigan, Ohio, and Indiana was compelled to reduce medical complications and dollars paid out by the company. They, too, doubled the number of prophylaxes annually among diabetics; pregnant members with periodontitis; those with kidney failure or receiving dialysis; patients receiving chemotherapy, radiation, bone marrow or organ transplant; or those with HIV infection. This Delta Dental and Delta Dental of Tennessee also approved paying benefits for an early detector for oral cancer, OralCDx® BrushTest™. According to Jed Jacobson, DDS, MS, MPH, senior vice president of professional services and chief science officer of Delta Dental of Michigan, Ohio, Indiana, and Tennessee, the company paid benefits for an oral diagnostic to prevent a systemic diagnosis because the detector’s accuracy is “substantially greater than other accepted life-saving tests, such as the Pap smear, mammogram, or prostate PSA test.” By the time oral cancer is detected and diagnosed through conventional biopsy, it can be at an advanced stage.

It may sound like it was a snap decision for the insurance industry to increase dental benefits; however, Dr. Jacobson says that Delta Dental’s Research and Data Institute had to weed through a collection of dental claims data that may be “the most extensive in the world—more than 10 terabytes of information—comparable to the estimated print content in the U.S. Library of Congress.”

Interestingly, both Delta Dental and Aetna are listed on the Web site of the Partnership to Fight Chronic Disease, an organization described as a nonpartisan coalition of leaders from health care business, policy, and labor communities “committed to making chronic disease the key health care issue in the 2008 presidential election.”

What do the data show us about causal effects of periodontal pathogenic bacteria or inflammatory molecule burden? From the available evidence, it is a little early to use the word “cause” in the same sentence as “periodontitis” and “systemic disease.” Dr. Matthews explains that parties with conflicts of interest often jump the gun by drawing conclusions from studies without convincing statistical design. She says, “That is why it seems that one week the media tell you red wine will increase your risk for a heart attack, and the next week, it says that drinking red wine is protective.” Dr. Matthews said it would behoove the profession and patients if all new dental graduates knew how to judge the quality of evidence.

Dr. Genco has been a pioneer in many of the studies relating periodontal disease to diabetes and cardiovascular disease. He recognizes that there is a large body of literature discussing the periodontal-systemic link and suggests that reading review articles and recent papers that can be accessed through PubMed on a regular basis may help dentists stay abreast of the data in this rapidly advancing field. “Do that, and you are up on the literature. Or, e-mail known authors in the field, and they will e-mail you their papers,” he says.

In 2007, Michael Glick, DMD, editor of the Journal of the American Dental Association, cautioned researchers, in the interest of doing good, against trying to “claim causation by means of leaps of faith rather than by scientific rigor.” In the article, he says that: “A risk factor for a specific disease in certain populations does not tell the whole story, because susceptibility is an individual-by-individual proposition.

“Odds ratios and relative risk values reported in available epidemiologic studies on the association between oral and non-oral diseases and conditions are not sufficient to distinguish people who will develop non-oral maladies from those who will not.”

According to Dr. Ylöstalo (Journal of Clinical Periodontology, February 2006), uncontrolled or partially controlled confounding and effect modification may induce spurious associations between oral and systemic diseases, which could explain the variation in study findings. Dr. Hujoel and colleagues and Bruce Pihlstrom, DDS, MS, have pointed out that subjects with cardiovascular disease may be smokers (and may be too embarrassed to admit it when participating in health care studies) and that the possibility that subjects hide the fact that they smoke is rarely considered in studies.

Dr. Genco counters that suggestion and says that there are multiple solid studies that have been adjusted for many possible co-risk factors; there also are several randomized and controlled periodontal intervention studies. He refers to a 2005 study in Diabetes Care and a 2007 report in the European Journal of Epidemiology that show that periodontal disease is a risk factor for cardiovascular disease in nonsmokers.

He says, “There is noise in the epidemiology, but the evidence gathers every year rather than getting less strong. We clearly need randomized control trials before we can recommend that prevention or treatment of periodontal disease will prevent or modulate systemic diseases. For diabetic glycemic control, and for prevention of respiratory disease, pilot randomized control trials exist. We now need large multicenter trials in several populations to fully establish the efficacy, if any, of periodontal interventions.”

Oral disease is associated with diabetes control, cardiovascular disease, respiratory infection, and pregnancy complications, but exactly what that association is remains unanswered. Control of overall health and preventing or minimizing systemic disease is beneficial to maintain oral health. This two-way relationship likely will result in a slow but steadily increasing phenomenon of physicians and dentists working together—if only through increased communication—to co-manage the total health of patients. A 2007 study in the Journal of Periodontal Research found that 25 to 50 percent of dental patients from the third National Health and Nutrition Examination Survey with a family history of diabetes, hypertension, high cholesterol, and current periodontal disease probably had undiagnosed diabetes.

Perhaps it is time for dentists to fulfill their screening capacity by instructing patients to check their blood sugar if those risk factors are identified. It is important for oral health care providers and physicians to communicate patients’ health histories to prevent adverse outcomes. Patients will recognize the importance of sharing oral health conditions with physicians who are monitoring their conditions. We can expect patients who read their insurance policies and find that their “special” medical-dental issues make them eligible for enhanced benefits to discuss this topic at the dental office as well.

Dentists should not feel that they can only think about, look at, and limit their expertise to the mouth, according to Dr. Halliday. “The mouth can be viewed as a mirror, providing an image that can gauge the general health status of an individual, and there is no doubt of a relationship between oral health and quality of life. There are opportunities for all health care providers to work together to improve a patient’s overall health.”

To comment on this article, send an e-mail to impact@agd.org.

1. The possibility that poor pregnancy outcomes increase from periodontitis awaits the completion of several high-quality randomized controlled trials, since the evidence to date has been mixed. It may turn out that periodontitis is not specifically a low-birthweight risk, for example, but a stillbirth and spontaneous abortion risk.

2. Increase in stroke risk for periodontitis sufferers is bedeviled by mixed study findings. More systematic reviews that include prospective studies are needed.

3. Coronary heart disease incidents have shown a small but strong association with the presence of periodontitis. According to Dr. Matthews, one recent systematic review showed periodontitis as a stronger risk factor than hyperlipidemia, obesity, or smoking. What is missing are interventional treatment trials. Because cardiovascular disease has so many risk factors, it likely will be years before this relationship is better defined.

4. Bacterial respiratory infections (pneumonia mortality), especially in the intubated, are shown to be preventable by oral hygiene. Dr. Genco noted that several pilot randomized control trials have shown that simple twice-daily oral cavity swabbing with chlorhexidine can reduce the incidence of respiratory infection by 30 to 50 percent over a two-year period.

5. Diabetes blood sugar control problems are associated with periodontitis (and any other type of bodily infection), but large, multi-center clinical trials with multiple treatment modalities and diabetes endpoints are needed to show if periodontal therapy will have a beneficial effect on blood sugar levels. Another concern is that diabetics risk tissue damage (glucose attached to proteins can cause blood vessels to balloon, thicken, or weaken) when compromised sugar control and inflammatory cytokines are in the bloodstream long-term, making these patients more prone to circulatory impairment, heart and kidney disease, and other possible diabetes complications.

6. Insurance companies are acting on existing information in the literature, as well as their claims data suggesting that management of periodontal disease will assist in the modulation of systemic diseases, such as diabetes and cardiovascular disease.

1996: The Journal of Periodontology publishes a supplement summarizing studies relating periodontal disease to heart disease, diabetes, low birth-weight, and respiratory diseases.

1997: Sunstar Oral-Systemic Disease Symposium at UNC Chapel Hill: The first-ever symposium about the oral-overall health link that brought together physicians and dentists.

1998: Compendium prints a supplement on periodontal aspects of systemic health.

2000: With the release of the landmark Oral Health in America report, then-Surgeon General David Satcher, MD, PhD, says, “New research is pointing to associations between chronic oral infections and heart and lung diseases, stroke, low birth-weight, and premature births. Associations between periodontal disease and diabetes have long been noted. Oral health must be a critical component in the provision of health care, and in the design of community programs.”

2001: American Academy of Periodontology (AAP) and National Institutes of Dental and Craniofacial Research (NIDCR) hold “The Periodontal-Systemic Connection: A State of the Science Symposium,” and its proceedings are published in the Annals of Periodontology.

2006: Journal of the American Dental Association publishes the supplement The Oral-Systemic Disease Connection, and Scientific American produces a special issue, “Oral and Whole Body Health.”

2007: A panel of 18 leaders involved in the oral-systemic research (seven of whom were physicians) meet in Scottsdale, Ariz., for “The Scottsdale Project,” a summit designed to evaluate the literature, report on the strength of the data for existing systemic disease associations, determine whether guidelines could be developed for medical-dental interaction on behalf of patient care, and report their findings to the dental and medical professions. The panel’s findings, “Report of the Independent Panel of Experts of the Scottsdale Project,” were published in September, in a supplement to the clinical journal Grand Rounds in Oral-Systemic Medicine.

2008: New York Academy of Sciences (NYAS) holds the meeting “From Basic Science to Clinical Practice and Policy: A Medical-Dental Dialogue on the Relationship Between Periodontal Disease and Systemic Health,” drawing more than 160 attendees.

The American Association of Periodontology hosts an invitation-only, multidisciplinary meeting entitled “Inflammation and Periodontal Diseases: A Reappraisal,” in Boston (proceedings available as a supplement to the Journal of Periodontology in August 2008).

In June 2008, the American Diabetes Association 68th Scientific Session includes “Links Between Periodontal Disease and Diabetes,” a symposium on acute and chronic complications.