In 2017, Shawn Kane M.D., said “the oral cavity is the intersection of medicine and dentistry and the window into the general health of a patient”.  Bidirectional relationships between oral and systemic conditions are becoming better understood and scientific research is plentiful. The health of your mouth appears to have a profound impact on the rest of your body. Hippocrates was ahead of his time when reportedly he cured systemic conditions by pulling infected teeth. Even low-grade gum disease has been associated with serious systemic problems. Your mouth mirrors what is happening in your body and equally some systemic conditions produce signs in the mouth. An estimate of more than 100 systemic diseases and upward of 500 medications have oral manifestations. To understand the general term of oral systemic health we should look at the diseases related to poor oral health and periodontal disease.

Cardiovascular Disease, Endocarditis and Strokes

Endocarditis is an infection of the inner lining of your heart chambers or valves typically when bacteria or other germs from another part of the body spread through your bloodstream and attach to certain areas of the heart. If you have been in dentistry for a long time you are very aware of the changes of recommendations from the American Heart Association in regard to pre-medicating patients prior to dental treatment to help prevent endocarditis.  Cardiovascular disease has probably been the most studied of all relationships with systemic health and periodontal disease. In 2017 a landmark study published in Post Graduate Medical Journal proved a causal relationship between periodontal pathogens and heart attacks.¹ Just the year before in a 2016 meta-analysis ² of 7000 people found those with periodontitis were more than twice as likely to suffer heart attacks as compared to people with healthy gums. This data is far from new. In 2008 an analysis published in the Journal of General Internal Medicine found that periodontal disease was a risk factor for heart disease separate from other risk factors. ⁴ In 2018 the American Heart Association published a study confirming the independent association between periodontal disease and incident stroke risk, particularly cardioembolic and thrombotic strokes.

Pregnancy outcomes, cancer and rheumatoid arthritis

Scientific research also shows the association between gum disease and pre-term, low birth weight babies. There has been research also showing that oral bacteria, specifically Fusobacterium nucleatum,  traveling through the bloodstream have been found to cause stillbirth.⁴  Bacteria in the mouth have been linked to oral, esophageal, lung, colorectal, pancreatic and breast cancers.  A 2016 study found that subjects who had high levels of Porphyromonas gingivalis (Pg) had a 59% greater risk of developing pancreatic cancer. Harvard School of Public Health found men who had a history of periodontal disease have a 64% greater chance of having pancreatic cancer.  Since inflammation is related to cancer the answer may be the bacteria could cause inflammation in the pancreas or the bacteria could simply be a marker for cancer-causing inflammation. All the way back in 1926 an association was found between periodontal disease and rheumatoid arthritis which has led to research showing the inflammation caused by periodontal disease may be a key initiator of the systemic autoimmunity seen in rheumatoid arthritis. In one study, patients who were diagnosed with periodontal disease, with higher levels of Pg and Aggregatibacter actinomycetemcomitans, were 73% more likely to develop rheumatoid arthritis when compared to 38% of the control group.⁵ Researchers believe there is a connection between the two diseases because both are inflammatory disorders.

Pneumonia

Certain bacteria in your mouth can be pulled into your lungs, causing pneumonias and other respiratory diseases. Hospitals are starting to take oral health much more seriously and for patients having outpatient surgeries the recommendation is too brush prior to and after surgery. In February of 2019 in the American Journal of Nursing, a study was published that found nurses improved pneumonia outcomes by providing oral health interventions to all adult patients admitted to the hospital. The benefits are abundant, reducing overall hospital costs, length of stay and patient mortality. Ventilator associated pneumonias (VAP) is an enormous issue for hospitals. Under programs set up by the Affordable Care Act, the federal government cuts payments to hospitals that have high rates of readmissions and those with the highest numbers of infections and patient injuries such as VAP. 

Diabetes

Current evidence shows a strong link between periodontal disease and controlling blood sugar levels. Approximately one half of all diabetics suffer from some sort of periodontal disease. Those patients with diabetes have more severe periodontal issues than those without diabetes. And patients with periodontal disease have a higher risk of diabetic complications. An interesting side note comes from a study by United Concordia (a dental insurance carrier) and Highmark (a medical insurance carrier) looking at periodontal treatment and its association with health care costs for diabetics. The longitudinal study over 3 years compared diabetic patients with periodontal disease who received treatment versus diabetic patients with periodontal disease who did not get treatment. Medical costs significantly dropped for the diabetic patients receiving periodontal treatment. An average of $1400 saved on prescription drugs and almost $2000 per year on hospital and doctor visits compared to those who did not treat their periodontal disease.

Alzheimer’s Disease

One area that is beginning to emerge is the relationship between periodontal pathogens and Alzheimer’s Disease. Pathogens such as Prophrymonas gingivalis and Treponema denticola have been implicated in Alzheimer’s Disease and specific pathogens Porphrymonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Aggregatibacter actinomycetemcomitans antibodies have been found high levels in Alzheimer’s patients compared with health controls. Currently researchers are merging two hypothesis for Alzheimer’s Disease and that is one they named the Antimicrobial Response Hypothesis. Bacteria and viruses are entering the brain and our brain is trying to stop itself from getting infected my laying down the hallmark we know as amyloid plaques and tau tangles. What is interesting is that not only periodontal pathogens are implicated but Candida Albicans, or yeast and HSV1 or cold sores. When it comes to how does bacteria actually enter the brain the routes are plentiful. Pathogens of the mouth can travel through sinus cavities and periodontium, the olfactory tract, they may cross the blood brain barrier or by passing through blood vessels, through the perivascular space in the brain and finally through circumventricular organs in the brain.

The abundant evidence showing prevention and treatment of periodontal disease may reduce chronic systemic disease risk and we in the dental profession, therefore, have an important role in ensuring that oral disease does not contribute to systemic disease in any individual. Whether dentistry is removing infected teeth or treating gum disease we have a responsibility.

What does any of that have to do with you the implantologist? A lot! More and more implants are being placed so the increase in complications will rise as well. Even though there is no great data as to failures we know they happen for a multitude of reasons. Systemic conditions and habits influence dental implant survival to varying degrees. Illnesses that impair the normal healing cascade worsen surgical success. Arguably the most essential factor for implant success could be proper case selection and that rests on choosing patients in whom wound healing and metabolic stability exist. Many diseases and conditions warrant careful assessment but do not necessarily automatically preclude treatment in every affected patient. Reviewing health histories with scrutiny and mitigating the bacterial load of periodontal pathogens in our patients will lend itself to not only for implant success but for better health for the patient.

Please see related articles: Oral Symptoms of Systemic Disease and Up to Date Health History

References:

1. Bale BF, Doneen AL, Vigerust DJ. High-risk periodontal pathogens contribute to the pathogenesis of atherosclerosis. Postgrad Med J. 2017;93(1098):215-220. doi:10.1136/postgradmedj-2016-134279 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5520251/
2. Shi Q, Zhang B, Huo N, Cai C, Liu H, Xu J. Association between Myocardial Infarction and Periodontitis: A Meta-Analysis of Case-Control Studies. Front Physiol. 2016;7:519. Published 2016 Nov 4. doi:10.3389/fphys.2016.00519 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095113/
3. Humphrey LL, Fu R, Buckley DI, Freeman M, Helfand M. Periodontal disease and coronary heart disease incidence: a systematic review and meta-analysis. J Gen Intern Med. 2008;23(12):2079-2086. doi:10.1007/s11606-008-0787-6 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2596495/
4. Han YW, Fardini Y, Chen C, et al. Term stillbirth caused by oral Fusobacterium nucleatum. Obstet Gynecol. 2010;115(2 Pt 2):442-445. doi:10.1097/AOG.0b013e3181cb9955 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3004155/
5. De Molon, Rafael & Jr, Carlos & Thurlings, Rogier & Cirelli, Joni & Koenders, Marije. (2019). Linkage of Periodontitis and Rheumatoid Arthritis: Current Evidence and Potential Biological Interactions. International Journal of Molecular Sciences. 20. 4541. 10.3390/ijms20184541. https://ard.bmj.com/content/annrheumdis/77/Suppl_2/222.1.full.pdf
6. Warren, Chastity DNP, MSN/Ed, RN, CCRN-K; Medei, Mary Kathryn BSN, RN, CMSRN; Wood, Brooke BSN, RN, CMSRN; Schutte, Debra PhD, RN A Nurse-Driven Oral Care Protocol to Reduce Hospital-Acquired Pneumonia, AJN, American Journal of Nursing: February 2019 - Volume 119 - Issue 2 - p 44-51 doi: 10.1097/01.NAJ.0000553204.21342.01 https://journals.lww.com/ajnonline/Abstract/2019/02000/A_Nurse_Driven_Oral_Care_Protocol_to_Reduce.26.aspx