Overall Health Issues and the Oral-Systemic Link

Chronic diseases are on the rise worldwide.2 Declines in health status and higher health care use are more likely to be driven by these chronic diseases than by age itself. More than a quarter of all Americans and two out of every three older Americans have been reported to have multiple chronic conditions. In addition, treatment for this older population accounts for 66% of the total US health care budget.11

The most frequently reported chronic diseases in the US in order of occurrence are:

  • Hypertension
  • Heart disease
  • Diabetes
  • Cancer
  • Stroke
  • Chronic bronchitis
  • Emphysema
  • Asthma
  • Kidney disease

Inflammation is closely linked with several of these chronic diseases. Diabetes for example has been shown through numerous studies to have a negative impact on oral health (i.e., if glucose levels are not under control, then periodontal disease manifests). As a result, the American Diabetes Association has listed periodontal disease as the sixth complication of diabetes.12 However, research has also shown a two-way relationship exists with diabetes and periodontal disease in that if oral inflammation is kept under control, glucose levels as well tend to normalize.13

With any chronic disease that is inflammatory in nature such as cardiovascular disease, kidney disease, some cancers and several respiratory diseases, C-reactive protein (CRP) levels are elevated in the body. CRP is a non-specific marker of systemic inflammation produced in the liver. There is strong evidence from cross-sectional studies that plasma CRP in those with periodontitis, is also elevated compared with controls.14,15 Periodontal disease is a chronic inflammatory disease during the course of which, microorganisms present in the periodontal pockets, trigger the inflammatory process resulting in elevated levels of cytokines such as IL-6, and PGE2. These cytokines in turn, particularly IL-6, trigger the liver to produce CRP.15

This perpetuation of inflammatory biomarkers is now believed to play a contributory role in the pathogenesis of diseases such as: aspiration pneumonia, atherosclerosis, stroke, diabetes, rheumatoid arthritis, Alzheimer’s disease, and end-stage renal disease. It is therefore imperative that oral inflammation be kept under control in order to reduce CRP levels even if to a lesser degree. Although no cause and effect relationship has been shown to date between these oral-systemic linkages, what has been shown is keeping one’s periodontal disease under control can reduce the overall burden of systemic inflammation.

Numerous studies have been conducted to examine the effects of periodontal therapy in lowering CRP levels. A systematic review of these studies was conducted by Paraskevas et al., which revealed a modest effect of periodontal therapy in reducing CRP levels.14

The following table highlights the results of several studies testing various periodontal interventions on not only reductions in CRP values but also on improvements in cardiac endothelial function as well as improved lumen size of the carotid intima media.

Table 3. Periodontal Disease, Inflammation & Cardiac Function.

StudyInterventionOutcome
Seinost G, et al. Periodontal treatment improves endothelial dysfunction in patients with severe periodontitis. Am Heart J. 2005Scaling & root planing (S&RP) plus chlorhexidine rinses and systemic antibiotics

CCT
Significant improvement in endothelial function (P=.0003)

Significant decrease in CRP (p=.026)
Piconi S, et al. Treatment of periodontal disease results in improvements in endothelial dysfunction and reduction of the carotid intima-media thickness. FASEB J. 2009Non-surgical periodontal therapy (NSPT)Significant improvement in both CRP and carotid intima-media thickness

Reductions in oral bacteria
Tonetti MS, et al. Treatment of periodontitis and endothelial function. N Engl J Med. 2007Intensive periodontal therapy

Control: community care
Endothelial function and CRP values improved in both groups
D’Aiuto F, et al. Short-term effects of intensive periodontal therapy on serum inflammatory markers and cholesterol. J Dent Res. 2005 1. S&RP
2. S&RP + Arestin (ITG)
3. Control (no tx)

RCT
CRP was reduced in both treatment groups

Statistically significant difference between treatment groups in LDL cholesterol for the intensive treatment group (ITG)
Higashi Y, et al. Periodontal infection is associated with endothelial dysfunction in healthy subject and hypertensive patients. Hypertension. 20082 Tx arms (those with and without hypertension) each of which received either no Tx or S&RP & Antibiotics

RCT
Reduced CRP and improved endothelial function in the treatment groups for both those with and without hypertension
Elter JR, et al. The effects of periodontal therapy on vascular endothelial function: a pilot trial. Am Heart J. 2006S&RP

Surgery and extractions, as needed
Statistically significant reductions in endothelial dysfunction (p=.034)

CRP reduced but not statistically significant
Source: S.E. Lavigne, 2011.