The severity of periodontal disease has been observed to be affected by multiple systemic conditions, such as diabetes, arthritis, and cardiovascular disease (CVD), as well as metabolic, neurological, and haematological disorders. Possible mechanisms have been suggested to explain these bidirectional relations, and researchers have hypothesised the aetiologic role of periodontitis in the pathogenesis of these systemic illnesses. Therefore, patients diagnosed with periodontal disease may be at higher risk due to a compromised immune system.

The inflammatory biomarkers and pathogens which originate due to periodontal disease can transfer through the bloodstream and can compromise endothelial function in distant organs. The presence of large numbers of bacteria can cause tissue destruction indirectly by activating host defence cells that produce and release mediators, stimulating those responsible for connective tissue breakdown. Periodontal disease may be associated with CVD due to mutual risk factors for atherogenesis and periodontal disease. A recent hypothesis links chronic subclinical inflammation with insulin resistance, initiating the development of type 2 diabetes. There are many triggers of inflammation and potentially include oral infection, which may lead to a cascade of events, including increased cytokine production, activation of acute-phase protein synthesis, and consequent insulin resistance that produce pathogenic changes resulting in type 2 diabetes. The oral complications of some systemic diseases, coupled with periodontal disease progression, may directly affect the quality of life of the individual. Difficulty in speaking, xerostomia, dental caries, halitosis, gingival recession, taste disorders, periimplantitis, prosthetic complications, and general dissatisfaction with oral health are all major problems for those patients. Thus, periodontal treatment may help in reducing this systemic inflammatory load that has a favourable effect on patients’ health and improve the patient’s satisfaction and quality of life.

The aim of this Special Issue is to investigate the effect of systemic disease on periodontal and peri-implant tissues. Papers exploring the links and possible mechanisms between periodontal disease and conditions such as diabetes, arthritis, and cardiovascular disease are of great interest, as is research into the quality of life of periodontitis patients. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Prevalence of periodontal disease in medically compromised patients
• Alzheimer’s disease and effects on periodontal and peri-implant health
• Dental implants for periodontitis patients
• Dental surface modification for enhancing osseointegration in compromised conditions
• Dental implant complications
• Periodontal risk factors
• Quality of life of periodontitis patients
• Smoking and periodontal disease
• Halitosis
• Prosthetic treatment
• Periodontal surgery