Current scientific evidence for why periodontitis should be included in diabetes management

This Perspective provides a brief summary of the scientific evidence for the two-way links between periodontal diseases and hyperglycemia (diabetes mellitus [DM] and pre-DM). It delivers in a nutshell current scientific evidence for manifestations of hyperglycemia on periodontal health status and effects of periodontal diseases on blood glucose levels and in turn incidence, progression, and complications of diabetes. Of outmost importance is presentation of scientific evidence for the potential of routine periodontal treatment to lower blood glucose levels, providing a novel, economical tool in DM management. Non-surgical periodontal treatment (“deep cleaning”) can be provided by dental hygienists or dentists in general dental offices, although severe cases should be referred to specialists. Such therapy can decrease the costs of DM care and other health care costs for people with DM. The great importance of a healthy oral cavity free of infection and subsequent inflammation – especially periodontitis that if untreated will cause loosening and eventually loss of affected teeth – has largely gone unnoticed by the medical community as the health care curricula are largely void of content regarding the bi-directional links between oral health and systemic health, despite elevation of blood glucose levels being an integral part of the general systemic inflammation response. The importance of keeping disease-free, natural teeth for proper biting and chewing, smiling, self-esteem, and pain avoidance cannot be overestimated. Medical and dental professionals are strongly encouraged to collaborate in patient-centered care for their mutual patients with – or at risk for – hyperglycemia.


Effect of hyperglycemia
People with DM in the US have a 40% greater risk for periodontitis than those without (13),with around 50% greater prevalence (12,13).Periodontitis among seniors aged >65 years with DM, 83.1 % have periodontitis with 10.8% being severe (14).

Costs
The estimated direct costs of dental diseases amounted to $356.80 billion and indirect costs were estimated at $187.61 billion, totaling worldwide costs due to dental diseases of $544.41 billion in 2015 (15).Periodontitis treatment costs in the US in 2018 were estimated at $3.49 billion with another $150.57billion in indirect costs mostly due to periodontitis-related edentulism (16).The latter represents on average 0.73% of the annual gross domestic product (GDP).
The corresponding costs in Europe were Euro2.52 billion and Euro156.12 billion, respectively, with the indirect costs amounting to 0.99% of Europe's annual GDP (16) Periodontitis is associated with greater medical care costs (17), whereas receiving preventive dental care (dental cleaning and non-surgical periodontal therapy) leads to decreased financial costs for outpatient (including emergency department visits for dental issues) and inpatient medical care in general (18)(19)(20)(21).

Prevalence
The International Diabetes Federation (IDF) estimated the global prevalence of DM in 20-79 year-olds in 2021 was 10.5% (536.6 million) --that is more than half a billion people --and is projected to increase to 643 million by 2030 and to 12.2% (783.2 million) in 2045 (22)(23)(24), with older age groups suffering most.

Costs
IDF estimated the DM-related global health care costs at USD 966 billion in 2021 and USD 1.054 trillion by 2045 (22,23).
The estimate global cost of diabetes for 2015 was US 1.31 trillion (1.8% of global GDP, of which indirect costs accounted for 34.7% with North America being the most affected region relative to GDP and also the largest contributor to global absolute costs.(26).
In the US, DM care increased from $37 costs billion in 1996 to $101 billion in 2013 (27).The most recent total estimated cost of diagnosed diabetes in 2017 was $327 billion, including $237 billion in direct medical costs and $90 billion in reduced productivity (DM-related morbidity and premature mortality), representing about 25% of all health care costs, with half of that for DM care (28).Additional costs are USD 31.7 billion for undiagnosed diabetes, USD 43.4 billion for prediabetes, and nearly USD 1.6 billion for GDM, totaling USD 404 billion (29).
According to the American Diabetes Association (AD(M)A), people with diagnosed DM in the US incur average medical expenditures of approximately USD 16,750 per year, of which approximately USD 9,600 is attributed to diabetes care (28).This is similar to the IDF's estimate of USD 8,208.90 for the North America and Caribbean region (22).
The mean medical expenditures were 2.3 times greater than in those not suffering from DM (28,30).

B) How to screen for periodontitis in the medical setting
Because the relevant topics are not generally included in the curricula for medical health care professionals, they are often unaware of the important role periodontitis plays in DM management, or feel unqualified to assess their patients' periodontal health status (34,35).
Periodontitis may be symptomless until the tooth is loose (36), at which time it is too late to salvage it.However, all health care providers recognize inflammation and suppuration, which signs also are displayed by gingivitis and periodontitis.Here follow verbatim the items for the patient to watch out for listed in the 2018 IDF/European Federation of Periodontology (EFP) consensus document published simultaneously in the two organizations' scientific journals, Diabetes Research and Clinical Practice and Journal of Clinical Periodontology, respectively (37,38): • Red or swollen gums; • Bleeding from your gums or blood in the sink after you brush your teeth; • Foul taste; • Longer looking teeth; • Loose teeth; • Increasing spaces between your teeth; • Calculus (tartar) on your teeth.
Responses to self-report questionnaire items regarding a patient's periodontal health have good correlation with the clinical status (39-41), except when using non-validated questions (42).The following validated, easily answerable questions for self-report were developed by the Centers for Disease Control and Prevention (CDC)/American Academy of Periodontology (AAP) workgroup (43)(44)(45): • Do you think you might have gum disease?• Overall, how would you rate the health of your teeth and gums?
• Have you ever had treatment for gum disease such as scaling and root planing, sometimes called "deep cleaning"?• Have you ever had any teeth become loose on their own, without an injury?• Have you ever been told by a dental professional that you lost bone around your teeth?• During the past three months, have you noticed a tooth that doesn't look right?• Aside from brushing your teeth with a toothbrush, in the last seven days, how many times did you use dental floss or any other device to clean between your teeth?• Aside from brushing your teeth with a toothbrush, in the last seven days, how many times did you use mouthwash or other dental rinse product that you use to treat dental disease or dental problems?
These questions were validated in several countries in several languages, including in Japanese adults (39); and based on these items (43)(44)(45), a Dutch easy and quick, free online screening tool was developed for the medical settings without an oral examination (46)(47)(48)(49)(50). Importantly, general physicians are obligated to screen their patients for periodontitis in The Netherlands (47).A 3-item question (51) and a 7-item tool also screen for periodontitis in non-dental settings (52).Finally, self-reported bleeding on brushing (BoB) is correlated with clinically assessed bleeding on probing (BoP) (53).