Skip to main content Skip to footer

Risk factors

Print this page

Risk factors for periodontal diseases

Plaque biofilm is necessary for the development of periodontitis. However, there are multiple factors, both systemic and local, which increase the probability of periodontal disease developing or progressing for an individual patient. These may be modifiable (i.e. something the patient can change) or non-modifiable (i.e. something the patient cannot change).

Both the BSP implementation of European S3 – level evidence-based treatment guidelines for stage I-III periodontitis in UK clinical practice (BSP-S3)6 and the Delivering Better Oral Health (DBOH)7 toolkit note that smoking, diabetes and plaque biofilm are well established risk factors for periodontal diseases. The guidelines also note that there are possible associations with other systemic conditions, although the evidence for these is less clear.

The BSP-S3 guideline6 recommends risk factor control interventions as part of the first step of therapy in periodontitis patients. To facilitate this, risk factors must be identified and discussed with the patient (see Assigning patient risk). 

Systemic risk factors

Systemic risk factors can be identified by collecting information on patient demographics, and their medical and social history, with a focus on identifying the following potential risk factors.

Smoking is a well-established risk factor for periodontitis. Patients who smoke do not respond to periodontal treatment as well as non-smokers and are also more likely to lose teeth.16 The risk is dose-related, with a patient who regularly smokes ≥10 cigarettes per day considered to be at higher risk than patients who smoke <10 cigarettes per day.17 The reduced blood flow caused by smoking can suppress the signs and symptoms of disease activity. The use of other forms of tobacco, such as chewing tobacco, also carries a higher risk of periodontitis.

The use of e-cigarettes, or vaping, may also be associated with worse periodontal outcomes,18 but the overall risk appears lower than in those who currently smoke. Many people who vape are former smokers and their periodontal health may still be affected by their previous smoking habit.

E-cigarettes are viewed as a helpful transition to cessation for smokers and a Cochrane Review found that e-cigarettes increase quit rates compared to nicotine replacement therapy.19 However, these devices are not risk-free and may have the potential to cause harm. There is increasing concern about the uncertain risks to the growing number of individuals, especially young people, who have taken up vaping for purposes other than smoking cessation, particularly regarding the use of unlicensed products.

Patients with sub-optimally controlled diabetes and pre-diabetes have an increased risk of developing periodontitis.1, 20 Diabetes also has an adverse effect on wound healing; together these factors make management of disease in these patients more difficult. In addition to local improvements in periodontal status, there is moderate certainty evidence that successful non-surgical periodontal treatment can improve glycaemic control.21

While well-controlled diabetes is not a risk factor, many people oscillate between different levels of control and an increased risk of periodontal diseases should be assumed for anyone who has diabetes. The National Institute of Health and Care Excellence (NICE) guidelines on management of diabetes now recognise this increased risk of periodontitis in patients with diabetes and have produced guidance on the advice which should be given to these patients in medical and dental settings.22, 23 In addition, NHS England has produced a Commissioning Standard to ensure that people with diabetes can access effective oral healthcare services with the aim of improving their general and oral health and to ensure that these services are available.

A family history of periodontitis increases the risk of an individual developing periodontitis. This has a genetic basis with a complex, multifactorial mechanism.

Other factors potentially related to an increased risk of periodontitis include:

  • stress, diet, obesity, osteoporosis, rheumatoid arthritis – currently there is limited evidence concerning these relationships; 
  • socio-economic status – periodontal diseases are more prevalent in lower socio-economic groups;
  • ethnicity – certain ethnic groups (e.g. Afro-Caribbean) may have an increased risk of more severe periodontitis (e.g. Grade C disease in younger age groups) but it is unclear whether this is related to genetic phenotype or other factors.

The systemic factors which are clearly related to an increased risk of gingival inflammation and/or enlargement include:

  • pregnancy – hormonal changes and modified immune response implicated in gingivitis and gingival enlargement;
  • puberty – hormonal changes can cause increased inflammatory response to plaque, causing gingivitis and gingival enlargement; 
  • medications – calcium channel blockers for hypertension, phenytoin for epilepsy and ciclosporin, an anti-rejection drug, which can also be prescribed for some autoimmune disorders, may increase the risk of gingival enlargement.

In addition, a large number of medications may cause reduced salivary flow (e.g. tricyclic antidepressants, beta blockers) leading to increased plaque accumulation and risk of disease. 

Local risk factors

Dental plaque is the community of microorganisms found on a tooth surface as a biofilm, embedded in a matrix of polymers of host and bacterial origin.24, 25 The biofilm provides protection for the microorganisms from both the inflammatory and immune systems and from chemical agents. The presence of plaque biofilm* is necessary for the development of periodontal diseases.

* The phrase ‘plaque biofilm’ is used in this guidance, in preference to other descriptors such as dental biofilm, to encompass wording that is familiar to patients (i.e. plaque) and to describe the structurally and functionally organised community of microorganisms and supporting matrix adhering to the tooth surface (i.e. biofilm).

Factors which increase the retention of plaque biofilm or make it more difficult for a patient to remove, such as calculus, dental crowding, overhanging restorations and partial dentures, may increase the risk of periodontal diseases.