Priority collection: preventing tooth decay and oral disease in the elderly

Cochrane Oral Health have undertaken a priority-setting process to find out the most important topics for research in the field of oral health. You can find out more about our priority setting process on our priority setting page.

The top priority question was: what are the best ways to prevent tooth decay and oral disease in the elderly? 

It is estimated that by 2050, one in five people across the world will be over the age of 65 (Oral Health Foundation, 2021), so it is not surprising that this topic was a high priority for Cochrane Oral Health's stakeholders. People are living longer, and also keeping their own teeth for longer. What are the best ways to keep teeth and gums healthy as we age? This collection of Cochrane Oral Health reviews examines preventive care of teeth and gums for adult populations, including the elderly.

Elderly people in nursing homes

Oral health educational interventions for nursing home staff and residents 

Nursing home residents are often unable to carry out proper oral care, which is an important factor in maintaining the health of the mouth, teeth, and gums. Nursing home staff may not be prepared to provide adequate care. Therefore, oral health care education for residents and/or nursing staff may be one strategy to improve this situation. We searched for relevant studies that had been conducted up until January 2016 and identified nine trials involving a total of 3253 nursing home residents. The average age of residents across the studies ranged from 78 to 86 years. In all of the studies, most of the people taking part had dentures (between 62% and 87%).

The trials evaluated a variety of approaches including educational programmes, skills training, and written information material. Topics included dental issues that were particularly relevant for older people such as care of dentures and covered dental and oral diseases, prevention of oral diseases, dental hygiene tools, and oral health care guidelines. The length of the trials ranged from three months to five years. We could not identify a clear benefit of training of nurses and/or residents on residents' dental health as assessed by dental and denture plaque. No study assessed oral health, oral health‐related quality of life, or adverse events. As education programmes were not fully described, results do not allow for clear conclusions about the effectiveness or potential harm of specific oral health education interventions in nursing homes. Overall, there was a low quality of information from the studies regarding all of the results. We conclude that there is a need for clinical trials to investigate the advantages and harms of oral health educational programmes in nursing homes.

Keeping the teeth and mouth clean

Home use of interdental cleaning devices, in addition to toothbrushing, for preventing and controlling periodontal diseases and dental caries

Tooth decay and gum diseases affect most people. They can cause pain, difficulties with eating and speaking, low self‐esteem, and, in extreme cases, may lead to tooth loss and the need for surgery. As dental plaque is the root cause, it is important to remove plaque from teeth on a regular basis. While many people routinely brush their teeth to remove plaque up to the gum line, it is difficult for toothbrushes to reach into areas between teeth ('interdental'), so interdental cleaning is often recommended as an extra step in personal oral hygiene routines. Different tools can be used to clean interdentally, such as dental floss, interdental brushes, tooth cleaning sticks, and water pressure devices known as oral irrigators.

This review included 35 studies, and the age range of the people involved was 18 to 78 years old. We found that mild gum disease may be reduced in the short term by using floss, an interdental brush, or an oral irrigator. Evidence for a reduction in dental plaque was found using an interdental brush (in the short term) but there was little evidence to show that oral irrigators or floss reduce plaque. There is some evidence that oral irrigation may be better than flossing for reducing mild gum disease (but not plaque) in the short term. The available evidence for interdental cleaning sticks did not show them to be better or worse than floss or interdental brushes for controlling mild gum disease or plaque. The evidence is low to very low certainty, and there were no studies in people over the age of 80 years.

Listen to a podcast by the review authors. Podcasts in Spanish and Croatian are available. A summary of this review is also available in Spanish, Persian, Chinese and Portuguese.

Powered versus manual toothbrushing for oral health

Toothbrushing is an important method of removing plaque from the teeth. This Cochrane review aims to find out whether a powered (or electric) toothbrush is better than a manual toothbrush for removing plaque and preventing gum diseases and tooth decay. 56 studies were included, three-quarters of the studies were in adults. The age range of the adults involved in the studies was 18-70 years old. 

The evidence produced shows benefits in using a powered toothbrush when compared with a manual toothbrush. There was an 11% reduction in plaque at one to three months of use, and a 21% reduction in plaque when assessed after three months of use. For mild gum disease, there was a 6% reduction at one to three months of use and an 11% reduction when assessed after three months of use. The benefits of this for long‐term dental health are unclear. Few studies reported on side effects; any reported side effects were localised and only temporary. The evidence relating to plaque and mild gum disease was considered to be of moderate certainty. There were no studies in very elderly populations.

Summaries of this review are available in Spanish, French, Portuguese and Chinese.

Fluoride toothpastes of different concentrations for preventing dental caries in children and adults 

This review was produced to assess the effects of toothpastes of different fluoride strengths on preventing tooth decay in children, adolescents and adults. Fluoride has long been used to prevent decay, through a variety of different methods including toothpaste, water, milk, mouthrinses, tooth gels and varnish. Regular toothbrushing is recommended to prevent decay and other oral diseases, and toothbrushing for 2 minutes twice daily with fluoride toothpaste is generally recommended. The typical strength of regular or family toothpaste is around 1000 to 1500 parts per million (ppm) fluoride, but many other strengths are available worldwide. There is no minimum fluoride concentration, but the maximum permissible fluoride concentration for a toothpaste varies according to age and country. Higher concentrations are rarely available over the counter and are classed as prescription‐only medicine. 

Only three of the 96 studies in this review looked at the effects of different strengths of fluoride toothpastes in adults. The age range of adults included in the studies was 18 to 93 years. In permanent teeth of adults of all ages, 1000 or 1100 ppm toothpaste reduced decay compared with non‐fluoride toothpaste (moderate certainty evidence). There was no evidence to report on whether higher strength fluoride toothpaste (1100 ppm +) was effective for reducing decay in adults.

Summaries of this review are available in Spanish, Persian, French and Chinese.

Water fluoridation for the prevention of dental caries

Fluoride is a mineral that prevents tooth decay. It occurs naturally in water at varying levels. Fluoride can also be added to the water with the aim of preventing tooth decay. Fluoride is present in most toothpastes and available in mouthrinses, varnishes and gels. If young children swallow too much fluoride while their permanent teeth are forming, there is a risk of marks developing on those teeth. This is called ‘dental fluorosis’. Most fluorosis is very mild, with faint white lines or streaks visible only to dentists under good lighting in the clinic. More noticeable fluorosis, which is less common, may cause people concern about how their teeth look. We carried out this review to evaluate the effects of fluoride in water (added fluoride or naturally occurring) on the prevention of tooth decay and fluorosis.

20 studies were available on the prevention of tooth decay and water fluoridation, and 135 studies on dental fluorosis. Only one of the studies on the prevention of tooth decay was in adults, and none of the 135 fluorosis studies was in adults. The only study in adults reported on the percentage of participants with dentures, and the oldest participant was aged 55 years. There are no data to determine the effect of water fluoridation on levels of tooth decay in the elderly.

Summaries of this review are available in Spanish, French and Chinese.

Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 

People sometimes use mouthrinses containing chlorhexidine in addition to conventional tooth cleaning, especially if they have difficulty controlling plaque build‐up and preventing gum disease using only toothbrushing. These mouthrinses are readily available over the counter; prescriptions generally not being required outside the USA. This review looked at the use of chlorhexidine mouthrinse for controlling and improving gum disease, and whether the frequency of rinsing or the concentration of the solution affects the result.

51 studies were included. 41 of the studies were in adults, the age range was 20 to 83 years. There is high‐certainty evidence that the use of mouthrinses containing chlorhexidine in addition to usual toothbrushing and cleaning for 4 to 6 weeks or 6 months leads to a large reduction in the build‐up of plaque. There is also high‐quality evidence of a moderate reduction in mild gum disease, although because the level of disease was already low this is not considered clinically important. The nature of the available evidence does not allow us to determine the level of reduction of mild gum disease in people with moderate to severe levels of it. There was no evidence that one concentration or strength of chlorhexidine rinse was more effective than another. Rinsing for 4 weeks or longer causes tooth staining, which requires scaling and polishing carried out by a dental professional. Other side effects have been reported, including the build‐up of tartar, temporary taste disturbance and temporary shedding of/damage to the lining of the mouth.

A summary of this review is available in Spanish

Xylitol-containing products for preventing dental caries in children and adults

Xylitol is a natural sweetener, which is equally as sweet as normal sugar (sucrose). As well as providing an alternative to sugar, it has other properties that are thought to help prevent tooth decay, such as increasing the production of saliva and reducing the growth of bad bacteria in the mouth so that less acid is produced. In humans, xylitol is known to cause possible side effects such as bloating, wind and diarrhoea. This review was produced to assess whether or not xylitol, a natural sweetener used in products such as sweets, candy, chewing gum and toothpaste, can help prevent tooth decay in children and adults.

10 studies were included, but only one study included adults (age range 20-81 years). There is some evidence to suggest that using a fluoride toothpaste containing xylitol may reduce tooth decay in the permanent teeth of children by 13% over a 3 year period when compared to a fluoride‐only toothpaste. Over this period, there were no side effects reported by the children. The remaining evidence we found did not allow us to conclude whether or not any other xylitol‐containing products can prevent tooth decay in infants, older children, or adults.

Listen to a podcast by the review authors. Summaries of this review are available in Spanish, French, Japanese and Chinese.

Visiting the dental clinic

Recall intervals for oral health in primary care patients

A dental check‐up helps to keep your mouth healthy and lets your dentist see if you have any dental problems. It allows your dentist to deal with any problems early, or even better, to prevent problems from developing. Leaving problems untreated may make them harder to treat in the future. Having check‐ups every six months might help to keep your mouth healthy and avoid dental problems in future, but could also lead to unnecessary dental treatments. However, having check‐ups less often might let dental problems get worse and lead to difficult and expensive treatment and care. We wanted to identify the best time interval to have between dental check‐ups.

We found two studies with 1736 people who had regular dental check‐ups. One study was conducted in a public dental clinic in Norway in children and adults aged under 20 years. It compared 12‐monthly and 24‐monthly check‐ups and measured results after two years. The other study was in adults at 51 dental practices in the UK, the mean age of the participants was 45 years. It compared six‐monthly, 24‑monthly, and risk‐based check‐ups (where the time between check‐ups was set by dentists and depended on an individual's risk of dental disease), and measured results after four years. In adults, there was little to no difference between six‐monthly and risk‐based check‐ups in tooth decay, gum disease and quality of life after four years; and probably little to no difference in how many people had moderate‐to‐extensive tooth decay. There was probably little to no difference between 24‐monthly and six‐monthly or risk‐based check‐ups in tooth decay, gum disease or well‑being, and may be little to no difference in how many people had moderate‐to‐extensive tooth decay. Whether adults see their dentist for a check‐up every six months or at personalised intervals based on their dentist's assessment of their risk of dental disease does not affect tooth decay, gum disease, or quality of life. Longer intervals (up to 24 months) between check‐ups may not negatively affect these outcomes. 

Summaries of this review are available in Spanish, Persian, French and Thai.

Routine scale and polish for periodontal health in adults

Scaling and polishing removes deposits such as plaque and tartar from tooth surfaces. Over time, the regular removal of these deposits may reduce mild gum disease, and stop it progressing to more serious forms of gum disease. Many dentists or hygienists provide scaling and polishing for most patients at regular intervals even if the patients are considered to be at low risk of developing gum disease. There is debate about whether scaling and polishing is effective and the best interval between treatments. Scaling is an invasive procedure and has been associated with a number of negative side effects including damage to tooth surfaces and tooth sensitivity. 

We included two studies with a total of 1711 participants in our review. Both studies involved adults without severe periodontitis who were regular attenders at dental appointments in the UK, the age range of the participants was 18 to 92 years. The studies were conducted in general dental practices, which is the most appropriate setting to evaluate 'routine scale and polish' treatments. One study measured outcomes at 24 months and one study at 36 months. The studies found little or no difference between regular planned scale and polish treatments compared with no scheduled scale and polish for the early signs of gum disease. There was a small reduction in tartar levels, but it was uncertain if this is important for patients or their dentists. Participants receiving six‐monthly and 12‐monthly scale and polish treatments reported feeling that their teeth were cleaner than those who were scheduled to receive no treatment. However, there did not seem to be a difference between groups in terms of quality of life.

Listen to a podcast by the review authors, a version of this podcast is also available in Chinese and in Malay. Summaries of this review are available in Spanish, Persian and Chinese.

Screening programmes for the early detection and prevention of oral cancer 

Oral cancer is increasing worldwide and it is the sixth most common cancer overall. The highest rates of oral cancer occur in the most disadvantaged sections of the population. Important risk factors in the development of the disease are tobacco, alcohol, age, gender and sunlight although a role for candida (which causes thrush) and the human papillomavirus has also been documented. This review was conducted to investigate the effectiveness of current screening programmes in detecting oral cancer at an early stage and whether or not they can assist in decreasing deaths due to oral cancer. The aim of preventive screening for early detection of oral cancer is to screen individuals for pre‐cancerous conditions which present as sores or lesions in the mouth. The most common screening method is visual inspection by a clinician but other techniques include the use of a special blue dye, the use of imaging techniques and measuring biochemical changes to normal cells.

We could only find one study to include in this review, the participants were based in Kerala, India. All of the participants were aged over 35 years. The review found that overall there is not enough evidence to decide whether screening by visual inspection reduces the death rate for oral cancer and there is no evidence for other screening methods. However, there is some evidence that screening might help reduce death rates in patients who use tobacco and alcohol although the only included study may be affected by bias.

Summaries of this review are available in Spanish, French and Chinese.

One‐to‐one oral hygiene advice provided in a dental setting for oral health 

Poor oral hygiene habits are known to be associated with high rates of dental decay and gum disease. The dental team routinely assesses oral hygiene methods, frequency and effectiveness or otherwise of oral hygiene routines carried out by their patients; one‐to‐one oral hygiene advice is regularly provided by members of the dental team with the aim of motivating individuals and improving their oral health. This review's aim is to determine if providing patients with one‐to‐one oral hygiene advice in the dental setting is effective and if so what is the best way to deliver this advice.

We found 19 studies, 15 of the studies were in adults (age range 15-91 years). Overall we found insufficient evidence to recommend any specific method of delivering one‐to‐one oral hygiene advice as being more effective than another in maintaining or improving oral health. The studies we found varied considerably in how the oral hygiene advice was delivered, by whom, and what outcomes were looked at. Due to this, it was difficult to readily compare these studies and further well-designed studies should be conducted to give a more accurate conclusion as to the most effective method of maintaining or improving oral health through one‐to‐one oral hygiene advice delivered by a dental care professional in a dental setting. We judged the certainty of the evidence to be very low due to problems with the design of the studies.

Summaries of this review are available in Spanish and French.


Most of Cochrane Oral Health's reviews on the prevention of tooth decay and other oral diseases contain little evidence on elderly populations. More clinical studies are needed on people over the age of 65 to find out about the most effective ways of preventing oral disease as we age. There is some evidence that powered toothbrushes and chlorhexidine mouthrinse may help to prevent oral diseases in adult populations. We need more studies on interventions such as xylitol, high concentration fluoride toothpaste, interdental cleaning, water fluoridation and one-to-one oral hygiene advice in the dental setting to determine whether these interventions may help prevent oral diseases in older people. We also need more studies on how to improve the oral health of older people living in nursing homes or other institutions.

The following Cochrane reviews that impact oral care for the elderly are currently in progress:

Interventions for managing denture stomatitis
Interventions for managing root caries
Topical silver diamine fluoride for managing dental caries in children and adults
Psychological interventions for improving adherence to oral hygiene instructions in adults with periodontal diseases
Non-fluoride topical remineralising agents containing calcium and/or phosphate for controlling dental caries