Evidence
Alert

Dental check-ups every six months are unnecessary for people at low risk of oral disease, research finds

Dentists invite most people for dental check-ups every six months. Despite being common practice in the UK and many other countries, this interval is based on low quality evidence. 

The results of a large trial across the UK (INTERVAL) did not support such frequent dental appointments.  

It found that the 30% people at low risk of oral disease could be seen once every two years without detriment to their oral health. Over a four-year period, more frequent check-ups had no added benefit. The research concluded that a check-up interval based on each person’s individual risk of oral disease did not adversely affect their oral health. This approach was acceptable to patients and dentists and could save money.

What’s the issue?

Routine NHS dental check-ups include a clinical examination, monitoring of oral health, and advice. Regular check-ups aim to detect the early signs of dental disease such as decay and gum disease. 

NICE guidelines recommend that dentists and patients agree on a suitable interval between check-ups. This interval ranges from every three months to every two years for adults. Most dentists encourage people to have check-ups every six months. But these recommendations and customs are based on low quality evidence. 

There is a growing need to reform dental services and prioritise the prevention of oral health problems. The risk of developing oral disease varies between individuals, and resources should therefore target those at higher risk. COVID-19 has prevented many from accessing dental care, and made these needs more urgent. In work carried out before the pandemic, researchers sought to update the evidence behind current guidelines. They wanted to identify the check-up interval that would best maintain oral health while offering value for money. 

What’s new?

The four-year INTERVAL trial was a randomised controlled trial. It included 2,372 adults from dental practices across the UK. Approximately 70% completed all aspects of the trial and attended the follow-up appointment four years later. 

Participants were randomly allocated to one of three groups:

  • fixed check-ups every six months (high- and low-risk participants) 
  • check-up intervals based on each person’s risk of oral disease (high- and low-risk participants) 
  • fixed check-ups every two years (only for participants who were considered to be low-risk by their dentist).

Oral health was determined in this study by measuring the extent to which gums bled when probed. This indicates inflammation, and early gum disease. The researchers also looked at the extent of tooth decay, tartar build-up on teeth, the need for preventive treatment (such as removing plaque and tartar), the need for intervention (such as filling cavities), and dentists’ attitudes towards recall intervals. They asked patients to describe their anxiety, satisfaction with care, knowledge of oral health, attitudes and behaviours. 

The results suggest there are no dental health benefits to 6-monthly check-ups compared to risk-based intervals or 2-yearly check-ups (for people at low-risk). There was no difference in bleeding gums or in oral health-related quality of life. Nor did the evidence show any differences in the other clinical outcomes.  

Overall, participants were satisfied with the dental services they received and were not anxious about their dental health. They had good knowledge about how to brush, though few participants knew to spit without rinsing after brushing. 

The research included an analysis of costs to the NHS and to patients, and explored peoples’ willingness to pay for dental appointments. Three different analyses looked at which treatment interval offered the best value for money, while maximising general health-related quality of life, overall benefit to society, and benefits to dental health.

The results of the economic evaluations were mixed.  The benefits to general health were uncertain, possibly because the measure used may not have been sensitive enough to pick up differences in dental health. However, with respect both to general health and dental health, the 2-year recall period (for low-risk patients) is likely to be the most cost-effective approach because of the potential cost savings from fewer appointments.

With respect to society, there were benefits to six-monthly check-ups because most people valued and were happy to pay for them. 

The researchers conclude that a risk-based interval personalised to each person could save money without having a negative impact on oral health.

Why is this important?

The findings suggest that the custom of providing six-monthly check-ups, regardless of the person’s risk of developing dental disease, does not improve oral health. 

The results of this study can inform clinical guidelines to aid decision-making on check-up frequency by dentists. A personalised check-up frequency, based on individual risk, could be a more efficient use of NHS resources.

The results of this study are reflected in the updated Cochrane Review, Recall intervals for oral health in primary care patients.

What’s next?

The evidence from this study and the related Cochrane Review could be integrated into clinical guidance for dentists. Moving towards a personalised, variable recall strategy will need close cooperation between policymakers, clinicians, and patients. 

People valued check-ups every six months in this study, and said they were willing to pay for them. However, the economic analyses were based on surveys of regular attenders who may value frequent check-ups more than other people. The researchers say more information is needed on why check-ups are so valued – perhaps due to it being an established routine, a recommendation, or other reasons. They say careful messaging may help people to understand that personalised, risk-based intervals between appointments are safe.

The researchers would like to develop risk assessment tools to help dentists choose recall intervals, based on their patients’ likelihood of developing dental disease. 

This study included adults only. More research is needed before any change is made to recall intervals for younger people.

You may be interested to read

The full paper: Clarkson JE and others. Risk-based, 6-monthly and 24-monthly dental check-ups for adults: the INTERVAL three-arm RCT. Health Technol Assess. 2020;24

The results of the clinical outcomes are summarised here: Clarkson JE and others. Examining the effectiveness of different dental recall strategies on maintenance of optimum oral health: the INTERVAL dental recalls randomised controlled trial. Br Dent J. 2021;230:236–243

The protocol for this trial, as described in another paper: Clarkson JE and others. INTERVAL (Investigation of NICE Technologies for Enabling Risk-Variable-Adjusted-Length) dental recalls trial: a multicentre randomised controlled trial investigating the best dental recall interval for optimum, cost-effective maintenance of oral health in dentate adults attending dental primary care. BMC Oral Health 2018;18:135

The recent Cochrane Database Systematic Review, which included the results of this study, also concluded that there was little to no difference in tooth decay, gum disease and well-being between 6-monthly and risk-based check-ups in adults: Fee PA and others. Recall intervals for oral health in primary care patients. Cochrane Database Syst Rev. 2020;10:CD004346

An infographic overviewing how to perform a risk assessment and allocate an appropriate risk-based recall

Funding

This research was funded by the NIHR Health Technology Assessment programme.

Commentaries

Study author

The results convey the positive message that dentists can accurately assess patients’ risk of oral disease and allocate appropriate risk-based recall intervals. 

This research is especially valuable when considering the impact of the COVID-19 pandemic. Patient access to dental treatment has been limited and may remain so for some time. But the results of this study provide reassurance that intervals between check-ups can be extended beyond 6 months without detriment to oral health.

Patrick Fee, Clinical Research Fellow and Specialty Registrar in Restorative Dentistry, School of Dentistry, University of Dundee

Dentist

This research provides robust evidence that risk-based recall intervals should replace ‘routine’ six-monthly check-ups. Dentists should consider 24-month (and appropriately shorter recalls) for patients who are suitable. This study is relevant to every member of the dental team, and practices should update their staff members and provide training on the factors to consider for risk-based recall. 

Patients should be engaged with the decision-making process; it is important for the dental team to effectively communicate the reasons behind the recall interval. There is a risk of misunderstanding if a patient is not made fully aware of the justifications and potential risk/benefits of a longer interval. They must also be reassured and reminded that they will be seen if they encounter toothache or have any dental concerns. 

Implementing longer recall intervals may be trickier in a mixed private/NHS practice. Clinicians would want to avoid the perception that private patients have more frequent check-ups. It would also be difficult to decline a patient’s wishes to be seen more regularly, six-monthly for example, if that is what they are used to.

Shalini Kanagasingam, Dentist and Senior Clinical Lecturer in Endodontology and Restorative Dentistry, University of Central Lancashire

Retired Dentist

The concept of the 6-monthly check-up is so ingrained in the psyche of motivated patients that it could be difficult to change. However, the ever-increasing charges for NHS dental treatment may influence some patients to favour less frequent reviews. Commissioners will grasp the concept of saving money, but for non-exempt NHS patients, the charge for a check-up is not much less than the 1 Unit of Dental Activity earned by the dentist, so the cost savings to the government of extending recall intervals may be minimal.

The paper does not include screening for oral cancer, which is usually symptomless until too late to treat. This is an important aspect of an oral examination and an essential consideration when assessing recall intervals for those particularly at risk.

Paul Hellyer, Retired Dentist, Bexhill-on-Sea

Conflicts of Interest

One author has received fees from toothpaste manufacturers.