fLuOridaTion for adUltS (LOTUS study). V3
Research type
Research Study
Full title
How effective and cost-effective is water fluoridation for adults? A 10-year retrospective cohort study
IRAS ID
274705
Contact name
Deborah Moore
Contact email
Sponsor organisation
University of Manchester
Clinicaltrials.gov Identifier
ISRCTN96479279, ISRCTN Registration
Duration of Study in the UK
1 years, 7 months, 31 days
Research summary
Research Summary
Tooth decay is the most common disease affecting mankind. It causes pain, infection, sleepless nights and time off from work. Having dental treatment creates worry for many, because of the discomfort involved, the inconvenience and the costs. Tooth decay is costly for the NHS, and patients themselves if they are not exempt from NHS charges. The NHS currently spends £3.4 billion on NHS dental services, and patients pay another £653 million in patient charges. The majority of these costs are spent on the treatment of tooth decay and its consequences.
It has long been known that fluoride can prevent tooth decay. Since the 1940s, fluoride has been added to some public water supplies and it was first added to toothpastes in the 1970s. Since fluoride toothpastes became available, there has been dramatic improvement in dental health. People have fewer cavities and keep their teeth for longer, particularly in more affluent communities. In America and Australia, almost all public water supplies have fluoride added. In England, only 10% of our water supply contains fluoride. Local Councils decide if they want to add fluoride to the water to improve the dental health of local people. The problem for Local Councils is there is very little modern research on water fluoridation to help them decide if this is a good idea. We don’t know the present-day costs and benefits of water fluoridation, when almost everyone uses fluoride toothpastes. There is also very little research on adults, because it is difficult and very costly to enrol lots of adults into a long-term research study. For children, it is much easier and cheaper because they can be followed up in school. This study will provide added information to give a full picture of this issue.
We plan to use the information collected in NHS dental practice records to understand the impact of water fluoridation on adults. We will compare the number and type of dental treatments provided to around 6 million people living in fluoridated or non-fluoridated areas over ten years. NHS dental records include lots of useful information about the patient, their dentist, and their dental practice. All names and identifying information will be removed before we look at the records. We will only compare people who are as similar as possible, except for the fact they have lived in a fluoridated or non- fluoridated area. Comparing people who are very similar is called ‘matching’. Knowing the number and types of treatments received will tell us if living in an area with water fluoridation reduces the costs of NHS dental care, for both the NHS and for patients. Using the information recorded by NHS dental practices means that we will be able to access information on very large numbers of people, over a period of ten years. This will keep the costs of the research low, and provide answers quickly.
Summary of Results
Fluoride is a natural mineral that prevents tooth decay. It is added to some drinking water (‘water fluoridation’) and toothpastes to improve dental health. Most research on water fluoridation was carried out before fluoride was added to toothpastes in the 1970s. We wanted to know if water fluoridation still produced the large reductions in tooth decay seen in the past, now that most people use fluoride toothpastes and decay levels are much lower.
When we asked patients what concerned them most about their dental health, they said they worried about needing uncomfortable dental treatments, losing their teeth, and paying for their NHS dental care. To see if water fluoridation could help with these aspects of dental health, we compared the NHS dental records of 6.4 million people who received fluoridated or non-fluoridated water in England between 2010-2020.
We found water fluoridation made a very small difference to each person. Between 2010 and 2020, the number of NHS fillings and extractions received was 3% lower in people who received fluoridated water. This difference is smaller than what most stakeholders we spoke to thought would be a useful effect of water fluoridation on dental health over 10 years.
We found no difference in the number of teeth lost per person, and no strong sign that fluoridation reduced differences in dental health between rich and poor. On average, NHS dental patients who received fluoridated water between 2010-20 paid £7.64 less per person in NHS dental charges, and cost the NHS £22.26 less per person, over the 10-years.
The benefits we found for dental health are much smaller than when water fluoridation was first introduced, before toothpastes contained fluoride. Helping people eat less sugar is another option to reduce decay which would add to the benefits of fluoride toothpastes.
REC name
North East - Tyne & Wear South Research Ethics Committee
REC reference
20/NE/0144
Date of REC Opinion
27 May 2020
REC opinion
Favourable Opinion