For Prof. Helen Whelton, the central challenge in dentistry today is not the lack of evidence but the ability to interpret it critically, communicate it honestly and translate it into better care. (Image: Prof. Helen Whelton)

Prof. Whelton, what makes evidence reliable in oral healthcare today?
There is an enormous amount of scientific literature being produced across all areas of oral health. The difficulty is not generating evidence but interpreting it and deciding what can be trusted. Having spent much of my career both conducting research and using evidence to inform policy and practice, I have seen first hand how difficult it can be for busy clinicians, policymakers and members of the public to navigate an increasingly crowded information landscape.

Artificial intelligence is likely to become a valuable tool in helping researchers and clinicians navigate this expanding body of knowledge. It has the potential to assist with literature searches, evidence synthesis and the identification of patterns that might otherwise be missed. However, artificial intelligence does not remove the need for critical appraisal. Like any other tool, its outputs are only as reliable as the information on which they are based, and it can reproduce biases, inaccuracies and oversimplifications.

As clinicians and researchers, we therefore need to understand the difference between high-quality evidence and evidence that has important limitations. That sounds straightforward, but it is becoming increasingly difficult as the volume of information grows. The challenge is compounded by the fact that scientific information is no longer confined to journals and conferences. Social media has made a vast amount of information directly accessible to the public, and patients are now exposed to high-quality evidence, as well as opinion, commercial messaging, misinformation, disinformation and, increasingly, information that may be technically accurate but presented without appropriate context.

This makes trusted systems for evidence synthesis more important than ever. Cochrane, an independent global network that produces systematic reviews and other trusted health evidence, is a good example. It applies rigorous methods to reviewing evidence, publishes protocols in advance and provides transparent assessments of the quality of the available research. Importantly, it also makes the findings accessible through plain language summaries.

In research, we often talk about hierarchies of evidence, in which systematic reviews and meta-analyses of randomised controlled trials sit at the top. However, the methodology must always be appropriate to the question being asked. Some important public health, health systems and policy questions simply cannot be addressed through randomised trials. Water fluoridation is a good example. In today’s environment, it would be virtually impossible to randomise comparable communities to receive fluoridated and non-fluoridated water supplies and follow them over many years.

This reminds us that reliable knowledge is not always synonymous with perfect evidence. In many areas of healthcare, we are required to make decisions based on the totality of imperfect evidence, drawing on findings from different methodologies, disciplines and sources of knowledge. Observational studies, qualitative research, health services research, implementation studies and policy analyses may all contribute important insights that would be missed if we focused solely on traditional hierarchies of evidence.

Researchers must also pay careful attention to confounding factors and other sources of bias. In oral health research, socio-economic status, diet, oral hygiene practices and access to care can all influence outcomes and may materially affect the conclusions reached. Methodological advances have improved our ability to draw meaningful conclusions from observational studies and evaluations of complex public health interventions, but they do not eliminate uncertainty. Critical appraisal remains essential, particularly when decisions must be made on the basis of imperfect but converging evidence.

How can dentists distinguish robust evidence from noise?
Good science now sits alongside opinion, advocacy, commercial messaging and misinformation. The first step is recognising that not all information carries equal weight.

Dentists need to understand where evidence sits within the hierarchy of evidence. A well-conducted systematic review of high-quality studies will generally provide a stronger basis for decision-making than a single study, and a single study is usually more informative than an opinion piece or a social media post. That does not mean that lower levels of evidence have no value, but it does mean that they should be interpreted appropriately.

“The difficulty is not generating evidence but interpreting it and deciding what can be trusted.”

The responsibility does not lie solely with individual clinicians. Governments, regulators, universities and healthcare organisations also have a role in ensuring that reliable evidence is readily accessible. Access to trusted information should not depend on whether an individual works in a university or can afford expensive subscriptions. If we want evidence-based healthcare, we need evidence to be accessible.

Perhaps the greatest challenge, however, is recognising bias in all its forms. It is remarkably easy to find information that supports a position we already hold, and confirmation bias is a tendency to which all of us are susceptible. The harder task is actively seeking evidence that challenges our assumptions. Equally, we need to be aware that financial, commercial, professional and ideological interests can influence the research ecosystem itself, from the questions that are studied and the funding that is available to the ways in which findings are communicated and amplified. This is why transparency and disclosure are so important.

Science progresses because we remain open to changing our minds when the weight of evidence changes. That willingness to reconsider our views, combined with an awareness of the interests and incentives that can shape evidence, is one of the most important safeguards against bias.

How can dental professionals communicate science clearly on social media?
Social media offers a tremendous opportunity for dental professionals to communicate directly with the public, but it also presents challenges. The very features that make social media effective—speed, brevity and accessibility—can make it difficult to communicate scientific nuance.

Throughout my career in teaching, research and public engagement, I have come to believe that one of the hallmarks of expertise is the ability to explain complex issues clearly. The goal should not be to make science sound complicated but to make it understandable. It is perfectly possible to communicate a simple message while still respecting the complexity of the underlying evidence. Providing links to further information or trusted sources allows people who are interested to explore the topic in greater depth.

Healthcare professionals also bring their own experiences, assumptions and perspectives to the interpretation of evidence. Two professionals can reach different conclusions from the same body of evidence. That is not necessarily a problem, but it makes transparency important.

When individuals have strong advocacy positions, commercial interests or particularly strong views on a topic, I think it is helpful for those perspectives to be openly acknowledged. Equally important is being transparent about uncertainty. Science does not always provide definitive answers, and there are many situations where evidence continues to evolve. Acknowledging uncertainty should not be seen as a weakness; rather, it is an honest reflection of how science works. In my experience, people are more likely to trust experts who are open about the limits of current knowledge than those who project a degree of certainty that the evidence cannot support. Ultimately, public trust depends not only on the accuracy of the information being provided but also on confidence in the integrity, transparency and credibility of the person providing it.

What role does the dental team have in countering fluoride misinformation?
Dental professionals have an important responsibility in this area, and that responsibility extends beyond dentists to include dental hygienists, dental nurses, dental therapists and the wider oral healthcare team. Misinformation, disinformation and the selective use of facts taken out of context can all have real consequences. If families decide, for example, to stop using fluoride toothpaste, but make no changes to other risk factors such as frequent sugar consumption, they may inadvertently increase their risk of dental disease.

At the same time, we should not approach these conversations by assuming that people are being irrational or difficult. Most parents and patients are trying to do the best they can with the information available to them. The starting point has to be listening respectfully to their concerns and understanding where those concerns originate.

What we know from experience is that people are often more likely to trust their local dentist, dental hygienist or dental nurse than a distant expert or government agency. Unlike many other healthcare professionals, dentists may see the same patients regularly over many years, sometimes across generations of the same family. Through those repeated interactions, a deep level of trust naturally develops. Local healthcare professionals understand their communities, speak in language that people understand and often have long-established relationships with patients and families. Having worked in oral health for more than four decades, I have learned that trust is often more influential than data alone.

Whether through conversations in the surgery, community events, local radio or social media, dental professionals can help people navigate conflicting information and improve oral health literacy. Countering misinformation is not simply about correcting facts. It is about building trust, encouraging dialogue and helping people understand how evidence is generated and evaluated. In my experience, trusted relationships are often our most effective tool for supporting informed decision-making.

“Good science now sits alongside opinion, advocacy, commercial messaging and misinformation.”

In the case of fluoride use, it is not simply a matter of individual choice; it is also a matter of public policy. Public engagement in policy decisions is therefore essential. The difficulty is that decisions about interventions such as water fluoridation must draw on a complex body of scientific evidence that can be challenging for non-specialists to evaluate. One approach that I think deserves consideration is the use of citizens’ assemblies or citizens’ juries, which bring together a broadly representative group of citizens and provide them with balanced information from a range of perspectives before they deliberate on the risks, benefits and wider implications of different policy options.

How can dentistry close the gap between evidence and practice?
It is often said that it takes around 17 years for new knowledge to be incorporated into routine clinical practice. Whether that figure is exact or not, the broader point remains valid: there is often a substantial gap between what we know and what we do. This issue has become so important that it has led to the development of implementation science, a field dedicated to understanding how evidence can be translated into practice more quickly and effectively.

Generating evidence is only part of the journey. The real challenge is ensuring that patients benefit from it. Much of my own work over the years has focused on the interface between research, policy and practice, and I have often been struck by how difficult it can be to move good ideas beyond publication and into routine care.

Education clearly has a role to play. We need graduates who are comfortable appraising evidence and adapting their practice throughout their careers. However, education alone is not enough. Many of the barriers sit within systems, regulations and organisational culture. Regulation is essential for patient safety, but there are occasions when bureaucracy can slow the adoption of innovations that would benefit patients. Delays can have consequences too.

Healthcare can learn from other fields that test, evaluate and refine new approaches quickly, provided this is done safely and rigorously. Too often, our systems are better at avoiding risk than enabling improvement. There is also a tendency in healthcare to become paralysed by the pursuit of perfection. We can find ourselves waiting for the perfect solution or the perfect evidence before acting, particularly when evidence is needed to support investment decisions in an environment of scarce resources. Yet clinical practice itself rarely operates with complete certainty. Every day, clinicians make decisions based on the best available evidence, combined with professional judgement and patient preferences. The same principle should apply to service improvement and innovation.

Over the years, I have become increasingly convinced that the biggest barriers are often cultural rather than scientific. We need organisations that are curious, adaptive and willing to learn. We also need to value people who are prepared to question the status quo and ask whether there might be a better way of doing things. Those individuals can sometimes be uncomfortable for organisations, but they are often the catalysts for improvement and innovation.

Rather than waiting for complete certainty, healthcare systems need to become better at working iteratively—testing ideas, evaluating outcomes, learning from experience and adapting accordingly. In many cases, the evidence already exists; the challenge is creating systems that can absorb new knowledge and translate it into better care for patients. Evidence-informed improvement is often a journey of continuous learning rather than a single leap from uncertainty to certainty.

Editorial note: