Q&A: EBD Where’s the evidence?
Preparing to step down after 20 years, the editor of the Journal of Evidence-based Dentistry looks back at watershed studies
Derek Richards qualified from Cardiff Dental School in 1977 and came to public health dentistry after working in hospital, general and community practice. While undertaking his dental public health training in the Anglia and Oxford region he developed an interest in evidence-based health care and in 1995 helped to establish the Centre for Evidence-based Dentistry in Dundee.
He was also instrumental in founding the Evidence-based Dentistry Journal, which he currently edits. Derek is a specialist advisor to the Scottish Dental Clinical Effectiveness Programme and led the development of the Scottishdental.org website and completed the development of an online training programme for the National Dental Epidemiology programme.
Derek was involved in the York Review of water fluoridation and the NICE dental recall guideline and chaired a selective update of the SIGN guideline on the prevention of caries in children, which was published in March 2014. He has been involved with teaching evidence-based dentistry and a wide range of evidence-based initiatives both nationally and internationally since 1995. He is also a co-author of the book Evidence-based Dentistry: Managing Information for Better Practice (Quintessential of Dental Practice).
“As I [was preparing] to step down as editor after 20 years with the journal it was suggested that I might like to select 20 topics we have summarised that I felt were important,” he said. “Given that new evidence is emerging all the time and that some Cochrane reviews have had two or three updates since the journal started this was a bit of a challenge. As it is also a very personal choice, it comes with my personal biases, so be warned!”
Most of the studies selected by Derek have been Cochrane reviews. “The development of the Cochrane Oral Health Group and the number of reviews have to me been one of the important drivers of evidence-based dentistry over the past 20 years,” he said. “Over that period, we have also seen significant growth in the number of non-Cochrane systematic reviews conducted. This, together with increased teaching of evidence-based dentistry at under and postgraduate level, has helped its development.
“However, there is still much to do to develop dentistry’s evidence-base, and many of the reviews we are doing are highlighting the need to improve the quality of our primary research. We need to rapidly adopt and implement the best research practices. There is plenty of guidance out there in resources such as the EQUATOR Network.
“We also need to build on the work that some dental groups are doing with common outcome sets. Using common outcome sets helps compare outcomes in similar studies and assists systematic reviewers to aggregate data which should help us to build a more robust evidence base, answering important questions more quickly. As the volume of published research continues to grow, I feel there will be more than enough for my successor to digest and summarise.”
Professor Elizabeth Kay has been appointed as the new editor. Elizabeth, who qualified from Edinburgh Dental School in 1982, has a long and distinguished career in dental public health and dental research and is a long- standing member of the BDJ editorial board. She is the author of 200 research and professional papers, six books and two book chapters, and has previously been Scientific Advisor to the BDA. In 2017, she was awarded an MBE in recognition of her services to dental education and is currently the Foundation Dean at the Peninsula Dental School at Plymouth University and Faculty Associate Dean for Equality and Inclusion. She will take over the position from the current editor with the June 2019 issue.
“I’m really excited about the new post and to have the privilege of working with some excellent people,” said Elizabeth. “I have spent quite a long career trying to do research and translate it so that it’s relevant to practitioners who are delivering good dental care to the population. I’ve been a great proponent of evidence-based practice and the evidence base being used properly ever since I did my PhD.”
Derek Richards’ highlights from 20 years
- The review of the prophylactic extraction of third molar teeth by Song et al., helped inform the NICE guidance on third molars and an announcement is awaited as to whether an update will go ahead.
- The York review of water fluoridation was an extensive and unique review in that it was overseen by a steering group involving both pro- and anti-fluoridation.
- The first publication of the Cochrane review on powered versus manual toothbrushes, summarised by Rick Niederman, coincided with an evidence-based dental meeting in Boston, and received a significant amount of media coverage with different interpretations of published evidence on whether powered or manual brushes performed better. Subsequent updates of the review are now clearer that powered toothbrushes reduce plaque
and gingivitis more than manual toothbrushing in the short and long term.
- Summaries by Hannu Hausen of just two of the Cochrane reviews undertaken by Valeria Marinho on topical fluorides was very helpful in clarifying the effect size of a range of topical fluoride interventions.
- The summary by Sergio Uribe of the Cochrane review of pit and fissure sealants, the latter providing evidence of the effectiveness of sealants, with the most recent update of the review demonstrating caries reductions in occlusal surfaces of between 11-51 per cent at two years, an effective preventive intervention.
There is still much to do to develop dentistry’s evidence-base, and many of the reviews are highlighting the need to improve the quality of our primary research”Derek Richards
- Jim Bader’s summary of the NICE guideline on dental recall. The key recommendation of the guidance was a move away from fixed six-monthly recall intervals to a variable risk-based interval for both children and adults. While there has been some change within the profession, this still seen by some as controversial and later this year the results of a UK-based trial will be available, which will add another contribution to the debate.
- Orthodontic retention regimes are also a topic of much debate and Chung How Kau summarised the Cochrane review by Littlewood et al., that looked into the evidence for this which at the time found insufficient data. The review was updated in 2016 and while more evidence was included in the review there is still not enough high-quality evidence to make recommendations.
- The only randomised controlled trial on Derek’s list is a large trial of the Hall technique for restoring primary molars summarised by Aronita Rosenblatt. A simple and effective approach for managing carious molars that has been supported by several other trials and is now considered as one of a number of biological options for managing carious primary molars.
- In 2008 Toru Naito summarised a Cochrane review addressing the issue of whether single or multiple visits were the best approach for root canal treatment in permanent teeth, a topic of some debate. However, the review found no evidence of a difference in effectiveness between the two approaches, with the latest update to the review also finding no apparent difference.
- For many years the early extraction of primary canines had been recommended to facilitate the eruption of the palatal ectopic permanent canines. Carlos Flores-Mir summarised a 2009 Cochrane review which found no evidence to support this and there is now a new expanded Cochrane protocol in development.
- Toothpastes of different concentrations was, Derek believes, the Cochrane Oral Health Group’s first published network meta-analysis. Published in 2010 and summarised by Graciella Racines, it confirms the benefits of using fluoridated toothpaste to prevent caries and provides information on the relative effects of the different concentrations of fluoride.
- Debra Ferraiolo and Analia Veitz-Keenan summarised a Cochrane review that compares paracetamol and ibuprofen for pain relief following third molar removal, finding high quality evidence to show that ibuprofen was superior to paracetamol.
- Sugar consumption is an important risk factor for caries and Ruth Freeman summarised the systematic review by Paula Moynihan that underpinned the 2015 WHO guidance on sugar intake.
- Periodontal disease remains a significant public health problem and Shalini and Neeraj Gugnani examined a Cochrane review on whether interdental brushing in addition to toothbrushing compared with toothbrushing alone was better for periodontal health with the review finding low quality evidence of a benefit.
- Three authors, Caitlin Stone, Andrew Hannah and Nathan Nagar, summarised a review of the long-implicated link between occlusion and temporomandibular disease (TMD). The Manfredini review summarised found very little clinically relevant evidence supporting an occlusal cause for TMD.
- Another summary by Debra Ferraiolo and Analia Veitz-Keenan looked at a Cochrane review comparing surgical versus non-surgical approaches for endodontic re-treatment, another area where there are differing views on the best approach. The review found evidence that surgical approaches lead to better outcomes, but the available evidence was of low quality.
- A number of studies have suggested links between periodontal disease and a range of medical conditions. One of these, adverse birth outcomes in pregnant women, was assessed in a 2017 Cochrane review, summarised by Silvia Spivakovsky. It found it was unclear if periodontal treatment during pregnancy has an impact on preterm birth (low-quality evidence). However, there was low-quality evidence that periodontal treatment may reduce low birth weight (< 2500 g).
- A summary by Parthasarathy Madurantakam of another Cochrane review which looked at the question of whether open or closed surgical exposure of palatally displaced crowns had the best outcomes, again a topic where there are different views. The review found no evidence to suggest that one approach was better, but the available evidence was of low quality.
‘20 years – 20 highlights’, by Derek Richards.