Questions are still asked, but are rarely answered satisfactorily about how frequently dentists should recall patients. The guidance from the National Institute for Clinical Excellence was supposed to provide definitive answers, but it was so woolly that it can mean anything you like. To paraphrase the words that Lewis Carroll put into Humpty Dumpty’s mouth: 'When I issue a report, it means just what I choose it to mean – neither more or less.'
My mind went back to this issue when I read an ‘evidence summary’ in the British Dental Journal (yes – we all have to do our CPD and even Apolline is moved to read scientific articles occasionally). It posed the question: ‘does routine scaling have any beneficial effects or is it a waste of time?’ It is a topical theme as this procedure has become an endangered species under the new National Health Service contract, although it is alive and well in the private sector.
The conclusion this evidence summary reached should perhaps be read in full: ‘The research evidence is of insufficient quality and limited quantity to allow confident statements to be made regarding the beneficial and harmful effects of routine scaling and polishing for periodontal health and regarding the frequency of provision of this intervention to different patient populations.’ In other words the authors haven’t a clue either.
They were thorough in their research, going right back to 1950 and finding 86 papers that they thought relevant, but rejected 85 of them. The one they let through was a review by the Cochrane Oral Health Group in 2007. They then refined their search terms to identify studies since that date, but again rejected all but a handful. They concluded that since the Cochrane Review of 2007, they could find ‘no new randomised controlled trials to assess the beneficial and sustained effects of routine scaling and polishing.’
As I thought about this article (and even non-verifiable CPD is supposed to make us think) I said to myself: ‘There’s something wrong here’. Sixty years of research and no one can give a straight evidence-based answer to the question of whether this simple procedure, carried out millions of times a year in this country and around the world, is of benefit or just an expensive waste of time and money.
So I read it again and thought that the problem lay in the randomised controlled trial (another RCT to challenge dentists). Look at drugs trails: the doctor hands out pills both those with the active ingredient and those that are just a placebo without knowing who has which. The patients are randomly selected to have one or other pill. So the only variable is the pill. If patients do better with the ones containing the active ingredient, then the test is considered a success.
But you cannot do this with scaling and polishing, because the success of the procedure depends to a great extent on what the patient does in the privacy of the bathroom until the procedure is repeated. The beneficial effect of the scaling lasts 24 hours, by which time plaque starts to grow, unless an effective plaque control regime is followed. This introduces two further variables: the skill of the dentist or hygienist in putting across the plaque control message and the motivation of patients in managing to keep their plaque under control.
The actual scale and polish represents a very small part of the management of a patient’s periodontal condition. The article mentioned two split-mouth studies, where only half the mouth was scaled. They found no difference in plaque levels between the sides over the following year. Of course they didn’t and anyone in practice could have told the researchers why; because most of the work to keep down their plaque is done by the patient.
This brings me back to the recall interval, because the NICE report looked for randomised controlled trials with all the enthusiasm of a medieval knight searching for the Holy Grail and with about the same success. They could only find evidence about caries and this in turn depends largely on the patient’s relationship with cariogenic foods and drinks, not on how often they have a check-up. It also depends on how good the dentist is at putting across the preventive message.
This is important as the recall interval has become a totem for NHS administrators. They look at the fact that just over half of all courses of treatment do not lead to any treatment intervention. So, the bean-counter argues, these are unnecessary. Thus PCTs wish to encourage dentists to extend the recall interval, by the carrot of a ‘quality payment’ and the stick of a request for ‘further and better particulars’ as the lawyers would say.
Like the optical illusion drawings - whether you see the pretty young girl or the old crone - depends on how you look at it. Whereas the PCT manager sees the six-month check-up as ‘inappropriate’, the dentist sees it as an opportunity to re-motivate the patient and thus help them not to need treatment every time they attend. Most regular patients see it this way as well.
The moral of this story is not to put your trust in researchers to find the answer, but to rely on your own professional and clinical judgement. The pity is that the NHS doesn’t see it this way.