Making sense of evidence

Alif Moosajee says trust your gut more and keep your patients’ interests at the heart of everything you do.

When teaching or lecturing I often get asked by younger dentists how I got to where I am now and how they can get better at confidently planning the correct treatment for their patients.

I know how it can feel as a young dentist. As a young graduate I was riddled with insecurity. I was massively aware of how good my colleagues were and how inadequate I was, and fuelling much of this feeling, was the uncertainty of not knowing if the decisions I was making about my patient care were correct or not. I would sit in lectures seeing how well people were treating their patients, wishing I could be the same.

I was told as an undergraduate that I must practice evidence-based dentistry. Now, while I wholeheartedly agree with that sentiment and appreciate that there is very good evidence to help us to direct the way we treat, I also understand that it’s not always practical in the real world. That’s not because I wish to cut any corners or because I am not bothered to read the evidence. The truth is that there are many times where we, as dentists, are unable to set up an experiment so that evidence can be gained to support treatments that we carry out.


We are taught about the hierarchy of evidence where meta analyses of randomised control trials are the most powerful and where case reports are thought of as very weak. In medicine it is very easy to do root canal treatment (RCTs) because when prescribing pills it’s possible to withhold certain information from patients and from clinicians so that double-blind conditions can be met. However in dentistry most of our interventions involve hands-on involvement by the operator. This means that double-blind conditions are not easy to attain without risk of serious injury to the patients involved!

The other big challenge we have as professionals is interpretation of evidence and how statistics can be manipulated to support practically every point of view. This is something that materials reps are notorious for doing, showing only evidence from selected studies or even packaging those results in a way that make their products seem more attractive to you as the customer.  I think it’s a very powerful tactic because they understand that the interpretation of evidence is not taught very well at undergraduate level, but yet we are all meant to look at evidence (however good or bad it is) when making decisions about how we treat patients.

One of the classic studies that suffers from bias is the Cochrane Review into looking at whether manual tooth brushing or electric toothbrush is better. The evidence stated that manual and electric brushing were both beneficial (which I completely agree with) and that they were beneficial to the same level. One of the downfalls of this study though was the fact that patients were aware that they were being monitored and having their oral hygiene assessed and this created a bias which we call ‘the Hawthorne effect’. This means that everybody that was undertaking the study was brushing better than they normally would and so, in some respects, it spoils or at least skews the evidence that was gained.

Electronic toothbrushing

I know anecdotally that when I use my Sonicare electric toothbrush my teeth feel cleaner than when I use a manual toothbrush. I can also see that when I recommend electric toothbrushes to my patients and show them how to get the best out of the brush that it’s evident that their oral hygiene improves drastically. Therefore what I can see as plainly apparent and logical in my own experience and in my own practice is contrary to what the evidence tells us.

Appreciating the worth of your own conclusions about what works in your hands is something that comes with the self-esteem of reviewing your own successes. The wisdom of being flexible and not becoming entrenched in a rigid ‘one size fits all’ approach comes from reviewing and learning from your failures. Both can help to affirm that what we are doing as dentists is the correct thing for our patients, even if it goes against what some notional evidence base might recommend.

A great way of helping to get the results you want quicker is by seeking the help of a professional mentor. This is someone who ideally is where you want to be and is getting the results that you want to get. If you can model what they’re doing then you’ll be able to get the results and replicate the success that they get.

But I would also encourage you to trust your gut more and if you keep your patients’ interests at the heart of everything you do, then on the whole you won’t go too far wrong.

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