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All that's new in the world of dentistry
MAY
17
0

Material facts

Composite material

Back in the past, I used to hate dental materials lectures. It all seemed so irrelevant. I just wanted to know the material worked. I couldn’t get excited about the chemistry. Oh, I remember the important stuff. 

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APR
14
0

Just Drifting

Walking to dental school one day, I met one of our professors, carrying a cage.

A conversation ensued.

‘May I ask what is in the cage, Professor?’

‘You may, Mr. Hellyer – it’s a monkey of the species Macaca Irus.’

‘Really?’.

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FEB
25
0

COVID-19 – when the rubber hits the tooth

Positive tests

I have a friend who is a proper scientist. You know the type, PhD after their name, and understands all the stats stuff like Cronbach’s alpha, Spearman’s r and the Wilcoxon Rank Sum test. Their area of research was water quality and they spent 3 years gathering data from the outfall from sewage works. Three years collecting dirty water samples and theirs is the prefix of doctor and the suffix PhD.

Collecting waste water has become a bit of a trend during the Covid pandemic. The BBC reported that fragments of the virus’ genetic material can be identified from sewage, even when there are only asymptomatic cases in the area. Identification is not easy because of other contaminants but clusters of infection may then be identified before symptomatic cases appear and preventive strategies targeted earlier than would otherwise be possible.

And if the virus is shed from one end of the gastro-intestinal tract, then it’s almost certainly at the other end too. We know that the virus gets up your nose and gathers round your tonsils. Never in the field of public health, has so much sneezing and gagging gone on in the bathrooms of this country as we test, test, test, desperately hoping for that single pink line to appear on the test kit. But what about that fluid that dentists spend their time fighting against? What about saliva?

Lateral Flow tests

There have been multiple research papers published in the past months, about the link between saliva and Covid, many fast tracked for dissemination in the fight against the disease. A recent study from the US confirmed that the virus was present in the saliva of both asymptomatic and pre-symptomatic patients. A quite specific review suggests that as saliva is easy to collect and saves the need for swabs-on-sticks-up-the-nose, which are uncomfortable and pose a risk of bleeding in some cases, then saliva testing for evidence of the presence of COVID-19 might be a more acceptable test mechanism. The review found that passively collected saliva had a high sensitivity rate to detect Covid in asymptomatic and mildly symptomatic patients when compared to naso-pharyngeal swabs. Passive collection – drooling, basically – means there is no contamination of the saliva from coughing or nasal discharge.

So there’s Covid in spit – who knew? All those prevention strategies for aerosol generating procedures must have been worth it.  But as the Government appears to remove all restrictions to normal life, how long before all those restrictions on dentistry are removed? Abandoned to the whims and fancies of the asymptomatic, untested – ‘it costs money, guv’ – maskless patient. Do we assume everyone is Covid positive, just as the basis of universal precautions is that everyone carries HIV or Hepatitis C? Back to normal then, with current screening depending largely on questions regarding symptoms and test results.

When carriers of Covid can be asymptomatic and there’s no longer testing freely available, questions about symptoms and test results appear to have limited use. There may be a future for a simple saliva test, to check what precautions are necessary before treating any patient. But I suspect that would be considered discriminatory and ethically unacceptable.

What then can be added to the standard procedures to help prevent spread of Covid? A pre-operative mouthrinse reduces the viral load in saliva for between 15 and 45 minutes. Maybe a 30 second swish of Chlorhexidene or hydrogen peroxide will become the norm for everyone.

Rubber dam is of course another weapon in the armoury of the dentist to reduce contaminated aerosols in the surgery Those of us of a certain age will recall the enthusiasm of Keith Marshall’s ‘Dam it, its easy’ courses. There’s surely an opportunity here for an entrepreneurial educator to set up some hands-on dam refresher courses.

And since condom sales fell by 40% during lockdown, there may be some good opportunities for sponsorship from manufacturers as they seek alternative outlets for their rubber. Presumably there will be fewer contaminants in the wastewater, too.

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Copyright

© Paul hellyer, GDPUK Ltd, 2022.

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FEB
04
0

It’s not all black and white

Black & White

 

Last night (03/02/2022) on Dragon’s Den (BBC1 8.00pm), an entrepreneur walked away with an investment of £50,000 in her company selling cosmetic dental products – charcoal toothpaste, bamboo handled toothbrushes and home whitening kits. The company, SmileTime, is generating over £1m in sales annually online, and probably more after last night’s TV exposure.

The evidence of the efficacy of charcoal based oral products appears to be lacking. A recent paper in the BDJ stated ‘Charcoal-based dentifrices, in the absence of supporting scientific evidence, may be considered to be a fashionable, marketing 'gimmick' based on folklore.’ SmileTime’s website, however, claims that their tooth whitening kit (using ‘advanced active whitening ingredient called PAP that whitens and brightens your teeth without any pain or sensitivity’) is ‘scientifically proven to whiten and brighten teeth after a few uses as shown in the clinical trial study by the Journal of Applied Oral Science.’

So let’s look at this evidence for their tooth whitening kits. The study was published in 2017 and carried out by a team at Witten/Herdecke University in Germany. The active materials under test were a non-hydrogen peroxide bleaching agent phthalimido peroxy caproic acid (PAP) and calcium lactate gluconate (a remineralisation agent), available as an over the counter (OTC) product called iWhite. iWhite is a brand sold by Sylphar, who supported the quoted research project with funding for the materials and compensation for the participants. A disclaimer states, however, that ‘the company was not involved in the study design, the data collection and analysis, the decision to publish or the preparation of the manuscript.’

iWhite is intended as a self applied bleaching gel, using trays provided in the kits. After some explanation of the legalities of the use of hydrogen peroxide as a dental bleaching agent, the authors introduce PAP and calcium lactate gluconate (as a remineralising agent) as a novel OTC bleaching agent. For the research, they recruited 40 participants (the paper doesn’t say how they were recruited) and randomly divided them into an active group and a placebo group. The active group received application of iWhite and the placebo group received iWhite but with the active ingredient removed.

All participants were examined, confirmed as disease free and had no teeth lighter than VITA Lumin shade A2. Using the shade guide (numbered 1-16), the blinded examiner recorded tooth colour at baseline, immediately after gel application and 24 hours later, under similar light conditions (not defined). The middle one third of each upper and lower anterior tooth was used to select the shade and an average score was produced for each participant. All participants were supervised during application of the gel by the researcher.

According to their results, the mean shade score fell significantly (i.e. whiter) by about 2 points for the active group immediately after application and after 24 hours. There was no significant change in the placebo group. That’s the scientific evidence.

But there’s a few anomalies. Forty one percent of individual teeth showed no shade change. This means the gel is not as effective as it might be or, even under supervision, was unequally distributed in the one-size fits-all trays. The product is sold to be used unsupervised at home. The discussion states that the examiner found no mucosal irritations immediately after application nor 24 hours later. However, the results section states that the examiner found 5 subjects with gingival irritation in the study group and 3 in the placebo group after application. At baseline, hypersensitivity was measured by blowing air on the teeth. After 24 hours, hypersensitivity was measured by asking the subject. Even with that ambiguous method, hypersensitivity was recorded in 4 subjects. There’s no description of how the ambient light was controlled, surely important in discussing anything to do with shade and colour. The authors state that ‘the colour stability after bleaching has been largely confined to weeks or months’ – but they didn’t measure that.

On the whole, it’s all a bit wishy washy. One examiner? Why not 2 for a much stronger conclusion? Only one application? That’s because ‘the products may cause irreversible damage if used on a long-term basis.’

And I’m not convinced by the stats. A shade guide is basically a stack porcelain or acrylic teeth, named subjectively for convenience A1 to D4. You could name them white, whitey, whiter, whitest, yellow, yellowy, yellower etc etc. By ascribing numbers 1-16 doesn’t make them numbers. They are still simply labels. And just as you can’t create an average of white, whitey, etc, you can’t create a mean or average of these number labels. The mean is therefore meaningless which undermines the validity of the whole paper. But I’m happy to see if greater statistical minds come along to correct me!

Even if I’m wrong on that, the study certainly doesn’t show that the product ‘whitens and brightens your teeth without any pain or sensitivity’ as claimed on the website. The study does not show that ‘PAP formulas have been scientifically proven to whiten and brighten teeth after a few uses as shown in the clinical trial’ as claimed on the website. The study does not show that ‘results will last anywhere between 2 weeks and 3 months,’ as claimed on the website.

I can find no other in vivo research of the use of PAP as a bleaching agent, although a recent in vitro study found non-peroxide mouthwashes had minimal bleaching effect.

I guess the jury is still out.

But, as they say on Dragon’s Den, I’m afraid I’m definitely out.

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Copyright

© Paul Hellyer, GDPUK Ltd, 2022

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JAN
24
0

The puzzle of TMD

The puzzle of TMD

There have been a few common phrases around recently that would not have been heard some years ago.

‘You’re on mute!’ in the first year of lockdown and ‘Have you had your jab yet?’ in 2021.

This year it is ‘Have you heard about Wordle?’

Wordle for those who have yet to discover it, is a web-based word game, with a 5x6 grid of boxes. Participants enter a five-letter word into the top line and are then informed, by the highlighting the relevant letters, whether the choices are either in the correct place for the word to be guessed (green) or present in that word but in the wrong place (a shade of sickly khaki). Using that information, the process is repeated on the descending lines until either the correct word is found or the 6th guess is incorrect. A new game is set each day.

Diagnosing tempero-mandibular joint disorder (TMD) strikes me as similar to playing Wordle, but without ever getting to line 6 with the correct answer. All responses to questions are about as helpful as those squares of sickly khaki.

‘Does it hurt when you open your mouth?’

‘Sometimes’

‘Does it click when you open wide?’

‘Oh yes, listen …… and it drives my partner mad at meal times.’

‘Do you grind your teeth in your sleep?’

‘Oh yes, and it drives my partner mad to 2 in the morning.’

‘Do you clench your teeth at all?’

‘Occasionally, when my partner’s mad at me.’

‘Do you get headaches?’

‘Well, my partner and I aren’t getting on too well at the moment, so yeah, I guess I do.’

‘Have you had any knocks to the head recently?’

‘Look, I said we’re not getting on too well but its not as bad as all that!’

 

And so it goes on, checking for tenderness to palpation and whether the occlusion looks OK and writing ‘TMD?’ in the notes and offering generic advice about self-care, all of which is available on the NHS website, such as don’t chew pen tops, eat soft food, take some analgesics and if it doesn’t get better, see you GP, who might refer you to a dentist (who might make you a soft bite guard).

According to a recent paper in the Journal of the American Dental Association (JADA), dentists in the USA offer similar advice. One hundred and eighty five dentists were recruited to record details of a sequence of patients attending with TMD. They recruited 1,901 subjects who fulfilled their criteria for entry to the study. Almost half of these had had painful TMD for at least 3 years and diagnoses included combinations of myalgia, arthralgia and headache. A quarter had only muscle pain and 10% only joint pain.

Treatments offered were mostly non-invasive and reversible:

  • Avoid oral habits
  • Relax your jaw muscles
  • Apply heat or ice
  • Eat a soft diet
  • Avoid chewing gum
  • Keep your teeth apart
  • Chew food on both sides
  • Reduce caffeine intake

Three quarters of dentists in the study recommended an intra oral appliance of some sort and two thirds recommended referral to ‘allied care providers.’

And there’s the rub. To whom does one refer? Who are the allies in the management of TMD? Outside of a large conurbation with a dental hospital, I suspect most end up with the local maxillo-facial surgeon. But how often is surgery required? Orthopaedics, maybe – that speciality which diagnoses and treats ‘a wide range of conditions of the musculoskeletal system, (including) bones and joints and their associated structures that enable movement - ligaments, tendons, muscles and nerves?’ I’m not sure their interest stretches superior the hyoid and anterior to the atlas and axis. Oral medicine? Physiotherapy? Osteopathy? Aromatherapy?

It is perhaps not surprising that a further paper in JADA found that TMD is linked with other chronic conditions such as chronic back pain, myofacial syndrome, chronic stomach pains, migraine, irritable bowel syndrome, fibromyalgia and depression. They conclude that their review ‘supports the idea that clinicians, including dentists, treating patients who had received diagnoses of TMD should be attentive to the presence of signs and symptoms of other chronic pain conditions that could require collaborative care across medical specialities (for example, neurology, rheumatology and psychiatry.’

The temporomandibular joint is the Cinderella of all joints, falling between the specialities which may be able to help. Since 1892, it has clearly failed to be recognised as part of the ‘anatomical arrangements of the human body.’ Yet 80% of dentists report treating up 3 patients a month with TMD.

TMD therefore is not uncommon and these papers show that its diagnosis and treatment is a complex, multi-disciplinary exercise and not one to be passed down like the rows of a Wordle puzzle, eliciting sickly khaki responses in the hope of finding a successful result of 5 green squares.

Paul Hellyer BDS MSc

The puzzle of TMD

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