Program: Why do people become dentists?

Preeya Alexander: How do you feel about going to the dentist, Norman? 

Norman Swan: I haven't been for a while, I'm ashamed to say, but I do get anxious going to a dentist I don't know.

Preeya Alexander: I do too. What are you worried about?

Norman Swan: That they can do a nerve block well.

Preeya Alexander: I do not like going to the dentist. I am up to date with my dental check-in, and I took the kids and myself. I wanted to get it done by the time 2026 came around. I don't like it, Norman, the scratching around, it's a very vulnerable position, lying back with your mouth open is just not for me, with sharp utensils.

Norman Swan: With a one-way conversationalist.

Preeya Alexander: Yeah, that's right, I don't get to talk, and we know that I love that. 

Norman Swan: So I'm glad there are dentists, I'm glad there are people who want to become a dentist. But I'm sure that lots of people are lying there thinking about, you know, why would somebody want to do this job, apart from the money? So we're going to find out later, because Shelby Traynor, our producer, has wondered exactly the same thing, and she went to dental school for a day.

Preeya Alexander: She did. That is coming up on the Health Report. I'm Preeya Alexander on Wurundjeri land.

Norman Swan: And I'm Norman Swan on the lands of the Nacotchtank and Piscataway people. 

Preeya Alexander: And where is that? Because it's not ringing any bells for me. 

Norman Swan: Well, it's not on the Australian continent. These are the traditional owners of Washington DC, which is where I am.

Preeya Alexander: Miles away.

Norman Swan: Miles away.

Preeya Alexander: Miles and miles.

Norman Swan: Also on the show, data which suggests that CT scans, CAT scans, could be responsible for up to 5% of new cancer diagnosis annually if current practices don't change. But of course there are important caveats. Aren't there always?

Preeya Alexander: Aren't there always. And this is one of my conundrums, sometimes you absolutely need a CT scan, but the benefits must outweigh the risks. 

Psoriasis is fairly common, it's an autoimmune condition that shows up as itchy, dry and sore skin, but it's deeper than the skin that's affected. 

In the news, vitamin B6 has likely been in everybody's news feed again this week, and that is because the Therapeutic Goods Administration has decided to take action on something that we've spoken about previously on the show, vitamin B6 toxicity, which is people are often taking more vitamin B6 than what they realise. It's often in multiple supplements, and it can have significant side effects, including peripheral neuropathy. So it can impact those nerves outside of the spinal cord. You can get numbness, tingling, and in some cases even if you stop the B6, the symptoms can persist. It might be irreversible.

Norman Swan: And it's in all sorts of products. It's not just in supplements you might buy in the pharmacy, it might be in a food supplement that you could be taking. So the TGA decision…we'll tell you what the decision is, and then I'll tell you why I'm gobsmacked about it. So they'll still allow the sale of products with 50 milligrams or less in them for general retail sale but…

Preeya Alexander: In the daily dose, it's worth pointing out. So the daily dose has to be 50 milligrams or less, yep.

Norman Swan: Products containing between 50 and 200 milligrams are available over the counter. So in other words, they are kind of behind the counter, and you need the advice of a pharmacist. And if it's more than 200 milligrams per day, you're going to need a prescription. And of course not that many people need vitamin B6, you can get it from the diet. But here's the gobsmacking thing which I fail to understand, our 'lightning action' from the TGA, this doesn't come in until the 1st of June 2027. So if you really want to have a peripheral neuropathy, you can go right ahead until 1st of June 2027. Why oh why does it take so long?

Preeya Alexander: Well, they've actually said it's because they're trying to give the industry time to prepare.

Norman Swan: Stuff that, is my view.

Preeya Alexander: Well, I agree with you, but we've talked about this before on the show, and I just think the regulation of supplements is baffling. Like, you're gobsmacked about the deadline of June 2027, and I just think I can't believe the claims that supplements can make that are unfounded and unproven and they can get away with it, and it's sold in pharmacies and online. I just had a patient tell me this week what they were taking for their ADHD, which lacks evidence completely. And I thought, I can't believe this is allowed to be sold. The regulation of supplements is baffling to me.

Norman Swan: Well, there's regulation on paper, but the TGA doesn't necessarily police it unless there's a complaint, so you can make a complaint. And if you are looking at labels and wanting to see if there's vitamin B6 in there probably, prior to 1st of June 2027 it's not just called vitamin B6, there are other names for it; pyridoxine, pyridoxamine and pyridoxal. So just be a little bit careful when you're buying supplements as to what is in them. And if there's B6, probably just leave it there, go and have a nice Mediterranean rainbow meal, as Preeya would say.

Preeya Alexander: You're merging us together. But also we do bang on about this as well, but most people don't need a supplement. So Norman and I don't take anything extra. We share this offline, don't we. I'm not taking anything. Are you?

Norman Swan: I'm not. No, no, no, there was no hesitation. I am not taking anything. Look, there are a very small number of medical conditions where you need vitamin B6, but that's it.

Preeya Alexander: Yes, always exceptions to everything. If you're planning a pregnancy or you're deficient in something, you need supplements. Most of us don't. Also back in the news, H5N1, which is bird flu, that's that strain of influenza A virus, has now been detected in an Australian territory, Heard Island.

Norman Swan: Yeah, 4,000 kilometres south-west of Perth, so it's not exactly on mainland Australia yet. Why are we worried about this? This is the one that they're worried could be the next pandemic of flu because it's got high mortality rates when it does infect humans, but it's not spread human to human. At the moment it's animal to human. And so we've got to keep an eye on this, and we've been expecting for a while for it to land on Australian shores. It has landed on Australian shores, but not too close to probably anybody listening.

Preeya Alexander: And people might be wondering, well, how has it been detected on this remote island? Because a population of elephant seals had died on the island, and so they were tested, and that's how this was detected. So this has, of course, health impacts. Are we prepared? Are we ready? Do we have vaccines if this does come to the mainland if there's human to human transmission? But also this is going to have impacts for nature as well and for animals. And so certainly something to be aware of.

Norman Swan: And very briefly, the Breast Cancer Network Australia, which is a consumer-based organisation representing the interests of women and men with breast cancer, has released really quite astounding findings of the number of people living with breast cancer that's spread.

Preeya Alexander: Metastatic breast cancer, yeah.

Norman Swan: And it's nearly 21,000 Australians, so about 20,800 women and about 150 men living with breast cancer that's spread.

Preeya Alexander: And the thing that's significant, I think, is that it's been underestimated previously, so they think it's double the previous estimations. And this impacts funding and supports for these patients, who often have really complex care needs.

Norman Swan: They have complex care needs, psychological impacts of having that, and the treatment of breast cancer that's spread. We've got a lot of research that goes into the first-line therapies when you've initially got the cancer, and breast cancer probably represents the most sophisticated, advanced treatment of any cancer at the moment, and they're getting remarkable results. And they're also getting remarkable results with cancer that's spread, such that in many women it's become almost like a chronic disease where they can live for many, many years with cancer that's spread. But we still don't know a lot about why cancer spreads, how to prevent it, and how to treat it effectively. Because what oncologists say is that once you've got cancer that's spread, it's very hard to achieve a cure. The time you achieve a cure is at first pass, when you first diagnose. And we simply don't know enough about metastatic cancer of any kind to say, well, we actually can cure that, and we can't yet.

Preeya Alexander: But hopefully this is a push in the right direction. 

Norman Swan: On ABC Radio National, you're with the Health Report.

Preeya Alexander: CT scans are sometimes absolutely necessary, but there are always risks. And you've got a story about how you balance those risks and benefits, and if you actually need a scan.

Norman Swan: If you look at data from the United States where they actually looked at 93 million CAT scans performed in 62 million patients in 2023, they projected in this research that that would result in approximately 103,000 future cancers. And they're talking about lung cancer, they're talking about bowel cancer, they're talking about leukaemia, breast cancer. It depends where the CAT scan has been done and the exposure to radiation, and based on this study they estimate that, over time, if CAT scans go on at the current rate in the United States, 5% of all cancers could have CAT scans to blame for it. So this is a serious issue. It's one that's been monitored by Associate Professor John de Campo, who actually is a radiologist, a practising radiologist, has also been a health administrator, and he's very concerned about it.

John de Campo: The regulator, that's ARPANSA, says that in Australia there's about 5 million scans done a year, and that's much less than in America, one-third less than in America, so their rates of cancer, we might expect ours to be one-third less because we do one-third of the CTs that the Americans would do.

Norman Swan: Now, ARPANSA has made a comment on CT scanning, or looked at this area, and they did it in April of this year, I think that they published it in May, where they said, well, CT scanning technology has changed, you get a lower dose because it's a faster scan. And the extrapolations in the US study were based on radiation exposure and Hiroshima and what was found after that, and these are not necessarily relevant to ascribing risk. What's your comment on that?

John de Campo: Well, earlier on in that same paper, Norman, they said we've always known about these risks, there's nothing new in this paper, the risks are well known, and those risks are based on the atomic bomb dropped in Japan, and they've been gone over with a fine-toothed comb for the last 25 years. And no one has said that's not a risk, everyone says it is a risk, actually including ARPANSA says the risk is well known. So I think the time has come to sort of do something about it, rather than hope that scans will be used in an evidence-based way, we can do better than hope I think.

Norman Swan: We'll come back to the evidence-based way in a moment. So when you talk to radiologists, and I predict if I talk to the College of Radiology about this they'll say, look, CT scanning 25 years ago was a long involved process, you were sitting in the scanner for ages, but now you're in the scanner for a few minutes and it's transformed and the radiation dose is lower. What do you say to that?

John de Campo: Two things. CT is fabulous. It's so accurate in finding cancers or useful in trauma. Across the board it's been a revolution in imaging. So I wouldn't want to in any way dismiss the value of CT. But there's a risk because the pictures are so great now, they do require radiation, and perhaps more radiation than those back at the start. And we have improved the detectors. Well, we've improved the software so that small patients get less than big patients. So there's been a lot of improvement in the way the scans are done, but they do involve radiation. And the radiation doses in the recent article are the current doses (actually from 2019 if I remember), but these are current doses on current machines.

Norman Swan: But is there any sense of who's really at risk here? So, you know, I'm getting my coronary arteries checked and I have a CT scan of the heart, and I have one in my 40s, so does that put me at risk? Or is it somebody who's got a chronic illness and is having multiple CT scans? Or is it just a graded risk, depending on how many scans you have…?

John de Campo: The number of scans, but each scan has got a risk. Now, age is another factor. So if you're a one-year-old or a six-month-old, then the more scans you have, of course the risk will be higher. And some of the CT scans are quite complex these days. Say, looking at the liver, you might go into the machine and have four scans before you come out.

Norman Swan: Now we come to the question of how essential the scans are and how evidence based they are. Do we know what proportion of CT scans are inappropriate? 

John de Campo: About a third of scans are not indicated and not useful. 

Norman Swan: Can you give me an example of the sort of scans that…?

John de Campo: Oh, from last week, 'asthma, CT chest please'. Or 'woke up this morning with back pain, CT back please'.

Norman Swan: So this is from your personal experience of requests?

John de Campo: Yes, personal experience, but the biggest culprit is probably in back pain, where we know that in six weeks, 95% or 98% of back pain will get better by itself, so that unless there's a red flag, then waiting is the best plan. Arthritis would be the next commonest one, with plain films increasingly being replaced by 'CT of the knee please'. The results are the same for a first visit, you know, the knee looks a bit sore.

Norman Swan: It's a complicated story. I mean, one is that you, as the radiologist, are serving the referring doctor, so they know the patient, and who are you to say no? The other is conflict of interest financially, which is that you've got…we've covered this story before, you've got heavy corporatisation of private equity and even listed companies in the radiology space, where they are telling their shareholders how much they're making out of the volume of scans that they're doing, and therefore if you say, 'we don't really need to do the scan, back to the GP', you're reducing the earning. I mean, there are lots of forces here against rational imaging.

John de Campo: Yes, I think I want to talk about rational, not rationing. There are forces. There's also the medicolegal force on busy general practitioners not wanting to (in inverted commas) 'miss anything', that's a force, particularly if you happen to be on a visa, that provides an extra anxiety for practitioners, and the financial drivers of the radiology industry doesn't really foster best practice. It's not to say my colleagues wouldn't do their very best each day to do what they think is best for their patients, but there are drivers around us all, all the time, and it's hard to ignore them.

Norman Swan: So what's the solution for this? I remember (and I don't know whether it's sustained itself) Massachusetts General Hospital in Boston had a problem with exponentially rising radiology costs, and what they did was that when a referring doctor referred for a particular scan and it looked inappropriate according to the clinical notes on the order form, they sent an email back to the doctor saying, 'In this situation it's not really indicated', and they gave some facts and figures. 'We're not stopping you doing the scan, but have another think about it'. Did that work?

John de Campo: I don't know that example, but evidence-based imaging has proven very, very difficult to introduce in any country. You know, you gave an example where it might have worked. But even the guidelines for lung cancer nodules, they are not religiously followed actually, you know, people still having follow-ups when the follow-ups are not indicated. It's a great difficulty in doing the right thing. 

Norman Swan: So if you were a dictator, what would you say should happen?

John de Campo: Oh, a dictator, yes, if only. I think the solution, being a benign dictator, would be to first make MRI more available to general practitioners for red-flag spinal imaging. So that's cervical, thoracic and lumbar, let's open up the gateway, that would replace CT of the spine for red-flag cases.

Norman Swan: Just to be clear, what you're talking about here is not straightforward back pain, you've got weight loss, you've got bruising, there's other symptoms going on.

John de Campo: Yeah, it's where the GP thinks there's something not quite right here, I need imaging. MRI is zero radiation, and the price is not that different to CT. Then it would be an easy step, you know, stroke of the pen, done in one day. No cost, lots of benefits. MRI is better than CT for the spine. Same for ovarian lesions that are suspicious on ultrasound, CT is not very good for that, MRI would be great. 

I think the next activity would be to make sure that patients gave informed consent before they had a CT. This is controversial because it's said, even by the regulator, patients might get worried and not have an important CT. I think that's paternalistic. Patients deserve the right to know the risks of an examination and the benefits and then to decide if that's something that's good for them. Actually, I don't think you can exclude the patient really, it would be unreasonable, but we have for a long time excluded the patient from this decision, and I think that hasn't been a reasonable approach.

Norman Swan: And the question that you need to ask your doctor if they're ordering a CT is, 'Do I really need it? Is it going to make a difference to my care? Can you substitute for MRI?'

John de Campo: 'What's the benefit for me? What important information are we looking for here? What are the risks? And are there alternatives?' And written consent is just a little hurdle that people should step over that makes them recognise that there is a risk here, but it's acceptable, or not.

Norman Swan: Associate Professor John de Campo, a radiologist based in Melbourne. So, as with everything, Preeya, it's only do it when you need to.

Preeya Alexander: That's right. And for some people the benefit definitely outweighs the risk, but it's worth a discussion. I often say to patients this is what we need, but these are the potential risks. So I think if you have questions, ask about the potential risks and get the information.

Norman Swan: I mean, I think one of the most useful questions you can ask your doctor when they're doing any test on you is, 'Why are you doing the test, and is it going to make a difference to how you treat me?' And if it's not, if it's just to settle down anxiety in the doctor, then you can choose not to have it. It's up to you.

Preeya Alexander: Yeah, I agree. That question of 'how does this change my management' I think is a key one.

Norman Swan: We asked the Royal Australian and New Zealand College of Radiologists for a response to the issues mentioned in John's interview, and if you want to read that, it'll be on our website.

Preeya Alexander: You're with the Health Report on ABC Radio National.

Norman Swan: Coming up soon on the Health Report, our producer Shelby Traynor goes to dental school for the day and actually does a filling, all in the search for the reason why people do dentistry.

Preeya Alexander: Psoriasis is often just considered a skin condition by many people, but it's actually a lot more complex, Norman. People don't realise that it can impact your risk of heart disease and increase your risk of mood disorders like depression. It's also pretty common, it affects about 2.4% of Australian adults.

Norman Swan: And it runs in families. It's actually in my family. I don't have it but people in my family do.

Preeya Alexander: There you go. It does have a very strong genetic component. But there's been a lot of updates in terms of management options, and there's some work being done to better guide people with the diagnosis of psoriasis when it comes to their risk of heart disease, which is actually higher than you might realise. I spoke to dermatologist, Dr Annika Smith.

Annika Smith: It's a chronic inflammatory skin disease, but our understanding of this condition as a systemic disease has really evolved in recent times. So we know there's a number of important conditions associated with psoriasis, namely psoriatic arthritis, that affects about 30% to 40% of patients with psoriasis. Perhaps most importantly there's about a two times increased risk of heart attack and stroke in this cohort, and that's owing to accelerated rates of atherosclerosis, and, along with that, we have increased prevalence of all the known cardiovascular risk factors; hypertension, hyperlipidaemia, diabetes. The metabolic syndrome obviously is increased in this cohort. 

We now understand too that the altered inflammatory burden in the skin, if you like, can also impact on brain neurochemistry, and may in part be responsible for some of the depression and anxiety we see in this cohort. Other well-established associations include other autoimmune diseases, such as celiac disease increase. But I'd say the main ones that we focus on in clinic and that may influence our therapeutic decision-making in terms of choosing the right drug for the right patient, strongly rest with the joints and also now the heart risk.

Preeya Alexander: Wow, it's a lot, isn't it? I think a lot of people still don't realise just how much is involved in this diagnosis. When you talk about the metabolic risk and heart disease risk, at the moment is there a clear consensus or a guideline for prevention of heart disease in people diagnosed with psoriasis? Should they be getting extra checks, cholesterol checks, blood pressure checks?

Annika Smith: Look, there's acknowledgement amongst international cardiovascular guidance that psoriasis should be included or considered as a cardiovascular risk enhancer. The actual truth is that psoriasis is an independent cardiovascular risk factor, so having psoriasis is equivalent to having hypertension, diabetes, dyslipidaemia, and that, as you've already…

Preeya Alexander: Oh wow.

Annika Smith: Yeah, it's under-appreciated by clinicians in the space, and also patients simply are not aware. Our national cardiovascular prevention guidelines, concerningly psoriasis doesn't get a specific mention. Rheumatoid arthritis does, but actually the cardiovascular risk that psoriasis carries is equivalent to diabetes or rheumatoid arthritis. So we're really seeking to address this, and there's a national consensus happening as we speak, so we can best serve our patients and obviously identify those most at risk.

Preeya Alexander: But for people listening, if they have psoriasis, so if you're in the car driving and you've got psoriasis, it's probably worth thinking about having a heart disease risk assessment, at least talking to your GP about cholesterol, blood pressure, smoking status, physical activity.

Annika Smith: Absolutely, anyone with psoriasis should have a heart health check annually. And we don't say this to alarm patients, it's really to inform and empower so patients can self-advocate, modify lifestyle.

Preeya Alexander: When it comes to management, there are more options available now, and if we just focus on the skin for a moment, so we're talking about those thick plaques that can impact people, really impact quality of life, I think people often envision the tar, the messy tar or steroid. But are there more topical therapies now available?

Annika Smith: The treatment space has really evolved. Fortunately our topical therapies have become a little bit more elegant, and obviously if they're smelly and cosmetically displeasing, people aren't going to use them. So the most effective topical agent we've got at the moment is a combination of a potent topical steroid and a vitamin D agent, and that's a foam-based formulation. But obviously choice of topical very much depends on the site you're treating, the person you're treating and their history. So we start off with topicals and phototherapy according to severity, as you've already mentioned. 

But I think an important point to note is it's not necessarily how much of the body is covered in psoriasis. We now understand that high impact site involvement, such as scalp, palms and soles, genitals, which take up on the whole a very small percent body surface area, still impact on quality of life enormously, and they are deserving of appropriate therapy, including systemic therapy. 

In the systemic realm, so that's tablet therapy and injectable therapy, there's been massive evolution. We've got new tablets which are really great at switching off skin inflammation, and also treating joints. And then in the injectable space are these specially designed proteins, if you like, that target the key inflammatory or immunologic pathways that are very specific for driving psoriasis. We now think that the drugs that are most effective at clearing the skin are the ones that are probably going to be most influential in terms of reducing the risk of developing these co-morbidities, but also are the most powerful when it comes to quality-of-life improvement.

Preeya Alexander: So the systemic therapies actually help disease management, but also reduce the metabolic risk, so might actually have an impact on the risk of heart disease.

Annika Smith: Correct. So we've had other researchers internationally show reduction in some of these high-risk coronary plaque phenotypes, if you like. What we now need to establish is whether that translates to less heart attacks and stroke.

Preeya Alexander: Is the risk of heart disease and metabolic risk with any psoriasis? So I'm just thinking, for someone who's got a couple of plaques maybe on the arms, is it more disease, more risk? Or any disease there is a risk? 

Annika Smith: Yes, you've hit the nail on the head. Any disease, there is a risk. But that risk increases according to severity, so more than 10% body surface area denotes the highest risk. So that's more than 10 palms worth. But it is well established that even just 3% body surface area, so that's a small amount of skin psoriasis, does carry an increased risk, albeit not as great if you have more inflammatory burden on the skin.

Preeya Alexander: There was a recent study in JAMA Dermatology, Annika, that looked at the Mediterranean diet, in addition to the medical therapies. Are there particular lifestyle interventions that do have evidence for people with psoriasis? 

Annika Smith: Yeah, we assessed recently compliance with Mediterranean diet in a local cohort, and it seems as though it's somewhat underappreciated that the Mediterranean diet holds value for a lot of inflammatory skin diseases, including psoriasis. Exercise is beneficial as well. Reducing weight. Weight is a really important one if we carry excess weight, because we know it can drive psoriasis severity, but also mediate resistance to therapy, in particular the biologics. So we're seeing a lot of promising data evolve with the GLP-1 agonists in this space. That doesn't exclude addressing those critical core, foundational components of diet and exercise.

Preeya Alexander: That was dermatologist Dr Annika Smith.

Norman Swan: On ABC Radio National, you're with the Health Report.

But now we go to dental school, and we've got our producer Shelby Traynor with us, Preeya.

Preeya Alexander: So Shelby, you have done something that Norman and I have not, which is you've gone to dentistry school.

Shelby Traynor: Yes, for half a day, if that really counts, at the University of Sydney.

Norman Swan: I'm sure it counts. Why did you do it?

Shelby Traynor: Honestly, I spoke to the University of Sydney, I asked them, 'Do you have anything cool going on?' And they told me, 'We've got this vending machine,' and I was like, okay, and they were like, 'We have this vending machine that is full of teeth. Do you want to come down and look at it?' And I was like, 'Absolutely, sure. Why in the world do you have a vending machine full of teeth?'

Norman Swan: So you put in $1 and you get a tooth out?

Shelby Traynor: You put in $15 and you get a tooth out actually.

Preeya Alexander: A real tooth?

Shelby Traynor: No, a plastic tooth. 

Norman Swan: So can any of us do this, or is this just for dental students? 

Shelby Traynor: I think you could actually test it out. I don't want hordes of people going to the University of Sydney to steal the plastic teeth from the dental students who desperately need it. I will also say, before we head into this story, that you're about to hear a bunch of Canadian accents, and I should probably explain. Australia and Canada have a reciprocal agreement. Basically, you can train in Australia and go back and practice as a dentist in Canada, and dental schools in Canada are apparently very competitive, so it's a bit easier to hop over to Australia to train.

Norman Swan: So, we're full of Canadians.

Preeya Alexander: Canadian dentists with a vending machine, this sounds interesting, I'm tuning in.

Shelby Traynor: I'm standing in the Dental School Simulation Centre, and there are vending machines but they're not full of food, they're full of teeth, and I'm gonna buy one. 

It was a pair of plastic teeth actually, a set of adult molars. The students have to buy these teeth like they buy their textbooks. They're required for the dental simulation clinic we're about to head into. In these four-hour sessions, the students learn how to use the tools of the trade—mirrors, drills, burnishers—and how to do common procedures like fillings.

And their teacher is Dr Tanya Wiendels.

Tanya Wiendels: I am an education-based lecturer here at Sydney University.

Shelby Traynor: And a dentist. 

Tanya Wiendels: Oh, and a dentist, that too, yep, and a dentist.

Shelby Traynor: I'm sure I'm not the only person who often thinks; what makes a person want to become a dentist, to spend their days looking in people's mouths?

Tanya Wiendels: Yeah, I do describe it kind of like medicine on a really small scale, because there is the disease aspect, there is the returning the body back to health, but there's also…you're like Bob the Builder on a tiny scale, you get to take something that's broken and then recreate it.

Shelby Traynor: We don't talk about dental care all that often on the Health Report, maybe because giving the advice 'just go to your dentist' is even more complicated than telling people to see their GP.

Tanya Wiendels: Especially in Australia where dentistry isn't part of Medicare, we've sort of separated the mouth from the rest of the human body, which is a little bit unfortunate because it does tie into the rest of your health.

Shelby Traynor: Millions of Australians are skipping or delaying visits to the dentist. When they do go it's often to fix something that's gone wrong, rather than to prevent it going wrong in the first place. So it's no wonder it can take between five and seven years to become a dentist.

Tanya Wiendels: I find that it is a very demanding job where you need to be a motivator, you need to bring the energy, but you're also doing fine detail work, backwards, upside down and under water, so it can be quite intense.

Shelby Traynor: Today's dental simulation clinic is full of first-years who are just starting that journey.

Tanya Wiendels: So they're learning this all for the first time, so they don't know how to hold a drill, how to sit, and that's one thing that they're really concerned about. They are high achievers, they're type A personality, and they're used to trying something and excelling at it. And so to come in here and then have to learn how to sit and where to put your finger and how to hold a drill, and how to do these tiny minute movements and experience that failure and that ability to build on that, that can be quite challenging for them, but it's really good to watch their progress through the year.

Shelby Traynor: Today the task is to learn how to do an amalgam filling, probably better known as a silver filling. The students have between five and seven minutes to pack the amalgam into the tooth before it hardens. If they mess up, they have to start the process again, which is why they're going to practice this a lot, first on clay models, then on their mannequins with plastic teeth.

Student: Right now we're doing amalgam restoration. So these are a metal mercury alloy that we're putting into teeth that would have been prepped for cavities. And so clearly a patient would come in, they'd have some sort of decay or cavity going on, we'd remove that decay, and now we're just filling that so that you don't get a cavity in the future. And so sort of what we're doing is lining it so there's no damage to the structures beneath the tooth. And then we'll prepare to get that amalgam into the tooth cavity itself. So there's some steps, like mixing, putting it in, packing it down, and polishing it, that's involved, and you end up with a nice, shiny little covering over the tooth that protects it from future damage.

Shelby Traynor: It's kind of a bit like chemistry, a bit like sculpting, a bit like everything.

Student: There's definitely an artistic side to dentistry that I think gets overlooked sometimes, and that's a nice quality of the training here.

Shelby Traynor: What are you up to at the moment? What are you prepping? 

Student: I am just waiting before I can mix my amalgam material and I can pack it into my tooth.

Shelby Traynor: So you've prepped the tooth. That's that thin layer that they were talking about.

Student: So it's a very thin layer, and it's supposed to only cover the dentine, which we can't see very well on these 3-D printed models but in real teeth we'll be able to see, and it's not meant to cover any of the top sort of enamel layer of the tooth.

Shelby Traynor: How do you tell the difference between the dentine and the enamel? I'm sure that's a very basic question.

Student: No, it's a great question. In real teeth there's quite an obvious colour difference. So the enamel will be very pearly white. Dentine is more yellow. It also feels different. Enamel is quite hard, if you feel it with any instrument, whereas dentine is a bit softer because it's quite a bit less dense.

Shelby Traynor: I hadn't thought about the fact that, yeah, when you're poking around, it will feel different.

Student: Yeah, actually dentistry is quite a bit tactile, which is really cool. So there's the vision component, which is really important, but also feeling around. A lot of that goes into how we prepare cavities as well when we drill teeth. So when your dentist drills your teeth, it's a lot of visual feedback, but also a lot of tactile feedback as well, which is quite an acquired skill.

Shelby Traynor: Just having brief chats with people, there seems to be so many aspects that go into this, like there is a bit of artistry about it, someone was talking about how tactile it can be, these things that I, as someone who doesn't have this background, I work on a health show but we don't talk about teeth that much. It's surprising what has come up. Is that something that you've experienced in your journey as well?

Tanya Wiendels: Definitely. You know, there are times where I see fillings done in people's mouth where it's just a standard filling, and it's fine and it's acceptable, but there are other times where I can see that someone's put an artistic tint to it, where they've built up beautiful cusps, and you can see the anatomy, and it looks like they've recreated the tooth, like you almost don't even notice the filling is there. And I get a little bit of joy out of that, from that artistic effort that someone's put in. So it's nice to watch the students be able to create and re-make nature so that it's a fully functioning tooth that still is very beautiful and aesthetic as well.

Shelby Traynor: And I guess that somewhat goes into the motivations. I've been curious to ask people, why did you get into this? What was the interest for you? What was it for you, and what are some of the things that you hear from other people?

Tanya Wiendels: Originally when I was in my undergrad, I was going more toward gastroenterology, so the other end of the tube, but most of the patients are sedated. And I'm a big chatter, so I do like to talk and develop relationships with people. It also is a good career if you want to also have a family, it's more of a nine-to-five job. I have friends who work in the emergency department and they're working 48-hour shifts through the night. Nobody dies on my watch, which is lovely (not yet, thankfully). So it's a nice way to combine that medicine and that health, but also if you've got an artistic side to you, while still having sort of patient contact and communication. So, it's nice.

Shelby Traynor: And that's what these clinics are preparing the students for. They learn the skills in a controlled setting so they can gain confidence before working on real people. For now, as I said, they're working on mannequins. They're these disembodied torsos with their mouths agape, revealing rows of pearly white plastic teeth. 

Yeah, I mean, this guy kind of looks like a person.

Student: Yeah, right, more or less, you got the cheeks, you got some realistic teeth. So as long as you just pretend that there's a head and a face there, then you can go for it.

Shelby Traynor: I have a really dumb question for you though; do you name your mannequin?

Student: I actually did. His name is Jeff. 

Shelby Traynor: Amazing. That's the perfect answer. Hi, Jeff. He looks quite terrifying. 

Student: Some of them have eyes, and they look even worse. 

Shelby Traynor: Oh no! Yeah, I'm glad this doesn't have eyes. Well, I'll let you get back to it. Thank you. 

One of the teachers points out that these mannequins don't move and they don't have a tongue, they can't swallow and they can't complain. They're pretty far away from being people who are anxious about going to the dentist, maybe they've avoided it for years or haven't been able to afford it.

Tanya Wiendels: I don't think going into dentistry I realised how much you almost are a psychologist, in a way. As a kid, I loved going to the dentist, I was super excited to go. Look at me now, right? But you do have to understand that the person who comes in doesn't want to be there. It's a very personal space in your body, and someone's now going to put their hands in your mouth, and you feel like there's a bit of judgement that goes with it, because a lot of what happens in dentistry can happen because you haven't taken care of your teeth, you've left plaque, there's decay, your gums are bleeding, and so it's our job to fix what's being broken. You have to be very careful with dentistry in the sense that you can't bring that judgement. You have to support the patient. You have to understand that it is a personal and anxiety provoking space.

Norman Swan: Okay, so that explains the vending machines, Shelby, but it was more than that; you actually had a go.

Shelby Traynor: Yes. So Tanya Wiendels, who you just heard, became my dental assistant.

Tanya Wiendels: So we're going to get you to do an amalgam. It's a class one, and class one means it's just the biting surface of the tooth.

Shelby Traynor: And she showed me how to do a filling. It was on a clay model of a tooth, it wasn't even on the plastic teeth. I didn't get to use my plastic teeth, unfortunately.

Norman Swan: And you didn't get to do a nerve block to keep them quiet.

Shelby Traynor: So, I am putting a mercury containing substance into someone's mouth.

Tanya Wiendels: And my patient has already had a cry, and they were super nervous with the needle, and I had to talk about their kids and their last trip and what their dog likes to eat.

Shelby Traynor: So basically you're working with amalgam, which is part mercury, which is an interesting experience.

Norman Swan: Oh, so they still use amalgam these days? It's a long time since I've had amalgam in my mouth

Shelby Traynor: Yeah, so they are going out of style. The EU has actually banned them because of the environmental impacts, but we still use them a lot in public settings. They're very reliable. So it's pretty easy to set and forget an amalgam filling.

Norman Swan: Before we go on, anybody who's been told to go in and have all your amalgam fillings out should go to see somebody else, because if you're worried about the mercury, the mercury is stable in your amalgam, but it's certainly not stable when they're drilling it out, unless they have to drill it out. So, you know, stick with the amalgam you've got until it needs to be changed.

Shelby Traynor: Yeah, and that's what's a bit stressful about doing the amalgam filling, is the exposure is highest when it's being done and when it's being taken out. So you've got a time limit. You've got seven minutes before the amalgam sets, and if you do it wrong, you have to then remove it. You're upping the exposure to mercury. 

Oh, thank you very much, assistant…

Tanya Wiendels: Yep, use your big end now and really just start packing it in.

Shelby Traynor: All right, we're really punching. Do you do grip strength exercises? 

Tanya Wiendels: Yes, sometimes.

Shelby Traynor: You can hear Tanya encouraging me. It's a hard task, I think, for a perfectionist, there's lots of things I would have done differently.

Tanya Wiendels: You're doing great, by the way. I'm very impressed. You've never done this before, and you're up for it and that's all I want.

Shelby Traynor: I think that this is not as strongly packed as it should be, I can already…

Tanya Wiendels: Don't focus on what its missing, focus on what's great and where you're going.

Shelby Traynor: Something else is that when the amalgam is setting, it starts to squeak. 

Tanya Wiendels: Once it starts to get a bit squeaky like that, and it's not that sort of softer, chalkier one, then we know we're getting close to carving. We don't want to carve too early. We don't want to carve too late.

Shelby Traynor: And then once it sets, you have to start carving it, and you try to match what an actual tooth looks like. 

Norman Swan: This is the art of dentistry. 

Preeya Alexander: Yeah, it's artistic. 

Shelby Traynor: Yeah, you have a proper molar sitting next to you, and you're trying to mimic what it looks like, and you're kind of making artistic decisions. You've got to think of how someone will bite down as well. But you do get to have a bit of freedom, I guess. 

Norman Swan: So, did you pass, Shelby? How did you go?

Shelby Traynor: Tanya says that I did pretty okay. And this is a radio medium, you guys can't see the tooth, so I'm just gonna say it was great. It looked fabulous. And I definitely, you know, pass…I think. 

Preeya Alexander: Thank goodness for radio.

Tanya Wiendels: Still somewhat acceptable. And it's your first one, so I never want you to look your…I want you to have that first one, I want you to keep it. And then when you do the second one, and the third one, and the fourth one, I want you to see your progress. You never do anything the first time and it's amazing.

Norman Swan: So are you tempted, Preeya, to sort of switch to general dentistry from general practice?

Preeya Alexander: Definitely not.

Norman Swan: Yeah, I think you've got be a bit surgical in your view of the world, and you're much more physician-ly.

Preeya Alexander: On ABC Radio National, you're with the Health Report.

Norman Swan: So Preeya, in the mailbag we've got more on allergies. They just don't stop.

Preeya Alexander: We do. We could do a whole spin-off podcast off this, I reckon.

Norman Swan: That's right; What's That Allergy?.

Preeya Alexander: We might pitch that after we log off this. Caitlin's written in, 'Hello from an avid listener. Your recent discussions around food allergies have enthralled me, as mum to a beautiful nine-month-old with multiple food allergies. In your last episode you said not to put food products on children's skin. Well, it took us years to find a sunscreen that worked for my older child, one that didn't leave him with any irritation or flaky, burning skin. Our current go-to is oat based.' And so Caitlin's basically saying that her daughter needs more sunscreen as they go outside more and is there a risk of food allergies? Is there any food protein in there if it's heavily processed? It's a tricky one, but she does say, 'For reference, my daughter is allergic to soy, peanut, cashew and wheat.' Wow, multiple food allergies.

Norman Swan: Yes, let's hope she grows out of a lot of those.

Preeya Alexander: It's a lot to grapple with.

Norman Swan: But, I have to say, Caitlin, if you're talking about oat-based sunscreen, that is food based, so there may be other stuff in it as well.

Preeya Alexander: Ideally avoid. And, look, we often say that food oil…so if you look at things like coconut oil or peanut oil, often they're so heavily processed that the oil doesn't contain a food protein in it per se, but with this there likely is, and I don't think I'd confidently say that you can use this particular product without increasing the risk of a food allergy.

Norman Swan: And don't hold yourself back if you want to write to us about allergies or anything else. The email address is HealthReport@abc.net.au. Don't forget our sister podcast, What's That Rash?. This week, the question we're going to be answering is; what's the best time of day to exercise? 

Preeya Alexander: Definitely the morning. 

Norman Swan: Yeah, you've done it by the time you get into the studio. See you next week. 

Preeya Alexander: Yeah, that's right. See you then.