Chapters
What a bioactive material is
[00:00:05 – 00:05:36]For most of the last century, a filling was a plug that sealed the hole left once the decay was drilled out, with its success resting on the edges holding. A newer family of materials claims to do more, releasing minerals and fighting acid. Used strictly, the word bioactive describes a material that interacts with the tooth, giving off calcium and phosphate or fluoride and prompting the tooth to respond.
Most white fillings, including those used day to day at OptiSmile, fall outside this group and are chosen for strength and handling. Modern bonding agents seal them to the enamel and to the dentine underneath. The injectable composites in this class are strong enough for injection moulding on front teeth and for building up back teeth.
Materials that do qualify as bioactive form a much smaller group, placed mostly deep in the tooth near the nerve and covered with a regular composite. Some biologic practices test patients for material sensitivities and then place their own mineral-based fillings, an approach that lacks support from Cochrane reviews. Patients have arrived at OptiSmile with these fillings worn down and cracking, and some went on to need root canals or lose the tooth.
Can a filling help a tooth heal?
[00:05:36 – 00:09:36]Lost enamel does not come back. Underneath, the living pulp can respond to calcium silicate cements such as MTA, first developed from Portland cement, which prompt the nerve to lay down a fresh bridge of hard tissue over itself. Even when a cavity reaches the nerve and it bleeds during preparation, the bleeding can often be stopped and MTA placed over it so the nerve can settle and heal.
Whether this works depends on the diagnosis. Cold sensitivity that lingers for more than about 20 seconds, or pain that starts on its own, points to a nerve too damaged for any material to save. For a deep cavity where the tooth tests normal, every effort should go into avoiding root canal treatment.
Older calcium hydroxide liners do not work in the same way as a modern pulp cap. European guidelines support leaving the deepest soft decay over the nerve, provided the edges are cleaned thoroughly and the tooth is sealed well, because the sealed decay is starved and stops. When studies reopened teeth with no symptoms where moderate decay had been sealed under glass ionomer, the dentine underneath had hardened.
Why the edges of a filling matter
[00:09:36 – 00:11:10]Decay creeping back in at the edges is the usual reason a filling fails. Breakage is the less common cause. Glass ionomer helps here because it releases fluoride when acid hits it, a little like a sprinkler that switches on when there is smoke.
It suits children and older patients, especially on root surfaces where the area is hard to keep dry. In countries with little access to care, scraping out decay by hand and sealing the cavity with glass ionomer has been shown to work.
As a permanent filling in adults, glass ionomer has a drawback. Teeth filled this way tend to stay free of new decay, but the filling wears badly and looks poor over time.
Self-healing claims and how long they last
[00:11:10 – 00:13:25]Fillings that claim to seal their own tiny gaps are not supported by current research. The idea may still hold promise for the future. A strong, ceramic-like composite that bonds to the tooth cannot also leach ions and deposit minerals, so the two claims pull against each other.
Longevity is where the marketing runs ahead of the evidence, since bioactive fillings do not outlast ordinary white fillings. In one clinical trial, a well-known material sold as bioactive failed at around ten times the rate of a standard composite.
When glass ionomer goes under a composite in a sandwich filling, none of it is left exposed at the edges, where it could wash out. Newer resin-modified glass ionomers are light cured and behave much like composites. In the mouth, they may release far less fluoride than lab results suggest.
Who benefits most
[00:13:26 – 00:15:17]These materials earn a real but limited place in patients at high risk of decay, such as older people with decay on exposed roots. After radiation treatment, when saliva dries up and cavities appear across the mouth, glass ionomer can help hold decay back. For frail patients in care, it can be smeared onto a sensitive tooth to make daily life more comfortable.
It bonds well in children, where some wear on baby teeth that will fall out anyway does not matter. As a replacement for resin sealants, it is backed by Australian research that remains current, though not every dentist has come across that work.
Do they look natural?
[00:15:18 – 00:16:48]Glass ionomer has an opaque look, although newer resin-modified versions are more translucent. MTA is grey, close to black. It is also costly, so a whole tooth is never filled with it.
Placed deep, these materials sit hidden under the composite or under a ceramic inlay or onlay, with crowns kept for cases that need them. Some dentists also use them along the gum line, where fillings are hard to bond unless placed with great care.
Is it worth paying more?
[00:16:48 – 00:20:21]Cheap restorative dentistry that fails early ends up being the expensive option. If an MTA pulp cap keeps a nerve alive and avoids a root canal, and possibly a crown, it can save you thousands of rand. Cochrane reviews have found no proven benefit from placing these materials routinely under every ordinary composite, so the spend makes sense for a deep cavity at risk of needing a root canal.
Some low-fee, insurance-contracted practices add liners or pulp caps to a filling. Once the filling is in, nobody can confirm the material was placed. If you see a pulp cap on a quote, it is fair to ask whether the decay is touching the nerve and whether you need one.
The fee reflects the time and care taken to remove deep decay without exposing the nerve, more than the cost of the material. At OptiSmile, an indirect pulp cap quoted in advance comes to just over R1,000 at the time of recording. If a pulp cap turns out to be needed mid-filling, it is done at no extra charge.
What to ask your dentist
[00:20:22 – 00:23:29]If the decay is deep, ask whether the nerve can be protected and a root canal avoided. A cavity can look as if it reaches the nerve on an X-ray, yet a tooth whose cold sensitivity fades within about 10 seconds is unlikely to need one. If your dentist is unfamiliar with MTA, a second opinion is worth getting.
Next, ask whether you are at high risk of decay and whether a fluoride-releasing material would help. With a dry mouth from radiation treatment or Sjögren’s syndrome, a glass ionomer filling may look less natural and need topping up. It can be the better choice if it holds back new decay.
Be wary of a bioactive filling sold as a premium upgrade, on social media or in the chair. At OptiSmile, most fillings are well-bonded composite. Glass ionomer goes under the composite in deep or high-risk cavities, and an exposed nerve is capped with MTA.
Transcript
Eon Engelbrecht [00:00:05 – 00:01:05]
Welcome back to Save Your Money, Save Your Teeth, the podcast that looks at what genuinely protects your teeth and also your wallet. Now last time we looked at aligners printed straight from a shape memory material. Today we’re staying with clever materials, but this time inside the tooth itself. For most of the last century a filling was basically a plug. You drilled out the decay, filled the hole and hoped that the edges held. Now there’s a family of materials that don’t just sit there; they release minerals, they fight acid and they can even coax the tooth into protecting itself.
Wow, so today, what are bioactive materials? Can a filling really help a tooth heal? Can they save you a root canal?
And how much of the marketing is actually real? Joining me as always is Dr Clifford Yudelman from OptiSmile in Sea Point, Cape Town. Dr Yudelman, welcome back.
Dr Clifford Yudelman [00:01:05 – 00:01:14]
Hi Eon, great to be back. Thank you very much, and that was as usual a great intro. I always say you should do this for a living, you know.
Eon Engelbrecht [00:01:18 – 00:01:33]
That’s funny, you’re very funny, thank you. But Dr Yudelman, this all sounds very, very interesting, you know, and we’re so used to fillings just plugging a hole. So what exactly is a bioactive material?
Dr Clifford Yudelman [00:01:34 – 00:05:36]
Yeah, nice intro, and it actually is a bit of a catch, because this isn’t the same as our podcast 116 where we’re talking about things that go viral on TikTok, but it is again, you know, Save Your Money, Save Your Teeth, and just to let consumers know where the science sits with these materials. And you know, the word bioactive is a word that marketing departments love, but it’s used very strictly, you know, it’s used very loosely. And you know, if you look at it more strictly, it means a material that interacts with a tooth, that releases calcium and phosphate and or fluoride, and it encourages a tooth to respond.
But most white fillings, including the fillings that we use day to day at OptiSmile, are known for their strength and their clinical handling and the way that they bond to the tooth and how they don’t wear down as much as previous materials. And these particular materials, and all the top of the class composite bonding materials, are actually not bioactive, and they’re very good at bonding and sealing, and the good seal to the enamel mainly, and we’ve spoken a lot about enamel being so important. But with the new bonding agents, they also seal to the dentine.
But the genuinely active materials are a much smaller group, and those are ones that are used mostly deep down near the nerve. And they are used by many dentists like myself underneath a normal, or should I say one of these latest and greatest, composites. The one that we use a lot is called G-ænial Universal Injectable, or G-ænial A’CHORD, which is similar.
The one is actually injectable. And these are very, very strong. We use them for injection moulding on front teeth, and we can use them to build up back teeth.
And if the cavity is deep, then we’re going to get into, there’ll be a few more questions coming up. But in an effort to try and keep today’s podcast to the 30 minutes, I’ll just sum up by saying, we’ve also spoken about biomimetic, which is one thing, copying nature. But then we’ve spoken about biologic dentists, and how mainstream dentists like myself actually don’t consider biologic dentistry to be mainstream, because it’s not backed by Cochrane, which is this evidence-based dentistry.
And they will sometimes test you for sensitivity and allergies to all the different materials. And then they go and put in some kind of bioactive material that only they have access to, that then, you know, seals. Obviously these won’t have fluoride, but it will have all these, you know, natural minerals, you know, taken from the bottom of the sea, who knows from where, and it’s going to, you know, heal your tooth. And it sounds great.
But personally, in my career, when I’ve seen patients come from some of these types of practices where they’ve had these types of materials placed, we see really bad failure, mainly mechanical, and they wear down and they crack and they break. And some of these patients then end up with root canals, or even worse, you know, losing their teeth. So a little bit more about that and what these materials are, but because I gave quite a good intro, I think the other questions will go a little quicker.
Eon Engelbrecht [00:05:36 – 00:05:45]
I also want to ask you, doctor, can a filling material actually help a tooth heal itself or even grow new dentine?
Dr Clifford Yudelman [00:05:46 – 00:09:24]
So, you know, we have to be careful about “regrow”. So enamel never comes back, but the living tooth underneath can respond. So there’s calcium silicate cements.
Originally, there’s something called MTA, which was originally made from Portland cement, which is basically cement. It’s calcium silicate, basically like a grey concrete. And this can encourage the nerve to lay down a fresh bridge of hard tissue over itself, like a wall that’s built from the inside.
And that is very well documented. Several of the doctors in my practice use that a lot. It’s well documented.
It’s not magic. It’s biology that’s responding to the right conditions. In fact, there’s sometimes cases where a cavity can literally be touching the nerve, and even in a case where the nerve is bleeding during preparation of a cavity, the bleeding can be stopped and the MTA can be placed over this nerve, and then the nerve will settle down and heal.
Every effort should be made to reduce the need for a root canal. And the diagnosis for a root canal is done on symptoms like tenderness to tapping, not to repeat some of our previous podcasts, but many of these things are well documented. If you get cold on your tooth and it lasts more than 20 seconds, or you get spontaneous pain, well then we’re not going to clean out the decay and then leave an infected nerve and put MTA over it.
That’s another story. But for a deep cavity that’s testing normal, a lot of dentists may go and do a root canal because of what we spoke about in our previous podcast. I think it was last week’s podcast, or the one about production dentistry.
But if a dentist is trying to follow modern principles, they will use what’s called a pulp cap. Very old-fashioned dentists will use something called Dycal, or calcium hydroxide, which unfortunately doesn’t work the same way. We don’t have to scrape every last little bit of soft decay off the nerve.
As long as we clean the edges thoroughly and we seal the tooth properly, the deepest decay, that spot is starved and it stops. European guidelines recommend that, so that we don’t expose the nerve. If the nerve is exposed, then we cap it with MTA, and also, like I said, any nerve that’s already badly damaged, there’s no material that will sort it out.
I was practising in Australia before the MTA era, and there’s a professor, Edwina Kidd, that made a glass ionomer. There’s something called Fuji, and there’s various versions of it. It’s mixed up in a little capsule, and you can leave even a moderate amount of decay in an asymptomatic tooth and seal it over with glass ionomer and then put your regular filling on top of it.
They did experiments where they went back in and they checked, and it hardened up the tooth underneath. That’s actually the method that I use. I think I’m one question ahead today, because I think you’re about to ask me about that now.
Well, why don’t we just do that for the whole podcast. Let’s keep going.
Eon Engelbrecht [00:09:24 – 00:09:27]
You can just keep on talking.
Dr Clifford Yudelman [00:09:27 – 00:09:36]
I’ll stay a step ahead of you. You shouldn’t send me these questions ahead of time. You should be checking my knowledge.
Eon Engelbrecht [00:09:36 – 00:09:45]
No comment. Smart release fluoride.
Why do the edges of a filling matter so much, doctor?
Dr Clifford Yudelman [00:09:45 – 00:11:10]
Most fillings don’t fail because they break. They fail because the decay creeps back in at the edges. Glass ionomer, which releases fluoride, can be used in the elderly, or in areas where it’s difficult to maintain moisture, root cavities for instance, or in kids.
When there’s acid on it, it’s like a sprinkler that switches on when there’s smoke. Basically, when these materials, these glass ionomers, are hit with acid, which is usually what causes a cavity, they release fluoride and they actually fight against the decay. The part that I mentioned about Edwina Kidd and minimal intervention, I think she was, shall we say, the mother, not the father, of the ART technique, where you actually scrape out the decay with little instruments and you put this glass ionomer in, and it’s used in poor countries where there’s no access to care, and it’s been shown to actually work.
But I don’t generally use these glass ionomers for permanent fillings in adults, but I do occasionally see patients come in where someone has used it as a permanent filling, and although they don’t decay, they do wear quite badly and they don’t look nice.
Eon Engelbrecht [00:11:10 – 00:11:18]
Well, some of these materials claim to self-heal tiny gaps. Can you tell us what’s real and what is actually just marketing?
Dr Clifford Yudelman [00:11:19 – 00:11:57]
So now we’re getting back to like the very beginning, where basically, according to the research, that’s actually bullshit, excuse the French, but it’s promising in the future. But you won’t get the same sort of strong composite materials like we’re using at the moment that bond to the tooth and then also now claim to release ions and deposit minerals, because you can’t have a very solid, inert, ceramic-like material that also, you know, leaches chemicals. So let’s not worry about self-sealing fillings right now.
Eon Engelbrecht [00:11:57 – 00:12:04]
And do bioactive fillings actually last longer than ordinary white fillings or not?
Dr Clifford Yudelman [00:12:04 – 00:13:25]
So as I’ve been hinting the whole time, like, no, they don’t. I mean, that’s where the marketing gets ahead of the evidence. And I found that one well-known material that’s sold as bioactive actually failed at about 10 times the rate of an ordinary composite in a clinical trial.
And even when we do a glass ionomer sandwich and we put Fuji and then put composite, we make sure that there’s no glass ionomer exposed at the edges, because it can actually wash out. So I only use the glass ionomer closest to the nerve, and then the rest of the filling is done with composite over the glass ionomer. And there are some better and newer glass ionomers now that are called resin reinforced. And they’re basically composites, because they’re light cured. They’re not the self-curing ones that you mix up and then you have to sit and wait for them to set. It’s like a powder and a liquid.
And the resin-modified glass ionomers that you then cure, they basically, as I said, act like a composite, and they don’t actually release much fluoride at all, except in the lab when they try to research it and sell it to you as a dentist.
Eon Engelbrecht [00:13:26 – 00:13:30]
And who benefits most from these materials, doctor?
Dr Clifford Yudelman [00:13:31 – 00:15:02]
I guess I already answered that earlier. So it would be patients with a very high risk of decay, older patients with decay on exposed roots, maybe very elderly or infirm patients, maybe in a sort of nursing home situation where you can just mix some up and almost smear it on the tooth with your finger, say in a patient that’s only got a short period of time to live and the tooth is very sensitive, affecting the quality of life. It can be used in patients that have had radiation treatment, where there’s no saliva and they’re going to get a lot of cavities everywhere.
In children, I like to use glass ionomer. In children, I just find that it bonds better to the tooth, and we don’t mind that they wear away a little bit, because the kids are going to lose those baby teeth anyway. I like the glass ionomers instead of sealants, instead of resin sealants, and that’s due to a lot of research I was exposed to, again by Professor Laurence Walsh, from when I was in Australia.
That was sort of my fluoride and glass ionomer era, but I went to Australia in 2002, so some of that research does go back to 2010 and so on, but it’s still actually current, and not all the dentists do that, because they haven’t all been exposed to that research. But yeah, look, I think I’ve really covered most of that. They do have their place, but it’s limited.
Eon Engelbrecht [00:15:02 – 00:15:06]
I was going to say now, thank goodness you didn’t pick up the Aussie accent.
Dr Clifford Yudelman [00:15:08 – 00:15:17]
No, mate, I did. It just depends if I’m speaking to an Aussie or an American. If it’s American, then I speak American.
I spent 16 years in America.
Eon Engelbrecht [00:15:18 – 00:15:39]
Yeah, I was actually surprised that you don’t roll your R’s more. You know what, this is quite an interesting, or very important, question, and I think a lot of people want to know this when it comes to what we’re talking about today. Do they actually look as natural as white fillings or porcelain?
Dr Clifford Yudelman [00:15:40 – 00:16:48]
Absolutely not. So glass ionomer has got a very opaque look to it, except if it’s one of these newer resin-modified glass ionomers; they make them more translucent, et cetera. But if they’re used deep down, they go underneath the composite.
MTA is actually grey, almost black. So you want to make sure that’s well hidden underneath the filling. You wouldn’t fill a whole tooth with MTA.
It’s also very, very expensive. So we’re talking about these bioactive materials closer to the nerve, and then covered up with an inlay, onlay or ceramic inlay. We don’t like to do a lot of crowns unless absolutely necessary.
But yeah, they don’t look great. Now, if you use them along the gum line, a lot of dentists like to use them there, because it’s hard to get fillings to stick unless they’re done very, very carefully. And with some of the later methods, we should actually do a podcast just about those gum line fillings.
I think we did cover it when we were speaking about sensitivity, but that was like about two years ago. Maybe it’s time for a refresher.
Eon Engelbrecht [00:16:48 – 00:17:01]
Sure. Yeah, I can’t even remember. But Dr Yudelman, also, I believe they cost a little more. How does it fit into your save your money philosophy?
Dr Clifford Yudelman [00:17:02 – 00:20:21]
So look, cheap dentistry that fails early is actually expensive dentistry. If an MTA pulp cap keeps a nerve alive and you’ve avoided a root canal and possibly even a crown, then you’ve actually saved thousands of rands. There are some Cochrane reviews that found that there’s no proven benefit from doing these routinely under every ordinary composite.
So one has to be careful. Like if you’re going to an HMO or PPO dentist in America, Blue Cross or Delta Dental, or you’re going to Bupa in the UK, or somewhere where the dentistry is being contracted by the insurance and it’s very low, they may encode some extra things in there, like a liner or a pulp cap. And if you see pulp cap on a filling quote and you’re paying privately, or even if the medical aid is paying, you could say, oh, is this literally touching the nerve?
Do I really need a pulp cap? Because obviously, once it’s under the filling, no one can ever prove whether the dentist even put it there or not. I hate to say these kinds of things.
As the podcast goes on, I just feel more and more responsibility towards the patient, and to good dentists, and not dentists that are doing the wrong thing. So the money is well spent if it’s in a deep filling and it’s at risk of needing a root canal. So in some practices, if you’re doing a filling and the pulp is exposed, you put on some MTA, even though it’s very expensive and it takes extra time.
Like in our practice, if it was a filling that’s deeper than we expected and we have to do a pulp cap and it wasn’t something that we quoted for ahead of time, then we would normally just do it at no charge. We don’t like to bait and switch or to upcharge people after we’ve already given a quote. But of course, if we’ve got a patient that’s coming in and we’ve done all the tests, and if they went anywhere else they’re going to end up with a root canal, we’re going to go to the extra effort of doing all of this and the extra expense. And normally, in those types of cases, it does take a lot longer to do a very deep filling close to the nerve in order to prevent a root canal than a similar surface, say it’s a three surface filling. So the pulp cap fee isn’t just to cover the MTA.
To be honest, I don’t even know what the pulp cap fee is in our practice. I’m actually quickly looking it up, if we even have it. Pulp cap.
Okay, so there we go. So indirect pulp cap, which is a code 8303. If we’re pre-quoting a patient for one of those, it’s just over a thousand rand.
And normally that reflects the extra time and care that’s taken to remove the decay carefully and prevent the root canal, not so much just the cost of the materials. Again, I was trying for a short answer, but it didn’t work. I think that’s good information.
What do you think?
Eon Engelbrecht [00:20:22 – 00:20:32]
Absolutely. And then just finally, doctor, what should patients ask their dentist? And how are you using these materials there at OptiSmile?
Dr Clifford Yudelman [00:20:32 – 00:22:56]
Yeah, so we’ve answered that already. We should call this the one step ahead podcast. It’s getting a bit awkward now.
So just to sum up, because it’s the last question and then we’re done. So you must ask three things. If the decay is deep, ask, can the nerve be protected rather than removed with a root canal?
So that’s very important. Not every deep cavity that’s close to the nerve needs a root canal. The dentist may not have heard of MTA.
In that case, it’s a good idea to get a second opinion. We have spoken about root canals and sensitivity. And if you get something cold on a tooth and it’s very, very sensitive and it only lingers for 10 seconds and it goes away, it’s unlikely that you need a root canal.
But on the X-ray, the cavity can look very deep and look like it’s in the nerve. And the dentist, depending on the dentist, may say, oh, that tooth needs a root canal. So that’s a very good question to ask the dentist.
The other thing is, am I high risk for decay, and would a fluoride-releasing material help me? So that is something for, like, if you’ve got an elderly parent, or if you yourself have had radiation treatment, or for some of the other reasons we’ve spoken about, dry mouth from Sjögren’s syndrome, where you have a very dry mouth and you’re always getting lots of cavities. You may be better off to fill some of your teeth with a glass ionomer, or even a resin-modified glass ionomer, knowing that they may not look as good and they may wear and need some replacing or topping up at times, rather than getting more decay.
And I mean, that’s the way I use it. The other question is, if someone’s trying to sell you on a bioactive filling as a premium upgrade, or you see it on Instagram or TikTok, it’s bullshit. You know, you heard it. Yeah, you can send them my podcast. Like I said, most of our fillings are just ordinary composite, best in class, well bonded. If the nerve is exposed, we cap it with MTA.
If it’s a deep or high-risk cavity, then we put glass ionomer under the composite. And the smartest dentistry is the quiet dentistry that lasts.
Eon Engelbrecht [00:22:57 – 00:23:09]
And those are very good words coming from Dr Clifford Yudelman, and that brings us to the end of today’s episode, or this week’s episode. Dr Yudelman, thank you so much once again.
Dr Clifford Yudelman [00:23:09 – 00:23:19]
Thank you. And I’m really looking forward to next week, where we speak about, to quote Dr Evil, “laser beams”.
Eon Engelbrecht [00:23:19 – 00:23:27]
Yes, laser dentistry. Okay. So looking forward to that, Dr Yudelman. Thank you. Until then, thanks so much.
Dr Clifford Yudelman [00:23:27 – 00:23:29]
Thank you, and chat soon.
[OptiSmile Announcer] (23:48 – 24:32) Discover the world of dental excellence with OptiSmile. Join us for a weekly podcast featuring Dr Clifford Yudelman, a seasoned expert with 40 years of dental experience across four continents. Gain unique insights and expert dental advice by visiting OptiSmile.co.za for articles that illuminate the path to optimal oral health. If you’re seeking unparalleled dental care in Cape Town, get in touch with OptiSmile or book directly online on OptiSmile.co.za. OptiSmile, where global expertise meets local care.
Disclaimer: The content provided in this podcast, “Save Your Money Save Your Teeth” on Medical Mondays, is for informational and educational purposes only. It is not intended to serve as dental or medical advice. The insights and opinions expressed by Dr. Clifford Yudelman and any guests are designed to foster a better understanding of dental health, preventive measures, and general well-being, but should not be interpreted as professional dental or medical recommendations.Dr. Clifford Yudelman does not diagnose, treat, or offer prevention strategies for any health conditions directly through this podcast. This platform is not a substitute for the personalized care and advice provided by a licensed dental or healthcare professional. We strongly encourage our listeners to consult with their own dental care providers to address individual dental health needs and concerns.The information shared here aims to empower listeners with knowledge about dental health but must not be used as a basis for making health-related decisions without professional guidance. Your dental care provider is the best source of advice about your dental and overall health. Please always seek the advice of your dentist or other qualified health professionals regarding any questions or concerns about your dental health.
