Episode 1 – Alveolar Ridge Preservation with Professor Simon Wright.
RB: Hello! And welcome to the first edition of the new Geistlich podcast. My name is Richard Bodimeade and I am the National Sales Manager for Geistlich UK and I am delighted to say I am joined today by Professor Simon Wright and we’re recording today from his practice Glencairn Dental in Bebington on the Wirral.
RB: Simon how are you today?
SW: I’m very well thank you.
RB: Great, thanks for inviting us here today. Just a little bit about Professor Simon Wright. The practice here is limited to Implant Dentistry, Simon is the Clinical lead of the MSc in Dental Implantology in collaboration with Salford University and is the Director of the ICE Dental Hospital in Salford Quays.
Our topic today is Alveolar Ridge Preservation, Simon was kind enough to lead our first Hands on at home session back in June, a post-COVID educational concept were delegates were sent a model and could follow a practical session from the comfort of their own home. It generated so much interest and questions, we wanted to spend some time delving back into the topic of ridge preservation and follow-up on some unanswered questions.
Simon, I’ll dive straight in:
Question 1: Could you tell us a little bit about your implant placement protocol and for example how many times would you undertake Ridge Preservation versus early or immediate implant placement?
SW Answer 1: Yes, so everything is very patient specific, and I complete a very detailed site assessment, an aesthetic assessment; it very much depends on the aesthetic demand of the patient and anatomical considerations. Particularly, I also assess the integrity of the socket, so in terms of the aesthetic demand its have they got high lip line? What’s their soft tissue biotype like? Is it think or is it thin? In terms of anatomical considerations its things like: What’s the proximity of the vital structures? And I suppose in terms of indications really what I’m considering is any time I don’t want the ridge to resorb, because really that’s the aim of alveolar ridge preservation; your trying to prevent the resorption as part of the normal remodelling process. It’s all those things combined really.
RB: OK, sure.
Question 2: What the likely outcome in your experience if you don’t undertake ridge preservation in a delayed or a bridge scenario?
SW Answer 2: The aim of ridge preservation is to prevent as much as possible the ridge resorbing, I suppose the answer to your question is the ridge will resorb more so if you don’t preserve it than if you do. There is evidence, and there has been loads of studies done; many by Geistlich that show you get less remodelling, less loss of bone volume if you do preserve the ridge. And, of course we know that this is much more effective for the width of the ridge rather than the height of the ridge.
RB: I guess taking that back to the impact on the patient, potentially this means a larger grafting procedure later down the line?
SW: Yes or even to the extreme if your doing a bridge like you highlighted there; you could get some recession and then some gaps underneath the bridge.
RB: Sure, OK
Question 3: Lots of questions following on from the Hands-on at home we did a couple of months ago, were around the surgical techniques. When would you take a CBCT ahead of specifically a ridge preservation case?
SW Answer 3: Again, this is very very patient and very site specific, but my protocol is I tend not to take a CBCT prior to the extraction. I normally find the most beneficial imaging before the extraction to be a normal 2D Xray, peri-apical for example. I would normally take the CT scan following the graft. The normal protocol would be, 2D Periapical Xray of the tooth prior to extraction and then CT scan prior to implant placement of the augmented ridge. Obviously if I am concerned about the proximity of vital structures or if there is any strange anatomy to the root structure, I’d take a CT scan then, but my normal protocol is just normal conventional imaging prior to the extraction.
RB: Sure, OK
Question 4: Another surgical technique question, would you always create a buccal pocket for the membrane, or would you consider limiting the membrane to just inside the socket?
SW: We have got to think really about the function of the membrane is here, and I see it as two-fold. First of all, it is to keep the particles in the socket and secondly it is acting as a cell exclusive membrane to stop any connective tissue down growth into the socket. And the only way I can really guarantee that is by creating a pocket and making sure that the membrane really is acting as a cell exclusive barrier, so yes I think the answer is wherever possible I do try and create a pocket to make sure that it provides that function.
RB: Making sure that your excluding the soft tissue and following those basic GBR principles? Absolutely!
Question 5: And talking in a similar vein really, related to the membrane use, would you ever leave the Bio-Gide membrane exposed and would you consider any risks associated with this?
SW: oh yeah every time if you try and advance a flap to cover the membrane what your effective doing is thinning the keratinized mucosa, and you want good healthy keratinized mucosa around an implant, so by routine, my standard protocol is I leave the membrane exposed. Obviously along with that you must educate the patient regarding oral hygiene and making sure that it stays nice and clean. You do find that if the patient looks after it correctly, then it does granulate over nicely, and you get nice thick keratinized tissue.
RB: Is there any limit to how much could be exposed in this sort of case? Or in your experience as long as the patient follows your instructions the membrane keratinizes over nicely?
SW: As long as the membrane is stable, that’s the key aspect in this, and that’s also the reason why I tuck it under the pocket; I don’t see there is any limit really in terms of a normal extraction size defect.
RB: Again, just membrane stability, the keys of basic GBR principles; and respecting those fundamental aspects of GBR.
SW: Exactly. And of course that’s why one of the sides of the membrane ha the fluffy side because that is stabilized by the blood clot.
RB: Great, OK.
Question 6: There have been a couple of questions here about techniques in regards how to enhance the bone regeneration process. A couple of ‘hot topics’; what’s your opinion on using technologies like PRF, and also in a similar vein; with your experience do you think there is any benefit is mixing Bio-Oss with locally harvested autogenous bone scrapings in Ridge Preservation?
SW: There are a few key items I’d like to draw out, the first is when we put the bone particles into the socket, they need to be mixed with something and I find that what works best is the patients blood. I’ve tried mixing it with the PRF like you said as well, and I do get very good results when mixed with blood or PRF. That’s one of the key things really, I can’t stress this enough in ridge augmentation, you need to make sure the socket really does fill with blood. When I have done it with PRF I have found that I get very good quality of bone, but it is all anecdotal; it is very difficult to the research around it because the results are so good, so it is difficult to demonstrate the difference when using PRF.
In terms of the second part of your question, mixing Bio-Oss with autogenous bone; I get the theory because the bone has morphogenic proteins and other stuff in it. But the problem is during ridge preservation is your very rarely raising flaps, so where do you get the autogenous bone from? So its not really part of my protocol, my protocol is really very straightforward, I do create a buccal pocket, I really ensure that there is bleeding in the socket, and if I have to stab the socket with a probe or something to make it bleed I will do that, I then mix the Bio-Oss with the blood or PRF serum, put the membrane in, tuck it in and suture it up. If I follow that protocol, I get very very few complications, and I get good quality bone to put implants into.
The other thing I need to highlight is that, when we decide if we are going to do ridge preservation or not, we do have to look very carefully at the thickness of the buccal plate. If its totally absent, then you need to think about doing a staged augmentation procedure rather than just simply augmenting a socket. And conversely if you have a really nice thick buccal plate like you have sometimes in lower 7’s or 6’s because its fortified by the oblique ridge; you don’t often have to do ridge preservation as you have a good intact bone socket that as long as you visually ensure you have a good blood clot in there, that would be sufficient.
RB: And that comes down to not only the site but also the factors related to the patient, whether they have a thick biotype, does that lead to them having a thicker buccal plate?
SW: Yes there is some research to demonstrate exactly that, those with a thick biotype usually have a thick buccal plate, but much more importantly the converse is true; those with a very very thin mucosal biotype usually have a paper thin buccal plate, and they are the ones that are very high risk and certainly if you were trying this in inexperienced pair of hands, I would stay away from those thin biotype cases at this stage.
RB: Those are the ones that make you think a bit more!
RB Question 7: So, people will be thinking is this a technique that I can try, but what happens if something goes wrong? So of course, we have got to come on to complications Simon, so in your experience what should people be aware of? How can they manage complications? But more importantly, how can they avoid complications in ridge preservation?
SW: Yes, so it is my experience and those of my students, there are two main errors that people make. The first one is they don’t ensure there is a good blood clot in the socket or that the Bio-Oss covered in blood, if its just granule when you leave it there, its likely that it will just be granules when you go back in there. So I cant stress how important it is having that socket nice and full of blood to mix in with the granules when they are put into the socket. So that’s number one, number two…If you pack the granules in very densely like packing amalgam for example, not only will you destroy the crystallised structure of the granules which is critical to their function, you’ll also cause a lot of pain. There have been a few cases where the patient has experienced a lot of pain afterwards, and when we looked into it, it was because clinicians were really packing the granules in. So you just want to tap them down, but not to pack them in. Another thing to make crystal clear is we ensure there is no soft tissue in the socket, normally when you take a tooth out it may have a peri-apical tissue on the end of the tooth, so really do have to make sure that the socket is clear first. A contrary indication, in my view to the procedure is if there is active pus there. If there is active pus there I won’t do preservation; I would extract the tooth, curette the socket out, make sure there is a good blood clot there and then if I need to do the augmentation, I will do it as a staged procedure.
RB: And do you have any experience of a dry socket, how would you manage that in this situation?
SW: I don’t get a dry socket per se, because you fill the socket up with granules and you put a membrane over it. The problem you get is exactly what I said in relation to the blood clot, it’s the same symptoms you get that’s similar to a dry socket because you haven’t got the blood clot there and the granules just sit there and don’t do anything.
RB: OK, great.
Question 8: We touched on it a bit, but what’s your experience in sing different grafting materials in ridge preservation?
SW: I used all sorts of different materials, and from an outcome measure if you look at the evidence, there is very little difference in terms of success of the implant and the research have been done by Geistlich, so my main go-to bone material is Bio-Oss. But equally, if I had a patient that didn’t want to use Bio-Oss for cultural or religious reason or something, I’m not too concerned because there is little evidence to state that one material is better than another.
RB Question 9: OK and just to pull it all together Simon, Alveolar ridge preservation what are the critical success factors you have absolutely got to get right to secure a successful outcome.
SW: I can’t stress enough that the most critical factor in my view is the blood clot in the socket mixing in with the granules, so the granules are there, they’re all covered in blood and that clot for a whole number of reasons including membrane stability. So that’s number 1.
Number 2 I guess is doing the site assessment, doing ridge preservation in the appropriate patient in the appropriate site. I suppose I mean by that is not performing the technique where there is infected material.
RB: OK Great.
Question 10: And what advice would you give to a General Dentist looking to find out more about this topic and to advance their skills in relation to implants, potentially what courses and support could they access through ICE for example?
SW: We run day courses on Ridge Preservation and of course it is a key part of any of our implant courses that we run. We always say that in implant dentistry, the implant procedure starts with the extraction of the tooth, because how you manage that as you correctly said earlier on can dictate the overall outcome and so the procedures that are needed to achieve the outcome