Running Time: 34 min
The Importance of Using Authentic Components
Release Date: January 08, 2016Subtitle:
Hi, I’m Steve Hurson. I’m the former Chief Scientist of Nobel Biocare, now retired. What I’d like to do is talk to you today about the importance of using authentic components on dental implants. We’ll look at what happens if you use aftermarket components versus authentic components, and how it can affect your cases and the maintenence of your cases long term. So I’d like to look at first of all is what are the requirements for long term performance of your cases? If you look at the cases, you really want to have cases that, when you put them together, you’re not taking them apart all the time, you’re not having to deal with screw loosening, things coming apart, possible fractures of the implants. So it’s really important that we have components that are properly matched together, have a precise fit, and that we have a proper preload on the abutment screws when we tighten the abutment screws into the implant. What I’d like to do first of all is go back a little bit in time, 30 years ago, and look at where we were then and where we are today as far as materials. Because this has a big importance on how the evolution of the implants has come about, and the quality of the implants and what we’re making today. If you look at 30 years ago when Professor Branemark first started making the dental implants, everything that they used was CP1 titanium. So the implants were CP1 titanium, the abutments were CP1 titanium, the abutment screws. And then the prosthetic screw is that little tiny gold screw. Today, we use CP4 titanium for the implants and titanium alloy for everything else. And if we look at the material strengths of the materials, we go back and you look into a journal or if you look online and you look up the strength of the materials, you can see that we start with the CP1 titanium, has a strength of 170 megapascals, going up to 480 for CP4 titanium and then 760 for the titanium alloy. But this is not what we used, and it’s not even what Professor Branemark used originally with the implants. Professor Branemark, the material that they used, had a strength of 260 megapascals, and the material we use at Nobel Biocare today for our implants has a strength of 680 megapascals for our large diameter implants and 750 megapascals for our narrow diameter implants. You can see that that material is within about 1% of the strength of the titanium alloy, so it gives us much, much stronger materials to work with than we had in the past when implants were originally brought to North America as rootform implants from Professor Branemark. When we look at the material strength on the implants, and if we take a bar and put it into a tensile testing machine, and we stretch that bar, and we graph the stress versus strain on that, we have a linear section, which is what we call the elastic deformation. And that is the zone below the proportional limit that you see there on the graph. This is the zone that we operate in when we work with dental implants. When we’re operating here, if you take a material and you elastically stretch it, then you take the load off of it, it goes back to its original shape, and we can do that over and over again. So we have very repeatable systems. When we get into plastic deformation, it’s when we go above the proportional limit. And that’s typically when you’re tightening the abutment screw and you over tighten the head of the screw and put too much torque on it, and the head of the screw pops off. That is plastic deformation, and that has to be avoided at all costs. So that elastic deformation zone is where we want to operate. And you can see that the higher the strength of the material we have, the larger zone we have to work within, and that’s what’s so important to us. So when we look at the CP4 titanium that we talked about having such high strength, the way we get that high strength is by cold working. And we don’t do it, the manufacturers that make the material do it for us. And they take a large diameter bar and they run it through a series of dies and then make it into a narrower diameter bar. And this is called cold working, and we use the material in that format. And as you can see on the right, you can see the grain structure of a sample of this material. And it has the elongated appearance. This is the cold worked appearance. If we were to take that same material and anneal it and put it in an oven and anneal it, it would go back to the shape of the material that we have on the left, which is the standard CP4 titanium. So we would go from a strength of 750 megapascals back down to 480 by annealing it and going back to that original grain structure. But as I said, we use the material in this elongated format to give us the highest strength. So you can see that if we look at the material strengths, the implant strengths are 680 to 750 as opposed to 260. The abutment strength are 760 as opposed to 260. The screw strengths are 760 to 260. And the prosthetic screw is titanium alloy, which is just a little bit stronger than the original gold alloy screw that was used many years ago. If we look at an abutment screw, think of an abutment screw as being nothing more than a very, very stiff spring. When you put the torque onto an abutment screw and we tighten it to 35 Newton centimeters of torque, what you’re literally doing is taking that screw and stretching it within the elastic zone. And we want to stretch that screw as much as we can possibly stretch it. Now, when we tighten a screw only, about 10% of the torque that we apply to the screw goes into the preload and stretching that screw. The rest of the torque is converted into friction, either under the head of the screw or in the threads of the screw, so most of it is lost to friction which turns into heat. But about 10% of that force goes into preload. And the preload is that clamping force that holds the abutment tight to the implant. And it’s so important for the performance of the implants. Now, if you look into any engineering manual, they’ll show you that you would like to have– the preferred preload on screws of this type, you’d like to have about 75% of the yield strength of the material as a preload. So we want to tighten that screw to 75% of its strength in that elastic zone. Now, if you look at today with our titanium alloy screws versus the CP1 screws that were used on the Branemark system, you can see a strength of 760 versus 260, we can tighten those screws to 2.9 times tighter than we could in the old days. So if you look at the original studies that were done on the Branemark system, quite often screw loosening, screw fracture was mentioned as a complication of those studies. And today with the higher strength materials, we have much, much lower incidence of screw loosening and much, much lower incidence of screw fracture than we did back then. So the importance of these high strength materials cannot be underestimated. Now, if you look in an engineering textbook– this is from my engineering textbook from college– it says, “The importance of preloading bolts cannot be overestimated. A high preload improves both the fatigue resistance of a bolted connection and the locking effect.” And if you look at what we talked about earlier where we’d like to have the preload of the screw of a 75% of the strength of the material, the problem with titanium is it has a very high coefficient of friction. And when we put a titanium abutment screw into a titanium implant, most of the torque goes into friction rather than preload. So in the testing that we’ve done, we see that we only get about 34% of the yield strength of the material in preload, so we’re about half of where we want to be with regular titanium screws because that coefficient of friction is so high. Back in 1996 when we were Steri-Oss, this led us to the development of the TorqTite screw. We realized that there’s got to be a better way with the titanium screws to get a better result than what we’re doing, so we did a bunch of experiments with a bunch of different surfaces, and looked for something that would give us a higher preload on the screw. And that’s when we came up with this black coating that you see on the screws today. So this is a proprietary coating to Nobel Biocare. And the purpose of this coating is that it lowers the coefficient of friction on the threads of the screws and under the head of the screw, and allows us to get a higher preload on the screws. And this is a graph from a recent study that was done at Nobel Biocare in our testing department. And you can see that the preload on the screws is much higher with the TorqTite screws than it is with the standard titanium screws. What they did was they normalized the preload on a titanium screw to 100%. So you can see with the first cycle when they tightened it, that the titanium alloy screw is labelled as 100%. When they tightened the TorqTite screw, it was 140% of that tightness. They loosened the screws up and retightened them. The preload on the titanium alloy screw went down. On the TorqTite screw, it went up to 165%. They loosened it and tightened it a third time and the preload on the titanium alloy screw went down to 94%, and on the TorqTite screw, it went up to 173%. What happens is as you loosen the screw and tighten it down, the coating is actually being forced into the little micro gaps in the threads– the little nooks and crannies in the threads– and it’s actually becoming more of a lubricant. With a standard titanium alloy screw what’s actually happening is you have a little bit of galling going on between the threads. So it’s actually going down each time as you tighten the screw. So it decays. And with the TorqTite screw, it actually gets better. So you see that it is a much better performing system than with the standard titanium alloy screw. By the way, you can tighten TorqTite screws about five times. After five times, that will drop off and start to decay as well. So the rule of thumb with a TorqTite screw is five times maximum, and then discard it and get a new screw. The other thing is you never want to let a laboratory use the TorqTite screws in the model. By the time the laboratory has put that in and out of the model in that very abrasive environment of the laboratory, when they deliver to you, that screw will be destroyed, and it’s all but useless to you. So you want to make sure when the lab sends you the screws, they’re in a baggie, they’re pristine, and they’re going into the implant for the very first time when you get them. And we talked about the importance of preload on the screw. We did a test back in 1996 when we were developing the TorqTite screws to see, does it in fact, the higher preload on the screw, give us a higher fatigue strength? So back in those days, we just had external hexed implants. So what we did was we put an abutment on an external hexed implant, put it in a fixture so we could load it in 90 degrees offset load. And we loaded this at a sinusoidal application of force at 14 hertz, and we loaded it for 5 million cycles. And when you look at the results of that, the black curve on the bottom is the titanium alloy screw. The top curve in red is the TorqTite screw, and the one in between is a gold screw that was from Nobel Biocare that we’re comparing it to. And you can see, they’re exactly the same screw between the black one and the red one. The only difference is the coating on the screw. So we have a much higher preload on the screw, we have a much better fatigue life of the system by using that coated screw. If we look at the different types of implant connections, we have the external hex, we have the internal tri-lobe, and we have the CC locking taper connection. With an external hex connection, the preload on the screw is everything, because the preload on the screw times the radius of the implant has to resist the entire occlusal load that is placed on top of the implant. So screw loosening is not a result of rotation of the abutment on top of the implant. If you put your teeth together and try and rotate your teeth, you’ll see that you can’t do that. But if you put your teeth together, you can certainly rock your teeth. So that rocking motion is what causes the loosening of the screws on the implant. If you visualize, if you put your abutment on top of an implant, if you can put enough load on the implant so that you can get the abutment to rock like this up and down, the screw will work itself out of the implant. And that’s one of the engineering principles that we learned in school. So it’s very critical that we have enough preload on the screw so that as the patient functions, they can never get it to lift like this. So you can see, if you’re putting a large diameter implant in the back of the mouth versus narrow diameter implant, that radius on that implant is much larger, and you have much better resistance to loosening. Now this is where the talk take screw you see we have a very high preload on the screw, and we have a very good range for the patient to function under. If by contrast we use a titanium screw– we substitute an aftermarket titanium screw instead of a TorqTite screw– and we have a much lower preload, you can see it’s much easier for the patient to cause that abutment to rock and to lift, and that screw to work its way out. So just by substituting a screw– going from a TorqTie screw to a non-TorqTite screw– dramatically affects the performance of the system and how well that system stays together. If we look at the tri-lobe connection, the internal connection, what we did here was we realized kind of the shortcomings of the external hex. When Professor Branemark designed it, it was really designed to make full arch restorations and to be something we would take apart all the time. And then the business changed. We started doing single tooth restoration, we started doing single tooth molars. And that was no longer the best system, really, to use for single tooth application, because 100% of the preload on the screw is what resists the rocking moment. So when we made the replace connection, what we did was we made that long skirt that goes down inside the implant. Now when the abutment tries to rock, you can see that the skirt hits the side wall of the implant and resists that. So it resists that rocking motion. The other thing we did was we made a very long abutment screw in the implant. By making a long screw, you can stretch a long screw more than you can stretch a short screw. Think of a rubber band. If you have a small rubber band, you can stretch it just a little bit. If you have a long rubber band, you can stretch it quite a bit. So with a longer screw, we still had the same preload on it, the same force on it, but we had much more stretch in that screw. Now any little microscopic settling that takes place between the surface of the abutment in the implant won’t have as much effect on that screw. So this implant was really designed for crown and bridge, for single tooth crown and bridge, and really designed to overcome those two shortcomings of the external hex type implants. It’s one of our strongest implants with this configuration. When we look at the internal connection, it’s a different animal. Because now, this abutment can’t rock. And when we put this together, this cone that’s inside the implant is what we call a locking taper. And when we put the abutment into the implant and we tighten the screw down, we actually expand the implant. So microscopically, if you take a micrometer and you measure it, you can see we actually expand the implant very slightly. When we do this, we wedge the abutment into the implant, and it’s a very, very strong connection. It allows us to make small connections, so it allows us to make narrow platform implants, even 3.0 implants, with this conical connection. And it’s what we call a locking taper. So when you take an abutment and you put it in and you tighten it down you take the screw out, the abutment is wedged into the implant. And some people call it a cold weld, but actually what’s really happening is the implant has expanded, and that spring force of that expansion is holding on to the abutment. It’s what gives us an extremely tight fit of the abutment into the implant, a strong connection, and gives us basically a microgap-free connection on the implant, which is really important. When you look at the cross-section of the implant, you can see that the fit of the abutment into the implant is very, very intimate. The red bar on here is a 10 micron bar, so you can see the maximum gap on that fit into the abutment into the implant at 1,000 power magnification is less than a micron in size. So it’s a very, very close fit, and it’s very critical to have this very perfect fit inside the implant so that we have that transfer of load to the implant, and it’s a strong connection. Now, when we look at the implant design, when we build an implant system, we do a lot of work to balance everything on the implant. So every aspect of the design has to work together. And when we start an implant design, we design the implant, we design the abutments, and then we start testing. And we test and we test to make sure that everything is in balance in the we’re able to get the kind of fatigue strength we need for the system. So if you look at the cone that’s inside this system. That cone has to be large enough to distribute the load into the implant. In this instance with the NobelActive implant when we designed it, we wanted to make sure that we could put solid zirconia abutments into that implant. So that cone was designed to accept zirconia abutments and to be able to transfer the load of the zirconia abutment into the implant with strength that’s high enough to be able to withstand the forces that are in the mouth. If you look at the internal hex, it’s extremely important that be very strong, because when we tighten the implant into the mouth, if that hex gets distorted in any way, then when you place your impression copings or your final abutments into that implant, they wiggle back and forth. And we want to have it so that when the surgeons are placing this implant, there’s absolutely no distortion of that hex, so when you as a restorative doctor go to take impressions, there is no wiggle. You can then take a very accurate impression. You can go to the model, you can pour up a model, put your final restorations on the model, transfer back to the mouth, and your contacts will line up without undue adjustment. And this is very critical. So this is one of the things that we always test. And we spent a lot of time working on the torque strength of the implant. And you can see these are the values for the different implants. We go from 100 for the 3.0 NobelActive up to 756 Newton centimeters of torque for the 5.5 NobelActive. And this is the number that actually strips the internal hex of the implant. And finally, the wall thickness of the implant must be thick enough to withstand the fatigue stresses that are placed upon it. And this is the most important factor we look at when we were developing implants, because it’s a bad day when you have an implant that fractures inside the mouth, and then you have to go in with [? trefon ?] and take that implant now and graft the case and start all over again. And you’re set back about a good year by the time you get that patient back to where they were with a functioning implant. So this is something we spend a tremendous amount of time working on to ensure that we have high fatigue strengths. The test that we do for the implants is what we call an ISO 14801 test. It’s a standardized test. All the different companies do it. And what we do is we load the implant in the configuration that you see here for 5 million cycles. And what we look for is the absolute maximum load we can place on the implant for 5 million cycles and not fail. Anything above that fails, anything below that runs out very easily. So we’re looking at the absolute maximum load. That’s what we call the endurance limit of the system. And you can see it ranges from 160 Newtons for 3.0 NobelActive up to 580 Newtons for the 5.5 NobelActive. So they’re very, very strong implants for their applications. Now, let’s look at what happens– we’ll walk you through a little bit of the development of an implant and how we go about doing this type of testing. When we’re developing the Replace Platform Shift implant, where we have a narrow platform abutment onto a regular platform implant. So we’ve got an abutment from a 3.5 implant we’re putting onto a 4.3 implant. One of our biggest concerns was, is this going to be strong enough? Is this abutment going to perform satisfactorily on this small abutment on a larger implant? So our criteria for the success of the implant was that the system had to be as strong as the original regular platform NobelReplace system– so with a 4.3 abutment on a 4.3 implant. And that strength, as you can see on the right here, is 320 Newtons of load for 5 million cycles. So the first thing we did is we took a standard platform narrow platform abutment and we put it onto the regular platform implant that is machined with a narrow platform connection. And in our first series of tests, we came up with a fatigue strength of 284 Newtons. So this failed our criteria, because it wasn’t nearly what we wanted for the fatigue strength of the system. So after our first attempt, we went back, we said, what can we do to improve the strength of the system? So we made a little undercut under the head of the screw, and by making an undercut, we actually were able to put a radius in it. Because you saw the head of the screw popped off, that was due to the sharp corner under the head of the screw. So by just making a small change, putting a small radius under the head of the screw, we now raised the strength of the system from 284 to 302. So we’re getting closer to the strength that we want. But when you look at the implant, you can see that there are little cracks in the implant at the corners of the lobes. And we’re still getting a bit of an imprint into the top of the implant from the abutment, which we don’t want to have. So again, we needed to make a change. So what we did was we changed the material strength from that 680 strength material to the 750 strength material, and we’ve repeated the test. And by doing that, we were actually able to make the system stronger than what we were shooting for. So we ended up with the strength of 342 Newtons as opposed to the 320 which we’re shooting for. So by carefully engineering it, making some subtle changes in the system, we’re able to actually make the system stronger. Now, this is an article that we published in the 2011 edition of Nobel Biocare News, the first edition of it. And this was an article that I wrote about understanding the integrity of the implant system, and looking at exactly what we’re talking about today. And in this article, what we did was we took a third party abutment and we put it onto the Platform Shift implants to see how it performed. First thing we did was we took a standard Replace 4.3 implant, and we put a third party 4.3 abutment on it. And as we saw before, our strength of that implant was 320 Newtons. And when we tested the third party abutment on our implant, the strength of the system was only 85% of that 320. So you can see by substituting an after market component– they don’t have the Torqtite screw, they don’t have the materials we were using or know which materials we’re using exactly for our products– the whole system suffers and the strength of the system goes down. We then took a narrow platform abutment from the same company and we put it on to the Platform Shift system that we just looked at, the 4.3 with a narrow platform connection in it. And when we tested that system the result was that the strength of the system was only 55% of that result that we achieved before. So the system fell off dramatically into an unsatisfactory result. So if you use an aftermarket component– they say, oh, it’s compatible. It fits in the implant, you can use it just fine. But you can see, it isn’t just fine. The system performance drops off dramatically and goes down to 55% of what we’ve designed it for for the patient. Now, as we said before, the locking taper is absolutely critical that we have a super tight fit so that we transfer the load from the abutment to the implant and we get that high strength out of the system, and we don’t have any settling between the abutment and the implant to cause screw loosening. And if you look, one of the biggest problems we have today is the use of gold abutments. Because the laboratories are not processing these components the way they’re supposed to. If you look at the label that comes on a gold abutment, it says do not grit blast this abutment. But the labs routinely grit blast the abutments to get it out of the investment. And so what should be a very, very perfectly machine smooth surface is quite often a rough surface. On the left, you see a chemically devested abutment that has been cast onto and chemically devested. The gold comes out looking exactly like it went in. On the right, you see a grit blasted abutment. You can see that the surface is roughened. And if we look at that with a higher magnification, you can see what was once a perfectly machined abutment now has a lot of irregularities on it. The problem with this is it doesn’t fit the implant the way it’s supposed to. Now you have a lot of high spots on the abutment that are fitting into the cone of the implant. And when the patient functions on that, these high spots wear, and as they wear the abutment settles inside the implants and then the screw loosens. And this can happen on any type of implant. We’ve seen an external hexed implants, we’ve seen it on the Replace tri-channel implants, we’ve seen it in the conical connection implant, we see it with frameworks on top of multi-end abutments. So if the lab in any way grit blasts or modifies the connection of the abutment to the implant, your quality suffers. You can see the fit on the left is at a 400 magnification and is much worse than the fit of the titanium abutment on the right at 1,000 power magnification. One of the things in the old days it was very common to use plastic patterns to make restorations out of. And so the labs would buy plastic patterns. Some of the original companies had them. We had them at Steri-Oss. A lot of the aftermarket companies had them. And what you had to do was then cast that. And when you do that, the abutment itself takes on the roughness of the investment, because that’s what it’s casting into. So if there’s any air bubbles in the investment, that gets cast onto the surface of the abutment. And today there are still companies that sell plastic castable abutments. This is an abutment that’s purported to be compatible with the Nobel Biocare system with a conical connection. And you can see if you have that kind of surface roughness on that comb that goes into the implant, it’s disaster. It’s absolutely a disastrous fit of that abutment into the implant. So what does the lab do to get rid of that rough surface? They polish it. And when they polish it, you now have an absolutely uncontrolled surface, and you don’t have the intimate fit of that abutment into the implant. That can lead to screw loosening, it can also lead to fracture of the implant, because the patient’s walking around with a loose abutment that’s rocking back and forth. It’s putting load on the implant in an uneven fashion, and can actually cause the cop of the implant to crack. If you look at some of the OEM components that are available, this is a third party component where they made a titanium abutment that fits and is purported to be compatible with Nobel Biocare CC connection. And you can see on the right is a Nobel Biocare abutment, and on the left is the third party abutment. And when we look at the connection, we very, very carefully– as I said before– design this connection, the length of the engagement of this connection, to have a very high strength. This company just arbitrarily chose to make the connection the interlocking portion half as long. And so what is the effect of that? We know what the effect of our connection is and how it fits together and how it wears and how the fatigue strength is, but what is the effect of half of the strength of that? This is a case that was just sent to us by a doctor recently. And you can see, this is a gold abutment, so in all likelihood the surface of the abutment is grit blasted. But you can see that the connection of the abutment into the implant is very small. So where that cone engages is very, very small compared to what we designed it to be. And this can lead to real problems. As a matter of fact, this doctor said, after only a week in function this abutment came loose inside the implant. So if you look at the fit of that abutment in the implant, you can see how short the connection is versus what we designed it to be. And again, this can cause screw loosening and it can cause fracture of the collar of the implant in extreme cases. Other third party compliments don’t fit quite as well. And you can see on the left here, we have an impression coping from a third party component on a multi-unit abutment, and there’s a gap at the top at the fit of the coping onto the abutment. On the right is a Nobel Biocare impression coping on a multi-end abutment. You can see the fit is very good. Now, one of the problems with reverse engineering and making aftermarket components is you’re only as good as your sample size. So what typically happens is a company will purchase a few of abutments or implants for whatever they’re trying to measure, and then they will measure these. And what they don’t understand is what was our tolerance? When you’re measuring an abutment, you don’t understand what the tolerance is, you don’t understand the sample that you have, where is it in the tolerance? So if we have a tolerance range that goes from the minor to the major here, did they buy an abutment that’s down here, did they buy an abutment that’s up here? They have no idea, because all they’re doing is taking a very small sample size. Theoretically, what you’d like to have is one that is exactly on center of the tolerances, but you have no idea if you do or not. So when the company buys a small quantity and they measure them, then they apply their tolerance. They make a measure and they apply a plus and minus tolerance on to that. And it all depends on how good is the quality of their measuring equipment, and do they have a knowledge of what our tolerances are. And I guarantee you, we don’t have a knowledge of each other’s tolerances in the business. So if you look at this again, you can see there’s quite a large gap between the impression coping and the abutment. So now, if you have six implants in the mouth, and you use these impression copings on a Nobel Biocare abutment, you can see that your fit is all over the place, because what they happen to do here was they measured a small abutment, and then they designed their tolerance. And when we put this on to an abutment that is on the larger side of the tolerance range, it doesn’t fit. And this would be disastrous as far as the fit of your framework, because your framework will fit with the same gaps once it’s made on to the implant. And you can see this is a temporary coping that has the same issue. You can see that the gap around the temporary copings on to the abutment doesn’t fit as it does with the Nobel Biocare abutment on the right. So if we look, as a wrap up, the requirements for long term performance of your cases so that you’re not having a screw loosening, you’re not having problems, you’re not having the patient coming in all the time, you really need to have properly matched compenents as we showed, a precise fit, and a proper preload on the screws. Properly matched components, you must use components that are designed for the system. And your first choice really is titanium zirconia, because these components are going to have the machine fit that we designed into the system. They’re not going to be modified by the lab, and they’re going to fit perfectly into the implant, and have a very, very good fit. Laboratory work is a big problem. When you want to make sure you never ever let a lab use plastic patterns on your implants, and always inspect the work that comes from your lab. I recommand that you buy a little loop to inspect things with. This shown here is a 10-power Bausch & Lomb loop. You can buy it on Amazon for $10. And I recommend that every doctor has this loop and you inspect what’s coming from your lab. And if the work isn’t perfect, if you can’t see the machine lines that we put into the abutments or onto the frameworks when we make them– if it’s been polished away or if it’s been grit blasted away, that is substandard work. You need to go and have a talk with your lab and make sure that they understand what they need to do to give you a high quality fit between your implants. So when you look at large frameworks, you want to make sure you use a verification jig for large frameworks so that you get a good fit, and you must use milled frameworks. Today, if you look at the whole concept of using cast technology to make frameworks. If you have a roughened surface caused by the grit blasting as shown here, you’re going to have a terrible fit of that framework on the implants, and you’re going to have constant screw loosening on the implants. So again, you must inspect for the quality of the lab work. Milled frameworks are much, much more preferable than cast frameworks, and make sure the lab’s give you proper quality work. Proper preload on the screws, you must have a torque wrench. If you’re going to be in this business, you cannot operate without a torque wrench. The studies have shown you absolutely cannot tighten the screw with your fingers tight enough to get the 35 Newton centimeters of torque on the implants. And you must use properly matched screws. Our system is designed specifically for TorqTite screws. If you substitute in a third party screw, it’s not going to be a TorqTite screw, immediately the whole system suffers and the performance of the system suffers. So thank you for listening. I hope I shed a little bit of light on the situation here, and that you can see the importance of using original equipment parts. Thank you.