Dental Implant Abutments

I've heard of this but my question is - would this have any affect on the sturdiness of the restoration? In other words, would there be any cause to worry about the abutment fracturing. There are implant companies promoting this "platform switching" but I have reservations. What are other thoughts/concerns on this matter?

It truely defines the meaning of "horizontal biologic width".

This procedure is sometimes coined "Platform Switching". This is the intentional (or nonintentional) placement of one size smaller restorative components on the platform of the implant. There are many positive outcomes using this particular technique namely better tissue aesthetics as a result of the preservation of the crestal bone.

Dr Woo has the key. The biologic width from the gap is still 1.5-2.0 mm. The cell may not know vertical from horizontal. It will keep the distance.

The Astra Tech Dental Implant System is essentially a "Platform Switched" prosthetic connection and has extremely favorable bone levels associated with it. However this system has been in clinical use for more than 15 years and was originally designed with a stable prosthetic platform and enhanced bone stability. Personally I have 13 years experience with this system ( over 900 implants in 300 separate clinical cases.)

correct!

Modification for the other night. The cells would know vertical vs. horizontal. In any case the biologic width is divided into vertical and horizontal components. The 1.5-2mm is respected..

Kudos to Dr. Moscovitch for pointing out that this phenomenon is nothing new. I am amazed that some manufacturers who for many years poo-pooed the bone maintainence qualities of the Astra Tech design have suddenly "discovered" a new abutment arrangement, i.e. platform switching, that seems to maintain crestal bone. One must note, however, that there are additional design elements in the Astra Tech system that contribute to the overall success in bone growth and maintainence as well as tissue health, which are not totally replicated in other systems. I do believe these improvements in other systems will yield better results for patients and that is a good thing. I can, as Dr. Moscovitch did, attest to several years of great results in bone level maintainence and overall success with the Astra Tech system.

One thing to also consider about this issue of biological width/length is that connective tissue and junctional epithelium recognizes surface area rather than linear lengths (unlike the human brain...). Thus, one can have a predictable and stable connective tissue seal with a wide transition zone (e.g., 6mm) off an implant and still have the restorative margin be only vertically 0.5mmm off the osseous crest. This is an issue lost on a lot of dentists (and Periodontist) who only focus on the linear height of soft tissue. "Platform Switching" is simply providing the surface area to accomplish this. It is another thing though if this is done at a compromise to the biomechanical strength of the implant-abutment connection. It is critical to use a long interference fit junction for this to be reproducibly created. Clark Stanford, University of Iowa

Clark: What do you mean by a wide transition zone ie: 6mm off an implant and still be .5mm off the crest of bone?

The xrays that I have have seen from cases with platform switching have still shown boneloss to the first threads, with the exception of one implant system (ANKYLOS). This implant has a microgap of .71 microns smaller than any bacteria that we know of. Its not the platform switching its the microgap or lack of that makes the concept of platform work. So what is the microgap in Astra implants?

PPaten - you raise the issue - most of the 'discussion' re: 'micro-gap', 'platform switching', etc. is anecdotal and more or less dental implant manufacturer driven. I'm not aware of multiple, long-term studies to substantiate one design over another. The evidence is suggestive, at best.

I see there is some interest in these issues surrounding implants with more predictable soft and hard tissue response.As well, implants that incorporate more stable prosthetic platforms and promote biological as well as restorative performance over extended periods of time. Astra Tech is certainly one of these systems with extensive scientific documentation..Dr. Clark Stanford being a significant contributer to this body of knowledge. I think any scientific questions could be directed his way....this system has proved to be the top performer in my practice for 13+ years and I will be glad to field any clinical questions ( most of my answers will be anecdotal, as is most clinical material..but it is still significant if responsibly reported.)

So which implant systems shows the least crestal bone loss over time? Been having problems with my Branemark implants showing crestal bone loss of 3-4 mm over a 2-5 year period. bone loss stablizes, but is present. Some cases lead to chronic periodontal infections. Ankylos has a lousy prosthetic connection. ITI ? Astra? Frialit? Which system has good prosthetics and the least crestal bone loss?

This whole notion of platform switching is quite interesting however I have not come across a single study in the literature looking at this specifically (do any exist?). My take is that the biologic width has both vertical and horizontal components and that platform switching essentially "lateralizes" the biologic width thereby minimizing the vertical bone loss traditionally seen with non-platform switched abutments. Hence, the minimal (if any) crestal bone loss seen!

When talking about which system has great prosthetics AND the least amount of crestal bone loss, has anyone mentioned 3i and their new Prevail implant? This implant has all the prosthetic pluses of their internal Certain connection as well as the medialized IAJ. Certainly should be an implant discussed in this blog. I do believe 3i has 10 year radiographs supporting the preservation of crestal bone via platform-switching as well.

I have placed several of these prevail implants, with mixed results, some showing some bone remodelling akin to a regular threaded implant. I have tried them because I have platform switched routinely for years; this was initially due to not having wide abutments at second stage surgery. I noticed a reduced vertical bone loss. So the jury is still out on prevail. Beware the Ankylos advocates because the placement criteria is different, ie much deeper, so you are starting with more bone coronal to the IAJ. All interesting stuff, but with an understanding of biological width, you can predict where your bone will finish on most implants.

I have been using the Astra now as my implant of choice for a while and had superb results. Previously my Nobel biocare experiences were very good, but not quite as precise and fine as the Astra. Ironically, as the first poster started this with, the "offset" was so counterintuitive to me, that I had a negative attitude about it until I understood it more. I recently looked at the Imtec Endure and at $79 each and with similar features to the astra such as platform switching effect, microthreads, short polished collar, internal connection, etc, I have to ask, why not use it at it's value pricing? regards fmn

i have used ankylos now for ten years.It is truly a one piece implant with prosthetic versatility.The A implant is what you need to stock the most.This has a 3.5 platform and the standard connection placed 1mm below the crest.The conection is patented and all the big guns like nobel, straUman would love to get there hands on this design-it is a true gapless conection,with a tapered abutment emergence for bundles of soft tissue-sometimes too much- but what a problem to have.It has the connection strenght and platform switch without the increase platform width of the prevail implant-here the platform is too wide and unless the width of the ridge is wide -8mm you will not be able to use it . If the bone isnt wide enough you will just see bone loss-rather like the 4.5 astra st.-its also cheaper- why wouldnt you you make this system your choice in the aesthetic zone jonathan ziff

Platform switching confirms the concept of biologic width that the 1.8mm Straumann collar provides. In addition, the implant system has published studies on SLA that demonstrate long term bone stability. SLA has functional loading earlier than the Astra surface even if nobody follows the guideline and is ahead of TiUnite surface by roughly 6 weeks. Now you can choose a knock off Implant, which gets an also indication from the FDA with if your lucky 1 supporting study, that has been published, the rest of the literature the also companies point to are based on Straumann, Nobel, etc published studies. I have used some knock-offs in my day when playing golf, but the only person who really suffers is me.

In the late '80's when Nobelpharma came out with their 5mm diameter Branemark implant, there weren't special 5mm platform abutments, so we just used the standard 4.1mm shoulder diameter abutments that were used on the 3.75/4.0mm Branemark fixtures. I have a number of those cases, and they look excellent today. It seems that because of the lack of availability of wide platform parts then, clinical or laboratory error, or intention today, platform switching does work and the biologic width is just as happy on a horizontal surface as a vertical one.

There is one system that has not been discuss, BICON. Vertical bone loss? no more... I've seen many cases that bone grow on the shoulder of the implant.

I just had my gold coated abutments (front teeth) replaced with ceramic abutments. My dentist says they are excellent, promote a more natural color to the teeth, and they are very strong. Your thoughts? Thanks, Diana

any studies on ceramic abutments?

I am amazed at the misuse of the term "platform switching" in the literature today. Platform switching was the deliberate use of a healing abutment SMALLER than the implant body. After soft tissue maturation, it was switched to the appropriate size. An implant that uses an emergence profile with a NEGATIVE emergence profile is NOT platform switching. Get it right guys!

The issue relavent here is: what is the reason for crestal bone loss? There are a number of theories out there as to why this occurs. Apart from stress loading issues, the main ones related to implant design are: the amount, if any, of polished collar below the crest of bone; the groove morphology of the coronal part of the implant, whether the connection is external or internal, the amount of micromovement that occurs at the interface if any, and now as is being discussed the length of the biologic width and the possiblity of increasing it by platform switching. At this time, there is no clear evidence which factors are likely to contribute most significantly to this problem of crestal bone loss. As is becoming more and more prevalent, unfortunately, it is the clinical based data rather than research data that is providing the slowly developing answers in the field of dental implantology.

What is disgusting? The name of the game is biologic width as stated by Clark Stanford (which can be taken up both horizontally (platform switch) or vertically (supercrestal connection ala ITI). Just because nobelbiocare chooses to ignore the problem why is this disgusting?

The person who posted on 11-18-2005 to this blog and stated that "the Ankylos system has a lousy prosthetic connection" probably has not used it. The concept of the "long" tapered cone precision fit connection is one of the strongest interfaces known to engineering. It is utilized with stress bearing screws in airplane wing manufacturing. Because the emergence of the neck of the abutment from the Ankylos implant body is more narrow than traditional systems, at first glance dentists might assume it is weak. In fact, the abutments are seated at 25Ncm and are incredibly strong. The Germans did some amazing "video radiography" of different implant/abutment systems all similarly mounted and loaded in a lab simulated chewing apparatus. The x-ray video measured to the micron level and showed significant deformation around the external hex platforms/abutment interface and even the Octabutment/Morse taper interface in the ITI system (which I love, by the way!). Amazingly, the microgap which repeatedly opened and closed upon loading/rebounding may help explain the horizontal bone loss seen with these systems in vivo. If that microgap is filled with crevicular fluid loaded with periodontal bacterial flora, the opening and closing of the microgap pumps/secretes these toxins around the periphery of the platform of the implant to bone junction on each loading cycle. Our biologic response to this is to turn on osteoclasts to get the most coronal osseous level away from the bugs. Not only did the x-ray videos show that their system, the Ankylos, did not open a gap, but neither did the two other long tapered cone internal connection implant systems, Bicon and Astra!!! I would love to see a longitudinal radiographic review from some of Dr. Ziff's cases who has been using the Ankylos system for 10 years. I have been surgically placing and restoring the Ankylos system in anterior and posterior sites, healed and immediate extraction sites for about a year, and with excellent success. The soft tissue proliferation and maturation around the narrow neck of all of the abutments for the system is something to see. It is a welcome treat in the esthetic zone.

the main reason the Astra System provides marginal bone stability is due to the micro thread which is the only way to stimulate marginal bone according to the wolff's law.

Does anyone have a title of the study, author's name and or university where the study comparing the lack of a microgap in Ankylos, Astra and Bicon appeared?

Does anybody have experience with Ankylos Implant system? If so, what are the pro's + con's.?

who offers the best program to learn the restorative aspect of implants?

As an individual responsible for the procurement of implant abutments I'd like to ask a question. While most companies require the purchase of abutments made specifically for their implants (i.e. 3i or NobelBiocare) do you see any potential health related issues with buying abutments from a company that utilizes CADCAM (robotic) technology to manufacture custom abutments for a variety of flavors of implants? In addition, the guarantee that if an implant fails using their abutment - they will warranty the implant. Just wondering if this topic has ever been discussed here.

Try an Osseonews search on Atlantis.

Actually I'm familiar with Atlantis. Is there any other company that manufactures abutments using the same technology (that can customize an abutment no matter the implant manufacturer?)

Nobel Proceria. However the warranty on replacing the implant will likey mean with a Nobel fixture. I doubt that Nobel will purchase a Straumann, 3i, Astra, Zimmer etc. implant for you to place with the surgical kit you have in house. The Straumann CARES system is supposed to be coming soon adding another custom option to the marketplace.

its a combination of microgap size,amouny of micromovement at implant abutmaent interface and some not very clear rationals of biologic width theory combined with a smaller abutment that makes platformswitching a reliable method, there is still way to go for thorough understanding of marginal bone loss.

What have other dentists here noticed when using the Ankylos system? Has bone loss, a microgap bacterial issue, or a higher than usual fracture rate been associated with the Ankylos? The Ankylos uses an internal connection, right?

I have been an implant rep for Ankylos for the past several years and will give you the low down of what I see in the field- I know I am biased in some respects, but am also honest- Pros- Bone and tissue response is phenominal, I have converted many high profile specialists, and many are loving Ankylos in this respect. Single size abutment implant connection is great for inventory and simplicity. Extremely versitile components- posterior, anterior and overdenture. Can be as simple or complex as you like. It is a whole mouth implant solution. Cons- Learning curve is a little higher for those who have used other systems. just a lot different from others. removing cover screw is an extra step but once you get it down, it is not too bad. Packaging and ordering is cumbersome. Your rep can help make it much easier. The use of external index is somewhat of a jump for some doctors, but it really is easy and many labs are making the jigs for all systems as it makes the transfer much easier. I have posted as "annonymous" as I don't want my company to know I also tell the cons of the system. But really it is a phenominal implant, that in the right hands is the best implant on the market.

have anyone used Endure implants by IMTEC? I always used 3I Biomed, never had any problem except the price is too high, and I decided to try Endure system. After I placed these implnats and load them I got bone lose around total microthread, I though it happened to only one of the implant, after I placed about 10 of ot them they all show the same problem loss of bone around microthread. if you using implant 11mm the microthread on the implant about 40% of the implant, imagine you get bone loss that much after you load them with in 3-4 month. I switch back to 3i and very happy with the system except the prices. Have any of you had that experience with Endure system please share, I want to know. Thank you

Two great implants for general use, that have a great price and high quality are from MIS and AB Dental.