Bacterial Colonization Around the Micro-Gap?

Dr. H. asks:

Recently I have been hearing a great deal about the problem of bacteria
colonizing around the micro-gap between the dental implant fixture and the
abutment. I have heard that this micro-gap and bacterial colonization
can produce bone loss.

Is this a real problem to be concerned with? If so, what are the best ways to prevent this? Is it simply an an issue related to a specific dental implant design? Thanks.

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79 thoughts on “Bacterial Colonization Around the Micro-Gap?

  1. Exactly right…. Implant design is the biggie but I encourage you to look at the study that recently compared different sized microgaps and got some interesting results.

    The location of the IA interface is proving to be a critical factor as well as what (if any) movement occurs there based on the connection type.

    Best,

    Jackson

  2. The internal hex system has abument that ‘flush’ with the implant fixture. This interface however is not totally stable during function and microgaps do form when loaded, especially from lateral forces.

    Bacteria gather around these micro spaces. This dynamic movement pumps the toxins that form in the gaps and creates a ‘zone of toxicity’ at the level of the microgap. Aveolar bone will then remodel to below the zone, resulting in the typical bone loss down to ‘first thread’.

    This is one of the reasons for the bone remodelling noted at the crestal area. Any micro-movement compounds the effect of bone loss.

    (Influence of the size of microgaps on crestal bone changes around titanium implants. A histometric evaluation of unloaded non-submerged implants in the canine mandible. Journal of Prosthodontics. Hermann et al, 2001.)

    To reduce crestal bone loss, smaller abutment is used with larger implant (platform switching).

    Cheers
    Yue Weng Cheu
    Singapore

  3. Do you mean externally hexed implants? And lets remember where Ankylos got this information from (specifically the Hermann studies). Astra has the internal conus with lateralization of the IA interface and therefore no “BW” establishment and has the longevity research to back it up.

    Bone loss to the first thread is common when a lack of stimulation from compressive / tensile forces occur AND when the implant neck lacks rigidity. BW establishment is a bit different. That is one of the two primary reasons the microthreads are surging in popularity following Astra’s lead.

  4. There is a book on marketing entitled “Differentiate or Die” which points out the importance of noting how your product differs from the competitors and then to drive home the point that what differentiates your product is the key factor for success. In other words, “our success is do to our conical connection which our competitors do not have.” At the same time the competitor may be saying “our success is do to our internal hex which provides rotational stability.” There is another by Seth Godwin entitled “All Marketers are Liars.” The point being that microgap issue was manufactured years ago as a marketing tool by Straumann and then my Astra, both designs of which had better lateral resistance to the external hex but not to the internal hex connections. Along came Ankylos and Bicon claiming the same thing. In reality, it is a non-issue today. There may have been some concern about microgaps with the external hex implants before torque ratchets and a better understanding of pre-load on the fixation screw. The fixation screw on an external hex implant is exposed above the external hex and can flex, causing screw loosening and that is when the microgap became a problem as it opened and closed. With internal connections, whether hex, tri-lobe or connical, this is not a problem as the screw is protected by the male projection of the abutment. Metal only can hit at 3 points so there is no greater seal with a connical connection, an internal bevel, and external bevel or a butt joint. What effects the joint is the precision of manufacturing, the stability between the mating parts and use of adquate torque and prosthesis design maintaining the pre-load on the screw so that the parts stay fitting together. ALL THE REST IS JUST MARKETING.

  5. Does anyone recall the VA Study with about 12 -1500 Omnilock implants? All of which were submerged.
    The subject of the Biologic Width always attracts interest. We talk about it in the vertical and lateral directions. I suspect its more than a 2 demension concept. More like a biologic volume of tissue to separate the bone from the oral environment, and provide for circulation. I am not sure what Dr. Jackson ment that there was no biologic width concerning certain implant macro geometry. I assume that the BW is a vital function. Also, if the implant is a 2 piece design there always is a microgap, somewhere…
    I suspect that the micro thread design concept was in fact to better distribute load to bone. In the Astra perception where there is such a tight junction between the implant and the abutment the conus attachment is non forgiving and there is very little energy loss dissapation accross this interface, thus the micro thread 3to1 ratio. Better to distribute the load at the top of the implant..This is more like how many angels can dance on the head of a pin? All of this is stimulation dialog. The real major issues are the skills of the surgical and pros. as well as lab team. Most of all proper treament based on accurate diagnostic assessment. The way I see it that is the 96-98% success criteria. All the rest is new wiz-bang stuff.

  6. Thank you Dr. Niznick! You are, as always, a voice of reason! I often wondered how airplane engineering was related to dentistry. All these implants which have the morse taper (Astra, Strauman etc.) have moved on a provided us with a “timed” indexable connection. Otherwise they could not be used with any angulated abutment and in multiple unit cases. Please stop debating this rediculous matter. Implants work. They all have micro gaps. Even a solid implant will have a micro gap between the crown and the implant itself. Most implant connections today are excellent, if done right. Lets talk about proper patient education and even more important–dentist education. In my Implant-Prostodontic practice, I see mostly problems with improper treatment planning by our well meaning, yet misinformed colleages, rather with the implants themselves.

  7. ever take off a screw retained prosthesis? IT STINKS. Reason is colonization of the dirty margin and leakage. Astra still has a gap but the lateralization reduces the effect of crestal remodeling. Strict biology proven over and over again. Occurs with platform switching as well(to a varied degree) Ankylos does not coase this do to the true conical connection and the integrated platform switching. Hard to get restorative docs on board with it. By far the best fixture out there today(or even in ’86)

  8. Periodontal pathogens have been linked with increased risk of systemic illness and complications in existing disease. Recently, several articles detailing these findings have been published, emphasizing the importance of the association between periodontitis and systemic health problems. In fact, a recent meta-analysis reports that oral infections have been shown to be associated statistically with mortality. By entering the bloodstream, periodontal pathogens have been shown to increase the risk of cardiovascular and pulmonary diseases, and hinder glycemic control in diabetes. Studies have shown that periodontal pathogens surrounding dental implants contribute to peri-implant infections and can be the main cause of implant loss. However, this is not the only location where periodontal pathogens are sequestered. In vivo and in vitro studies have shown that dental implants with varying designs are capable of harboring bacteria within the micro-gap between the implant and the abutment. These periodontal pathogens are the same bacteria that cause periodontitis. Although there has been some debate as to the origins of peri-implantitis and any relationship there might be to periodontal disease, the microbiota and clinical presentation of peri-implantitis are the same as with periodontitis around a natural tooth. The initial colonization of peri-implant pockets with periodontal bacteria is suspected to occur rapidly after implant placement. Even in the absence of clinically significant inflammation, detection of post-inflammatory molecules may indicate peri-implantitis. However, many patients may have significant infections and bone loss, with no symptoms, and may not pursue adequate follow-up care that would identify those conditions. Professional implant maintenance and diligent patient home care are important factors, but because the location of the peri-implant surfaces are subgingival, patients and clinicians have limited control over hygienic measures to prevent infection. Even patients who are scrupulous in their hygienic care can suffer with implant infections if bacteria are harbored within and around implant components. Because the micro-gaps at the implant abutment junction (IAJ) are non-cleansable, dental implants may pose a risk to systemic health, if peri-implant infection leads to the same consequences as periodontitis. Oral disease will and can affect the systemic system. We as part of the health care professionals, must accept that some implant systems have problems and not use them, no matter what the BIG companies say in their ads.

  9. Have been studying and placing implants since 1977, and as an Oral Surgeon I also place permanent abutments and temporaries for the restorative Dentist. I have placed almost every design out there, and from personal experience they all work for the most part. I agree with many of the previous posts that micro gaps do exist and are a direct function of the design of the implant. I too discovered years ago by accident that platform switching gave less bone loss, but have found the screw-vent internal hex and lead in bevel to provide an excellent seal that I augment with thread adhesive, specifically Omnibond, prior to it’s availability I used over the counter locktite. I can look back almost 20 years to cases done and actually see bone growing up the sides of the abutment, and have consistently seen this.

  10. I’ve been involved with implant treatment since the mid 80’s, and as a prosthodontist, restore all types of implant designs. I believe the crestal bone loss/microgap issue has many facets, with each manufacturer responding to crestal bone loss by espousing its design as the best i.e., their thread design, abutment connection method, platform switching etc.

    Crestal bone loss, in my opinion is multifactorial. In the early days we saw bone loss to the first thread. It was uniform, whether it was the old corevent screwvent, with a 3mm polished collar, and the bone moved 3mm apically or a Branemark, with a platform and a machined thread design where the bone dropped 1.5mm. My take on that is that bone doesn’t stick to smooth titanium (read polished collar) and needs a macro or microsurface for dependable retention. The manufacturers began to recognize this and began making smaller polished collars (1.5mm) and Tarnow began lecturing on the so called biologic width. At a similar time, manufacturers were discussing the flexing of the coronal aspect of the implant and the implant abutment interface (see above blogs about screw loosening and stronger internal connections) and believed that stress distribution and lack of micromovement led to better bone retention at the crestal level. Hence the integration of microthreads in some designs. We are now beginning to understand there is a zone of localized inflammation around the abutment/implant interface, and by moving the “microgap” medially, it seems to help keep crestal bone from resorbing (see blogs above discussing platform switching and narrower abutments of Ankylos and Astra)

    I’m not sure there is such a thing as a “biologic width”. This is a term coined by Dr. Tarnow to explain the crestal bone loss. Is it really 1.5mm? Will bone drop from the microgap? Will bone stick to roughened surfaces better, thus decreasing crestal bone loss? By moving the zone of localized inflammation medially, will we keep crestal bone? If we roughen an implant to the flange, and move the microgap medially, will it stop bone migration apically? Will using microthreads and internal connections to distribute stress at the crestal bone eliminate bone loss? Which theory is correct? Do they all partially play a role?

    I think this is the next great frontier in implant dentistry and researchers are getting closer to an answer. Unfortunately, we clinicians often follow a manufacturers claims and believe whatever they say.

    As clinicians, we should keep an open mind and treat manufacturers with skepticism. We need to come to our own conclusions, based on science, so we can treat our patients in the best possible way. Our choice of implant should not be “which is cheaper” but what is best for the situation, and for the patient.

  11. Mr. Callan: you wrote:

    “We as part of the health care professionals, must accept that some implant systems have problems and not use them, no matter what the BIG companies say in their ads.”

    Question: in your years of experience in placing implants, what are a few implant systems that DON’T have the microgap bacterial issue? or aren’t there any?

  12. This discussion of whether or not there is a microgap and is it relevent can be distilled down into a single question;

    Does it ever smell when you take off an abutment that’s been in the mouth for a while?

    If it never does, you don’t have a clinically relevent microgap.

    It it does, you have a septic connection with bacteria multiplying in the gap.

    Which would you want in your mouth?

    Happy New Year,

    Bill Schaeffer

  13. Question:
    Does it ever smell when you take off an abutment that’s been in the mouth for a while? If it never does, you don’t have a clinically relevent microgap.

    Answer: I put two implants in my mother-in-laws mouth 20 years ago and have not taken off the bridge or taken out the abutments to find out if it smells or not. My guess is that if the 3 unit bridge that the two implants supports is still in function and there has been very little bone loss in 20 years, then if there is a micro-gap, it doesn’t matter and if there isn’t it is because the abutments stayed firmly attached. This most likely was due to the stability of the internal connections, the amount of torque I applied to the screws and the type of occlusion I built into the restoration. IN OTHER WORDS, MAYBE THE ABUTMENTS YOU REMOVED THAT SMELLED, HAD A REASON FOR BEING REMOVED AND IT WAS THAT REASON THAT LEAD TO THE LEAKAGE AT THE MARGIN AND ULTIMATELY THE SMELL.

  14. Jerry,

    You are absolutley right! Sometimes you take off an abutment because there’s a problem (like if it was loose!) and that may be the reason why it smells.

    Correct – but you don’t always take off abutments because there’s a problem. Sometimes you take off an abutment because it’s a temporary abutment, sometimes because there’s a problem on another part of the bridge or the porcelain’s chipped etc……

    In these situations there is absolutely no reason why it should stink. If it does, then there has to be a septic connection – why else would there be a smell.

    In some implant designs there is never a smell.

    Kind Regards,

    Bill Schaeffer

    p.s. I’m glad that your Mother-in-law’s implants are still fine after 20 years – you wouldn’t want those going wrong!!

  15. Dear TD,

    Long tapered internal connections tend to have good seals and are clean e.g. Ankylos, Astra and Bicon to name just 3.

    External hex connections are strong connections but tend to be a poor bacterial seal.

    All other designs are somewhere in between in terms of a bacterial seal.

    I have never (and I mean NEVER EVER) got a bad smell coming from a bicon when I remove one of their abutments.

    Kind Regards,

    Bill Schaeffer
    Everything

  16. Marketing, is Price, Product, Place and Promotion. While I have no doubt that “Differentiate or Die” and “All Marketers are Liars” are interesting books for people who don’t understand marketing they tend to focus on what lay people view as Marketing, ie advertising or message. If only it were so that the dentists of the world were actually interested in science as opposed to message or price. If science were important would new products be launched with only one supportive animal study? If science were important would Dentists buy knockoff implants or abutments with almost no research behind them in order to pocket an additional $100 per implant placed. Would a periodontist ask for studies on Emdogain, while they use PepGen?

    As a sales person I love talking to and working with Dentists who actually look for a scientific bases for what they do. Mainly because in those conversations I learn something new or grow my understanding of a concept or procedure. These Dentists act when enough evidence is delivered to substantiate a product or procedure. Instead I walk into offices where Arrestin is pumped into patients with 9mm pockets who should be having surgery. Why? Because the hygeine team is being spiffed on each patient who goes forward with this treatment.

    As for the Microgap, how much research has to be produced to confirm this issue? Bone loss is widely reported moving away from the Implant and Abutment interface? The explanations for this occurence may be hooey, though I doubt it, but the evidence is overwhelming. The message of whichever company on how they are addressing the issue may also be loaded with conjecture. But do they show sceintific evidence in a multi facility random clinical trial that the problem is resolved? If so then how they deliver the message should be irrelevant, science does not depend on a good sales message.

    As for me my favorite marketing book is “Marketing Management, Knowledge and Skills” by J. Paul Peter and James H Donnelly Jr. Dr. Peter being a professor of mine. Although I am rare in this feild as most Sales Reps do not have business degrees. Which is why they will sell a year and half supply of something at a “great deal” to a dentist who they bring in lunch for once a week. I am also a big fan of continous improvement which is not highlighted by the numerous times I have heard someone tell me “…the patient doesn’t know how much that procedure should hurt.” or “what difference does 2% or 3% make in regards to implant failure rates.”

    Implant companies and their staff are not the only ones delivering questionable messages.

  17. LAST COMMENT:
    As for the Microgap, how much research has to be produced to confirm this issue? Bone loss is widely reported moving away from the Implant and Abutment interface?
    RESPONSE: How much research has been produced is a better question? I recall the one study by Cochran who is a Straumann spokesman, claiming bone loss associated with a two-stage external hex implant, but when he repeated the study soldering the two parts together so that there was no micromovement (a study he told me about but which I am not sure he published), he found no difference compared to the one-piece ITI implant, which is probably why he did not publish it. I told him that this was not surprising because it is not a microgap problem but an unstable joint problem and in his first study he was using external hex implants with a sloppy unstable fit. The problem with “science” is that you can prove whatever you want depending on the design of the study. If micro-gap caused bone loss, then why was Nobel having 2-3mm of bone loss around their 1-piece NobelDirect implant? Micro-gap is a pure marketing issue created by companies with connical connections or morse tapers with no proof that they have any better a fit than internal hex connection implants. No doubt they were more stable than the Branemark extenal hex, but that can not be extrapolated to all implants without a connical connection

  18. This is the second time of posting this message – the controller in the sky keeps deleting them…

    Dr. Niznick, can you say that your implants suffer no bone loss, either vertically or horizontally around the abutment/implant interface when they are placed at crestal level?

    Hopefully whoever is in charge here will let this question through this time!

  19. Does Micro-gap equal Micro-movement? Are the two interchangeable in a sentence? If the Micro-gap is a farce then why does bone remodel to the first thread on so many implant systems? Keeping bone level where you want it for tissue support and long term esthetics seems to have value. Is the move from internal connections vs. external irrelevant as long as the milling specs for external hexes aren’t to sloppy? If the issue is Micro-movement then hermetic seals are irrelevant and when building an external stack your tolerances increase. If Stability is the key then which company manufactures with the most precision? If you or your lab are using abutments from knock off companies that claim to fit in a variety of systems wouldn’t the knock offs have built in more slop to account for the various manufacturing specifications? And would a company that outsources all manufacturing therefore have greater issues with tolerance?

    All of these these questions are R&D product design issues not advertising or promotion issues. It also appears to not be settled science. A poorly designed study will deliver poor information, BS in BS out. Straumann or David Cochran did not invent the Microgap although they may have, perhaps inaccurately for Dr. Niznick, named it, just a Tarnow named Biologic Width. There appears to be an underlying truth, bone remodels away from the Implant Abutment connection or the Implant Crown connection, in most cases, with Straumann. If the Micro-gap does not exist and if instead this an issue of poor workmanship then why would companies spend so much R&D on new ideas when they could quickly and cheapily improve their specifications on precision fit and eliminate this problem? In turn delivering a higher return to investors without wasting money on pointless R&D. They must just enjoy wasting money I guess.

  20. I really enjoyed reading all these comments and now I am scared about my future implants. I’m just a patient, not a doctor, and I feel like nobody here has an answer regarding the microgap issue or the stability differences between the connical connection and platform switching implants. How can I find a dentist that will be profesional and not commercial?

  21. I seem to be debating with Astra sales people instead of real dentists – why else would you not post your names? Regardless your points deserve answers although you may not like them

    Question: Dr. Niznick, can you say that your implants suffer no bone loss, either vertically or horizontally around the abutment/implant interface when they are placed at crestal level?

    Answer: No I can not say that but neither can any implant company honestly say that either. The VA study that I funded in the early 1990’s, of which Tarnow was on the peer review committee, proved that bone loss is almost directly proportional to the thickness of the labial plate at time of implant placement. There was a study that compared the Astra implant to the Branemark external hex implant… and reported no difference on bone loss.

    Question: Does Micro-gap equal Micro-movement? Are the two interchangeable in a sentence? If the Micro-gap is a farce then why does bone remodel to the first thread on so many implant systems?

    Answer: The word Micro-gap means a small gap. Poorly manufactured implants and abutments exhibit a micro-gap between the mating parts. That is not the case with any of the major implant companies’ products that I am aware of. The word Micro-movement means rotational instability between mating parts. Here there is a wide range even among the products of leading implant companies with internal hex or tri-lobe connections. This is not a factor with implants like Bicon or Astra or Straumann that do not rely on interdigitating mating parts for stability, but these products have to accept a limitation that the mating abutments can not fit flush with the outside diameter of the implant. They need to fit into a conical internal shaft leaving the top of the implant exposed and creating an undercut between the height of contour of the abutment and the top of the implant. Since this could not be avoided they gave it a name…platform switching and claimed it had some advantage. I know the disadvantages it has in emergence profile establishment but I am not sure there is any real soft tissue advantage as some claim. As I said there is a wide range or rotational instability with the Branemark external hex having 6.7 degrees down to the Screw-Vent’s friction fit abutment having zero. My new implants with internal hexes and internal tri-lobes have less than ½ degree rotation whereas the Tri-lobe connection on the Nobel Replace has considerably. Even rotational micro-movements on the higher with internal connections does not translate into micro-gaps because the internal connection itself protects the flexing of the fixation screw… and that is what causes a functional micro-gap between mating parts. Bone loss to the first thread was associated mostly with the Branemark external hex implant which had 3 things going against it… flexing of the fixation screw, countersinking and a smooth machined neck. To extrapolate the results of these design shortcomings to all other implants that are not Astra or Bicon is pure marketing rhetoric.

    Question: Keeping bone level where you want it for tissue support and long term esthetics seems to have value. Is the move from internal connections vs. external irrelevant as long as the milling specs for external hexes aren’t too sloppy?

    Answer: It is not that simple because I have a patent on friction fit external hex implants that eliminate rotational stability. Precision fit is important but less so with internal connections

    Question: If Stability is the key then which company manufactures with the most precision?

    Answer: The closest tolerances a manufacturer can consistently and economically hold is plus or minus 0.0005” which is 5/10,000 of an inch. Zimmer has to hold those tolerances to make their friction fit abutments. Implant Direct holds those tolerances in order to create what I call precision fit… less than ½ degree rotation. Nobel does not hold those tolerances… I know because I reverse engineered from their parts and it is evident when you put an abutment or transfer into an implant or implant analog.

    Question: If you or your lab is using abutments from knock off companies that claim to fit in a variety of systems wouldn’t the knock offs have built in more slop to account for the various manufacturing specifications? And would a company that out sources all manufacturing therefore have greater issues with tolerance?

    Answer: The answer is maybe and yes. Implant Direct makes two implants with Nobel compatible tri-lobe connections and makes a full range of tri-lobe abutments. Any one that takes the time to fit our abutments into a Nobel implant or Nobel Abutments into our implants, and then compares that fit with placing a Nobel Abutment into a Nobel implant will see that our fits are better. Companies that outsource the manufacture of their products can not hope to achieve and maintain close tolerances because they are doing the quality control when the parts arrive at the implant company and not when they come off the machine.

    Statement: There appears to be an underlying truth, bone remodels away from the Implant Abutment connection or the Implant Crown connection, in most cases, with Straumann.

    Answer: This is an overgeneralization and certainly not an underlying truth. There are thousands of documented cases with no bone loss even with the implant abutment junction at the crest of the bone. There are also many documented cases where bone resorbed 3mm on a one-piece Nobel Direct Implant.

    Question: If the Micro-gap does not exist and if instead this an issue of poor workmanship then why would companies spend so much R&D on new ideas when they could quickly and cheaply improve their specifications on precision fit and eliminate this problem? In turn delivering a higher return to investors without wasting money on pointless R&D. They must just enjoy wasting money I guess.

    Answer: Companies spend money on new designs and research to differentiate their products form their competitors and/or in order to justify their high prices. If all they did was improving their precision, they would be no different that the high quality companies that already have good precision. In fact, Nobel should spend money and effort improving its precision fits but the relationship between precision and bone loss gets blurred by the overriding surgical factors so they could never prove a clinical advantage. They will do better hiring more salespeople, like Astra and 3i to tell their marketing stories of no bone loss and faster osseointegration etc, all to justify their high prices.

  22. I have used lots of different implant systems including 3i, Astra, Nobel (2 or 3 different designs) and Bicon. I honestly get less bone loss around the abutment/implant junction of the Bicon system than the others and can only put this down to Bicon’s claim of eliminating the microgap. I’ve often seen bone growing up above said junction. Dr. Niznick would therefore suggest that Bicon’s components are of greater precision which they would have to be to as there is no screw used to join the abutment to the implant.
    I have absolutely no affiliation with any implant company (and think that many are guilty of spin), but have been particularly impressed with Bicon’s system and its engineering.

  23. The Bicon type connection with mating 1.5 degree tapers, called Morris Taper has been around for 25 years dating back to Miter’s imlant where the post projected up from the implant and the abutment fit over it. While it provides great lateral stability, it has many prosthetic limitations that are not present on internal hex or tri-lobe connections. There have been reports of the narrow post fracturing and also coming loose under fixed briges. Think about it..anything that needs to be tapped in to create the connection can also come loose. That is why Ankylose combines a screw with the Morse Taper. There is no ability to do implant level transfers with the Bicon because there is no internal index. Implant level transfers made implant prosthetics easier than conventional impression procedures. Another shortcoming of the Bicon design is that it often requires a surgical step to remove bone at time of abutment attachment becuse it is placed sub-crestal. As far as preserving crestal bone your observations may be related to the fact that it is placed subcrestal and your observations about more bone loss with 3i may be due to micro-gap from an external hex connection. Once can not tell without side-by-side clinical evaluation of different types of connections, comparing Bicon to a good internal connection like the Screw-Vent Implant.

  24. Dear Jerry,

    You are clearly hugely knowlegable in this subject (way more than me), but there were some factual errors in your last post so please forgive my impertinence by saying the following;

    The locking taper is a Morse Taper (not a Morris Taper).

    You say there have been reports of the narrow 2mm post fracturing and you are absolutely correct – there is a 0.5% fracture rate when these are used to support unsplinted single molar and pre-molar crowns. Might I suggest that this is not unreasonable if using such a narrow component in this scenario. I would “never” use a narrow implant in this situation, but a 0.5% fracture rate still isn’t bad! I believe that there has NEVER been a report of a 3mm post fracturing.

    I have never heard, (from myself or anyone else), of a post coming loose under bridges, though my experience is fairly limited as I’ve only placed a little over 900 of them.

    The dentists who restore my Bicon implants do implant-level impressions (if that’s what you mean by “transfers”)every day. I’m not sure why you don’t think that’s possible with Bicon, but I’m afraid you are mistaken.

    There is another surgical step if you place Bicon implants as 2-stage implants, in exactly the same way as there is for every other implant system – including yours! If you place them one-stage or immediately-loaded then there is obviously no second surgical stage.

    As far as preserving crestal bone, my experience matches MS.

    I hope you don’t mind me correcting these points.

    Kind Regards,

    Bill Schaeffer

  25. Dr. Niznick, if your implants were placed subcrestally (as you presume my Bicons are)would they also experience NO bone loss? – I cannot believe for one minute that they would.
    I sometimes place Bicons subcrestally, but this is because I know I won’t get bone shrinkage in the aesthetic zone – I don’t believe that you can say the same about your implants because they have a microgap and this is why you have to place them at crestal level or supracrestally.

    As for post fractures, Bill Schaeffer is correct – these pertain to the incorrect use of narrow implants to replace molar or premolar teeth.

    The Bicon system isn’t perfect (nor I believe, is any system…yet..), but bear in mind that many of Bicon’s ‘firsts’have been copied widely by other manufacturers including the factory-direct manufacturers.

    Osteo-Ti is the latest manufacturer to copy the plateau design with a morse/locking taper.

    Dr. Niznick, if you could do me a Bicon type implant for half the price, I’d have your arm off!!

    Best wishes to all for the New Year.

  26. Dr. Niznick, thanks for your responses to questions in previous posts. Although I am not an Astra rep as you assumed. I agree that their are thousands of examples where crestal bone stays put on a variety of systems, and that bone thickness plays a roll in these results.

    I appreciate your participation on these forums even if you are overly annoyed by business people who are not Dentists. Some of us are as interested in fully understanding dental implants as you, even though we lack a DDS.

  27. Response to Bill Schaefer:

    1. Yes you are correct on the spelling of Morse.
    2. With 900 Bicon implants you are certainly very experienced and a small number of fractures .5% when the implant is overloaded would be acceptable although prerably avoided by using internal connect implants that transmit the stress to the top of the implant and not just to the post as with Bicon.
    3. Implant level transfers maybe possible with Bicon using some mickey-mouse index jig, but this is not as simple or as accurage as using a transfer component that fits into the implant and interdigitates with the internal hex, like the fixture mounts that are provided free on the Screw-Vent and with my new implants.
    3. Bicon can be a 3 stage surgical procedure (1) inserting the implant (2) uncovering the implant and (3) countersinking the crest of the ridge to make room for seating the abutment. Bicon has drills specific for this function

  28. COMMENT:
    Dr. Niznick, if your implants were placed subcrestally (as you presume my Bicons are) would they also experience NO bone loss? – I cannot believe for one minute that they would.

    NIZNICK COMMENT: I do not think what you “believe” is relevent. What do you know for sure? Two-stage implants are not placed subcrestal for the same reason Bicon’s shouldn’t be placed subcrestal…it complicates the attachment of the abutment and gives up added bony support in the dense bone crestal region.

    COMMENT: I sometimes place Bicons subcrestally, but this is because I know I won’t get bone shrinkage in the aesthetic zone – I don’t believe that you can say the same about your implants because they have a microgap and this is why you have to place them at crestal level or supracrestally.

    NIZNICK RESPONSE: Same as above.

    COMMENTS: The Bicon system isn’t perfect (nor I believe, is any system…yet..),

    NIZNICK’S COMMENTS: You are right that there may not be one perfect implant for all applications, but can you really compare the Bicon implant with the 5 different Application Specific Implants from Implant Direct that can all be inserted using the same drills? If you are that anti-microgap, then what about the ScrewDirect, ScrewInDirect and ReDirect one-piece implants from Implant Directt? No fracture concerns with a one-piece implant, no micro-gap, no countersinking to attach an abutment since the abutment is already part of the implant, and best of all, no abutment to buy. Also, if you want a two-peice implant but are concerned about the micro-gap, there is the ScrewPlus which has a 2mm neck like the ITI implant. But I can tell you with a great deal of certainty based on my 25 years manufacturing implants, that there has never been a better, stronger, more precise connection than the combination of overlapping an external bevel with a 2mm deep internal hex having less than 0.5 degrees of rotational wobble.

    COMMENT: Dr. Niznick, if you could do me a Bicon type implant for half the price, I’d have your arm off!!

    NIZNICK’S RESPONSE: I would sooner spend the time educating you as to the advantages of an internal hex connection than to copy a design that has so many prosthetic limitations.

    COMMENT – many of Bicon’s ‘firsts’have been copied widely by other manufacturers including the factory-direct manufacturers

    NIZNICK RESPONSE: As for Bicon’s great innovations like factory direct marketing, I have a lot of respect for the owners of Bicon and how they have grown their business. I would sooner be know for design innovations like the internal connection, first sterile packaging, fixture-mount packaging, selective surfaces and about 25 other patented features many related to prosthetic simplicity and versatility. Ultimately, Implant Direct will be know for bringing factory direct sales to dentists worldwide with the most user friendly online shopping cart ordering system. More importantly, Implant Direct will be know for creating a price point shift in the implant industry with real factory direct pricing. Tell us what you pay for a Bicon implant, healing cap, transfer (if they have one) and abutment. Then compare that to $150 from Implant Direct for any of the five Application Specific implants.

  29. COMMENTS: I am not an Astra rep as you assumed. ..I appreciate your participation on these forums even if you are overly annoyed by business people who are not Dentists. Some of us are as interested in fully understanding dental implants as you, even though we lack a DDS.

    NIZNICK RESPONSE: My annoyance is from people espousing a companies marketing story as if it were based on facts, and then not identifying their business relationship with that or some other company having a similary BS marketing story. I see that you still did not identify yourself by name but thank you for at least admitting you have never placed an implant, are not a dentist, and thus everything you know about implants is based on what you heard from an implant company or one of its paid oppinion leaders.

  30. Dear Dr. H,

    the story around the implant connection is very old. Many companies tried to maintain externally Hexed Implants in the Market due to the sales strategy….

    Today they all went to internal connections, that we knew since years was the best connection…

    Astra, Niznick’s design, Ankylos..formerly Frialit II match all the requirements for implant and prosthetic connections stability reducing bacteria around the prosthetic abutment and allowing soft tissue to stay more predictible.

    We knew it….now companies try to” re-fried the eggs”….

  31. so from what i have read in this very long thread, it looks like NO implant system totally solves the microgap bacterial issue;

    some lessen it but still do not do totally away with the problem.

    if anyone knows of an implant system that really COMPLETELY ELIMINATES the microgap bacterial issue, please post the name of it and who makes the implant.

    thanks.

  32. TD, Bicon is the only company that claims to completely eliminate the microgap. The results of their studies seem impressive and the results I and others (with regard to minimising bone loss) get are impressive.

  33. There was an article in IJOMI a while back on Bicon’s bacterial seal:

    Dibart, S., Warbington, M., Su, M.F., Skobe, Z., In Vitro Evaluation of the Implant-Abutment Bacterial Seal: The Locking Taper System, The International Journal of Oral & Maxillofacial Implants, Vol. 20, No. 5, p. 732-737, September 2005.

  34. After reading the cited article, it sounds like the Bicon implant might really lessen or even do away with the microgap bacteria issue.

    QUESTION: Are there any other implants on the market today that really do away with the microgap bacterial issue? In this regard, what have the dentists here seen in their clinical practice?

  35. Obviously on -piece implants will answer al those questions aboved…

    There is not and will be not the best implant system to reduce, or improve anything….again we are looking the best implant company to cover our weakness of Oral Biology!

  36. LAB to DENTIST!!!
    What effects the joint between implant parts, such as an abutment interface, is
    (1) the precision of manufacturing of the parts, (2) the final position (closeness of fit) of the mating parts to each other when all clinical and lab steps are completed, and
    (3) the stability between the mating parts under occlusal force load, once inserted.

    re
    (1)Precision manufacturing of parts is easily confirmed by you or your lab when parts are obtained for a particular case scenario.

    (2)Closeness of fit, that is, a guarantee of framework fit within a 2.5 micron range with any number of implant interfaces has been established since the early 1990s by me and others. See KAL-Technique references, US Patent 5,106,300 and the recently evolved Impant Borne Bridge (IBB) solutions.

    (3) Since the early work by Niznick on the internal hex connection, stability of mating parts under load has also not been an issue.

    If anything needs to be said in addition, it should echo more of Dr. Zev Kaufman’s comment regarding education and training: Implant case planning and execution of case work, both clinically and lab-wise, using the appropriate materials and methods are the areas of much needed improvement.

    ajvoitik@dentalartslab.com

  37. In Germany is a System called ZL-Duraplant, which showes since 15 years with Platform switching, Anodized Surface (TiCer) (copied by “Nobel copy care”!) best results, and other advatages and the special external Hex design seals the Platform. Now many other Systems follow the Duraplant System. It is made in Germany and offers a save treatment. Best regards!

  38. Mr Hall,

    you said in your ealier post that “Obviously one -piece implants will answer all those questions above”

    are there any pitfalls to one piece implants? why aren’t they used as much as 2 stage dental implants?

  39. Gentlemen, we might be making too much of an issue regarding the mcirogap and bone loss.

    In our 10 years clinical study of an one-piece implant/abutment device, we have observed the following regarding the bone remodeling around this one-piece device: 1) A significant amount of negative bone remodeling (bone loss) at the crestal areas occurred early during the healing or unload period (10 weeks) for all implants. 2) Crestal bone level was at a steady height to about 2 mm apical to the prosthetic margin (inital bone level at placement) and 1 mm apical to the r/s border. 3) The crestal bone level remains virtually unchanged up to and over 84 months. 4) There were 27.93 % of the devices in this study that appears to have positive bone remodeling (bone gain) in the crestal areas after the initial negative remodeling period.

    From all practical clinical perspectives, the bone remodelling, the microgap or lack of it might not be as significant as one hopes, however, the real advantages of an one-piece implant are the drastically simplified implant placement and restoration procedures including the laboratory process. There is only one restorative component needed, the over all prosthetic complications was reduced to less than 1% over the study period.

  40. Mr. Kwan:

    So are you saying that one stage/one piece implants have virtually no bone loss given they don’t have the microgap where the bacteria can colonize?

    And are you saying that two piece/2 stage implants are a lot more risky than one stage implants because two stage implants have the microgap?

  41. Jack,

    I think there is an initial bone remodeling period (usually associated with bone loss) when you introduce any implantable device into the bone through the periosteum. After the initial healing process (10 weeks)we did not mearsure any more bone loss. The lack of microgap certainly contribute to the perservation of crestal bone level but I am sure there are other contributing factors at play here, e.g. micro-movement between components; surface textures etc.

    I think that the ideas of internal connections, platform switching etc, where the prosthetic/implant is the only margin on the device, the microgap effectively was sealed by dental cement, would also preserve crestal bone as the one-piece device.

    I am saying that 2 piece 2 stage implant works equally well, and for all clinical purposes they have proven to be safe and effective over the last 30 some years.

    The amount of bone loss with our 2 piece- one stage implant (abutment pre-asembled and torqued to 20 NCm) placed and restored the same way as the one-piece are showing more bone loss but ceratinly could not say that they are more risky. There are more components involves, naturally you would expect there will be more complication relating to the components before the bone loss becomes of an issue.

    What I am saying is that this bone loss/bacteria issue is more of an academic discussion than of a clinical one.

  42. QUESTION: if anyone knows of an implant system that really COMPLETELY ELIMINATES the microgap bacterial issue, please post the name of it and who makes the implant.

    NIZNICK’S ANSWER:
    You miss the point…there is no microgap problem with any internal connection if the implant and abutment are made by the same reputable manufacturer and the fixation screw is properly screwed down to at least 30Ncm. The micro-gap issue is a straw man argument created to sell…

  43. Jerry,

    the implant name is Duraplant, and is produced by ZL-Mircrodent in Germany! It´s a great German.

    20 years clinical datas! Involved is the University of Leipzig, Prof. Dr. Graf.

    Best regards

  44. Dr. Niznick states: “…but thank you for at least admitting you have never placed an implant, are not a dentist, and thus everything you know about implants is based on what you heard from an implant company or one of its paid oppinion leaders.”

    You say this as though it is a bad thing. If that’s the case, then why should we listen to YOU? You are an opinion leader of YOUR company and are getting paid for what you do.

    Aside from that, do you honestly believe that those of us without a DDS learn “everything” from implant companies or one of their paid opinion leaders? Not true.

  45. Has anyone had any microgap bacterial issues with the Bicon implant system?

    What about the PerioSeal implant system? Their website seems to say that their implant system also eliminates the microgap. Has anyone had any microgap issues that the PerioSeal?

  46. Jack Says: Has anyone had any microgap bacterial issues with the Bicon implant system?

    Niznick Comment: A better question is whether has anyone had a “microgap bacterial issue” with any internal connection implant system…we know that it was a problem with the Branemark External hex primarily because of flexing of the fixation screw caused the gap to open and close during function in some situations.

  47. Response to Question: .. why should we listen to YOU? You are an opinion leader of YOUR company and are getting paid for what you do. Aside from that, do you honestly believe that those of us without a DDS learn “everything” from implant companies or one of their paid opinion leaders? Not true.

    Niznick Answer: Since you are not a dentist and have never inserted an implant and followed up on the results of your cases 5, 10 or 15 years as many of us have, you must have learned what you think you know about implants from some implant company or opinion leader. As for why you should listen to me, for one thing, I have 35 years experience in the implant field, placed thousands of implants, taught 10,000+ dentists how to place implants and I built the Core-Vent Company to the leading implant company in the world in 1990 when Dentsply took over. After taking it back in 1997 and renaming the company Paragon, I created and manufactured the Tapered Screw-Vent, Advent and SwissPlus implants which are the mainstay of the Zimmer product line today. That does not mean that I have all the answers but it a good reason to listen to my oppinions and if beleive you have evidence to the contrary, feel free to disagree with me, but disagreeing with me because someone told you something different is just matching one person’s oppinion against another, in which case you should also match each person’s credentials, involvement with different companies, basis for his oppinion etc. START OUT WITH THE PREMISE NOT TO BELEIVE ANYTHING THAT AN IMPLANT COMPANY TELLS YOU IS THE REASON FOR THEIR PRODUCT’S SUCCESS AND YOU WILL BE WELL ON YOUR WAY TO BEING DISCERNING.

  48. Niznick wrote: A better question is whether has anyone had a “microgap bacterial issue” with any internal connection implant system … we know that it was a problem with the Branemark External hex primarily because of flexing of the fixation screw caused the gap to open and close during function in some situations.”

    Mr Niznick — so are you saying that all INTERNAL connection implant systems are therefore bacterial free around their microgap?

    And are you saying that only implant systems that have the bacterial microgap issues are the EXTERNAL hex systems?

  49. Brilliant stuff Jerry Niznick I have only been placing implants for 16 years and agree 100% with you , it is logic denuded from marketing speak. Bicon , Ankylos are designed to be placed sub crestally ( hence that sales talk that the bone can grow over the implant)thus they need a “better” seal due to this positioning.As for micro gap it is a non issue (good for marketing to new graduates).Correct placement is vital always supracrestal,the last thread at the bone level and bone loss is nonexistent. Most systems facilitate that with higher threads and minimal polished collars.Just my thoughts!!
    A blog of great intrest , and a fun read ..

  50. QUESTION: And are you saying that only implant systems that have the bacterial microgap issues are the EXTERNAL hex systems?

    NIZNICK RESPONSE: I am saying that all internal connections made by quality conscious companies will have a stable, well fitting junction between the implant and the abutment and that is all it takes to eliminate concers about “bacterial microgap issues” What determines a quality conscious company… one that depends on its reputation for quality moreso than a repuation for low prices, which is not to say that a company can not have low prices and also provide a quality product. One thing I found to be true is that to assure high quality, an implant company must make its own products because quality must be controlled at the machine, not by a QA department sorting for bad parts… what is defined as bad will then vary with the backorders when this happens. Some external hex implants provided stable connections including 3i and Paragon’s in the 1990’s when both companies achieved friction fit external hexes using different methods. Nobel on the other hand had 6.7 degrees of rotational wobble. External hexes are inherently less stable than internal connections because the lateral forces are applied to the fixation screw causing it to flex and the margin to posibly gap open. External hex implants, once considered by many as the gold standard because Nobel advocated it, is rapidly becoming of historic importance only.

  51. Mr Fairbairn,

    There are many of us that use Bicon, Ankylos and Astra etc and appreciate the fact that we lose less bone around these implants.

    We are not new graduates and many of us have post-graduate qualifications. You seem to have a BDS only, which is the basic qualification to practise dentistry in the United Kingdom. Let’s see some commitment to post-graduate studies before you start criticising the rest of us.

  52. At least Mr. Fairbairn understands the Queen’s English. When you say the Bicon, Ankylos and Astra “lose less bone around these implants”, you need to say less than what. Do you mean less than if you did not use an implant, less than a blade implant etc. You ask for post-graduate studies but I am sure you can not cite a single study that did a side-by-side comparative study of any of these three implants showing less bone loss than any other implant. Claims based on anecdotal case reports are even better than saying you get less bone loss but do not provide the comparative or any references to back it up.

  53. Dear Mr Wrinkler as I said I have only placed for 16 years (about 200 a year) and hence agree I have limited experience and yes I do enjoy many aspects of general dentistry.(grad 1981)
    Anyway I am not critical as I know all the systems work well when utilized correctly this field of dentistry is generally very succesful.
    Anyway as I said these are my thoughts only ,when I have time I may do further study but presently am interested in the future not studying yesterdays news.
    I apologise if you were offended in any way but this a dicussion site and should be treated as such.
    My Mentor has been placing implants since 64 ,is the founder of systems and the main institutions here and he has only a BDS…

  54. Someone wrote: “There are many of us that use Bicon, Ankylos and Astra etc and appreciate the fact that we lose less bone around these implants.”

    Do any of the 3 named implant systems have a high fracture rate?

  55. I changed the http to hxxp beacuse OsseoNews removes posts with URLs in them. Try this (copy and paste into your browser):

    bicon.com/b_difference.html

    To me, this image shows vastly different crestal bone maintenance by a sealed system (Bicon) and a septic system (Zimmer?).

  56. JL, the pictures on the site you posted look the same to me. Are you seeing substantially more bone loss on the threaded implant picture there?

  57. Unfortunately the other implant is placed soooo far up (possibly 2 mm) that is impossible to compare, but the Bicon does look good. This is the issue the level at which implants are placed.
    Ps I am only a dentist

  58. I checked out the side-by-side pictures of a Bicon implant and an external hex implant on bicon.com/b_difference.html. This is typical BS marketing that does not prove anything to knowledgeable dentists but apparently does influence the less knowledgable which might be Bicon’s target market.
    First thing is that the implant on the right with the bone loss is an external hex implant which is well established to not be able to maintain as stable a connection as any internal connection, hex, tri-lobe or otherwise. The reason for t his is that the fixation screw can flex under lateral forces causing the shoulder margin to gap open and closed.
    Second is that the external hex impant has a wider neck which requires countersinking that removes more bone on insertion and concentrates stress near the crest of the ridge. – internal connects also solved both of these problems.
    Thirdly, there are many other reasons that could account for the differences in bone loss including how thick the labial plate was in the area of external hex implant vs the Bicon implant.
    The fact that a company would post a single picture and claim that it proved their design better only shows that that company has no legitimate proof to support its marketing claims.
    COME ON GUYS – If you are continuously going to buy into the marketing stories of companies, you are never going to figure out what really is important in an implant design, or more important, an implant system.

  59. i am curious whether this bacterial microgap issue has been seen on all implant surfaces [that is, on all implants no matter what they are made of].

    for instance, is it less of a concern on pure 100% titanium implants? what about titanium alloy implants? or doesn’t the implant *material* have anything to do with the microgap bacterial issue?

    also, just curious which companies are still making pure 100% titanium implants. anyone know?

  60. Nobel uses CP titanium for its Branemark external hex implants and for its Replace TiUnite Tri-lobe implants (but not its HA coated implants. Tiunite will not grow on Alloy. Straumann also uses CP on its implants. Forget the micro-gap issue…it is a marketing story created by companies with nothing else to use to differentiate their products. The old External Hex Branemark implants were the only ones where the gap was a problem, and that was because of the sloppy unstable connection and the flexing of the fixation screw projecting above the external hex.

  61. anyone know if the Ankylos and Astra are prone to fracture? has anyone here had any other particular problems with the Ankylos and Astra?

    and anyone know if the Ankylos and Astra are made of pure titanium [or an alloy]?

    it seems most here seem to think these these 2 systems [along with the bicon system] have less bone loss and less microgap bacterial issue that a lot of other systems on the market.

  62. Astra: titanium dioxide-blasted pure Titanium
    Ankylos: uncoated pure Titanium
    Bicon: grit-blasted, acid-etched, Ti-6Al-4V ELI alloy (Extra Low Interstitial)

    I know that the Ti-6Al-4V ELI is considerably stronger than pure titanium, but I don’t think any of the sytems above are prone to fracture.

  63. Jim: I don’t think that this is a fair assessment of the comments made on this blog:

    It seems most here seem to think these these 2 systems (Ankylos and Astra, along with the bicon system] have less bone loss and less microgap bacterial issue that a lot of other systems on the market.

    Two metal pieces can only make contact in 3 points so the non-existent “micrograp” would be the same for any high quality implant, which includes many companies making their own implants. Where a gap between the abutment and the implant becauses a problem is when the margins open and close during function which can only happen if the fixation screw loosens or flexes. Historically that happened on Branemark External Hex implants because the exposed top of the fixation screw could flex. ALL COMPANIES TRYING TO DIFFERENTIATE THEIR PRODUCTS FROM THEIR COMPETITORS BY CLAIMING LESS MICROGAPS OR MICRO-LEAKAGE APPARENTLY HAVE NO SERIOUS FEATURES THAT DIFFERENTIATE THEIR PRODUCTS SO THEY FALL BACK ONTO THIS. THE ONLY COMPARITIVE STUDY I EVER SAW WHERE BACTERIA WERE PLACED IN THE INTERNAL SHAFT OF THE IMPLANT AND AFTER THE ABUTMENT WAS SEATED, A CULTURE WAS DONE TO EVALUATE LEAKAGE, HAD ASTRA AS #11 OUT OF ABOUT 13 IMPLANTS WITH AN IMPLANT HAVING AN 0-RING SEAL WAS #1.

  64. Mr.Bill Schaeffer :

    You state that the Bicon, Astra, Ankylos, and Straumann systems do NOT have the bacterial issue around the microgap given their design.

    If you were to get an implant placed in your own mouth, what system would be your FIRST choice?

    And WHY would that particular system be your first choice [based upon what you have seen while placing implants in others]?

    Thanks for posting your thoughts.

  65. In response to Jerry Niznick’s comment that two metal surfaces can only meet on 3 points.

    That would be true if materials did not flex under loading. But all materials flex under load.
    Engineers use the term modulus of elastisity to desribe and define this. Under loading from the abutment screw, all implant fixture and abutment joints have to deform and typically when they do they seal up. Vertical loads applied from mastication would only add to this. Lateral and offcenter loads are a different issue. A strong enough lateral load on a “flat joint” would certainly open a momentary micro-gap. Wider implants and higher screw preloading would diminish this. On tapered implant joints, the abutment screw preload would seat the abutment with an even better seal in the unloaded or vertically loaded situation. Please note that most high pressure hydraulic and pneumantic joint fittings use a tapered seal-seat arrangement without a gasket and depend on the two metal surfaces to elastically deform so close to one another that even the smallest molecules cannot pass between them. Lateral loadings on tapered joint fixtures would transfer the stresses to the outside wall of the fixture and not depend on just a screw.

    My conclusion is that there is something to the tapered seat joint sealing better, probably much better.

    Most tapered joint systems end up with a platform switching type design by geometric necessity. An interesting feature of platform switching is that there would be more room for tissue interproximally at the osseos level. In anterior teeth there is more bu-li dimension than m-d dimension and an implant is round: possibly crowding interproximal tissue. A platform diameter reduction at the osseos level could add back some space for interproximal tissue development.

  66. Since all implants from credible implant companies are manufactured to high standards, and no studies have been produced to prove any advantage of one over the other since the VA study showed HA was better than an acid etched surface, it is all about which company provides the best thought out prosthetics and surgical protocol. All-in-one packaging adds to the simplicity of the inventory and ordering procedures. The most undisputed difference between implant systems like Zimmer, 3i, Straumann and Nobel at $550 for implant/Abutment/transfer/healing collar and Implant Direct at $150 for the same components. is that the dentist saves $400. All the rest is just conversation.

  67. It would seem that the patient’s health should be the MOST important factor in the implant the dentist chooses to use.

    If one implant shows lesser bone loss and lesser bacterial microgap issues, then that implant should be the one that a dentist, who truly takes his or her patient’s health into consideration, should choose.

    If a tapered implant seats better than other implant designs from an enginnering perspective, then there really might be an advantage, from a patient’s health perspective, to the dentist choosing a tapered system with platform switching [like bicon or one of the other tapered systems].

    Should a few extra bucks in a dentist’s pocket cause a dentist to deviate from this standard.

    I say no.

  68. Someone posted further up in this thread that the Bicon, Astra, and Ankylos systems tend to do a good job at eliminating the bacterial microgap concern.

    When I googled microgap and bacteria, I also ran across the PerioSeal implant system and its website says that it too addresses the bacterial microgap concern. The website details the design of the implant, and says that it has a collet locking connection that is different from most systems in that it has a conical opening above an internal hex and the interior of the implant is not threaded. The abutment is held in place inside the implant by a locking mechanism that expands when a screw inside the abutment is tightened. The site says that this feature eliminates the possibility of a broken or stripped screw, and if a problem ever occurs with the abutment, you can simply remove the screw and the implant will not be damaged in the removal process.

    On some other internal locking implant systems when the abutment is actually *tapped* into the implant (instead of being screwed into the implant), wouldn’t it be real hard to remove the abutment if it needed to be removed? Would the force it takes to remove those type of implants cause the implant to be more prone to be damaged if one needed to remove the abutment?

    For example, I think the bicon system might be like this [unless i’m confusing its components with some other system]. Any thoughts on this? In other words, would a screwed in abutment [like the perioseal] be alot easier to remove than an abutment that taps into place? Also, any thoughts on whether the design like the PerioSeal is really unique vs other systems now on the market?

  69. COMMENT: If one implant shows lesser bone loss and lesser bacterial microgap issues, then that implant should be the one that a dentist, who truly takes his or her patient’s health into consideration, should choose.

    NIZNICK’S COMMENT: The operational word here is “if”. Since there are no studies showing less bone loss and less bacterial micrograp issues of any clinical significance, then a dentist should look at other factors in deciding his or her patient’s health and well being into consideration, like which implant design is more likely to provide better initial stability, better bone apposition, more stable prosthetic connection, better esthetics, or better value to the patient i.e. can reduce the costs to the patient.

  70. I don’t think the implant companies will ever do the detailed studies because they could end up seeing more bone loss then they thought would occur.

    Thus, all there really is to go on is what us dentists have observed in practice.

    And it looks like many here have noticed less bone loss with certain systems [like bicon, astra, etc], and more bone loss with other systems.

    Clinical experience is really the patient’s best friend when it comes to the microgap bacterial issue.

  71. I too (like David above) would like to know if systems like Bicon that are “tapped” into place are hard to remove -vs- systems that have internal connections but where a screw still connects the abutment to the implant[like in the PerioSeal]. And would the screw in the latter situation create any septic concerns?

    Any engineer experts here?

  72. Thanks JL. Seems like the Bicon implant should come out fairly easily if it needed to come out.

    Just curious, if you had to make a choice between a Bicon, Ankylos, Astra, PerioSeal, Nobel, and an external hex system, which would you choose and why?

    And does anyone know if the Ankylos, which uses uncoated pure 100 pefcent titanium (rather than a titanium alloy) has a higher fracture rate than most implants? what has been the clinical experience with Ankylos and fracture?

    Thanks all.

  73. I would go for a Bicon.

    From what I’ve seen in my own patients, the microgap is eliminated allowing bone to grow up over the implant-abutment junction. The integrated-abutment crown IAC is another great idea – the ceramic material is fused directly to the abutment, which means no cement, just 2 parts, the implant and the IAC. Very clever. This produces fantastic perio health and gingival aesthetics.

    We’ve used other systems (including Astra) and none of them produce quite the same result, although I can understand that some like the security of securing the abutment with a screw.

    The shape of the Bicons also allow much shorter implants to be used (perhaps avoiding GBR) as length for length they have a greater surface/bone acontact area than pretty much all other designs.

    The simplicity of the Bicon design and lack of Reps means that we can get 3 Bicon implants for 1 3i implant in the UK!

    On the negative side, the Bicon ‘technique’ is a little quirky. Immediate stability is sometimes poor (due to the push-fit design) and seating anterior crowns and keeping them seated can be a challenge if the occlusion is difficult.

  74. COMMENT: Googled this: “bicon abutment removal”
    NIZNICK RESPONSE: Any abutment that can be tapped off or twisted off can come loose under a bridge in function. You can not tap or twist off a screw retained abutment.

    COMMENT: On the negative side, the Bicon ‘technique’ is a little quirky. Immediate stability is sometimes poor (due to the push-fit design) and seating anterior crowns and keeping them seated can be a challenge if the occlusion is difficult.

    NIZNICK RESPONSE; These are a lot of negatives to have to accept just because you have some anecdotal experience that seems to indicate less bone loss compared to some other system

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