All-On-4 Implants System: Longevity and Durability?

Dr. S. asks:
There have been numerous advertisements promoting treatment plans based on the all-on-4 implant systems. When I first started restoring implants, the strategy was for the implants to be placed perpendicular to the plane of occlusion. This was supposed to result in more favorable transmission of forces to the implant and surrounding bone. This was also supposed to transmit the occlusal and lateral forces to the implant restorative system so that there would be less unfavorable force on the abutment and abutment screw and was supposed to result in decreased incidence of abutment or screw fracture or abutment screw loosening. With the all-on-4 design, the terminal abutments are tilted at a 30 degree angle from mesial to distal, thus extending the length of the metal framework that can be supported. So have the laws of physics change or do we just know more about implant restorations now. I have seen a ton of articles in the peer reviewed literature supporting the use of all-on-4 design. But what do you experienced practitioners who have used the system say about its longevity and durability?

43 thoughts on “All-On-4 Implants System: Longevity and Durability?

  1. Over the past 2yrs I have done around 10cases using the All-on-4 system. In my opinion the system works very well. It has both advantages and disadvantages. Main advantage is missing the sinus or mental nerve but a disadvantage is the angled abutments which although help with the easiness of fit are very expensive. I feel more confident doing an all-on-6 as opposed to four. Bone loss levels are minimal irrespective of the angulations. I think screw loosening occurs more often using the multi-unit angled abutments because the screw is a short one as opposed to the large screw down the centre of the implant itself. On the whole very happy with results, will keep on using all-on-6 design, 4not so much unless the patient has opposing complete dentures or is a small frail patient.

  2. Using co-axis implants (Southern implants) you don’t need expensive multi- unit abutments, just the regular. I have referring dentists who even use locator abutments for an overdenture on 4 coaxis implants in the maxilla… seems to work well. This is the cheapest overdenture I can imagine.

  3. The laws of physics have not changed. The restorations on implants should be much like natural teeth. Look very closely who funded the articles and the author. Call the authors and speak with with them personally.

  4. I have performed 238 “all on 4″ procedures to date. this is all within the last 3.5 years (spring 2006). I was at first extremely skeptical of the procedure, before I listened and learned about the science. The procedure has well documented success over 10 years. Bo Rangert, a PHD in Mechanical Engineering, helped develop the technique. Dr. Bo Rangert also wrote the book on why implants fail. “Risk Factors in Implant Dentistry: Simplified Clinical Analysis for Predictable Treatment, Second Edition”

    Author(s)/Editor(s): Renouard, Franck, DDS / Rangert, Bo , PhD)

    I trust his understanding of physics much more than some of the so called experts who base what they know on opinion rather than science. I have great success and offer this as a lower cost technique for those who desire immediate teeth (90% of the time I can immediately load these cases) without grafting and I have a much more esthetic result.

    For those who are critical of the technique they just have never looked into the science. One of my favorite quotes is from Albert Einstein.
    “It is what we think we know that stops us from knowing more”

    I am glad I finally looked into the science of the technique. Granted, their is a Paradigm sift that must occur. I am glad I stopped listening to the opinions of some speakers and I can know offer a great low cost treatment option to many of my patients.

    Personally, I am glad some of my neighbor colleages have not accepted this because it keeps my partner and I very busy. When they finally do, we will have more competition.

    I am grateful I can perform this procedure and highly recommend this to any dentists looking for a better way to treat their patients.

    Robert Schroering DMD

  5. With all due respect to the above clinicians, and no doubt vast experience; I would personally be very cautious in supporting a 14 unit bridge on 4 implants.

    None of the above authors have specified the type of fixed bridgework, but only mention a metal framework.

    If the framework used is to connect to the implants and reinforce a good lab processed plastic splint, I might be inclined to take a chance, with a very understanding patient….however, if the superstructure is built of precious metal castings and porcelain, I might shy away from this technique, because if any one of the 4 implants fail, the entire prosthesis is money down the drain for the patient, and potential legal problems for the dentist.

    What ever happened to hybrid solutions built on 4 implants… easier to sleep at night… for the dentist!!!

  6. My point exactly Dr. Rudick.
    All on four works, we know that. What happens if you lose one fixture – we all know this can happen despite perfect surgery and prosthetics.
    Here you have a useless prosthesis and a pt without many options for temporization.
    My quetsion to experts in all on four like dr schroering- what happens if you lose a fixture? how do you fix this? what works in your experience?

  7. Oh yee of little faith. Dr Schroering was right. You can always find reasons not to do an All on 4 but once you can find a reason to do one the avenues open to you to treat your patients better is incredible. I appreciate it is difficult to understand but belive me it works, it has (in my hands)a higher succes rate (even for immediate loading) than normal implant placement.

  8. I am newbie to all on 4 but been to alot of CE about it. I understand Nobel active implants are way to go for maxilla (Any Suggestions) or can I use up my stock of Replace tapered which are expiring as we chat. I am not getting alot of treatment acceptance with it (cost????recession???Obama? ME:)

  9. I will only do fixed on 6 and usually place 7 just in case one fails (99% success so far) but if finances limit, I do an open overdenture on 4, looks great (use top shelf teeth), functions well, pt’s love them, I sleep better, still a good $ maker for me. If one fails someday, can still use the denture on 3 while 4th is redone and denture can be easily relined to pick up redone 4th (haven’t needed to do this yet but the convenience of knowing I could is another reason for this restorative choice)

  10. Folks: You seem to be missing the point. All-on-4 is an entry level treatment designed to reduce costs for the patient. The original idea was to eliminate the need for any metal (PIB) framework and to connect the fixed bridge (denture) using metal temporary cylinders. This works well if you have a sufficient occlusal-gingival height prosthetically with a minimal cantilever length opposing a complete denture. If not, you will have prosthesis fracture which can cause damage to the terminal angulated abutments. The surgery is not a simplified version of the Branemark Classic technique but a modification of many years of observation. It works fine in experienced hands who understand all aspects (including lab). I have had to build PIBs in 2 cases where there was repeated prosthetic fracture. Remember to tell your patient that when the prosthesis is worn out, it is a total replacement if there is no PIB framework.

  11. I will try and answer a few questions since my last post. The “all on 4″ is not porcelain fused to metal with 14 teeth on 4 implants. It is a PIB framework with 4 to 6 implants and denture teeth to the first molars only. (a total of 12 teeth)
    One previous post stated.

    “What ever happened to hybrid solutions built on 4 implants… easier to sleep at night… for the dentist!!!”

    This is what an “all on 4″ or 4 plus one or two more implants, is all about.

    Not to be critical, but most people just do not understand the concept and they believe it cannot work. I understand this, because I had the same opinion before I went to a two day course to understand the principles. I have over a 99% success for 238 cases after the final prosthesis has been placed. I have only lost 3 implants after the final prosthesis. The patients did fine on 3 implants until I could replace the lost implant. I then luted this implant back into the PIB denture prosthesis, saving the patient from incurring anymore cost. Something you cannot do with porcelain fused to metal crown and bridge.

    I ask a similar question. What do you do with any full arch prosthesis when you lose the distal most implant. You replace the implant and redo the porcelain fused to metal. If it is a traditional “all on 4″ PIB with denture teeth attached, you do not need to replace the prosthesis, but lute this back into the framework.

    There is a reason the Clear Choice invested millions of dollars to establish 17 full service dental centers around major cities in the US. Believe me, it is not because the “all on 4″ does not work. It is because it does work and works very well.

    I know it is hard to change. Branemark is a great example. He stated the machined implant was the only surface to use. Until Nobel bought Sterios and the roughened surface implant became the only surface to use. It is amazing how quickly opinions can change.

    Dr. Rob Schroering

  12. Richard,

    Most any article in a reliable journal has been reviewed before being published for it’s authenticity and validity. Here are a few articles to answer your questions.

    Evolution of the concept of angulated abutments in implant dentistry: 14-year clinical data. Sethi, A, Kaus, T, Sochor, P, Axmann-Krcmar D, Chanavaz, M. Implant Dent. 2002;11(1):41-51.
    This study is with 3,101 implants with an average observation time of 10 years.

    Rosen and Gynther J Oral Maxillofac Surg. 2007
    This long-term follow-up study (mean time, 10 years) demonstrates that patients with a severely resorbed maxilla can be treated successfully …This simplified surgical technique can be an alternative to the more resource-demanding technique with bone grafting
    Each patient was examined clinically and radiographically. 97% implant success rate.

    I would suggest going to Nobel’s web site and click on research. There are over 90 articles about immediately loaded cases. They are not all Nobel articles, but other companies articles as well. 40 deal with full arch lower immediate load and 13 with full arch maxilla.

    There are too many articles to name. I think when you really look at the research you would understand the benefits of this system.

    Rob Schroering DMD

  13. I just need a bit of clarification. What is a PIB? Dr Schroering mentions that; “if it is a traditional “all on 4″PIB with denture teeth attached, you do not need to replace the prostesis ,but lute this back into the framework”. Noble Biocare has a Porcelain Implant Bridge called a PIB. It is a costly Zirconuim frame on which porcelain is fired in the lab.This zr frame is fabricated using the CAD-CAM technique.

  14. “All on 4″ means “None on 3″. If 100 implants supported 25 fixed restorations (4 per arch) a 80% implant survival could affect 20 out of 25 prosthesis, (if each failure was in a different arch). If 8 implants were used in each arch, a 87% implant survival would be enough for all arches to have a fixed prosthesis.

    Therefore, since “all on 4″ has higher risk than “all on 8″, the Doctor should charge twice the price for “all on 4″, to compensate for the complications and treatment required. In addition “all on 4″ often requires cantilevers and/or long options. Both situations increase prosthetics complications of screw loosening, fracture, etc. In short – use more implants and you will save the patient and your aggrevation and therefore you can charge the patient less money.

  15. Carl – I think that’s very well put. No bashing to those who successfully use the technique – I’m just not sold on it for every situation.

    I recently finished a case where the patient came for a second opinion from another practice with upper/lower all-on-4 same day treatment plan. We instead opted for a lower 6 implant design with immediate provisional and traditional ‘low water’ type fixed bridge. Upper was a hybrid design on 4 implants. Even with CBVT we still found an unexpected amount of fenestrations and defects on the upper which necessitated delayed placement and a conservative approach to loading. He has also had complications with one of the upper fixtures. The upper has finally been restored.

    The patient said it best when we were done: “Even though it took extra time, I’m glad we went this route. I can see now what you were saying – if just one of those implants came apart, i would have lost the whole top bridge and had to start over…” I think that was kinda your point too…

    thanks for all of the great articles and books.

    Ryan

  16. i love it when a leading clinician knocks the all on 4. that way there is less competition for me. since i’ve been very happy doing the procedure for the last two years .

  17. I support Brian Kucey’s point of view that this system works well only when anthologists are complete dentures, which cannot load unnaturally angulated implants too much.

  18. Wow, Carl Misch – are you suggesting that you only get an 80% implant survival rate i.e. a 20% failure rate of your implants. Otherwise why would you suggest this should be used as the failure rate?

    Carl – lies, damn lies and statistics eh.

    Just for your information, All-On-4 does NOT mean None-On-3, as I have posted on this site before. It is generally rather easy to dismiss an idea or technique before you’ve taken the effort to learn about it properly. It often becomes harder once you’ve realised it works.

    Bill Schaeffer

  19. Sorry Carl, I get it now.

    You want to justify charging for 8 implants per arch and that that is really good value for money for the patient – ahh, it all makes sense.

    What was it someone once said? “Just follow the money!”

  20. Richard Hughes DDS, FAAID, FAAIP, Dipl.ABO/ID,

    Why is what Carl Misch said excellent and well-stated?

    His statistical proposition is utter nonsense. It is a ridiculous suggestion. Why would any knowledgeable clinician, (regardless of what they thought of All-On-4), say that nonsensical statistics is excellent and well-stated?

    Bill Schaeffer, BDS, MBBS, FDS RCS Eng, MRCS Eng, and cub-scout badge for keeping my bedroom tidy

  21. Bill – Your comment is well stated. If there is, in fact, a 20% failure rate in this modality, then it would call the whole paradigm into question. But nowhere in the literature have I seen anything approaching this figure for all-on-four. We can make the same statement for posterior terminal abutments on implant bridges. If you lose those implants, you lose the fixed segment in that quadrant. If you were to lose an implant in all-on-four, an overdenture can be fabricated. An additional implant can be placed again if desired. This is not an all-or-nothing phenomenon.
    One last thing…only Eagle scout credentials can be posted on this site!
    RJM

  22. Wow, alot of anger towards anyone who disagrees with a new method. Makes one question if the method is all that good in the first place, especially since there are limitations to All on 4, as even some big users seem to admit to.

    Anyway, can someone address Dr. Misch’s other point, which all the ardent supporters, have all conveniently ignored:
    “In addition “all on 4″ often requires cantilevers and/or long options. Both situations increase prosthetics complications of screw loosening, fracture, etc.”

  23. Hey Robert, it’s been a while – Florence last year if I recall correctly.

    You’re quite right about All-On-4 not being none-on-3 but it’s even better than you suggest.

    If one of the two middle implants fails to integrate, you keep the temporary bridge exactly as it is, except supported by 3 integrated implants, and you merely replace the middle implant.

    If one of the two distal implants fails to integrate, you reduce the length of the temporary bridge on that side, (just cut through the acrylic), and replace distal implant.

    At no time does the patient have to wear a denture again.

    For anyone who’s itching to post that “no bridge should only be supported by 3 implants!” – just remember that these are now 3 fully-integrated implants. When the temporary bridge goes in at the beginning of treatment (i.e. when the 4 implants are initially placed) it’s not sitting on any fully-integrated implants. And yes, they are told to go easy on it!

    As for Carl’s nonsensical-statistics, he knows better than that! He’s a whole order of magnitude out!

    Kindest Regards,

    Bill

  24. Calif – no anger towards anyone who disagrees and I’m sorry if that’s how it’s come across. I merely get frustrated when people who should know better, make silly statements as if fact – frankly, I was rather bemused by Carl’s suggestion of a 20% failure rate for implants (those pesky decimal points really are a nuisance!)

    As for;

    “In addition “all on 4″ often requires cantilevers and/or long options. Both situations increase prosthetics complications of screw loosening, fracture, etc.”

    Absolutely, you utilise cantilevers. In my practice, we use a milled titanium beam for the bridge. VERY rigid and light and the fit is immaculate. Does anyone have a concern about cantilevering back a unit off something as strong and rigid as this?

    I’m not sure what a “long option” is. I guess he means a long-span bridge. The most common bridges my patients choose for All-On-4 cases are milled-titanium beam with an acrylic wrap (acrylic teeth and gum). Easy to repair if chipped.

    If a patient chooses to have porcelain then the “gum” is made of composite and the titanium beam is milled with individual “cores” for each teeth. It’s expensive (though way less than 8 implants!) to make but if a “tooth” gets chipped you just replace the one tooth.

    Screw-loosening is simply something I rarely ever see. I guess that’s because of the fit and rigidness of the underlying titanium beam, or maybe it’s because I have half as many screws to loosen ;-)

    Is All-On-4 that you immediately load always possible? No. In just the same way that any technique is not always possible (even getting 8 implants into a jaw).

    Is All-On-4 the only option for a full-arch? Of course not. I’ve restored full-arches with 8 implants (four 3-unit bridges), and with 6 implants (both as a single full-arch bridge and in smaller units) and the usual way I restore them now is with an all-On-4 that I load with a temporary bridge the following day.

    Once again, when people tell me that All-On-4 doesn’t work it is frustrating because I use this technique regularly and I KNOW it works.

  25. Dear Richard,

    I have previously stated that I used to do things exactly the way you do them – with 6 or 8 implants per arch. Now I usually place just 4.

    I’ve done it your way and it works. I’ve done it on 4 and it works.

    I am not suggesting that you shouldn’t place 6, 8, 10 or 12 implants per arch. I am merely stating (from the perspective both of my own experience and that of published research) that you can also do it on 4.

    I’ve done it both ways – they both work. To say it doesn’t or won’t is incorrect. I remember people saying the same things about one-stage implants, immediate loading of implants and short implants and look how that turned out.

    As you so eloquently put it – Richard, it’s your practice and your patients. You will figure it out with time!

    Have a great day.

    Bill Schaeffer

  26. I can’t but anticipate that the pure Ti implants used in the all on 4 technique will suffer from metal fatigue and fail after cycling enough.

  27. Dear colleagues, those of you who haven´t done yet an all-on four procedure should try it before questioning it.
    We have done more than 60 cases in the last 3 years, many of them with a computer guided minimally invasive procedure, with 3 implants failed before loading. They were replaced before the placement of the final restoration. No implant failures post loading!
    Remember the final restration is metal-resin. The resin acts as a shock absorber.
    This treatment we offer to those patients with a severe maxillary and/or mandibular atrophy. Therefore almost no alveolar bone.
    Choose the correct restoration for each case!

    A. Coppel, DDS, Madrid-Spain

  28. It has to be understood that the All on Four procedure was developed, according to Nobel for “Financially challenged patients.” Which means patient who can’t afford a full mouth restoration or bone grafting procedures. It is not meant to be a replacement for traditional implant therapy which many times involves bone grafting, and many more implants, and expensive high end restoration. All on Four is a procedure that increases the function for many patients who can’t afford a full mouth reconstruction. I think it has to be noted as well that Dr Misch is in fact a paid consultant/speaker for a competing implant company to Nobel Biocare. Therefore his comments which were not based on any known clinical data or studies should be looked upon as somewhat biased.

  29. ” It is not meant to be a replacement for traditional implant therapy which many times involves bone grafting, and many more implants, and expensive high end restoration. ”

    RMEE – I absolutely use it as a replacement for “traditional” implant therapy.

    It is NOT an issue about money. I used to do the whole graft, place, wait protocol for my full-arches, using 6 or 8 implants per arch.
    Now I just use 4 – even if they’ve got “buckets of bone” and “money’s no problem” – and load them immediately.

    All-On-4 works.

    I have no financial interest in ANY implant system or product other than that I place a lot of them.

    Kind Regards,

    Bill Schaeffer

    p.s. as for Dr Misch’s comment on this thread, the best I can say about that is that he must have been having a bad day!

  30. I think it’s amazing that grown men who are so well respected in their fields would say some of the things they say in this thread.

    I am amazed that anyone would even accuse their colleagues of trying to use only one method for all patients.

    NO ONE SINGLE METHOD IS RIGHT FOR ALL PATIENTS. No one even tries to make it that way.

    The All-On-4 method works for so many people because of the ability to maximize A/P spread with minimal implants. Thousands of patients have been helped by this procedure, many of whom were told implants weren’t an option.

    As Dr. Schroering alluded, I have seen some of the greatest skeptics of this method change their minds in two days. I have yet to see anyone walk away and say “just what I thought! It’s a load of crap!”

    PIB is PROCERA IMPLANT BRIDGE or, more simply, a titanium substructure custom designed based on the position of the implants placed during a All-On-4(5-6) procedure. It is done typically 4-6 months after surgery and after integration has been achieved. It allows for the implants to be splinted together, the 5-10 year studies have success rates at 99-100%. Even if a single implant is lost due to whatever circumstance, the “bridge” prevails and can still be used for a long period of time with no major effect on the already integrated implants.

    THE PIB IS NOT CONSTRUCTED UNTIL AFTER IMPLANT INTEGRATION. All-On-4 protocol demands a minimum of 40 mm of implant at primary stability for a case is even provisionalized.

    The temporary bridge is constructed from an immediate denture and consists of only acrylic and temporary titanium copings. There is no more than one tooth cantilever on a provisional. You would never have an implant in, say, #12, and then cantilevered to #15. It doesn’t (shouldn’t) happen. It is during this period (the first 4-6 months) that you may “lute” a new implant back in to the existing prosthesis. You do not do typically ever do this with the final PIB.

    Implant failures during the provisional period are caused by the same things that cause implant failures with other methods. Smoking is a major contributor.

  31. I have completed 4 “all on four” cases with absolutely no problems. My patients love the treatment. My first case restored both the upper and lower archs. The first case was completed three years ago. I have restored all of these cases using no abutments. The titanium framework fits directly to the fixture head. Obviously this must be done very carefully and the fit must be perfect. Again to date no issues of any kind. This is an amazing treatment that patients love

  32. An inherent problem with all-on-4 is that it represents the minimal mechanical solution for the edentulous arch. For example, a bruxer with natural opposing dentition may have a hard time not breaking teeth or implants, or experience accelerated bone loss on the distally angled implants. The entire prosthesis is being retained by 4 screws, which will certainly experience fatigue and distortion over time. A relatively large amount of prosthetic space is required to fit the teeth, the pink, and the frame between the edentulous arch and the opposing dentition. Patients with symptomatic mandibular flexure will not know that this option doesn’t work until it is attempted. Denture teeth will not adequately resist wear beyond a decade, then it is remaking the entire prosthesis again.

    My greatest reluctance to put my name behind the all-on-4 concept is that in patients with minimal bone loss or who are losing their teeth, it may require an unacceptable removal of bone in order to create the necessary prosthetic space for the prosthesis. Thus, we would be making our patients fit our prosthetic solution. Also, mechanically and statistically (regarding potential failures in key locations), if a hybrid type of prosthesis is chosen, it is better for everyone to put just one more fixture in, making it an all-on-5.

    Finally, Nobel has pulled the wool over our eyes in the past by rushing products to market, to the chagrin of Dr. Branemark, including the earliest version of the all-on-4. I believe this is what Dr. Misch was referring to regarding the 20% failure rate, when Nobel used to advocate placing the final all-on-4 prosthesis at the time of surgery, using a crazy adjustable abutment that only led to an unacceptably high failure rate. They scrapped that for making the final prosthesis only after osseointegration could be verified.

    In regards to saving patients money, we provide an all-on-5 type of solution for approximately $17,000 including iv sedation, all temps and final restorations and minor grafting. We charge only $25,000 per arch for 8 or more implants, porcelain crowns, and a vacuum cast noble framework that has no pink, but retains the benefits of a single frame and individual teeth (we are the only ones in the country offering this). The local Clearchoice gives quotes ranging from $25,000-$35,000 per arch for the all-on-4 depending on their current demand.

    In summary, while all-on-4 can work for many patients, it is rarely the optimal solution for prosthetic longevity, clinician’s and patient’s ease of repair, and never optimal for patients who are gummy or who would otherwise need a significant alveoloplasty in order to have the all-on-4 prosthesis.

    King Regards,

    Joseph Kim, DDS

  33. Regarding milled titanium frames, there is still a guaranteed imperfect fit of the frame to the implant platform for the following reasons:
    1) The milling bur’s diameter dictates the minimal resolution of the tool marks which is usually on the order of 20-100 microns of tooling error due to ditching, grooves, and other milling artifacts.
    2) The scanning resolution has only in 2009 been brough down in the order of 20 microns.
    3) Most clinicians do not take a perfectly passive impression, i.e. by splinting connectionless transfer mounts together with a rigid medium, sectioning to release any latent stresses, and reluting.
    4) Die stone expansion adds to the distortion of the interimplant distance, which is only made more critical with fewer abutments.
    5) All titanium frames are hand polished, including the area that seats against the implant platform, creating a microscopic imperfection ranging from tens of microns to hundreds of microns, depending on the skill and experience of the particular technician who is polishing it.

    This only adds to my support for a final prosthesis that engages more than 4 abutments to minimize flexure and screw loosening. Remember, that the inter implant distance will cause an increase in flexure by a factor of 8, in any material you use. When the frame is not 100% passive (and it never will be unless you cement them), and is not 100% contacting the implant platforms, screw loosening will definitely become a problem down the road, depending on how much biting force the patient has, and what the prosthesis is opposing. Some clinicians use cyanoacrylate to cement their screws in, sort of like Lok-Tite, in order to minimize the screw loosening problem.

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