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All-on-Four Dental Implant Procedure -Ramsey Amin DDS Explains Pros and Cons

All-on-four is a dental implant technique specific to people missing all of their teeth and who want to avoid dentures.  Many patients that see me in Burbank ask me about “All on Four.”  Sometimes they call it “All Over Four.”  The all-on-four implant procedure has few advantages, but several disadvantages.

All-on-(or over) four is intended to replace all of your teeth on one arch with only four implants.  [It was popularized by an implant company, Nobel Biocare, that I once taught local Burbank courses for.]

That means that twelve to fourteen teeth are supported by only four implants.  The dental implants in the back of the mouth are purposely placed at a tilted angle to get implants farther towards the back.

Personally, I have surgically placed and made teeth for thousands of dental implants including the all-on-four type.

The biggest advantage, hands down is cost.  The price to do all-on-four is much less than traditional implants that are placed straight up and down in your jaw (not tilted).  Typically the MINIMUM number for FIXED dental implants in the lower jaw is five and the upper jaw is six.  These would be minimum numbers and would apply if your jaw is small, v-shaped, and you only want a few back teeth.  Additionally, some types of bone grafts can be avoided if you have all-on-four dental implants.

Bone grafting can be avoided by purposely tilting the implants away from the sinus (avoid sinus bone grafts) and away from the lower back area where there is a nerve.

Here are two cases I did about 7 years ago:

The biggest disadvantage to the all-on-four dental implant bridge is that it is UNDER-ENGINEERED.  Our natural teeth were created with multiple roots per tooth.  This gives a lot of support for our strong bites. This procedure only gives you four roots!

If you were building your house right now, would you only use four beams to hold up the entire house?

I doubt it!  You would want the foundation to be strong!  What if one of the beams was attacked by termites (gum disease) and you had to remove it?  If you only had four implants you would lose the whole bridge and have to redo it from scratch. If one of the angulated implants is the one that fails, it is going to destroy a lot of bone when I have to remove it. It will hold in the short term, but in a few years, it may have problems, and there are few qualified dental implant specialists in Burbank who can remedy the situation.

The other problem with most all-on-four fixed dental implant bridges is the fact that most dentists give you a bridge with plastic denture teeth as a final bridge!  It is really just a fixed denture made of plastic with teeth that commonly break off, stain, and need to be replaced every few years.  This will cost more in the long term. The rear implants can be in a bad position making your palate feel like it has a big lump on both sides.

My suggestion is that fixed dental implant bridges are made of porcelain.  Please read this post to learn why this is important.  When I do all-on-four, I make porcelain bridges instead, which are much less problematic than hybrid denture types.

All-on-four in my opinion should be used 1-3% of the time and is probably more of a marketing fad than solid, predictable treatment plans that involve a few more implants.  I am not opposed to tilted implants.  I am only opposed to using an absolute minimum number of implants. It is like jumping out of an airplane without a backup parachute.

If you are in need of full mouth dental implants, consider this a last resort.  Although, cost is important, keep in mind you are pricing out body parts.

Ramsey A. Amin, D.D.S.
Diplomate of the American Board of Oral Implantology/Implant Dentistry
Fellow-American Academy of Implant Dentistry
Burbank, CA

18 thoughts on “All-on-Four Dental Implant Procedure -Ramsey Amin DDS Explains Pros and Cons

  1. I’m glad you pointed out that it’s much cheaper to do an all-on-four full mouth implant than traditional, non-tiled implants. My mother-in-law has lost most of teeth and needs some sort of dental implant, but unfortunately her financial situation is not ideal. I’ll definitely talk with her about considering all-on-four arch implants.

  2. Hi ! I have a falling bridge on my upper jaw. Under I have 7 teeth from which only 2 are without root canals. I was recommended to remove bridge ( which is already in bad shape) and do all in four . Do you think this procedure will be good for me if is only on my upper jaw. Hoe my bite will be after as I plan to leave all my teeth on the lower jaw. My bridge will be made of Nano ceramic mix with some polymers . Is that a strong bridge?Please let me know what you think . Thank you so much for your answer.

    1. Nano ceramic is a fancy word for high density plastic. I would not suggest this as a final bridge. It will break!! It is mostly intended to use as a long-term temporary.

      The procedure is great and your bite can be made perfectly but I am very concerned about the material that is being suggested to you as a permanent solution.

      Nothing is truly permanent but other materials such as prettau zirconia are much more durable

      1. Hello, Dr. Amin.
        First, thank you for all your efforts in sharing your brilliance with the world via this site. I’m sure I’m merely one of thousands upon thousands you’ve provided much needed information and support to via your talents and efforts here. You are truly Heaven-sent.
        Ok, back down here on earth: below is the major issue I need some objective brilliance on:😬 I’m trying to decide, for needed full mouth restoration, do I go with OPTION 1 or 2 below, or other (what am I missing)?
        Please, if you have any time to provide your thoughts, or, if more appropriate, do a paid phone or web consult, I’d be so grateful for your input at this critical juncture. (Unfortunately, do to chronic illness/Stage IV Endometriosis, I’m not in a great position right now to fly to you repeatedly from DFW for this work….Otw, there’d be nothing stopping me from asking you to be my savior here directly!):

        OPTION 1. A highly- customized All-on-5-6 Plan with Xirconia Ultra, Prettau-looking type bridge (yeah, right?). – [Diplomat of Implantology/Prosthedondist/etc. says will add as many as can safely fit, will try/plans to (for upper arch first) extract & load 4-5 implants with fab temp bridge, same day if possible and safe (working an existing implant into the plan). He is very hands-on all phases, assumes many apts and months working w he and his lab in order to get teeth perfect for finals, has all the high-tech machines and processes you’ve recommended, guarantees all for 10 years, handles all maintenaces and fixes, has amazing tour-worthy high-tech lab w 8 full time techs & artists on site, etc]. Once healed sufficiently, repeat same day for mandible, adding 3, possibly 4 implants to the extsing 2 implants.

        OR / Vs.

        OPTION 2. Traditional, old school, conservative, snail approach: doing sinus lifts, extensive grafts, etc. and the many months (now years) of waiting in-between; trying to use existing teeth for temp bridges or eg flippers while healing; and dealing w the many side effects and other tortuous ssues we’ve discovered can happen with this old school approach! 🙇‍♀️ Note: done by different Diplomat of Implantology, etc. and he is very skilled as well (I love him, brilliant surgeon, very compassionate & patient, etc), but he’s a very busy and active general dentist, has no on-site lab, off site lab does terribly work thus far, office hasnt yet switched to many of the high-tech processes/machines/etc. you’ve recommended, he’s close to retirement and deservedly only workd 4 days a week, office closes early another day, and there is also much deserved vacay time that happens.

        A bit of key background: I have a VERY small mouth…literally kitten teeth in a child-size mouth. I need full mouth restoration via implants. 50 years of restorations, on literally every single tooth, and my unintended attempt at the Guinness World Record for most dental office visits starting as a child- has brought me to the inevitable point in the road; where I have insufficient surface area to continue to eg, swap out crowns etc. as I go through life further.

        Plus, i just cant take it anymore! Also, i have a hypersensitive immune system and have Stage IV, invasive endometriosis that’s created alot of chronic damage- from my intestines, to my spine…and somehow even an artery is now pressed up against my trigeminal nerve (MRI/MRa visible and confirmed, right side) that causes trigmeinal neuralgia. (Yeah, me!) So, i need to get out of these kitten landmines ASAP!

        I started on the slow and steady path with my current dentist about 2.5 years ago. The idea was to do one jaw at a time, each jaw split into 3 sections and restored accordingly, as would also help later upon opening and closing of lower jaw. We started with 3 implants placed simultaneously in anterior mandible about 4-6 months after exctractions.

        Unfortunately, some bad germs in hidden scar tissue from an aggresive childhood frenum muscle got angry from the surgery and the middle implant eventually failed casuing Osteomyeltis and a bit of Actinomycosis (signaled by a waxing and waning swelling directly under middle of my chin that ultimately created a fun supporative fistula!). Had successful surgery and abx treatment in 2017, middle implant was removed, no bone cavitations or unwanted new bone growth needed to be fixed or scraped away (i got lucky), bone has since grown back nicely in the hole (per July 2018 scan w oral surgeon), and the adjecent, anterior mandible implant, either side, so far remain infection-free and stable. Cleared by infectious disaese doc in Feb 2018.

        Had a right side upper jaw sinus lift, extensive graft and implant placed in #4 in June 2018. Surgery was successful so far, but the previously, nice flush gum margins on crowned #5 and #6 got destroyed in the process (crazy, u wouldnt believe my bad luck!). In addition, with all the wait time between procedures due these types of issues and also eg many scheduling hurldes (smart & lovely but very busy dentist), bad things happen; teeth shift after extractions, bine grafts dissappear and gums recede messing up margins on crowns flushed against adjacent gums, small cavities can form in those crown gaps,infections can be caused by the gaps, by the many procedures involved in this appraoch etc.

        Please let me know any thoughts, or any additional info you would like and need in order to even say “hello” back! As youve may gleened from my tone, im heavily leaning towards the more timely option. Even with its inherent risks, it seems somehow less risky than all the problems ive enciuntered thus far by going the slow, old-school route. I believe Ive found the best doctor, practice, approach and customized plan available in the DFW area, but thats nit really worth much in the end as im just a layperson rying to figure the basics out!

        Thanks so much for your time and consideration here (even in just reading my Manifesto above (i had to dictate it over a day, sorry so choppy and long)!
        – LA Phipps

      2. Dr. Amin,

        Apologies for any confusion: I sent below question earlier but forgot to add some key info that may actually change anyone’s answer to this issue (it did mine, anyway) – Completely understand if this is just too much info to read, btw – never mind to provide off the cuff thoughts on…especially during these awesome summer days! – thanks either way..for all you do!
        ******

        ADDITIONAL KEY FACTS:
        As noted below in the ORIGINAL QUESTION, the initial plan with my usual dentist (who is brilliant, compasionate, patient, completely trustworthy, etc) was to take a highly-conservative, phased, sectional approach to the implants and the restorations, which would have resulted in me ultimately having 3 (likely Xircon(sp.?)) separate bridges, supported by implants w custom abuttments and comprising the arch in each jaw.
        However, my dentist has recently concluded my lower jaw has insufficient bone and he believes (and we know-nothing laypeople here at my house concur) that an angled implant on each side plus anterior implants may now be best bet for my lower jaw bc the alternatives to rebuild the bone are likely too risky and involved..eg bone from hip, etc…probably too unpredictable, too risky and not best idea for given my chronic illness and resulting anatomical damage. ( Not sure if hes planning or can even add any implants to the lower canines. Mouth is just way too small and no idea if enough bone that area. The 2 crrently-remaining and viable anterior implants sit either side of the symphasis or whatever middle lower jaw is called.)
        That means, of course, cant do sections for the lower jaw restoration; will need full arch restoration mandible (hope the existing ones r screws, right?!).
        So, in my head, for symmetry purposes, occclusion, etc…it seems I would want thus 1 piece not 3 sections also on top jaw; aka the same as I had on bottom…though I am basing that on laypersons gut, not science or knowledge of course!
        In any event, our current dentist is anti anti anti All-on-4. Hes never even let the reps in his door! He has fixed too many disasters he says, and just cant get there in his head bc he finds the risks so prevalent/ominous/unpredictable/etc.
        However, my thinking is…Im basically going to be getting the same implant effect with him then in OPTION 2 as my highly customized, very highend All on 4-6 OPTION 1(below)…Except, actually, the customized All on 4-6 OPTION 1 i’d be getting may actually be better in the end bc I can only get the much much kighter, stronger, prettier Zircon ultra via the new OPTION 1 Dentist+ OPTION 1 new dentist has the awesome, state of the art in house lab + he is much more hands on with the prosthetics + he is much more focused on adjustments etc to tempories to perfect the finals, has the digital models, other fun processes etc throughout, + he gives ten year guarantee.
        Current dentist= I love him and his staff but…when middle implant failed last year…we had some 8-10k in out of pocket costs even after medical insurance paid for mostly everything. Not to mention, price to completion OPTIONT 1 = 38k all in, no matter what new dentist needs to do, graft if he has to, fix or add, etc. OPTION 2…spent 40K alone with this dentist past four years alone and I have a construction zone for a mouth so far, have already had failed implant, teeth have shufted, gaos have formed, infections have happened, etc. None if this has been anyones fault of course…its just a run of bad luck in circumstances I feel are probably ripe for such..and thats just how it worked out.
        So, Im just worried im wrong/wondering eg what am I missing in trying to get my arms around the meaningful differences between the two options, their risks and benefits, as under my facts?
        Eg: My mouth, jaw etc are so small, current dentist noted that he wouldnt be able to fit probably more than 6 implants total in each jaw = same as OPTION 1. Also, both dentists are similarly uber-qualified & experienced. And, when we add the other noted benefits from OPTION 1 new dentist and his practice, im just not seeing more risk, better results, etc w OPTION 2. Also, ive been on a soft diet for two years, ever since current dentist removed back molar each side to ready for implant and occlusion was thus changed (they were pretty much all metal w slip of porceline covers). Hence, im very good at literally zero chewing, etc and can easily do for many months after Option 1 front loading of temps. Plus, now that 5 & 6 gums have been altered from recent #4 big surgery, they cant be replaced snd fixed bc not enough tooth structure would be left upon removing crowns i understand. Point is, im running out of time for being able to wait the slow path of OPTION 2 while being able to avoid the need for an actual temp denture upper jaw. I can deal w the vanity issue for a few months (Husband is amazing Saint, cant believe he comes back home after work each day and doesnt just keep on driving!). However, im certain my very sensitive, lifelong dry, trigeminal neuralgia, teeny little mouth and face will not handle a big peoples full palate denture for any length of time…And infections, attacks, etc. will abound!
        Ok, Will stop. So sorry. Thanks again..even for just making it to this point!

        – LA Phipps
        *****

        ORIGINAL QUESTION SENT 8/18/18
        Hello, Dr. Amin.
        First, thank you for all your efforts in sharing your brilliance with the world via this site. I’m sure I’m merely one of thousands upon thousands you’ve provided much needed information and support to via your talents and efforts here. You are truly Heaven-sent.
        Ok, back down here on earth: below is the major issue I need some objective brilliance on:😬 I’m trying to decide, for needed full mouth restoration, do I go with OPTION 1 or 2 below, or other (what am I missing)?
        Please, if you have any time to provide your thoughts, or, if more appropriate, do a paid phone or web consult, I’d be so grateful for your input at this critical juncture. (Unfortunately, do to chronic illness/Stage IV Endometriosis, I’m not in a great position right now to fly to you repeatedly from DFW for this work….Otw, there’d be nothing stopping me from asking you to be my savior here directly!):

        OPTION 1. A highly- customized All-on-5-6 Plan with Xirconia Ultra, Prettau-looking type bridge (yeah, right?). – [Diplomat of Implantology/Prosthedondist/etc. says will add as many as can safely fit, will try/plans to (for upper arch first) extract & load 4-5 implants with fab temp bridge, same day if possible and safe (working an existing implant into the plan). He is very hands-on all phases, assumes many apts and months working w he and his lab in order to get teeth perfect for finals, has all the high-tech machines and processes you’ve recommended, guarantees all for 10 years, handles all maintenaces and fixes, has amazing tour-worthy high-tech lab w 8 full time techs & artists on site, etc]. Once healed sufficiently, repeat same day for mandible, adding 3, possibly 4 implants to the extsing 2 implants.

        OR / Vs.

        OPTION 2. Traditional, old school, conservative, snail approach: doing sinus lifts, extensive grafts, etc. and the many months (now years) of waiting in-between; trying to use existing teeth for temp bridges or eg flippers while healing; and dealing w the many side effects and other tortuous ssues we’ve discovered can happen with this old school approach! 🙇‍♀️ Note: done by different Diplomat of Implantology, etc. and he is very skilled as well (I love him, brilliant surgeon, very compassionate & patient, etc), but he’s a very busy and active general dentist, has no on-site lab, off site lab does terribly work thus far, office hasnt yet switched to many of the high-tech processes/machines/etc. you’ve recommended, he’s close to retirement and deservedly only workd 4 days a week, office closes early another day, and there is also much deserved vacay time that happens.

        A bit of key background: I have a VERY small mouth…literally kitten teeth in a child-size mouth. I need full mouth restoration via implants. 50 years of restorations, on literally every single tooth, and my unintended attempt at the Guinness World Record for most dental office visits starting as a child- has brought me to the inevitable point in the road; where I have insufficient surface area to continue to eg, swap out crowns etc. as I go through life further.
        Plus, i just cant take it anymore! Also, i have a hypersensitive immune system and have Stage IV, invasive endometriosis that’s created alot of chronic damage- from my intestines, to my spine…and somehow even an artery is now pressed up against my trigeminal nerve (MRI/MRa visible and confirmed, right side) that causes trigmeinal neuralgia. (Yeah, me!) So, i need to get out of these kitten landmines ASAP!
        I started on the slow and steady path with my current dentist about 2.5 years ago. The idea was to do one jaw at a time, each jaw split into 3 sections and restored accordingly, as would also help later upon opening and closing of lower jaw. We started with 3 implants placed simultaneously in anterior mandible about 4-6 months after exctractions.
        Unfortunately, some bad germs in hidden scar tissue from an aggresive childhood frenum muscle got angry from the surgery and the middle implant eventually failed casuing Osteomyeltis and a bit of Actinomycosis (signaled by a waxing and waning swelling directly under middle of my chin that ultimately created a fun supporative fistula!). Had successful surgery and abx treatment in 2017, middle implant was removed, no bone cavitations or unwanted new bone growth needed to be fixed or scraped away (i got lucky), bone has since grown back nicely in the hole (per July 2018 scan w oral surgeon), and the adjecent, anterior mandible implant, either side, so far remain infection-free and stable. Cleared by infectious disaese doc in Feb 2018.
        Had a right side upper jaw sinus lift, extensive graft and implant placed in #4 in June 2018. Surgery was successful so far, but the previously, nice flush gum margins on crowned #5 and #6 got destroyed in the process (crazy, u wouldnt believe my bad luck!). In addition, with all the wait time between procedures due these types of issues and also eg many scheduling hurldes (smart & lovely but very busy dentist), bad things happen; teeth shift after extractions, bine grafts dissappear and gums recede messing up margins on crowns flushed against adjacent gums, small cavities can form in those crown gaps,infections can be caused by the gaps, by the many procedures involved in this appraoch etc.

        Please let me know any thoughts, or any additional info you would like and need in order to even say “hello” back! As youve may gleened from my tone, im heavily leaning towards the more timely option. Even with its inherent risks, it seems somehow less risky than all the problems ive enciuntered thus far by going the slow, old-school route. I believe Ive found the best doctor, practice, approach and customized plan available in the DFW area, but thats nit really worth much in the end as im just a layperson rying to figure the basics out!

        Thanks so much for your time and consideration here (even in just reading my Manifesto above (i had to dictate it over a day, sorry so choppy and long)!

        1. FUNNY LINE!!!!!!!!! Husband is amazing Saint, cant believe he comes back home after work each day and doesnt just keep on driving!)

          If you have a dry mouth and you are decay prone it sounds like you have already decided on what to do! I hope all this works out for you. Please use more than four implants on the top jaw!

      3. Hi Dr Amin, i sent a corrected email earlier and noticed one more big correction I should make as could affect one’s assessment: The Diplomat of Implantology that would be perfoming my All-on-5/5/6+ (however many he can safely and appropriately fit, with whatever minimal grafting if any is abs necc) using the high-tech bionic robot machines, scans and amazing in-house lab provides a LIFETIME GUARANTEE, using Zircon Ultra in a beautiful, stronger then zircon, yet amazingly lightweight (which my small jaw and trigeminal neuragia would greatly appreciate) Prettau type Bridge for the full arch.
        I had said Ten year guarantee in my earlier emails and that could casue ome to scratch head esp as other top probiders back with Lifetime coverage and support.

        Thanks again and apologies for the neuroticism. I am hoping these emails go into a business box somewhere and you check eg many at once at your leisure vs Ive inadvertently become a stalker here! Ughh! So embaressing!

        1. LIFETIME GUARANTEE —no such thing. BEWARE!! 30% of what I do are redos! Unless you are 70 years old I think this is deceptive marketing. Dental implants and the teeth they are connected to can and do have some problems. WHO is offering this? I will NOT post the names….your reply will not be public

  3. Please can you help me. My teeth is keeping me from living the life I need to. My teeth are in such a state that I cannot function any longer. I am not able to afford all on four procedure. Please help me,

    1. If finances are a barrier you should consider some well Made dentures. This will give you the dignity you deserve and you can do implants later.

  4. Dr

    I have only 7 teeth left on the upper jaw. i have had bad teeth my entire life. i have been referred by many dentist to get a fixed bridge or the all on 4 or 6. I can not afford the procedure. I have 2 children and a wife. is there any way to volunteer for this procedure? as in being a teaching patient for other dentists?

    1. Hello Anthony,
      I feel for your situation. You may have good luck at a local dental school. There may be studies that you could take part in.

      You also want to consider long-term maintenance procedures. You will need to be able to afford general maintenance, x-rays on a routine basis to maintain your dental implants. Cleanings on a regular basis are going to be important.

      If the all on 4 procedure that you will be receiving will have acrylic fused to metal teeth, you need to expect this type of bridge to break frequently. This will necessitate repair costs.

      I much prefer the Prettau solid zirconia full arch dental implant bridge because it has a much lower chance of having long-term problems.
      Prettau Dental Implant Full Mouth Bridge

      Be sure to consider the long-term.

      Very respectfully,

      Ramsey A. Amin, D.D.S.

  5. i have gum problem, my doctor told me to do all on 4. with acrylic permanent bridge? i still have 8 teeth. on upper jaw. can i send you CT,and hopefully have different option. thank you

    1. Hi Riri,

      I would really need to see you to help you make those kind of decisions. X-rays alone are only a part of the diagnosis and treatment plan. You can’t use X-rays alone to plan your teeth.

      If you are local, I would be more than happy to see you. 😉

      Ramsey A. Amin, D.D.S.
      Diplomate of the American Board of Oral Implantology /Implant Dentistry
      Fellow-American Academy of Implant Dentistry

  6. Very nice article. I am a dentist also
    I agree 100% with you. All on 4 is designed for 2% of the patients with no teeth and marketed to 100% of them.
    I wonder if whoever is so aggressive marketing all on 4 to their patients, really discusses pro and cons with them. Or are they just selling something. Are they extensively trained in dental implants, or did they just take a short course on all on 4, and since then everything and everybody, is treated with this type of prostheses.
    Definitely they did not get the extensive training you have Dr Ramsey.
    I think we will see a lot of those 98% of patients (which were not good candidate for all on 4) coming back with complications.
    I am not surprised that at the “All-on-four-only Centers” they DO NOT want to see you for follow up and maintenance.

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About Ramsey A. Amin, DDS

Dr. Ramsey Amin has extensive experience in surgical and restorative implant dentistry. As one of only less than 400 Diplomates of the American Board of Oral Implantology/ Implant Dentistry (ABOI/ID) he is considered an expert, and board-certified in dental implants. He is a former instructor at the UCLA School of Dentistry.