Opinion in Off Occlusion Cantilevers in Immediate Load in All on 5 cases?

Not too long ago, I was I able to finish my very first All-on-5 case, in which two implants in areas #26 and 28 were placed four months prior before placement of 3 subsequent implants in the area of 20, 23 and 24. Upon conversion of the immediate lower denture to a temporary bridge, I left 2 teeth cantilevered  in the area 29/30 knowing the fact that implants were nicely integrated in areas #26 and 28, and only one tooth in the area #19. Although I was aware of the fact that cantilevers in the temporary prosthesis can lead to the fractures of the prosthesis, I had to make sure that all cantilevered areas remained in hypoocclusion.  I was wondering if someone could share their opinion on leaving cantilevers out of occlusion (by 1mm) just like we do in immediate temporization techniques for single unit implants. I also know that NobelBiocare discourages leaving cantilevers according to their All-on-4 protocol, yet their scholar Dr Steven Bongard in his educational All-on-4 treatment concept clinical case video leaves at least one to two teeth in cantilevers on each side. Please note that I used 13mm NP and RP Nobel Replace CC Implants that torqued over 45Ncm in placement of implants #20, 23 and 24.  What are your views and what do you recommend?  Your expertise in this matter is greatly appreciated.

18 thoughts on: Opinion in Off Occlusion Cantilevers in Immediate Load in All on 5 cases?

  1. roadkingdoc says:

    I am always more comfortable cantilevering against a denture. I think you are ok as long as you don’t violate the cantilever rule by going posteriorly farther than anteriorly off the most distal implant. I think your case looks nice. You may have been able to take the posterior implants a little more distally to nitpick. Nice job I think.


  2. Dok says:

    Occlusion is occlusion is occlusion. Cantilevers work until they don’t. Find out in about 5 yrs if the rules can be bent and with some luck, not broken.

  3. Dr Daneshgar says:

    The role that I am following and do not remember from where I learned it is if you draw an imaginary line from your most anterior implants and another line from your most posterior ones and measure the distance between these two lines you can go 2/3 of this distance cantilever . I go 1/2 to be in safer side.

    • Dr S says:

      Yep old rule of thumb described by Charlie English..except he said you can go distally by 1.5 times the anterior distance. I am like you…I do not exceed 0.5

  4. mwjdds,ms says:

    you should not leave more than a small tooth on the cantilever. Your right implants may be integrated so they won’t fail but the temporary prosthesis is acrylic. This will break if the cantilever is too long. The final prosthesis is metal reinforced so the cantilever can be extended without the prosthesis failing. It is very frustrating when the acrylic provisional breaks because there’s always a sharp edge or point to irritate the tongue. And it always happens on saturday.

    The final cantilever in the mandible should be no longer than 2 times the AP spread, or 20mm (preferably less) and the maxillary cantilever should be no more than 1.5mm the AP spread,preferably no more than 10-15mm.

  5. Raul R Mena says:

    I know that your question is regarding how much cantilever. My rule is no more than measurement of 2 bicuspids from mesial to distal, basically about 14 mm.
    Regarding your case, in my opinion you have room to place a distal implant both on the right and the lift side. That will give you a better distribution of forces not only because the number of implants, but because it will provide a better sctructural arch design.

  6. Alex Zavyalov says:

    I would splint all implants with fixed crowns and after that make a partial denture with metal frame in the posterior area. Upper teeth are naturally powerful, so any option that involves lower cantilevers will not be effective during mastication.

    • Ed Dergosits says:

      Alex I would be a very disappointed patient if I was given a RPD after having such extensive implant therapy. A small 7 mm cantelever is not going to cause this case to fail and the patient will not have a “denture”.

      • Dr A says:

        Thank you for your comments. However, patient currently have first molar to molar occlusion and I do not see the need to cover occlusion in second molar area. There is also no occlusal contact in cantilever area to avoid any acrylic fractures.

  7. Bill McFatter says:

    Having maxillary posterior occlusion changes the forces on this prosthesis. I don’t think you can expect the soft tissue to support the forces of occlusion in this case I would keep your cantilever shorter than normal due to the forces here. AP spread 1-1.5x that measurement

  8. roadkingdoc says:

    You are against maxillary bridge work. Your cantilevers do not have to be in occlusion to be functional.No worries of maxillary super eruption. Do the cantilevers. Be conservative with the length. It will fly and you will have a happy patient. I don’t think your patient would be very happy to hear they now need a partial. Good luck!

  9. Raul R Mena says:

    Dear All,
    All of the above postings confirm that the Treatment should not be performed until the case has been Treatment
    Planned. All this options should be analyzed ahead of time and it will avoid many of the complications and bad outcomes.
    Patients need to be informed before starting TX.
    Nothing new but many times forgotten.

  10. AllON4 says:

    Great job for first case. To answer your question about cantilevers…if you ever to get to do a case like this again, the last comment about tx planning is where you would need to start…
    For this case. First I would reduce bone on the lower anterior to make it more flat and get rid off the “hump”, so that your final prosthesis have enough vertical height to give enough strengths to them. Second, I would place distal implants more distally and increase AP spread and decrease cantilevers. Third, this patient would get a nightguard, if they don’t , you are either going to have failure on either arch….just my 2 cents advise

  11. yosef k says:

    Begin with the end in mind. Malo says the fifth mandibular implant is an emotional implant . You definitely should place distal implants more distally . also angle till almost 45 degrees using a 30 deg mua you’ll have about 10 deg distal tilt. Temporaries no cantilever occlusion on 3 to 3 . Permanent prosth one tooth cantilever is ok . If you can metal framework distal teeth also around distal titanium cylinders

  12. Greg Kammeyer, DDS, MS, DABOI says:

    After 19 years of doing full arch immediate load implants, I conclude the safe play is to not cantilever the provisional. When they break, it is a restorative hassle and decreases the patients confidence in the treatment and oporatory. As Carl Misch would say: over engineer your cases !

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