All on 4: Implant abutment misfit?

I don't want to discourage you, but FLAPLESS All-on-four, is not a kind of procedure you should not do for the first time. it is a delicate procedure to start with and Flapless will make it even harder. Seeing is everything while doing surgery even for experienced clinicians. What you had faced is a common problem with distally tilted implants, and should always be anticipated. However, if you had taken a PA , you could have seen the problem and probably could figure out how to fix it. Many implant companies who are promoting this type of protocol usually have a booklet to go over it step by step, and they have pointed out this problem that you had faced. Did you read such instruction book prior to your surgery? when the implant is placed sub-crestally, the conical abutment or MUA cannot seat. In that case you take a PA and identify the problem, then you use a appropriate Bone Profiler with its protective cover over the implant and adjust the surrounding bone to basically make it wider. there is a Bone Profiler for each implant diameter, so you need to choose the right size specific for that size and Brand of the implant you use. one question for you. If this is an ALL ON FOUR treatment, could you deliver the prosthesis, or you had to let the patient go without it. on the Pan, it only shows 4 healing abutments.

I don’t usually perform flapless implant placement. Too many issues at hand. It’s best to visualize the surgical site and associated anatomy.

PerioProsth: I am not sure if A) this is his FIRST all on X procedure which happened to be done flapless or B) this just happens to be his first FLAPLESS for the all on X procedure. Not that it is a critical point, since we all have to have our 'first ' one. I know it is a matter of semantics, but truly, gain knowledge and insight FIRST with the protocols especially subcrestal placement of MU Abutments. Once proficient, gain confidence and expand your service and procedures. It's all about a scale or gradient. At least this is how I train my clinicians I mentor. Be it as it may, the points raised are salient: was there a conversion Bridge 1 OR a soft liner over the protective caps. But more to the question at hand, the use of a bone profiler is the manufactuers go to tool to trough the bone to allow the 'ease' of placement of the MU abutment. Be aware, certain brands or implants (tube in tube connection/morse taper may have an easier time seating in place than the platform connection (BioHorizon/Zimmer et al). However, the geometry and profile of the actual MU abutment both straight as well as angled (15, 17, 30 degrees based upon brand) will more often then not, dictate the extent of the bone ostectomy required for proper placement. Hope this long winded answer helps to make your question completely undeniably ambiguous (humor).

Since the tilted implants are causing the problems, it is a simple matter to remove the healing collars, rinse the internal aspects of each of the implants with Peridex, to gently disinfect , and see if you have narrower healing collars that fit on the implants and do not engage or touch the crestal bone. Using the patient's denture, place some soft wax on the tissue surface and reinsert the denture to get the markings where the healing collars are located...…. with a lab bur, grind the area where the healing collars protrude....you may have to use the wax again to be sure you reduced the exact area....and the denture should sit on the ridge without rocking...….fill in your ground out portions with a soft denture relining material.....take out and trim.....in this way, the patient's denture will sit on the ridge, will not move around, and this will buy some time as the soft tissue is healing. After some time without pain or inflammation, consider reducing the crestal bone with the appropriate bone profiler around the offending implants, so that the MU abutments are properly screwed down

From what I can see, implant is placed subcrestal and you need to remove some bone / tissue to have the multi unit abutment fully seated. I agree with my fellow colleagues. Surgical guides are great but all on 4 is a whole other beast. It’s hard to get a good reference point on edentulous ridge. I like using guides when I have solid teeth I can use as abutments for my guides. Tried one case for an all on 6 a few years ago and it gave me a lot of problems. You can’t know your anatomy without seeing your anatomy; especially when you need to flatten out your ridge for better implant positioning. For a case like this, I always stress out over vessels and implants not exactly where I want them. Nice case though. Thanks for sharing.

It is hard to say exactly what is going on without a clinical examination of the problem. However from the radiograph it looks like it is simply a matter that not enough crestal bone was milled initially before implant placement. As such the healing abutment cannot be screwed properly in place and was either loose when initially done or has come loose because it is not fully seated. Probably the pain is simply the healing abutment moving slightly and impinging on soft tissue. If this is the case then you could explain this to the patient (by phone) and ask them to not touch or eat on that implant until you see them again. Alternatively they could return to you (probably not easy to do). However it is not life threatening and should be easily corrected when the patient eventually returns. Often when the patient knows it is not a serious problem, they relax and can tolerate the mild pain until you fix it – especially if they cannot get back to you easily for some time. When the patient returns you could raise a flap and mill/drill the excess bone around the platform and then replace the healing cap. It should work out fine. However depending on how long it takes for the patient to return to you, it may be that the bone has reduced in height a fraction and you can screw the abutment down properly without any surgery.

Check your left rx implant abutment !it will loosened again..take out the abutment,larger the bone above the implant you place sub crestal .rise with chx and after insert inside the implant screw gel with chx. Then close well with your abutment.

I’m not sure if you noticed but the abutment in the lower right is not completely seated also.

The ridge is not as wide as you think it is. You selected site #22 and there is not enough room. I would have grafted it while it was exposed. Implant at site #26 is placed too far lingual. All of this would have been seen after a 2 minute flap. I flap 100% of the time. You said ... " I had difficulty while screwing the distal implant multiunit abutment but managed to do and healing cap was placed. Post op OPG reveals the gap and misfit in distal abutments. " When a healing cap doesn't feel right and then the X-ray confirms it, just seat the patient back in the chair and take off the healing cap and put in a cover screw. You should familiarize yourself about how a properly seated abutment feels. It is like closing a door. There must be a solid stop when you are done. Another good rule, don't do surgery if the patient is unable to return the next day or the next week. You were tired at the end of this big first-time all on four. You need to practice how to use a profiling bur first on a easy to reach anterior implant...not an angled posterior implant especially for the first time.

All good answer regarding bone profile and MU. Flapless all on 4 make little sens to me as most case end up needing bone profile or bone / ridge modification. But a very important thing is the soft tissue. From picture of the case, there is clear lack of KT around implants from the tissue punch used. This case may need FGG now.

Great learning experience for everyone reading this. As has been discussed previously, when you're doing surgery flapless you're blind. Your abutments are impinging on the alveolus since you went so far subcrestally with your implants. Easy to fix. Flap it, profile the bone then fully seat the abutments. But.... More importantly, when you have enough bone to try"flapless" surgery you probably have too much bone for a conventional hybrid or a bar retained denture. What pre-planning did you do? Mounted models to evaluate interarch space? ( You need at least 15mm). What type of prosthesis? What material? Fixed or removable? How many dentures do you fabricate? Hopefully you're comfortable with dentures because this is essentially a fixed denture. This patient should have been flapped, excess crestal bone removed then the implants get placed. There's more to an all-on-4 than putting in four implants. My guess is, judging by the size of the ridge and the bone height on your pan, your interarch space will be very limited. Bone impingement will be the least of your problems. I hope all turns out ok for the patient!

Great point on prosthetic planning. All on 4 is complex tx. Don't just plan 4 screws in bone. Start with proper training, proper planning. I had a mentor look over me for my 1st all on 4 case and I had 600+ implants placed before, with many 4 implants lower arch cases, but none with tilted implants and immediat loading (denture conversion). Inter arch prosthetic space is really important, soft tissue quality also. Placing the implant is 10% of the work.