I need your opinion on this case. female patient, 60 years old, bone 4, wearing a scheletrical upper prosthesis, has 2 broken implants in the premolar canine area on both sides. The broken implants are not infected. I performed an all on 4 with tapered implant but I positioned the right tilted implant 2 mm more distally, invading the sinus. The implant insertion torque was 50 ncm. I used a removable full denture in acrylic for temporary provision. what do you suggest me to do? should I wait and monitor the situation? or I have to extract the implant?I reconstructed the position of the implant on the pre-surgery CT scan and in my opinion the distal part of the fixture is only 2 mm in the bone. In this case, is a Toronto or a bar overdenture prosthetically indicated? If I had to extract the tilted implant and the patient refused to have the surgery done again, would a bar overdenture on the 3 surviving implants work? Thanks for your attentions
yes, from your radiographs. it’s difficult to be 100% certain. but your “A” implant don’t seem to be fully in bone (best viewed w/ CT). which can cause failure when used as an abutment for a full arch implant supported prosthesis. resulting a do over. out of your own pocket since i would say is dr error.
but a few questions
From your PAs. there seems to be 6 implants total. Why do you say 3 surviving implants? what are the 2 super apical anterior implants. Also if you doubt your “A” implant position in the sinus why don’t you take a post op CT? Using a preOP CT and drawing an implant shape doesn’t really quantify the position of the implant. And during osteotomy you should have felt the drop sensation when you went through the sinus. did you not check after osteotomy? If doing an AO4 freehand is too challenging. i would recommend surgical stent to be safe.
If you turn a FUD into a provisional. why do the implants have cover screws. Shouldn’t temporary abutments or MUA be on the implants? a removeable denture is not considered temporary provisional. A temporary provisional is you convert a removable FUD into a fixed FUD. You’re just having the patient use a removable denture while the implants are integrating, that is not a temporary provisional. If your implants all torque >35Ncm, by guideline you should be able to place a fixed provisional on the implants, ie place MUA/temporary abutments on implants, drill holes and remove the palate of your existing FUD to fit on the temporary abutments. which doesn’t seem like you did.
Also shouldn’t the decision to restore w/ overdenture or fixed denture depend on patient request and prosthesis space which is determined at presurgical planning. So if the broken implants need to be removed due to alveolar reduction. they should have been removed during implant placement.
And correct me if I’m wrong, but by textbook, upper overdenture should be retained by a minimum of 4 implants. with 3 implants only. there’s a higher chance of implant failure. but hopefully your treatment will last longer than your patient.
Best of luck.
I think many clinicians are too impatient and in a haste to place implants before designing the prosthesis (could be due to improper training or deficient experience) . I understand you feel/think once you place implants, $$$ is in and you locked the patient to your office. but lots of times after implant placement you are left worry about the prosthesis and micky mouse the treatment and pray for it to “work”. which isn’t the best method for an AOX.
the 2 anterior implants are old broken implants that the patient refused to remove. fortunately there is sufficient prosthetic space for both an AO4 and possibly an overdenture. I used a removable prosthesis during osteointegration due to the patient’s economic choice. Unfortunately, after having placed many implants, I have lost the habit of doing a ceck x-ray of the osteotomy with the pilot drill. I know the literature recommends using 4 implants for upper overdentures and not exceeding 2 mm of protrusion into the sinus but I wanted to know if clinically any of you have managed overdentures on 3 implants or implants over 2 mm into the sinus. clinically, practically, not from scientific literature. so if this were your case what would you do? Thanks for your reply
As with just about everything in implant dentistry 4 implants vs. 3 for an upper overdenture is simply a suggestion. While I have always “tried” to follow this suggestion I have, on more than one occasion, managed and even planned upper snap on dentures with 3 and even 2 implants. I have found success, and failure, regardless of the number of implants and I assume that is because I get to work with some really good restorative docs who make good dentures so these fixture are simply retaining a denture rather that supporting the prosthesis. As far as an implant protruding into the sinus 2mm I think again it is merely a “suggestion” that we shouldn’t do that and I have been guilty of successfully ignoring this one many times, sometimes intentionally. About 20 years ago I met the Becker brothers, Drs. Bill and Burton Becker, when they came to spend some time with us during my perio residency. I still remember Burt showing all of these images with implants protruding 1-2mm into the sinus and back then he was doing it for improved stability and it apparently worked well for them. While I likely failed to answer your question I hope that this is at least helpful or at least a reminder that we really don’t know what we are doing in this unregulated field of implant dentistry so the best we have is mere suggestions… IMHO we get stuck when we use textbook definitions and small sample sized case studies as gospel because if we actually knew much of anything about implant dentistry then there would likely be a lot more consistency among the materials parts and pieces associated with the craft.
