Patient Pulled Out Implants on Overdenture: How Should I Treat This?

Dear Dr. A. I see no body have answered you. May be in my country is different, but are you sure the implants were 4.5 x 13 Hybrid?

This has happened in my practice. Just leave it to heal 3-4mos and reimplant. It would be virtually impossible to get graft into such a small osteotomy. You could go up in diameter but I would just try to move a bit from your original site. Did you load these same day? Even in these minis I tend to wait a month before loading. Just put some lynal in the relieved plate and wait. In my hands there is always one or two that don't meet the force requirement for loading.

Any infection? Any soft tissue issues? How does the area look on radiographs? Maybe you could place a slightly larger and longer implant and let it sleep for three or four months and then include it in the prosthesis' support. Try to determine the cause of the loose implant first though. 4.5 hybrid?

Imtec/ESPE are only known for mini-implants. Could you please restate the diameter of the implant. This sounds more like a mini-implant scenario

According to what you wrote, the diameter of this implant was 4.5 mm is that correct?

Do you mean the Endure implant? Can you place an implant adjacent to the current site? if yes then place a new fixture there and socket graft the old site. if you cant then socket graft the site wait 6-8 weeks and place a new implant at that site. How long did you want before loading the implants?

You didn't give us the amount of time that the implants were in prior to that one pulling out. I bet money that it came out anywhere from 1-6 months after placement. you might look into RAP as defined by Carl Misch. I wouldn't wait for one month prior to loading as that is when bone surrounding the tooth is the weakest. Use the retainers at time of surgery and loosen the plastic or rubber retainers. When in use for a month that will loosen it up even more. At one month after surgery the retainers will be well worn in and less likely to pull so hard on the implants. I've used the Endure implants and they are decent implants although not made anymore.

If you have a mini and it fails I would just move over a few mm's (4) and drop a new one in. Any body placing mini's into grafted sites? Does it work? I was taught not to place these in grafts.

This will probably stir comment but the use of mini implants wherever denies all of the massive research done in the past in regards to bioengineering. See studies by Gene Roberts on bone remodeling, etc. While I can see use for these, I fear that many are doing them because they are afraid of using conventional implants and the mini implants are marketed to be so simple. Never forget the concepts (read Fundamentals) of bioengineering. The surface areas are exponentially small as we move from large to small diameter, more so than if we move from long to short. Implants that support a complete denture take lots of load off-axis. If you are going to use these, place enough for proper support. But then, I've been at this game since 1982 so I might be a little biased given all past research. Hard for me to toss that out based on marketing.

My first concern is, that it doesn't seem like your certain as to what you have placed. Is it imtec or did you place traditional root form implants? Did you load these immediately? While you may have saved the patient money by placing inferior implants, now it's costing him more, not to mention the major inconvenience. There is nothing convenient about restoring a patient that has lost all of their teeth. With that being said , place real implants and let them integrate first. If you did all these things and the implants failed, then the patient is smoking , not cleaning or the interface was poor, thus loosening the implant. Keep it simple, and follow this basic principles. Your and your patients will be happy. Bv

Regardless of the implant size, the problem appears to arise from not allowing enough time to integrate properly. If it was indeed a 4.5mm diameter implant, then I would wait for it to heal, maybe 2 months, before replacing it. This time I would ensure that there is no pressure from the overlying denture on the implant site whilst healing, and i would give adequate time for integration (3-4 months) before loading. Like Dr H, I've been in this game for many years and I don't see any role for mini implants as a longterm solution.

Dr. A. established the fact that the implants were 4.5 x 13....so forget about condemning Minis....... but what can be learned from this dialogue, is that immediate load implants connected to a denture by a ball attachment/female cap with an O ring or Nylon retainer can be overtaxing a non osseointegrated implant. In praise of Mini implants, Dentatus with their Atlas Mini Implant system, uses a silicone putty ( "Tuff - Link") for retention rather than a female cap.This material is durable, will not get hard as standard tissue conditioners do. For immediate stablization of a lower denture after implant placement, rather than use ball attachments, use healing collars that have more surface area and will be snugly adapted to hold the denture secure, but will put no stress on the implants when the denture is removed. Tuff LInk comes with instructions on how to prepare the denture base before applying the silicone. Generally it is advisable to place more than two implants in the lower arch.......but if two are used, it is advisable to splint them with a bar. Gerald Rudick AF-AAID; F-D-M-ICOI Montreal,Canada

Many good comments above and I have very little to add. I tend to use four mini's in the mandible and six in the maxilla - I have had good results with that. If indeed, these are 4.5mm diameter implants (mini's being <3mm in diameter), two "may" be enough in the mandible with good bone density and a negative patient history for bisphosphonate's (among other systemic and local contraindications.) - I haven't been doing implants as long as some above (since 1985 for me) but do have reservations concerning the sub-two mm diameter implants. Rarely are these a first choice treatment consideration in my practice. That said, existing bone width, the patient's health, age, mental status and etc. sometimes make mini's the most practical option in lieu of grafting. - We do have to remember that early in their lifetime, mini implants were used primarily for temporary (intermediate) stabilization until traditional implants could be placed. Their longevity, in clinical practice, has changed that. I have seen stats all over the place regarding their average lifetime. I can only say that, from what I have seen inside and outside of my practice, they don't survive as long as their larger diameter big brothers. To support that, when I have placed mini's for my colleague's to be utilized for temporary orthodontic anchorage, I have never had a problem removing them (just use unscrew - even those with a textured surface.) - Experience is a great thing if for no other reason than it enables one to determine what works in your hands - and that is what you should use and do. - Best of luck, Dr. No

Dr. No, in twenty years I've never seen a mandible that needed to be grafted in order to utilize standard implants. I have placed bosker implants in a 6mm mandible. I have discontinued using the transmandibular system, primarily because cojoined variables, creates too much risk and secondly, I feel like 2,3 or 4 standard implants is a better option. With implant overhead cost going down , why would you place mini's if you admit that they are inferior? By the way, the science associated with four mini implants in the maxilla is questionable. The science for four standard implants in the maxilla isn't a whole lot better, unless you are having them restored as tissue borne. Just wondering. Bv

The 3M(IMTEC)hybrid implant is 2.9mm in diameter. For sure, one hundred percent!!!.....so you didnt place a mini for sure, one hundred percent!!!.... For the sake of discussion, even if you did place a mini in the mandible with the prescribed protocol you should have gotten an insertion torque in excess of 50 upto 70Ncm. Since the system explicity wants you to just perforate the cortex and thats it, with the implant auto-advancing into the cancellous bone gaining fixation with each turn. Ive palced hundreds of minis and if i dont get an insertion torque in that range, if not place a mini but place a larger conventional implant in the same site and load it after atleast 8 weeks. I suggest placing a mini this time at another site if avaiable if you're in a hurry and make the patient another denture. Best of luck.

Just a follow-up to Baker - good questions! First though, I didn't say that the mini's were inferior. I just stated that I had "reservations" about them. For example, I also have reservations about the standard implant surfaces versus Strauman's SLA active but I don't use the ITI exclusively just because they stabilize faster. I don't feel that all other products are inferior and, as you well know, each system has it's weak and strong points. For me, matching a quality implant type and manufacturer to the case at hand is part of the process. - As for never seeing a mandible that couldn't support standard implants without grafting, I can only say that I have seen mandibles that I wouldn't place implants at all, with or without grafting. I've seen to many masticatory induced pathologic fractures in 6 and 8mm mandibles (through the symphysis and peri-symphysis areas associated with implant sites) to be comfortable. I've also seen many anterior mandibles with severe sub mental depressions or other irregularities/deficiencies that would require implant placement at moderately severe angulations. These angulations causing significant prosthetic problems and/or emergence into unattached vestibule or FOM tissue. I could go on but, maybe on this point, we should agree to disagree. - Most of my concerns surrounding the mini's revolve around my perceived decrease in their longevity. Good chance that, if true, is due to less individual implant surface area. I can make up for some of that by using more implants. As for what decrease is left, maybe an 80+ y/o patient with moderately severe heart problems or some life limiting systemic process doesn't need an implant with a 96-98% twenty year success rate. He/she may also not need a or be a good risk for more extensive procedures either. Lastly, as these individuals lose their mental capacity, dexterity and ability to clean their implants, it may not matter what is placed since ultimate failure is a foregone conclusion. Please don't read more into this than is stated - just considerations used to try and develop an appropriate treatment plan for the patient. - Lastly, paint me a picture of an implant case that is most likely to fail and I would expect to see an edentulous maxilla. All that I can say here is that more and larger implants are better. Easy to write a book on the theoretical best restorative option and it is probably true that prosthetic's are sometimes a contributing factor in early failure. However, it seems to me that Type IV or V bone is the major factor in premature loss. Thanks for your comments! Dr. No

Maybe not exactly pertaining to the original question, but, IF there is still some bone above the Inferior Alveolar canal, mandibular ridge splits with the short Bicon implants (4.5 x 6.0 or 4.0 x 50 or 5 x 6 pr 6 x 5.etc) can allow 2 to 4 posterior implants to augment a few anterior implants for a more balanced loading. John

Also, a close reading of the FDA approval for mini implants states that they were approved because their design is "substantially similar to approved designs ...". The approvals I've read do not address the possibility of difference performance relating to difference in the diameter/size/length between traditional submerged implants and mini-implants and provisional implants. So I do not think the FDA is stating that there is an expectation of equal performance, just that there are some situations in which some level of performance would be acceptable. Even Bicon advises caution in single placement of 3.5 diameter implants and the extra short, 4 x5 mm implants in molar areas. Another side note is that I have several hygienists, one of whom is a recent graduate from the local Dental Hygiene School, which up til now had no Dental School component. She relates that they often saw older retired ppl with implants of all sizes showing long exposed thread runs, etc., and the patients were still thrilled with their implants compared to dentures alone. John

Back to the original question posted by A as to why the implant may have pulled out: - Something bothered me about using the Imtec (3M) hybrid in the mandible and I dug out a downloaded technique printout from Imtec (before or approximately when they officially became 3M.) In that document, Imtec did not recommend using the hybrid 2.9mm in the mandible at all. They excluded D1 and D4 bone types entirely and had a questionable notation for D2 bone. They stated that the coarse thread pitch was designed for softer bone only. Currently, 3M only excludes D1 and D4 bone types from their recommended uses with no mention of the mandible. - - A few thoughts: Self threading wood and metal screws have different threads (coarse and fine respectively) for a reason. - Many of the scans that I have seen in older females demonstrate a very loose medullary structure (D4 bone is not uncommon.) With a coarse thread and a D1 cortex, only one of those threads may actually engage it at the crest of the ridge (depending on it's thickness) which may be essentially all the support that is realistically available. - Lastly, if the implant is over seated, the polished, non-threaded collar is driven into the cortex and further diminishes the holding power of the already limited cortical thread engagement. - Sorry to further litter up this forum with another posting but thought that some of this may be useful in explaining what possibly happened. - Dr. No

Thanks for the thorough response , dr. No. . While I agree that the aged , atrophied mandible does typically present with unusual anatomy, the advent of immediate cbct scans and angled abutments allows me to restore these patients with confidence.I have restored several 5-7 mm mandibles, and I feel like this might be the single most satisfying service that we provide( dollar for dollar). Granted placing implants (standard) in these patients is not suited for the gp or even the well trained perio guys. Repairing a fractured edentuluos mandible is technically challenging

Got cut off, before editing . I have yet to fx one , but have fixed three, all requiring trans neck open anatomic reduction. I do find myself placing 3.5 diam. Fixtures in extreme cases , however. Bvinci

Hello Put the implant adjacent to the previous one, wait for about 8 weeks & then load it so that the previous implant area may also heal properly.

Dr. Samir, that sight is harboring 5 diff. Variants of anaerobes . I don't think that is advisable . As far as FDA approval; the vitek joint implant was FDA approved I believe, and you all know the rest of that story. Again , everything we do is empirical to some degree , this is why we consider ourselves artist???? Dr. No, i 'm just incorporating strauman into my practice , you seem to be satisfied with the system/support??? Bv

Baker: Have used Straumann since the early nineties and overall, I am pleased with the system. Not to say that I don't have some issues but they are mostly instrumentation. I do like the shortened wait until restoration with the SLA Active and the esthetics/biologic response with the BL implants in the maxillary anterior. Currently have an excellent rep. and happy with the support and documentation available. Probably should stop here and not abuse this forum further with this off topic response. Would be glad try and answer any questions that you might have in a more appropriate venue. Dr. No

Dear All Thanks for your comments!! The implants were definitely 4,5mm x 13mm 3M Hybrids. I left the implants to integrate for about 4 months before loading. The torque was in excess of 30Ncm. Would 2 conventional implants be sufficient to support a lower denture with ball attachments as opposed to hybrid implants?

Dr.a ,in my opinion, two standard implants at the mandible placed @ 5mm anterior to the mental foramen is the preverbial workhorse of dentistry, especially if the patient has experienced years of difficulty wearing a complete lower denture . A cbct scan preop will allow you to engage the inferior cortex,thus engaging both the superior and inferior cortex giving each implant the greatest amount of stability. Allow the implants to integrate and restore them with the simplest abutment . Remember these people didn't become edentulous because they have good oh.. Compex restorations ie. Bars,spark erosion devices etc. Are ill-advised in that a lot of the patients become so satisfied,they become " lost to follow up". I have found that torque seatings greater than 35ncm, allows me to uncover at two months, and gradual load for the last month,assuming they have no risk factors. In my hands, Nobel,bioh, and strauman all do well for these cases and I feel sure any standard implant will suffice. A guide can be useful,just to keep yor fixtures in attached tissue and to provide appropriate alignment. Please don't place mininimplants in this situation. If the ridge appears knife edged, some minor alveoloplasty will at least allow you to place a 3.5 or 3.75 diam.. Bv

Dr. A: - Very solid advise from BV. I also like the two piece root form implants over the one piece hybrids even if they are 4.5mm in diameter. Just more options for retentive devices and possibly angulation correction. Never have been a bar fan with just two implants for support. That may be to much of a rigid load and potential torquing for them to withstand depending upon design. I think that you may want to use elastomers for cushioning and break away in heavy function (i.e. Locator's, OSO's and ERA's.) Since there are no PDL's surrounding implants and it seems wise to minimize the direct transmission of forces to bone with external devices. - Good Luck! - Dr. No

Dear Dr. A, your question is if it´s enough 2 implants in the anterior mandible, yes it is a very good treatment. As Dr. OMS says, I prefer the use of the Locator system (Zest Anchorage), because it is more flexible, talking about paralelism. That maybe that was the reason you lost the implant, no paralelism of the two hybrid implants. Just an advice, on anterior atrophic mandible, always do a flap surgery. I have done flapless surgeries in that area and in the same surgery open a flap, with big surprises: many threads exposed because you place the implants where you think the bone might be, and another thing the periosteum attachement gives you a lot of resistance, so you may think you have an acceptable torque even when you are not in the right position.

Good luck.

Dr. Moeen,non of us are/is 100 percent certain of anything. Just a suggestion,but give every scenario it's appropriate level of respect. I have two rn's and a surgery tech. In the room every time I operate,and I ask and get advice every day. I call colleques routinely for suggestions and read nightly. Just something about your entry made me respond. Hope you don't take offense. B Vinci

One addition to dr. Moeen, i have never seen a mini placed through both cotices. Now, again my experience is limited to only placing minis for ortho and temporary usage, as well as removing some failures. But It does make a lot of sense in my mind, that if your are going to place such a narrow fixture you should engage both levels of dense bone. Bvinci

Dr A. 3M does not make an implant > than 2.9mm. a 4.5MM implant is a 2 piece conventional implant, not a mini or hybrid.