Failing implants after wearing full upper denture?

Were the implants loaded? if loaded was there much depth to the vestibules? or was it a low ridge. Was there a deep or shallow palate and was there any palatal coverage to the overdenture? in cases where there is shallow vestibule and palate lateral movement is not braced by the ridge and is transmitted to the implant which leads to bone loss over time.

It's like when 3 legs of a wooden chair make contact with the floor and the 4th one doesn't...wouldn't it rock each time when you sit on it and move even a Lille bit?.... That's like your denture. It would have been to have used those implants merely for retention rather then loading them for support. Load them primary stress bearing areas like the hard palate or the alveolar ridge, buccal shelves in the case of the lower arch. Larger surface area with palatal coverage translates to spread out loads, shared by every one even our darling implants. Pateint history of previous gum disease may be acting up? Bone resorption which happens anyways and over those 5 years may be more cause of some systemic influence. But you still have 2 implants left so use em to make a better denture with an easier, balanced occlusion. More hygiene on the part of the patient for sure.

Uncovering the implants brings the oral environment into play around the implants. As is so often the case, peri-implantitis and implant failure is intimately related to poor oral hygiene ( especially under a denture ) and is bacteria/biofilm related just as it is with natural teeth. If the patients is predisposed for perio problems and has poor hygiene, the stage is set for failure.

Research proves maxillary over-dentures on un-splinted implants are more likely to fail. That shouldn't come as a surprise. Every time your patient takes their denture out they're torquing the implant(s). Micro movement in the lower jaw probably doesn't occur in osseointegrated implants given the bone type in which they reside. Certainly the same can't be said for maxillary highly-cancellous bone. Saying that, we all know what happens after cumulative micro-movement on an implant. I also find that as the lower jaw bone atrophies, the bone becomes skewed toward type 1 bone. This is in contrast to upper jaw bone (especially toward the posterior). These poor implants don't stand a chance. Most people would argue a bar to tie the implants together for cross-arch stabilization is a clever idea. I guess the advantage to using individual Locator-type attachments is if an implant fails it isn't as big a deal to replace and re-convert the existing denture. Having said all that, at this point I'm recommending my referrals suggest a bar whenever possible and inform the patient a Locator isn't optimal and has a higher implant failure rate.

There are many factors to speculate on, where the implants were placed to retain the denture, the width and length of the implants and how well the denture was balanced. Not seeing the patient for five years, a lot can happen. The tissue changes over time and denture fit is affected. Poor oral hygiene will lead to peri-implantitis. I don't buy micro movement osteointegrated implants are anklylosed. I thought that the locator housing needed to be maintained and replaced over time. I would speculate that there were multiple factors. If the patient wants another go then if there is enough bone, replace without a guarantee and explain the need for follow up. If the implants are placed in key locations in solid bone they don't need to be splinted in a well balanced denture. Splinting is a hygiene issue. Bilateral bars work well also with a clip type retention. You might want to run this past a prosthodontist when replacing.

Hello all, The editor has changed my wording. Please amend to: Implants were placed and covered (gingivae closed over). Implants were not uncovered, patient moved away and the implants had remained under a full acrylic denture

I feel that bars are passe'. There are guidelines for free standing maxillary implants supporting a complete denture: at least 5 implants, 3.5mm diameter minimum, 10mm length, lingualized or flat occlusion, 8mm spacing, 2mm of facial bone support minimum. See Tarnow's article. This case probably used the old occlusal scheme and not a flat plane causing off axial loads, inadequate number of implants, maybe too narrow and spacing unknown or inadequate facial bone support. Dennis Flanagan DDS MSc

Int J Oral Maxillofac Implants. 2007 Sep-Oct;22(5):808-14. Unsplinted implants retaining maxillary overdentures with partial palatal coverage: report of 5 consecutive cases. Cavallaro JS Jr(1), Tarnow DP. Dennis Flanagan DS MSc

People, Address the question. Poster placed implants in maxilla. Burried them. Patient wore denture. Patient comes back months later with dehiscence and failed implants. I've seen this same case posted many times in this blog. If you are going to let implants heal under a denture, be aware that you face a risk of losing them. Patients will wear the denture no matter how poorly it fits. They will use adhesive. This can open incision lines or cause spontaneous dehiscence over otherwise burried implants. It can cause the thin residual buccal bone over implants to resorb and cause failure. When I do these kinds of cases, and thankfully I don't anymore thanks to immediate load protocols, I bury the implant so the cover screw is at least 2 mm Subcrestal. And I tell the patient that the denture cannot be work for more than 2-3 hrs at a time. No adhesive. And then I pray. Immediate load protocols have ended this problem for me.

CRS is absolutely right. Improper pressure from the denture immediately after placement was the instigator of the problems that developed. I have seen this a number of times.

Hi Greg, nice articles. The soft tissue gives more than the bone around the implant so that any bracing provided by soft tissue is negligent. Notice how use of a flipper has a high rate of non-integration. Addirtionally, patients lose teeth for a reason, most likely poor oral hygiene. A bar is a huge thing to clean. Also bars are very un-esthetic, envision the patient showing his/her friends the metal monstrosity with plaque all over it. The friends will probably not want a bar. Locators are easier to care for and less expensive and give the same outcome with fewer complications and with lower maintenance issues and costs. Dennis Dennis Flanagan DDS MSc