Unsupported Area: Can An Overdenture Work?

Patient may be putting you in a bind. When restoring any case you must evaluate the shape of the arch, the opposing dentition etc. YOu can use a bar splint them together and tell her you can try it and see what happens, you can also try a telescope denture which in both cases will be tissue supported and implant supported.

Dr.S, Perhaps think about using locator attachments in the overdenture. They are easy to place and very retentive. The existing implants should be ample support and retention with the locator attachments.

Patient being unwilling for more surgeries,only alternative you have is implants retained,tissues supported overdenture with palatal coverage (for better stability).Bar is not a good choice,individual attachments should be used. In my opinion three implants in these locations (3,4,14)are not enough for support.

Dr S, I agree with the Locators, if she's not looking for something fixed-detachable. You've got 4 fairly long implants which I am assuming are stable. I'm curious why the other implants failed at #11 and 12 - and when they failed. However, 4 Locator attachments should allow for an open palate design to the denture. Too bad she's not open to at least 1 more implant! Good luck!

I would remind her that she is young and to utilize an inadequate amount of implants to help retain a prosthesis is almost planning for a major problems when bone loss and or implant loss starts to occur due to overload. How many procedures will she have to undergo in a few years or so to correct the new problems? I hope you don't have problems with this case but I think that compromising with this patient will lead to future problems for you.

In my experience restoring implants for the past 20 years, I have found that Maxillary Overdentures that are implant and soft tissue supported are among the least predictable restorations regarding pt satisfaction. I have posted previously regarding why, but mainly because most patients do not want the Overdenture to move during function (and even when they play with their teeth in eccentric closures.) If there is an inadequate number and geommetry of implants for a fixed case, then there needs to be some movement of the implant attachments so the implants are not overloaded and prone to failure. When this movement occurs, I have found many pts are dissatisfied. Regarding your situation, a 4 implant bar would not be recommended due to the unsupported nature of the bar between 6&14. A key factor for Overdenture success is adequate interocclusal space especially when a bar is used. It seems reasonable to place 4 Locator abutments, followed by an Overdenture with full palatal support & an adequate postdam(due to no implants in the 7-13 area.) This should be acceptable and more stable for the pt than a complete denture except when she bites in the 7-13 area. This will either release the overdenture or likely prematurely loosen the attachments at which point the pt likely will not be happy. Replacing the Locator attachments is easy and it is reasonable to change them yearly with a nominal fee charged to the pt. Six months is about the minimum reasonable interval. Any sooner is a sign of too much stress in the system. This can be from misfitting attachments or more likely due to the esthetic positioning of teeth away from the ridge and implants, leading to an unfavorable fulcrum on biting. Bottom line- a Maxillary Implant assisted Overdenture has an increased risk of having an unhappy pt. Your case would best be managed with recommending she see a qualified Oral Surgeon to evaluate for grafting of the ridge(Iliac crest if necessary), then placement of an adequate number and geommetry of implants for either a fixed hybrid or PFM Rehabilitation. If the pt refuses, then you can offer to do the Overdenture but with her FULLY INFORMED before beginning about the risk of it not being stable enough for her satisfaction due to the implant number and positions. Personally, I would also inform her that no return of the fee would be considered as she is limiting your options and choosing a compromised tx plan. The unknown in this case is the same with all denture treatment in that a significant part of success is the pts adaptability. Hope this is helpful. Good luck!

Dear Doctors, Thank you very much for your help and keep giving and sharing ideas... to let the situation clear for all the doctors, i have reviewed the complete file of the patient, she got bilateral sinus lift and got the implants...the 2 failing implants was of a very bad primary stability and failed by lack of integration, the file state also that the bone was of very bad quality (seems D4). i agree with Dr.John about the evaluation of the shape of the arch, in this case it's a U shape and what seems good is that the size of the arch is small. Sorry Dr.John but i haven't understood what you mean by a telescope denture. I don't agree for the bar because usually we need a minimum bar splint of 15mm...implants at #3 and #4 won't do much with the bar. when i was thinking about an overdenture i was thinking about locator that i have tried before with success... Dr.D what would happen if she got one more implant at position #13( the only position that may be implanted without graft, if she agrees), what will change in the course of treatment, can we change to a fixed prosthesis? I would like to hear your opinion about a screw retained denture(Hybrid denture) that a colleague have suggested to her... Dr.Kimsey, i agree with all what you said but you may sometimes feel that patients are tired from grafting, waiting, implanting,waiting etc...of course i would have been happy to graft the anterior region, and put implants all the way but sometimes we need to do what patients ask for...mayb when she got some teeth in her mouth, she will feel better and agree for a grafting while she has teeth with good retention...

heres a few things to try:1]a mini implant at area 11 or 12 w/ an o- ring attach. along w/ individual locators on the others. i dont really like the mini implants myself but in this instance it might just be enough and cost effective for pt. make the palateless plate w/ a metal baseplate[like a partial framework].leave openings in frame to cold cure attach.'s in...dont weld housings to frame-too ridgid.when curing attach's seat denture in place w/ LITE occlusal pressure[not chomp down on plate till cured].this will assure max tissue support when attach.'s/denture is seated.the sinus grafted bone should be mature enough now to at least retain mini implants.2]make the horseshoe plate w/ locator attach.'s at existing implants and tell pt to use a little adhesive in trough of plate between 8-12 if it feels loose to her.i'm assuming pt.'s hang up is palatal coverage of plate and not fixed vs. removable.adhesive is not the bane of all dental-kind...tell her its a compromise she has to make if no further surgery is desired.3]flat plane occlusion w/ no excursive contacts and anterior end to end overbite/overjet. also,when you restore 19,30 zero tominimal occlusal contact.

I agree with Ron Haas and Satish Joshi.Best alternative for this patient who refuses for any more surgery is a complete upper denture with full vestibular and palatal extension with locators.It dose not matter what is a arch form, ridge shape or opposing occlusion.

I have read the previous comments and would advise you that because your patient is still young, and, having her own lower anterior teeth, that the current implant situaton is not sufficient to resist the forces being generated. She may be grinding or clenching heavily and the remaining implants may fail as more force is exerted on them. You must discuss these problems with the patient and document all your recommendations as well as the general treatment plan (with its shortcomings) that the patient accepts. My experience with implants here in Montreal spans 20 years, when I see the lower anterior teeth exerting excessive forces against the maxillary denture, the bar-retained dentures that have an anterior component, will fail, especially with the weak bone, D4. Make her a standard denture with no attachments but just space for each existing implant abutment to protrude into. Let her wear this for a few months and re-evealuate each existing implant for stability before a complete treatment plan is made. Good Luck

Fortunately there is a sound solution to this problem. The custom endosseous subperiosteal implant constructed from a CTscan and cast in titanium can be placed in a single surgery. The design will conform to the existing bonie contures and have posts coming through the gingival tissue where needed. The posts can be joined with a cast bar at the tissue level after the tissue has healed. I allow 6 weeks for healing and the level of the tissue to settle. during this healing period the patients old denture is hollowed out and a soft reline material is used to hold the denture in. The cast bar joining the 4 to 6 posts can have several forms of retention for the final overdenture. I have found the simplest and most reliable is to have a flexible acrylic processed by the lab into the final denture. The patient has plenty of retention and the denture is secure and comfortable. I have done several hundred of these custom subs with success running 96%. Do not be fooled by those who will say the subperiosteal implant does not work! Please note I said the "Custom" Subperiosteal Implant has been very successful for me and those who know how to construct and place this great implant on patients who have lost their maxillary or mandibular bone. The palatal portion of the denture can be removed for greater confort and more natural speech abality. The advent the CTscan and design modification,will work great with your patients problem. Check this modelity out, it will work well on the difficult no-bone cases. I would be happy to assist you if you feel I could help. My office is in Southern Calif. if you are near. Good luck, Dr.Bob Rens

Dr.Rens Main question is how to deal without surgery? You are advocating much more involved surgery.Does it make any sense?

Dear colleagues: To my mind it is impossible to advise something without seeing any Xrays and diagnostic models, especially in a case when the patient dictates his/her own perception of clinical situation.

This is a tough case being that she is dictating to you how to handle her case... I hate it when that happens.... I don't think a bar will work because of the placement of the implants....the denture must have palatal support...I personally prefer the (O) ring attachments to the locators...I have changed many locators out for the old traditional (O) rings and the patients are much happier... I think this patient will benefit more from theses than the locators...providing that ther is not a big angulation problem with the implants. I also think the (O) rings will last longer..retenton wise ..than the locators and they are just as easy to change out and just as easy for the patient to work placing and removing the denture

I think that a removable prosthesis is the answer to this case. Placing locators and making use of a full palate as cross bracing is prefrable to a horse shoe type of prosthesis. I have done some of the horse shoe type of appliances and have had to do repairs to almost all of them,with fractures of the appliance usually in the midline area. (Torsion of the appliance)This case is aggravated by the fact that there are no molars in the opposing dentition, most of the function is going to take place in the anterior region of the prosthesis.

Hi Guys, I'm new to this forum and UK based.I am not familiar with the term 'locator' abutment - are we talking about ball-attachments here? Perhaps someone could explain it for me? Many thanks, great forum! andrew fennell

Dear Dr Andrew I recently found out my self from the zestanchors.com that a locater is some what like a ball attachment may be smaller and consumes less vertical space and seems to have cheap "O" nylon rings. I have yet to see one for myself!

Dear Dr S I don't even have 20 implants to my credit with only one case seen to completion but I can say this with conviction. If there was a case in your practice where you had to rely on your "persuasive skills" it is this one. Try to persuade your patient to get additional implants with or without implants. You can guess what the patient is telling you, and "really means" to tell you. The patient may be broke which they wouldn't admit often. If that line fails to get response you have either the bar or the ball/locators to choose from. Bars are going to be structurally lopsided so locaters would be your next logical choice. Even the Locators would be a compromised solution, so the patient better understand clearly, what she is actually going to get. Have I summarized all advices well?