Mandibular Overdenture Design: Two, Three or Mini Implants?

Dr. S. asks:
Most of the implant retained mandibular overdentures that I have seen have two implants – one in each canine region. At some of the courses I have recently taken, the lecturers have recommended three implants – one each canine site and one in the midline. They claim that this design provides greater stability to the overdenture than two implants. My concern is that the alveolar ridge form in many patients has a thin bucco lingual dimension that would require considerable reduction to achieve a suitable ridge for conventional implant placement. One authority recommended using a narrow diameter implant (mini) if there was inadequate space for a conventional implant. What are your experiences? Do these narrow diameter implants provide the same kind of support and do they last as long as conventional implants?

12 Comments on Mandibular Overdenture Design: Two, Three or Mini Implants?

New comments are currently closed for this post.
Paul
7/14/2009
Are mini's as good as conventionals? No, I don't think so. But they certainly beat nothin'. If there's enough bone, I prefer 4 locators, 2 anterior and 2 posterior to the mental. Often times, there's only enough bone in the anterior, though. In that case, I prefer 3 locators (if there's enough width for conventional) or 4 mini's if there's not enough width.
Dr.Abhijeet , India
7/14/2009
Well there no second thought that theres no substitute for an implants but mini implants are the clever options avialable in the market for an implant.Well for an mini implant the diameter of the bone required is also less and they definitely provide a good functional stability to your prosthesis (Overdenture , Crowns) Well in case of bridges there placements need a lot of considerstion.But yes for your question you can opt for any number from two to four mini implant for an denture /overdenture placements as theres also an concept which says "ALL FOR FOUR IMPLANTS " so things vary from case to case and from Dr to Dr. Regards
Bruce G Knecht
7/14/2009
Conventional impalnts beat Minis every time. If you place three try for four. it will be more stable. The conventional implants have more versitility in case the pt wants to add implants to make a fixed case.
Ron H-- Prosthodontist
7/14/2009
In the Mandible, 2 implants in the canine region for an Overdenture and Locator attachments works excellently well compared to a conventional CD. The pt must be informed that it still must move somewhat or else it will overstress the implants. Once you get to 3 or 4 implant you might as well do a Fixed Hybrid, which can be done with as few as 4 implants, especially opposing a CD. The problem with Overdenture instability is increased when the anteriors are placed anterior to the ridge. This is practically always in the Maxilla and sometimes in the Mandible. As usual,a well informed pt with reasonable expectations will generally have the most consistent and predictable success.
Ron H-- Prosthodontist
7/14/2009
* implants
R. Hughes, DDS, FAAID,FAA
7/15/2009
Ron H, Right On!
Ryan Dunlop DMD
7/15/2009
Good post Ron H, I totally agree. I always do 2 implants in between the lateral incisor and canine areas (more anterior to prevent rocking of a class I lever rather than a class II lever, which rocks much less under occlusal load). Locators are superior to bars every time, and three implants doesn't add anything to my patient's function. And I really see no reason of using 4 implants for a mandibular overdenture because you can make a fixed hybrid using the "all on 4" technique for a little more of a lab fee. There is very little reason for a maxillary overdenture anymore with the all on 4 unless the patient requires a full labial flange for esthetic reasons. In my practice the most common full mouth reconstruction is the all on 4 upper and overdenture 2 implants lower unless the patient can spring for the all on 4 lower. And if the patient wants to convert from overdenture lower to fixed lower, they only need 2 more implants posterior to the ones they already have, which if you placed them between the laterals/canines, they are already in ideal position. Good luck!
John Willardsen, DDS
8/15/2009
After 10 years of practicing implant dentistry and learning that once you finish a case, that is it, you need to get new cases and also you want to see these patients on follow up only and not for replacement of attachments or loose dentures etc. All the patient remembers is that they paid a fee and the were getting implants. Often times in their mind they don't realize there are many different types of implant prosthesis', so if they have implants and a loose denture 5 years after it was done, I have found that they are many times frustrated. Even though you explained all of their options before you went ahead with the finalized treatment plan. Two implant attachment dentures will always become a problem at some point. And you can not charge enough for the clip replacements and the number of times you will see the patient over the years. It is not all locator patients, but all it takes is one or two and they can became very difficult. I have found in my hands and stress level, I will only place 4 or more implants and treatment plan them for a milled bar with PD or Bredent attachments, strategically placed, or even better I will place 5 or 6 implants, give them locators as a temporary, and tell them they are temporary until we do a fixed prosthesis. Or if finances permit go straight to a fixed prosthesis and avoid all the headaches. Attachments I have found give the patient a false sense of security and they blame you when the denture loosens, even if it is after 5 years. Our tongue is very strong and I have seen patients who will show me that they can remove their denture with their tongue and they dont think they should be able to do that because they have implants. Just a word of caution, Implant Dentistry is great, but control your stress and look out for possible future problems with patients and try to avoid them. trustimplants.com
Dr M
8/20/2009
I totally agree with Dr Willardsen.It is very stressful managing follow-up of patients with loose overdenture attachments, fractured acrylic adjacent to attachments etc,etc....Time-wise, this can be quite substantial, when you add it all up thru'the years. Patient's think once they have paid for implant-work, the prosthesis must last forever, problem-free. They get very upset and blame you for poor quality work and all sorts of unfair accusations. It doesn't matter how well you explain and document this prior to taking on the case. Patients forget and you end up being the bad guy. So, I have stayed away from overdentures now. For lower, I prefer at least 2 implants in the lateral incisor areas, then 4-unit bridge with distal milled attachments. A Co-Cr PD with milled lingual bar and milled attachments is fitted over this. This grossly reduces the bulk of the conventional acrylic overdenture.Best of all, due to the stability of the prosthesis, relatively problem-free.
Milo Garcia Tempone
11/22/2009
I think Mini Implants provide a great service for edentolous patients specially medical compromise patients with little bone width. You have many widths of mini implants now talking about Imtec 1.8., 2.1, 2.4, and now they have one that is like a hibrid between a conventional mini and a normal implant , that I think they refer to it as a "Hibrid" which is 2.9. Four years ago an old lady 84 y/o came to see me with her daughter complaining that her mother just couldn¨t wear her lower denture anymore , and was simply eating without it. I explore her and saw she did not had sufficiet bone for conventional implants besides her Drs. didn´t recommend conventional surgery for implant placement. She had an upper denture quite stable, so I went ahead and place her only 2 mini implants in the canine-premolar area diameter 2.4 Imtec. She has been eating with her lower denture with her 2 minis w/o any problems since 4 years ago. I see her every 6 months and she is just doing fantastic. With this I am trying to explain that it is not just a manner of 4 minis against 2 locators or whatever, or which one is best etc. We as Drs have to see the patient beyond implants and provide him or her with a service that will solve their problems.
Nailesh Gandhi
11/23/2009
I have been using mini implants since very long and in my experience they are very successful when done properly.They solve the problem of lesser bone width,lesser finance with patient and in minimum appointments.Old age geriatric patients are most suitable for mini mplants.On top of all it is immediately loaded and patient gets immediate result.At the old age they are very impatient and wants to even utilize the existing denture and if it is proper can be utilised with one step mini implants.I strongly recommend that the benefits to patients must be given with the technology we have now.
Roland Balan
11/23/2009
Mr Gandhi, you are perfectly right- especially the geriatric patient should be able to benfit from implant treatment before they die. Improving nutrition ability can be achieved even with removable dentures when fixed removable on ball attatchments of minis or midis. Grafting is definitively the wrong way for these patients- it often even deteriorates the general medical status of them. Talking about geriatrics- who of us bealives they will be able to clean and maintain sophisticated prosthetics ? I think it is a question of moral and smaks to ill advising to "sell" actively the wrong prosthetic solutions. We even loose credibility. It`s like selling somebody a formula 1 car for bad rocky roads and a tractor for the highway. Even if the patient asks us to do so !

Featured Products

OsteoGen Bone Grafting Plug
Combines bone graft with a collagen plug to yield the easiest and most affordable way to clinically deliver bone graft for socket preservation.
CevOss Bovine Bone Graft
Make the switch to a better xenograft! High volume of interconnected pores promotes new bone. Substantially equivalent to BioOss and NuOss.