Lower Overdenture Retained by Ball Attachment: A More Efficient Solution?

One regular implant.

Dr D All the mini Implant protocols require a minimum of 4 mini Implants in the anterior mandible You would need to place 3 minis in this case instead of the proposed 2 Ensure this is truly an Over Denture ie tissue supported and implant retained rather than the other way around (that is the most common mistake with Minis!) You will have no problem it produces a very stable denture with no rocking if you placements are even I do recommend attending a mini implant coarse if you have not already There is a lot more in the placement and restoration technique than most realise OR place ONE standard implant as suggested above ..it does work My preference with standard implants and overdenture is to have a minimum of 3 ..this creates a tripod and reduces potential rocking Two implants and over denture is not so fashionable any more.

I agree with DRMA, one regular implant in this case would offer a more predictable outcome than trying to place minis and getting everything to work together.

Start using the system syncone from Ankylos implants In the long term It is very useful to the patients

And why aren't "Two implants and over denture is not so fashionable any more." Dr S. Sengupta? I am treating a patient with two lower canine implants with balls and sockets and I am too curious to find out.

2 implants for denture support is not only "fashionable", it is even more beneficial than having 3 implants. Firstly, the tolerance to deviation for 2 implants is higher than that for 3 implants. The amount of tissue support from 2 implants is far greater than that from 3 implants. A tripod effect is exactly what the clinician should avoid in order not to put too much stress on the implants. (Refer to pg 140, Risk Factors In Implant Dentistry by Renouard and Rangert.)

Just to clarify my semantics on" fashionable" Over dentures in this context are going to be tissue supported by definition If not they are not properly designed and will cause problems That is understood so I agree with some of the above comments However from a retention and stability point of view .. It is clear another implant will create more retention ..I am sure you agree BUt additionally if the 3rd implant is added it removes a rotational axis that exists naturally between 2 implants ie it creates a tripod There will be an inevitable tilt or rocking with 2 implants ..(even if the denture is totally tissue borne) Picture the example of 2 canine implant positions Incisal contact(with bolus) will raise the denture posteriorly Bolus contact posteriorly will cause a tilt in the front Given time and the eventual resorbtion of bone ..or a poor fit the denture can actually dislodge itself The 3rd implant will remove this potential problem I agree that 2 implants will obviously retain the denture ..so will one implant ...but we ideally want retention AND stability The question becomes ..where to place the 3rd implant I have found this problem to be entirly eliminated with 2 implants in canine or better the first bi positions and the third placed anterior and central Further.... If you insist on 2 implants Keep them anterior and connect with a STRAIGHT hader bar (NO distal extensions ) This will end up being tissue supported at the back and PARTLY implant and tissue supported in the front But the denture will rock around the bar you cannot avoid that I have seen many tolerate this especially if opposed by full upper denture NEVER make a bar with a three implant tripod design ..you will now have a 12 unit fixed bridge !

One mini is an economical answer.But if 3 minis are used than there is not big economical advantage. I would rather place 1 regular implant as suggested by others.So in future when canine root get fracured or decayed. another regular implant can be used with ease. I am an old fashioned guy, and not aware of latest fashions in implant dentistry,but I would like to tell you that at NYU complete mandibular denture with two implants is a routine treatment plan protocol,and pre doctoral students are required to restore at least one case.For the sake of students implant fees are very much subsidized so more patinets will choose treatment plan. If patinet has nice height of ridge,favourable arch shape and favourable opposing occlusion, stability will follow.

...............and if everything is unfavourable than it is better to use four implants at least.

I've done a good # of two on the floor cases! The patients love them. It greatly improves their quality of life! I am not talking about mini's either.

Please note there is no indication for less than 4 mini implants for a stabilization of a full lower denture Again I agree with Dr Joshi more implants creates greater stability and retention ..more implants will always give more retention and stability ..that is CLEAR That is precisely why 2 implants is being seen as becoming less favorable vs 2

My last line should have read .....being seen as becoming less favorable than 3

With 4 implants, it doesn't really matter if your prosthesis is soft tissue supported. With 6 implants, you can effectively make a fixed prosthesis with no soft tissue support. With anything less than 4 implants, the prosthesis must be soft tissue supported. I'm surprised why nobody mentioed this. The implants should only be stressed during insertion and removal. 3 implants are not better than 2 because the tripod effect will place too much stress on the 3 implants when the denture is in function. With 2 implants, there is much better soft tissue support. It's all in the literature if anyone bothers to read up.

Iam a 56 year old male with good jaw bone. Iam having upper and lower overdentures. With 4 implants upper and2 lower. my question is 2 enough?

If you are talking Imtec MDI system it is 6 upper and 4 lower implants.Also why bother with canines if other teeth are missing these teeth will eventually give in. Extract remaining teeth and use Imtec MDI i.e 6 upper 4 lower and promote proper gum care.

It should be noted that strictly from an engineering perspective the concept of 4 mini Implants and a tissue borne denture is Biomechanically more sound than 2 standard implants and overdenture It has nothing to do with width or fracture strength of implant as there is no occlusal force on implants with properly designed overdentures More implants provide more stability and retention ..period. With Imtec minis the protocol is 4 no less With standard you can do 2 but 3 HAS to be more stable by definition

Dr. D, I have used many different attachments including hader bars (mostly for combination fixed and removable cases). As discussed above, the main objective with any nonrigid attachment is to protect the abutment (implant or natural tooth) during function while providing retention and stability. The PDL has been fashioned by nature, as a shock absorber, for this purpose. When we as dentists ask an abutment, used for fixed or removable dentures, to absorb more force than it has been designed it for we have created unstable situation. Using one of the many stress relieving techniques, along with a balanced occlusion, we can reduce the amount of stress to eliminate the destructive effects and create a state of equilibrium. The same principals of occlusion that apply to natural abutments must be applied to implant abutments. Since, implants are ankylosed to the bone, and have no PDL, it is the abutment/prothesis interface that must offer all the stress relief. The abutments should be positioned and the occlusion designed to reduce lateral forces. When functional forces are directed along the long axis the energy is transmitted to the bone beneath the implant. Lateral forces are transmitted into the bone surrounding the implant which can cause failure. The most important aspect is to be able to aware of the appropriate options for each individual situation and inform the patient of these options without regard to what you think the patient wants or can afford. Then let the patient make an informed choice which is then documented in the chart. There is no general requirement, that I know of, to use more than two implants. I do know that at a symposium at McGill University a Consensus Statement was released stating that an overdenture with at least two implants should be the minimum standard of care offered to full lower denture patients. I have found an implant that I believe offers the best of both worlds, and have started working with this company giving hands-on workshops. The system is called the Atlas overdenture system. The system uses NDI’s (narrow diameter implants) with a patented abutment head and attachment design that I believe is your best option for this situation. Histological studies have shown that the Dentatus implants do integrate and there are many published case studies about them. They are made of Class V titanium alloy and have FDA approval. As far as breakage, I have never seen a report of even one breaking and with the low profile design I can’t imagine what situation could create enough force for one to break. This system is used routinely for situations like yours. The protocol calls for four implant on an edentulous mandible. I your case you can use three now and add a fourth if the cuspid is lost in the future. I would also consider placing four evenly spaced in addition to the cuspid. Aside from it’s affordability, here are some other advantages that make it a good option: The retention and stabilization comes from the patented shape of the abutment head when paired with the proprietary attachment material called Tuff Link. There are no housings, o-rings, etc. The silicone is the attachment material, therefore the implant is protected 360 degrees with stress relief. Due to this the implant abutments do not need to be parallel, they can actually be divergent to follow the topography of the bone without any affect on the results. In addition the results are extremely consistent form patient to patient.

Why not going for a fixed denture (Toronto) instead of continuing with a detachable denture. With at least three more implants placed in a correct arch your patient will have a lot more benefits from your treatment and you will invest the same time and effort in the surgery and in the prosthesis as with the removable solution. If the problem is money....as you are investing mostly the same time and effort in both treatment modalities the only additional cost you will have for having chosen the fixed solution are those from the implants (none, one or two ) and the cost of the hybrid framework. According to the later don’t charge the patient for implants but for the treatment, you and your patient will appreciate this piece of advice.

PLEASE.. do not use 2 imp. to support over denture. I try that many time and I have many failers.

If you still need help with this go to the Dentatus web site and sign up to take the hands on Atlas course. I teach the course and think it's the perfect solution for this patient. The reason is that this system does not need the overdenture abutments to be in line or paralell to work. The attachment mechanism is very retentive but also very forgiving so it is ideal for incorporating existing abutments into the case. In addition, if the natural tooth abutment is lost in the future another implant can be added and easily retrofit to the denture. As a matter of fact, during the lecture from the hands-on course I show a case done in a quality of life study by Kelly Misch which easily incorporated existing abutments into an Atlas overdenture. To answer your question about breakage, I have been in contact with dentists and researchers who have used these for over 8 years and have never seen nor ever heard of one breaking. The stories about breakage,I believe, come from the first pure titanium minus that were made to be used as temporaries. These are solid class 5 titanium alloy. As far as the peridontium, it adapts beatifully to narrow body implants and in limited spaces or narrow ridges the results are better that with conventional implants. If you have some questions or I can be of any help give me a call: cell# 803-367-1557. Best wishes to you and your patient. Rick