Dr. K. asks:
I am treatment planning a full mouth rehabilitation where I will be completing a full mouth edentulation on a patient and restoring both arches with a dental implant supported prosthesis.
My patient wants the ultimate in aesthetics and comfort. Money is no object. I will be placing 8 dental implants in the maxilla and 8 in the mandible at the time of extractions. I am planning Diem Prostheses (3i) as the initial therapy. For the final and definitive restoration, I am planning a Cam-Structure bar (3i) with porcelain teeth. Will 8 dental implants be adequate in each arch? Should I consider using acrylic teeth instead of porcelain? Any advice?
Is the patient edentulous in the maxilla? Immediate loading cases (DIEM) in the mandible do excellent as long as proper protocols are followed and are supported by the literature very well. AS far as the maxilla the literature does not document this very well. There are cases reports with positive results though. But if you are extracting teeth in the maxilla and placing at the same time, be aware that achieving primary stability is a tough thing and you may have to compromise on ideal angulation of implants (angulation would be prosthesis dependant). This may be or may not be an issue depending on the type of prosthesis that is planned for the maxillary. As far as the cam structure bar goes you will need about 12-15 mm of interocclusal space. Give some more details of your plan and of the patient for better advice. If you haven’t done a case like this before you may want to consider seeking out a mentor that is comfortable treating cases like this, or refer out and learn from the process so you can possibly do these cases in the future.
Be aware not to connect implants with a bar if they are placed distal to the mental foramine. You can connect one side but two sides will cause pain on opening to do flexure of the mandible.
Dr K can you refer me to any sort of research or studies on mandibular flexure? I have been faced with some cases recently that are full lower rehabilitation on implants and wanted to see some studies. Has anything been published that you are aware of. Thanks.
1) If the patient has good oral hygen habit ,
2) If the operator has fit the crowns in a good occlusion ; bilateral balanced occlusion , low cuspid hights and equal pressure distribution bilaterally on the arches ,
8 (moreover in some cases 6 ) implants at each arch will be adequate
Regards ,
Wade,
Here is two reference to the literature, there are many more.
Zarone, et al (2003) Mandibular flexure and stress build-up in mandibular full-arch fixed prostheses supported by osseointegrated implants
Goodkind, et al Clinical Oral Implants Research 14 (1), 103–114. Mandibular flexure in opening and closing movements.J Prosthet Dent. 1973 Aug;30(2):134-8. No abstract available.
PMID: 4515668 [PubMed - indexed for MEDLINE]
Wade,
Here are two references to the literature. there are many more.
Zarone, et a (2003) Mandibular flexure and stress build-up in mandibular full-arch fixed prostheses supported by osseointegrated implants
Clinical Oral Implants Research 14 (1), 103–114.
RJ Goodkind, et al Mandibular flexure in opening and closing movements.J Prosthet Dent. 1973 Aug;30(2):134-8. No abstract available.
PMID: 4515668 [PubMed - indexed for MEDLINE]
8 implants is plenty assuming you have good support both anteriorly and posteriorly. Try to reduce posterior cantilevers especially in the provisional bridge and during the initial helaing period.
My recommendation is after extraction, make significant alveoplasty to reduce the socket heights. This will give help you achieve better promary stability. it will also allow you to create a stiffer/more rigid provisional bridge which will help distribute the chewing forces throughout the arch better with less change of bridge fracture. Your bridge will of course then be a hybrid type bridge, but you will have total control over the esthetics for the life of the patient. The key will be to evaluate the lip line prior to begining, so you know there the alveoplasty must be brought to. If this is done properly, the transition zone from prosthetics to natural tissues will be out of the esthetic zone and you will be able to control the prosthetics much better then you would if you were working with living tissue…particularly over a long period of time and maintenance.
As far as teeth, I recommend porcelain in the maxillary arch and acrylic in the mandibular arch. Avoid a porcelain implant supported bridge opposing a porcelain implant supported bridge always. There is guaranteed fracture of the porcelain. Use the acrylic in the lower arch (the less esthetic arch) in order to prevent numerous visits for repairs.
Good luck!
Do not reduce your socket height!!! DO NOT,
If you have enough bone apical to the socket, you will use it anyway to obtain good primary stability for your implants.
No need to remove your PRECIOUS alveolar bone which will provide your patient with beautiful esthetics.
Of course, if you have space between the implant and the cortical, it will need grafting.
Finally, place implants in the lingual portion of the socket. (change direction from the just extracted tooth)
If you ge rid of the socket, you will end up with long prosthetic teeth, or a flange to simulate gingival tissue. Also, you will increase at the end the crowm-root ratio.
Take care
Terry
dear friends,
kings questuon is , can he use acrylic teeth instead of ceramic,
yes i agree with k , that if a cam bar is connected beyound mental foramen then it will lead to pain when the patien opens wider, due to flexural mechanism of mandible.
instead you can make it in three unit if connecting to a bar.one in anterior, and one each behind mental foramen.
Overall a complex and multidiciplinary case
Do not reduce sockets preserve bone
Consider if teeth will be individual in anterior or splinted
Beware springloaded heavy contacts
Carefully construct temps ,…tissue is the issue
Regarding original question ..is 8 enough.?.
saying 8 ,7 or 5 implants is meaningless without context
Depends on bone density and bone quantity
Depends on spatial and symmetric placement
Depends on how you will restore /Splinting /cusp form/occlusal scheme /etc
If you have not done this a couple of times there are many many factors
Good luck and take care
Keep posting
If you are planning for 8 implants, I would do 4 bridges per arch… you avoid the mandibular flexure, easier lab work, increased precision and easier repairs when required. However, contacts between bridges may need some time to adjust perfectly.
Good luck!
Can anyone PLEASE send me photos or something to refer for myself (the patient)for the Hybrid using porcelain teeth?