Hello Dr. Nasser Alhajj,

This is a very good question. Helping patiënts with a minimal on implants and a maximal comfort. It is a very good way of thinking in a general practice.

From my opinion and experience it is possible in some cases, using the right abutment!

Keep in mind that you'll loose the periodontal resilience of your abutment teeth within some years. This is the most important disadvantage in cases when you make a 'rigid' FPD connection to an implant abutment.

If you will do that, use the TSA abutment (Proscan - Southern Implants) to ensures that the movement between the periodontal ligament and the rigid implant is synchronised.

The result is a continuous and even distribution of the chewing forces on the completely independent bridge supports. In certain cases, the number of implants can be reduced and expensive and time-consuming bone augmentation can be avoided.

The use of TSA in implant borne bridgework (not connected to natural elements) provides the patient with a more natural feeling in comparison to the fixed and rigid connection of bridgework on dental implants.

Philippe Nuytens

Thank you Dr. Philippe Nuytens for your informative answer. :)

Usually keeping implants and tooth supported FPD separate is the norm. The reason is that abutment tooth acts as a biological tissue meaning it shows slight movement in response to pressure, whereas implants do not. Binding a rigid structure with non rigid structure can lead to the rigid structure (implant) becoming mobile. While this is the general advise, in practice most, by their experience, suggest it is not a problem. I would not suggest connecting a natural tooth abutment and an implant abutment. But I may be too rigid / inflexible in my opinion perhaps. :)

Regards,

Dr. Akilesh. R

They should not be used together in a soldered fixed partial denture since the natural tooth moves and the implant does not.  Usually the natural tooth will depress in the socket.  It has also been tried with precision intracoronal attachments instead of a solder joint,but the natural abutment still depresses in the socket.  The only method that has been acceptable is to use a tube and screw ancillary system to hold the natural abutment from depressing in the socket.

Thank you Dr. Akilesh Ramasamy & Dr. Ira Zinner.

Dr. Ira Zinner , would you please provide us with a paper or illustrations dealing with tube and screw ancillary system?

Actually, I tried to find one but I didn't find any.

Thank you in advance.

There is NO long term substantiated evidence to support Implants connected to natural teeth.

In addition to the periodontal complex absence in implants, the differential tooth movements that occur on intercuspation will cause problems with implant and prosthesis. 

I would be very interested to see some case studies from our colleague Philippe Nuytens if you would be so kind?

i have seen recently an xray ...opg... of a Molar site implant connected to premolar... case was done 15 yrs back........its done by one of my friend senior oral surgeon in Kerala, India.... 

I agree with most - we teach our students to avoid linking teeth supported with PDL and fixtures osseointegrated into bone. UNLESS the implant restoration is linked to the natural crown with a minor moveable connector. We tend not to prescribe these so often any more, as laboratory experience is waning - but if needs must it is a good solution.

Hope this helps!

It should be avoided .....

https://www.periosouth.org/userfiles/files/WS11/Publications%20from%20WS11/TISP.pdf

Hello Mr. Alhajj,

I would not recommend to connect dental implants with natural teeth in a FPD. The survival rate of this work will be 15% less compared with FPD fixed purely on implants (researched in a study). The worst what you can do, is to connect the natural (tooth) teeth over a "minor moveable connector". This will intrude the natural tooth into the jawbone. If you want to connect natural teeth and implant in spite of this, the connections should be cementated. If there is a need for an attachement, it must be screwed.

I heard this on a lecture only yesterday from the prosthodontic professor Dr. Guido Heydecke from Hamburg. I myself noticed intrusions triggered by telescopes and other attachements on the natural tooth.

Best wishes

Rudolf Ritt 

Thank you Mr. Adam, Arun, James, Haroon, and Rudolf for your valuable comments.

Form all comments we could found some different opinions about this issue.

Sometimes experience goes in front of theoretical parts.

Can we say that this issue is a "clinical judgement"?!!

regards.

Several reviews have investigated this and a study by Greenstein explains the movement of TISP (TOOTH IMPLANT SUPPORTED Prosthesis) however does go on to make suggestions regarding this protocol

A review study undertaken by Serhat Ramoglu, Simge Tasar, Selim Gunsoy, Oguz Ozan, and Gokce Meric2013 concluded similar findings to Greenstein and also made similar recommendations regarding TISP   

Connecting Teeth to Implants: A Critical Review of the Literature and Presentation of Practical Guidelines

Gary Greenstein, Richard Smith, Dennis Tarnow,

Guidelines include

(i)Using with the teeth which have healthy periodontium and dense bone.

(ii)When connecting tooth and implant, using stress breakers instead of one-piece castings which increase rigidity.

(iii)A rigid connection should be used for preparation of implant and tooth, and parallelism should be taken in account.

(iv)Permanent cementation should be preferred.

(v)Usage of the short bridges. When using a long bridge, tooth-implant connections should be avoided as much as possible.

(vi)Occlusal forces must be distributed to all supported teeth in occlusion as evenly as possible.

(vii)Generally, use of implant-tooth connection should be avoided when the patients have parafunctional habits. If we have to, maximum implant must be used.

(viii)Cantilever extensions must be avoided.

(ix)Should be noted that the fixed prostheses which have minimum abutment support have high failure rate.

(x)Implant supported restorations were preferred.

(xi)Tooth-implant connection should be established with using the posterior tooth support as far as possible.

(xii)Using more than one natural tooth support increases the achievement rate tooth-implant connection.  Taken from the article by Serhat Ramoglu et al

Thank you very much Mr. Marc Slabbert for your valuable comment.

I'm wondering what is the difference between point (ii) and (iii) ?

in (ii) you mentioned using stress breakers instead of one-piece while in point (iii) you said A rigid connection should be used..!

Regards!.

(iii) I think this affects the connection between tooth and suprastructure and on the other hand implant and suprastucture

Regards, Rudolf Ritt

Connecting 3 Ankylos Plus implants with 3 endodontically treated teeth under a circular rigid metalceramic bridge cemented with GC plus cement is working perfectly fine for the last 5 years and 3 months. No bone loss around implants or natural teeth. Even one cantilever tooth on the left. The patient is a 50 year woman with upper total denture. Saving the natural teeth and placing implants only in healthy bone is worth it, when the occlusion movements are planned well. Than you can see that clinical evidence sometimes beats the scientific theory.

yes, of course, they can be joined successfully. Just following a few basic points.

Dear Dr. Mohammed Nasser Alhajj,

when examining the possible biological complications, we know (Heitz-Mayfield et al. 2004) that implant overloading will not challenge osseointegration and will not lead to bone loss. Regarding the tooth, it seems that a rigid connection does not affect tooth "resistance" to periodontal disease (Biancu et al. 1995) and by the study of Fugazzotto et al. 1999, the only times intrusion happened, was when the rigid connection broke.

When examining the technical complications, it is clear that when occlusal forces are applied to an FPD there is some flexion in the side of the tooth abutment and thus the FPD acts as a cantilever to the almost immobile implant. This results in stress concentrating on the neck of the implant and the abutment screw. In the Systematic Review by Lang et al. 2004, it was found that the 5-year survival rate of tooth-implant restorations was very similar to the one reported by Pjetursson et al. 2004 for implant-implant restorations, which were 94.1% and 95% respectively. At the 10-year mark, however, the survival rate of implant-implant restorations was much higher at 86.7% than tooth-implant restorations at 77.8%. Most of the complications at the 10-year mark of tooth-implant restorations were associated with loss of retention and abutment screw loosening.

So, when a rigid connection is utilized between a tooth and an implant, there's probably no reason to worry about biological complications. If all goes well, then it is probable that most complications (of technical nature) will arise close to 10 years after loading.

Personally, I would be very interested to know what would be the equivalent survival rates, if the implants used, had a strong conical connection (Morse taper), which takes the stress from the abutment screw and distributes it evenly to the abutment and fixture!

Let me know what is your opinion!

ideally no, to avoid leverage effect and implant failure