Joining of Natural Tooth to an Implant: Possible in Long-Term?
Dr. M asks:
A situation has arisen where a patient has a fixed partial denture [bridge] (FPD) from tooth 34 (first pre-molar) to the 38 (last molar- wisdom tooth) and tooth 38 is to be extracted (micro leakage under FPD). Now the FPD has to be removed. Patient is requesting a single implant in 36/37 area and a FPD placed from 34 (natural tooth) to implant. As for all the theory I have been taught, and from other sources, it is not to be attempted. Has anything changed to make the joining of a natural tooth to an implant possible – in the long term ?
7 Comments on Joining of Natural Tooth to an Implant: Possible in Long-Term?
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Dr. Dennis Nimchuk
2/2/2010
This question has come up several times in previous posts. The short answer is yes and there exists plenty of documented studies to support this. Having said that, a free standing implant bridge is always preferable for the obvious reasons of potential stress transference to the implant as a consequence of movement of the natural abutment due to the compression of the periodontal ligament. However a short span bridge anchored to a both a solid root and a solid implant can be a viable service particularly when the patient is placed at unnecessary risk or morbitity such as can occur in the area of the mental foramen.
In your example however, you are considering two pontics. Two considerations on this: firstly, two pontics will increase the lever arm more than one and a two-pontic bridge is more risky than a one-tooth pontic. Secondly, the issue of risk would seem to be minimal in this region (second bicuspid and molar). in the site you are referencing, I would recommend two implants, each with crowns or two implants with a three tooth bridge.
As for combining a natural tooth to an implant abutment, the protocol which I follow is:
• The implant abutment should be of substantial size and should be placed in type II bone to best withstand the increase in shear forces that can arise from this type of hybrid bridge system.
• The pontic should have a short span, preferably only a single tooth, to minimize torque forces on the abutments.
• The natural root abutment should have good stability, preferably with no mobility and the tooth should preferably be multi-rooted to minimize tooth displacement.
• Both abutment connectors should have a rigid connector design. Nonrigid attachments should be avoided as they are associated with a greater incidence of root intrusion.
• If telescopes or copings are used, avoid temporary cements; in particular, avoid the no-cement coping technique, as loss or absence of a rigid connection will induce the highest incidence of intrusion.
• Use highly retentive cements with superior design features for retentive preparation at the abutment to resist cementation failure.
• Eliminate or minimize unbalanced tooth contacts in excursive movements as well as in centric.
• Consider bruxism as a risk factor; if present, manage bruxism with an anti-bruxism splint, preferably placed on the arch that contains the bridge.
s.milbauer
2/2/2010
as a relative beginner to the implant dentistry I very often mull over this dilemma of linking teeth to implants. this explanation given by Dr Nimchuk is second to none and best one I have ever come across. Many thanks!
Dr.Amit Narang
2/4/2010
Really very informative and elaborate advice..
Thanks Dr.Dennis
dr rabbani
2/4/2010
i will stick to dr carl misch,s explanation about biomechanics and not advise doing so.best results can can found if patient be convinced on gettin 2 dental implants in region 34 and 36 and give 3 unit bridge on it.by having a tooth to implant bridge,no matter how well precautions taken,desasters are likely to be there.
Ian Miller
2/8/2010
Thanks to every one for their comments so far, the 38 has been extracted and the bridge cut off distal to 34.
dr purvesh
2/14/2010
Dr. Dennis Nimchuk
thank for nice information , its realy usefulll ,,,
Richard Hughes, DDS, FAAI
2/15/2010
Read Misch's text. He covers this very well. His first text is also an excellent read.