A single implant for two teeth?
Single implant with two teeth on top is an option in some areas of the mouth. Usually we reserve this option for the anterior where the forces are lower. The single dental implant is often a choice in these areas due to the small mesial distal area available.
Where should the single dental implant go to replace the two teeth?
A single implant for two teeth has several possible positions but the main two are right in the middle of the two teeth or in the position of one of the two teeth. The individual’s bone contours/availability and adjacent tooth root angles will dictate heavily how one decides where place the denatl implant. There are, of course, advantages and disadvantages to both positions and we will disuses some of those here. Greenstein has a nice article about this very topic in Dentistry Today in the August 2018 edition.
A single dental implant for two teeth that we place right in the middle.
The main advantage of this is to limit the cantilever effect and thus the force on the dental implant. However, there are many disadvantages and the main one is that the esthetics are harder to get. You must place the implant deeper to try to help with the esthetics but even with a deeper placement, making the two teeth look natural is just more difficult.
A single implant for two teeth with the dental implant in one of the two teeth locations.
This is typically the ideal choice. It is much easier to make the two teeth look nicer. There is usually more bone in one of the two areas vs in-between the two teeth, which helps with placement. The main disadvantage is that this creates a cantilever effect and we know that cantilevers, in general, result in more complications. In the anterior this really should matter much less, unless the patient is lacking posterior teeth and is hard on their teeth, due to grinding or clenching. The cantilever does not appear to impact dental implants themselves, just causes restorative complications. There is plenty of research that seems to say the same thing; Aglietta’s review, Wennström, Greenstein from JADA, and Tymstra.
Two things that are important for this type of dental implant placement is that when designing the prosthesis the cantilever should be as short as possible, ideally 6mm or less, and the connector should be as thick as possible.