In Dental Bridges, Can 4 Abutment Teeth Be Enough for 6 Pontic Teeth?

As a general rule, anything more than 4 teeth is not a good idea.  While a bridge might work for a short while (one year?  4 years?) when it does fail, it is catastrophic and likely all teeth involved will be lost.  If not, a problem with a single abutment tooth involved will require the entire bridge to be replaced.
Dental implants are likely the best choice and should be strongly considered.

I would be very hesitant to place a long span bridge as you stated in your question. The excess forces of eating would put excessive stress on your remaining teeth. I do agree with the other doctors concerning losing one of the supporting teeth would cause the bridge to fail. With such a long span, you are risking causing those abutment teeth to fail sooner, with catastrophic results. I would discuss all options with your dentist. Today dental implants are the treatment of choice in your situation, if your bone can support them.

I would seek the advice of a prosthodontist.  You have advanced dental needs so get the help of a dentist who has experience.

You can look into copings on the permanent teeth that fit under a super structure to replace all your teeth.  You should also talk about using Implants to replace the long span of missing teeth and leaving the good teeth alone.

There are all sorts of options so do your home work. 

Although it is common to replace the four upper central and lateral incisors with a bridge from canine to canine, bridges beyond that length are not advisable.  This anterior bridge usually works because the canines have the longest roots and thus ample support in replacing the front teeth.  Bridges to replace all six anterior teeth do not last and when they fail, it is catastrophic.

A better solution would be to look at implants.  My preference would be four implants placed in the canine and central incisor positions.  This would allow either a six unit bridge, or even better, two 3-unit bridges.  The three unit bridges would be more durable and if something did happen to require repair or replacement, a small section would be involved rather than the entire span of a 6-unit bridge.  Placing six implants with individual crowns is another option.

A last alternative would be a removable partial denture.  They are functional and inexpensive compared to implants or bridges, but relay on healthy, stable teeth to support them.  They are often not as comfortable as the fixed dental prosthesis.

 

What you describe is a pretty long bridge, even with double abutments. In the past, that would have been your only option other than a partial denture. The problem with long bridges is if one of the teeth fails, the entire bridge fails and needs to be replaced. Today you also have the option of dental implants. With implants, there can be either shorter bridges, or each tooth can be replaced by it's own implant. In this way, if something fails, you don't have to start over. The first question with dental implants is whether or not you have enough bone. Check with your dentist or an oral surgeon to see if you are a good candidate.