Paresh B. Patel, DDS

I don't think there is a specific time that a bridge would need to be replaced.  However certain factors might be met to consider replacing the bridge.

• Esthetic failure - cracks or chips in the porcelain would certainly need to be addressed
• Wear - even metal can wear so if you grind your teeth or have an imperfect bite then the bridge can wear down and create a hole in the metal substructure
• Gum issues - if the gum pulls away from the bridge you may see a dark line around the teeth
• Cement failure - if the bridge becomes unglued but does not come completely off decay may start

A few things will influence the cost of your Smile Makeover.

• Location
• Pre Implant Surgery...will teeth need to be extracted? Bone Grafting? 
• Type of Implants that will be used.  A two piece implant will be more expensive than a one piece implant.
• Type of Abutment.  Stock abutments (the part of the implant that comes out of the gum for the crown to hold onto) will cost less than a custom ceramic (tooth colored) abutment.
• Type of Crown
• Skill of the Dentist - you are in the end paying for his/her skill

While not typical to add bone after implant placement it sometimes is necessary. 

Reason can include part of the implant threads are no longer in bone and need to be covered.

Recession of the gum tissue.

Infection that has erroded the surrounding bone.

Yes the gum tissue is going to need to be pushed back to expose the implant, new bone material placed and then the gum will be closed around the bone graft and implant.

Typical healing times will be 4 - 6 months for the grafted bone to turn into living bone.

All the best with your case. 

It sounds like quite a bit of dentistry has been done on your front tooth.

First a Crown, then a root canal and then an additional root canal to correct the first one.

Once a Porcelain to Metal crown has a hole placed in it to access the center of the tooth for the root canal therapy the entire tooth and crown have been compromised. 

I think you may need a new post and crown to adequately carry the load that will be placed on your tooth. 

I see no reason why you should not wear your Essix retainer after the dental implants are placed.  The purpose of the Essix is yo provide you with the appearance of having the missing teeth while the dental implants heal into the bone. 

It is important to ensure that the Essix is designed properly off the tissue.  The gum tissue is providing the needed blood supply to heal the bone and tissue around the dental implants.  If the tissue is compressed in any fashion then the case is compromised. 

Best regards,

Paresh B Patel