Sour taste coming from implants after bridge loaded

On December 12th I had my healing collars removed and had a 3 crown primary bar screw retained bridge placed on three implants. I had previously had fisiograft, which is bone augmentation placed in the cavity after having the teeth extracted.

The bridge was loaded 15 months after having the teeth extracted and bone augmentation completed.   From day one I started to get a sour, unpleasant taste in my mouth which is worse when I eat, and sometimes bad enough to make me feel nauseous.  When I water pic with hot, salty water on the bridge I get a strong smell of burning eggshells, so strong that my husband can smell this while standing next to me!  

I informed the dentist of all this and he put me on a 28 day course of antibiotics, which I have completed with no change to the sour taste.  I have had the teeth x-rayed and no infection is showing in the implant area and two dentists have said the x-rays are good.  I have also had the surrounding teeth x-rayed and no infection is showing. To start with the dentist thought I may have a gum infection and I was told to rinse with Corsydol for two weeks but that made no difference to the problem.
I have had my cleaning technique of the bridge checked out by the dentists and I use TP brushes, superfloss, water pic with hydrogen peroxide, or salt, and use mouth washes.

There is no swelling, puffiness, redness around the area or pain when I eat.  The problem is just this very bad, sour taste which makes makes my breath smell and is having a bad effect on my self confidence.

I am seeing the dentist again tomorrow and have seen two other dentists at the practice but they all seem at a loss as to what is wrong.

If there is no sign of infection on the x-rays and I have no pain or swelling could one of implants still be failing?
I would be so grateful for help as I have today gone sick from work as feel under too much pressure to continue in my job.

[Jerome Tsang, DDS]

Sorry.  I don't place dental implants so I don't have the same experience as your own dentist.  You can ask this question in the Oral and Maxillofacial Surgery forum as the oral surgeon there would be able to answer your implant question.

I imagine that if there's a bad taste, it may be an infection in the area as well.  If this isn't the case, is there a possibility that you are allergic to a material in the crown itself?  Or possible the cement if it was used?  There may be a gap not visible on the x-ray that may be causing a leak and allowing bacteria to grow.  If possible, you may want to remove the bridge itself and place a temporary bridge to see if it is the bridge's fault.  

It sounds from the timing that the smell started the day the bridge was placed in.