infection in knee and through out the body.

In June 2007 I had a full knee replacement. I was doing real good; even joined a Gym. to get back in shape. In Jan. of 2008 I got my teeth cleaned. I took the antibotics prior to the cleaning, and had no bleeding or any other problims. A few days later I had a doctors appo. with my orthopaedic sergent. My doctor drew some fluid frome my knee and he said it did not look too good. The fluis sample was tested, alond with a blood test, within days I was ammited to the Hosp. because of an infection in my knee. The doctor performed surgery on my knee, doing a sort of flush and replacing some parts. I  stayed in the hosp. on an antibotic for 3 weeks, and test showed I still an infection.  The doctor then performen surgery on my knee again, taking everything out and filliing the void with an antibioc clay with plated inbetween. The doctor said it was a strain of infection from the mouth. I the went on a stronger antibitoc, twice a day for 8 weeks, via a pick line 8  weeks before blood test showed I was ok. Now I must wait 4 weeks and get my blood testes again. 

Should I be getting some other test mean while to see if I may have some other underlining problem with my mouth?

I do feel like my left ear is always pluged up, but all the test and doctors said they found no other problems.

!!! I do have a history of cancer in my family.