How severe must a UTI be to make capsular contracture of submuscular 410s likely? (Photo)

Some surgeons believe that contractures can be caused by situations that increase bacteria in the body such as dental work or infections. There is no conclusive proof for this.  I would continue with your antibiotics and continue to massage your breasts as directed. If there is any indications that your breasts are getting firm, please see your surgeon immediately. 

Any bacterial infection including a UTI can cause seeding to the implant
in a manner that may cause either a capsular contracture with or without an overt infection. Prompt antibiotic
treatment for bacterial infections are therefore indicated to minimize this
risk and since you did that you will most likely be spared.

Capsular contracture is not an immune response. We don't really know the reason for capsular contracture although the body always response to a breast implant is a foreign body. The possibility of infection leading to capsular contracture at a later time is theoretically possible.