This is not technically a risk per say in that scarring is something that will happen rather than 'might' happen. The scars that result from the surgical procedure to insert breast implants are quite typical of those resulting from other procedures requiring similar sized incisions.
However, in some patients, the scars resulting from augmentation can become thicker than usual. Some patients exhibit scars that are of a deeper red colour than normal and it is possible for both of these manifestations to occur together. Scars can sometimes take a long time, perhaps several years to improve in appearance.
With breast augmentation surgery, an inframammary incision is the most common and practical choice of UK surgeons. This is made underneath the patient's breast where the bottom of the breast meets the chest. Being located under the breast and at the fold where the body meets the breast, scars located there will be relatively well hidden in the body's natural contours.
Pain can sometimes result from scars but this is rare. Some patients do experience some discomfort from their scars and sometimes itching. There are products such as creams and oils on the market that claim to help reduce the appearance of scars.