There is really no significant risk to nipple tattooing or piercing with implants in place. The most important thing is to make sure the area is clean and sterile before the procedure and that you take very good care of the site after the procedure. Use plenty of antibiotic ointment and wash three times per day. At the first sight of any redness or swelling, go to a doctor to start antibiotics, but this is very rare. To make you feel better, you should know that nipple tattooing is common after breast reconstruction and causes no problems. Hope this helps.