How are dermal fillers related to hep c?

Not related: There are no relations between hep c and dermal fillers to the best of my knowledge.

Not really a concern: Modern dermal fillers that use non-human ingredients pose no risk for disease transmission. Some people try to reduce cost by "sharing a syringe." if you do this, make sure you don't share the needle.

Hep C & fillers?: They are not related. One is a virus and the other is use to fill deficient voids in the face. If your doctor is using unsafe protocols, you may contract hep c from a dirty needle, but only if that needle has been exposed to hep c.