▁add itive ▁manufact uring ▁for ▁serial ized ▁production ▁of ▁orth op edic ▁impl ants ▁( met als ) ▁is ▁also ▁increasing ▁due ▁to ▁the ▁ability ▁to ▁efficiently ▁create ▁por ous ▁surface ▁structures ▁that ▁facil itate ▁os se o integration . ▁Print ed ▁cast s ▁for ▁broken ▁b ones ▁can ▁be ▁custom - f itted ▁and ▁open , ▁letting ▁the ▁wear er ▁scratch ▁any ▁it ches , ▁was h ▁and ▁vent il ate ▁the ▁dam aged ▁area . ▁They ▁can ▁also ▁be ▁rec yc led . ▁ ▁F used ▁fil ament ▁fabric ation ▁( FF F ) ▁has ▁been ▁used ▁to ▁create ▁micro struct ures ▁with ▁a ▁three - dimensional ▁internal ▁geometry . ▁Sac r ific ial ▁structures ▁or ▁additional ▁support ▁materials ▁are ▁not ▁needed . ▁Str ucture ▁using ▁poly la ctic ▁acid ▁( P LA ) ▁can ▁have ▁fully ▁cont roll able ▁por os ity ▁in ▁the ▁range ▁ 2 0 % – 6 0 %. ▁Such ▁sc aff olds ▁could ▁serve ▁as ▁bi omed ical ▁templates ▁for ▁cell ▁cult uring , ▁or ▁bi ode grad able ▁impl ants ▁for ▁t issue ▁engineering . ▁▁▁ 3 D ▁printing ▁has ▁been ▁used ▁to ▁print ▁patient - specific ▁impl ant ▁and ▁device ▁for ▁medical ▁use . ▁Success ful ▁operations ▁include ▁a ▁tit an ium ▁pel vis ▁impl anted ▁into ▁a ▁British ▁patient , ▁tit an ium ▁lower ▁j aw ▁trans pl anted ▁to ▁a ▁Dutch ▁patient , ▁and ▁a ▁pl astic ▁tra che al ▁spl int ▁for ▁an ▁American ▁infant . ▁The ▁hearing ▁aid ▁and