A prosthesis for implant in a human patient body has an external envelope, at least one implant filling material, and at least one biologically compatible rupture indicator encapsulated in a sustained release delivery vehicle and disposed in a carrier medium, the rupture indicator capable of leaking out of upon rupture of the external envelope and triggering a signal detectable by the patient as it is released from the delivery vehicle, allowing for detection of a rupture or impending rupture by the patient.