Hard or soft tissue that is harvested from organ donors and is transplanted into a different person. In dentistry most allografts are of non-living tissue (i.e. bone and dermis). The tissue is cleaned, irradiated and stripped of all its living cells leaving a sterile non-reactive (non-allergenic) matrix of collagen, and or mineral which can be used to grow new tissue in a different individual. The tissue is considered universally safe.