Proper reconstruction of the ossicular chain is a fundamental prerequisite for good hearing results in staged tympanoplasties. The history of modern middle ear surgery shows that various synthetic materials have been proposed in past years for sound conducting mechanism reconstruction but all gave discouraging results and were soon abandoned. Plastipore is a new plastic material that seems to be well tolerated in the middle ear, and it is commercially available as pre-formed prostheses. We are reporting our experience with 140 cases operated on in our clinic (92 TORPs and 48 PORPs). Two groups of patients are reviewed: the first group consists of the cases in which the prosthesis is in direct contact with the tympanic graft; the second one includes the cases with interposition of cartilage between the head of the prosthesis and the tympanic graft. The purpose is to see whether extrusion rate differences exist in the two groups. Functional results (evaluated after at least six months show an air-bone gap of less than 15 dB in 57 percent of cases and an air-bone gap of less than 25 dB in 82 percent of cases. Five extrusions are reported (3.57 percent). We believe that staged tympanoplasties and tympanic reconstruction with molded heterograft can explain the excellent hearing results and the low extrusion rate of the prosthesis.