PubMed1977
This study suggests that: 1. The porous plastic material tested is compatible with and showed no undesirable reactions in subcutaneous, intracerebral, intramuscular, and especially, intraosseous sites. 2. By standardizing porosity (e.g., a desired hole, any dimension, uniformly distributed) with the implant material (P.P.M.M.), one can predict with a degree of certainty that connective-tissue (collagen fibers) or hard-tissue (osteogenesis and reparative bone) ingrowth into these micropores will definitely occur. 3. The various shapes employed for implantation of the plastic material were not carcinogenic and did not cause a malignant reaction in any implanted region. 4. A close "amalgamation" with adjacent tissues was a result regardless of the implant site (e.g., intramuscular, intracerebral, or subcutaneous). Intraosseously, there was a variation. Depending upon the pore size, one observes either connective tissue or osseous ingrowth into the micropores. At a 100 micron pore size (B material), connective tissue ingrowth into the P.P.M.M. was seen. At the 450 micron size (E material), osseous tissue ingrowth into the P.P.M.M. was clearly observed. 5. The P.P.M.M. implant material can be used as a tooth replacement (e.g., for a root) at a small pore size (100 micron) and as a bone replacement (e.g., for bony defects) at a larger pore size (450 micron). 6. To secure vascularization of the implant material, porosity throughout is indicated at a large pore size. Surface porosity regardless of size will encourage only soft-tissue ingrowth into the implant material. 7. Any hard-tissue size or shape can be duplicated with the material, at any pore size, with compatibility to the adjacent tissue, regardless of the region of placement in the body. 8. There is a possibility of bone "induction" or stimulation of bone growth in predetermined directions with all its implications (e.g., periodontal disease). The replacement and repair of any hard tissue in the body (e.g., bone and teeth) are possibilities.