The relationship between soft tissue attachment, epithelial downgrowth and surface porosity

Abstract

Millipore filters with pore sizes ranging from 0.025 μm to 8.0 μm were implanted in the backskin of pigs for periods up to 8 weeks. Measurements of the rate of epithelial migration along the filters showed an inverse relationship with pore size although the extent of migration was significantly less along filters with pore sizes of 3‐ μm and above than along those with smaller pore sizes. Histological examination revealed a difference in the extent of connective tissue infiltration which corresponded to the differences in the rate of migration; filters of pore size 3 μm or more were extensively infiltrated with cell and tissue elements whereas there was little infiltration of filters of 1 μm pore size and none of smaller pore size filters. It is suggested that 3 μm is the minimum pore size that permits connective tissue penetration into the filter and that when infiltration does occur the resulting soft tissue attachment markedly restricts the extent of epithelial downgrowth. These results support therapeutic attempts to modify the cemental surface and thereby facilitate soft tissue reattachment to the tooth.