This study was designed primarily to determine whether or not gingival fibroblasts attach to curetted cemental surfaces in periodontally-involved human teeth. Ten periodontally-involved human teeth were used. The superficial cementum from 5 teeth was removed by light mechanical curettage while no root treatment was performed on the remaining 5 teeth. Subsequently, the roots of all teeth were cut longitudinally to create 800 microns thick sections (slabs). Prepared slabs were then placed in 35 mm culture dishes, seeded with human gingival fibroblasts (HGF), and after 4 weeks processed for transmission electron microscopy (TEM). TEM results revealed flattened HGF on the noncuretted cemental surfaces that failed to attach. Fibrillar material was not seen between the HGF and cemental surfaces. In contrast, the HGF that grew on previously curetted cementum exhibited typical morphology of healthy, functional fibroblasts. Newly synthesized fibrillar material and collagen fibrils were noted, and both were apparently oriented towards the curetted cemental surface. Results strongly suggest that improved cellular attachment can be promoted on areas of root surface previously damaged by periodontitis if superficial cementum is first removed by mechanical curettage.