Journal of Periodontal Research 16: 611-616, 1981 The attachment mechanism of epithelial cells to titanium in vitro T. R. L. GOULD, D . M. BRUNETTE AND L. WESTBURY Faculty of Dentistry, University of British Columbia, Vancouver, B.C., Canada It has previously been difficult to examine the nature of the attachment between tissues and metal implants. To resolve this problem, a technique has been developed in which oral epi- thelial cells are grown on very thin films of titanium on epoxy resin. Discs of epon/aral- dite were formed by polymerizing the liquid resin in 60 mm tissue culture dishes. Discs were then placed in a vacuum deposition chamber and titanium wire vaporized onto the surface to a final thickness of about 300 A. Discs were cleaned in acetone and 70 % alco- hol before being placed in plastic culture dishes and plated with epithelial cells cultured from porcine periodontal ligament in MEM plus 15 % calf serum and antibiotics for four- teen days. Cultures were fixed in situ in 2.5 % glutaraldehyde, post-fixed in OSO4 and epon/ araldite polymerized on the surface of the discs. Thin sections were cut perpendicular to the surface and examined in the electron microscope. Results show that the epithelial cells attach to the titanium surface by means of basal lamina and hemidesmosomes, in much the same manner in which the epithelial attachment is applied to the surface of a tooth. (Accepted for publication March 9, 1981) Introduction There is continuing interest in the search for a suitable implant material that could be used to replace teeth lost due to injury or disease (for reviews see Adell et al. 1970, Branemark et al. 1977). Of all the materials that have been utilized, certain metals pos- sess some advantages, including excellent corrosion resistance, non-toxicity and tissue tolerance, suitable mechanical properties, abrasion and wear resistance, and reason- able cost (Weisman 1971). Of the metals, titanium is relatively inert and is commonly used in clinical applications, both in ortho- pedic surgery and oral implantology, with a high rate of success (Branemark et al. 1977, Freeman 1972, Williams 1977). A particular problem associated with oral implants is failure thought to be caused by a breakdown of the attachment between the oral tissues and the implant material and an apical migration of the epithelial attachment until the implant is ultimately exfoliated. Thus, studies on the nature of the attach- ment of epithelial cells to implant materials are required. The most direct and detailed method of investigating the nature of the cell-metal interface is transmission electron microscopy, but there is considerable diffi- culty in preparing ultra-thin sections of the tissue/implant interface. To overcome this problem, we have de- veloped a technique in which epithelial cells from oral tissue are grown on very thin films of titanium on epoxy resin and then sectioned for either light or electron micro- scopy. This technique has enabled us to