this study evaluated the effect of2% sodium desoxycholate combined with whole plasma from a single donor on gingival fibroblast attachment to diseased root surfaces. Twenty extracted periodontally involved teeth were cut into halves buccolingually and sterilized by moist heat under high pressure. The diseased root surface of each control half was rubbed with a sterile cotton pellet saturated with Dulbecco's phosphate‐buffered saline (PBS). The diseased root surface of each experimental half was rubbed with a sterile cotton pellet saturated with 2% sodium desoxycholate and then rubbed with a pellet soaked in human plasma. The control and experimental halves were placed in separate petri dishes, and a fibroblast cell suspension was added to each dish. The mean number of attached cells per half tooth was calculated for each group. Tooth surfaces treated with PBS (controls) showed a mean of 307 ±63 attached cells for 17 tooth halves; the experimental treated surfaces exhibited a mean of 650 ± 130 attached cells for 16 halves. The difference between these numbers was statistically significant (P<0.01). These findings suggest that the desoxycholate/plasma combination enhancedin vitrofibroblast attachment to diseased root surfaces.