Number of lacunar resorption pits formed on dentine slices after 14 day incubation in OA derived macrophage/UMR 106 co-cultures (with added 1,25(OH)2D3) in the presence or the absence of recombinant human M-CSF. The mean number of resorption pits for each case is shown in parentheses and the p value for the Student’s t test is also given