Figure. Changes in the median particle size for the unsupported (triangles) and supported new dentures (bar-clip attachment; circles) as compared with the old denture are plotted as a function of the median particle size (X₅₀) obtained with the old denture for 18 subjects. The results were obtained after 15 chewing cycles. Linear regression is indicated by the dashed lines. The changes in median particle size due to implant treatment and the median particle size before treatment were significantly correlated for the bar-clip and ball attachments (both p-values < 0.001) and for the magnet attachment (p < 0.05).