The Effect of Sample Selection on the Behaviour of the Periodontal Index in Rheumatoid Arthritis

Abstract

The effect of the selection of material on the periodontal index (PDI-M). determined for 93 rheumatoid (RA) males aged 15–44 years and 100 RA females aged 15–67 years (Material I), was investigated on the basis of general dental conditions in 337 RA males aged 15–44 years and 751 RA females aged 15–73 years (Material II), from which Material I had originated. the results were compared with corresponding findings in non-rheumatoids (NRA). In NRA, Material I consisted of 124 males aged 15–64 years and 129 females aged 15–63 years and Material II of 355 males and 677 females aged 15–4 years.

In the males, at limit values PDI-M = 2 and 3, the relationship between PDI-M scores in RA and NRA was not influenced by the selection of material. At limit value PDI-M = 4, the marked selection in RA had, in Material I, led to a smaller difference between RA and NRA than might otherwise have been present. In the females, at limit values PDI-M = 2 and 3, the differences observed in Material I decreased when Material II was considered. Beyond limit value PDI-M = 3, the greater selection of material in NRA than in RA had led to a situation which was the opposite of those encountered previously.