Some Comparisons of Two Methods of Assessing Periodontal Disease

Abstract

Periodontal disease was assessed by Russel''s method, PI, and by Ramfjord''s method, PDI, in a reasonable approximation of a sample of a population. The results of the 2 methods were analyzed by comparing scores of PDI for all teeth with scores of PDI for the 6 teeth which Ramfjord specified as representative of all of the teeth; by correlating scores of PI and PDI; by studying the effect of supplementing clinical information with radiographic information in each type of score. Conclusions from this analysis are: Scores of PDI for the 6 teeth specified by Ramf jord as representative of all the teeth approximate such scores for all the teeth. Although PI and PDI measure the same things to some extent, they are not equivalent measures. Scores of PDI obtained by substituting information from radiographs for measurements of depth of gingival sulci underestimate the severity of periodontal disease. Scores of PI obtained only by clinical examination underestimate the severity of periodontal disease.