Community periodontal index of treatment needs and prevalence of periodontal conditions

Background/aims: In 1977, the World Health Organization (WHO) proposed a ne w index, the community periodontal index of treatment needs (CPITN) to eval uate the periodontal treatment needs of populations. The aim of this study is to compare different approaches of recording and presenting the CPITN. Methods: A sample of 2110 subjects aged 35-44 years were examined between S eptember 1994 and July 1995, throughout the province of Quebec, Canada. For each tooth (3rd molars excluded), the presence of bleeding and calculus, t he level of epithelial attachment, and the depth of periodontal pockets wer e measured. Periodontal pocket depths were measured from the edge of the fr ee gingiva, at 2 sites (mesiovestibular and vestibular), as well as all aro und the tooth. Results: Only 8.5% of adults had at least one tooth with a 6 mm or deeper p eriodontal pocket when probing on 2 sites, whereas if probing is done all a round the tooth, this percentageis 2.5 x higher (21.4%). The partial record ing of pocket depths (10 index teeth recommended by WHO, or 2 quadrants cho sen at random) resulted in an underestimation of the prevalence of subjects with at least one tooth with a periodontal pocket (CPITN score 3 and 4). A mong subjects with at least one tooth with a 6 mm or deeper periodontal poc ket, 12% were not detected with the 10 index teeth recording, and 25% go un detected with the measure on 2 quadrants. Finally, using the % of subjects with periodontal pockets overestimates the prevalence of deep pockets compa red with using sextants. Indeed, close to 30.0% of sextants have no treatme nt needs, whereas only 5.2% of subjects are in this category. Similarly, 7. 7% of sextants have at least one tooth with a 6 mm or deeper periodontal po cket, yet there are 3 x more subjects in this category (21.4%).