Progression of periodontal pockets in the age cohort 35-44 years.

In 1985 the Health Department of the Italian Telephone Company decided to launch an oral health programme for all its employees and their relatives, with the collaboration of the WHO Collaborating Centre of the Clinica Odontoiatrica Ospedale S. Paolo, Milan. The programme started with an epidemiological survey of dental and periodontal condition; following data analysis, the company also contracted with private dentists to provide oral care.

Field trials of preventive regimens in Thailand and French Polynesia.

Field demonstration trials of preventive agents or methods are needed so that the effectiveness and acceptability of such methods can be evaluated when used as part of the prevailing system and life style in a particular community. Agents so tested should have already been shown in a clinical trial to have a positive effect. Field demonstration trials differ from clinical trials in having no traditional control group; the study is not 'blind'; there is no special supervision and there is no special selection of participants.