Generic Drug Usage in Dentistry across Japan: Analysis Using a Japanese National Database

The aim of this study was to identify regional disparities in generic drug usage and to examine related factors. The database used for the analysis was the 2018 national health insurance claims data published on the Japanese Ministry of Health, Labour, and Welfare. The drugs that were targeted were a combination of brand-name and generic tetracycline ointments for periodontal treatment and lidocaine injection solution used for dental anesthesia. The usage of generic drugs was calculated and compared by prefecture based on the number of health insurance claims. The comparison of related factors was conducted using data from other national statistical survey. The results showed that the mean generic drug usage of tetracycline for periodontal treatment in all prefectures was 71.2 ± 8.1%, ranging from 45.8% to 85.3%. The mean generic lidocaine used for dental anesthesia was 47.6 ± 10.0%, ranging from 30.5% to 66.2%. The rank correlation coefficient between the two was 0.359 (p < 0.05), and the tendency of using both generic drugs was low in major metropolitan areas. Generic drug usage in Japan is low; thus, in order to reduce healthcare costs, generic drugs need to be actively used in dentistry.