Trends in insurance claims for dental gold-silver-palladium alloy in private dental clinics in Japan from 2006 to 2021

抄録

Aim. The price of dental gold-silver-palladium alloy has been increasing. This study aimed to describe the trend in insurance claims for dental gold-silver-palladium alloy in private dental clinics in Japan from 2006 to 2021 and examine the association between the trend in insurance claims and the increasing price of dental gold-silver-palladium alloy.

Methods. We calculated the proportions of dental gold-silver-palladium alloy in all dental materials for inlays and crowns using the age-standardised number of insurance claims. We performed a segmented regression analysis to estimate unstandardised coefficients and 95% confidence intervals (CIs) for the annual trend changes in the proportions during periods with the increasing price. The periods were estimated using a change point analysis.

Results. In inlays and fillings, the proportion of dental gold-silver-palladium alloy decreased from 13.1% in 2006 to 6.8% in 2021. However, there were no significant downwards trends during the periods with the increasing price. In crowns, the proportion of dental gold-silver-palladium alloy decreased from 94.1% in 2006 to 71.8% in 2021, and a trend change occurred during the periods with the increasing price (2011 to 2016: -0.78 [95%CI = -1.27, -0.29]; 2017 to 2018: -1.01 [95%CI = -2.65, 0.62]; 2019 to 2021: -4.93 [95%CI = -6.89, -2.96]).

Conclusion. Since 2006, the age-adjusted proportions of insurance claims for dental gold-silver-palladium alloy have trended downwards. The increased price might have partially contributed to the downwards trends.