Press Releases

Patterns of Posterior Dental Restorations Analyzed in Privately Insured Americans

Alexandria, VA – A study aiming to provide estimates of current dental amalgam placement in order to guide policy in the context of evolving materials/techniques as well as national phase down commitment was presented at the 52nd Annual Meeting & Exhibition of the AADOCR, held in conjunction with the 47th Annual Meeting of the CADR. The AADOCR/CADR Annual Meeting & Exhibition took place at the Oregon Convention Center in Portland on March 15-18, 2023.

The study, conducted by Laura Eldridge of the American Dental Association, calculated the amalgam and composite posterior restoration numbers between 2017-2019 using dental claims data for privately insured patients. Kruskal-Wallis and multivariable negative binomial regression models tested differences in rates of amalgam and composite placement by age group, gender, urban/rural, and percent race/ethnicity in the area. Statistical significance was set at 0.05, with Benjamini-Hochberg correction for false discovery rate.

The study found that the rate of amalgam restorations declined over time from a mean of 6.29 per 100 patients in 2017 to 4.78 per 100 patients in 2019, while composite rate increased from 2.76 per 100 patients in 2017 to 2.88 per 100 in 2019. Mean number of amalgams placed per person were lower in females compared to males, urban compared to rural areas, and areas with >75% non-Hispanic White residents. The odds of having higher counts of amalgam restorations were lower 2018-2019 compared to 2017, females compared to males, rural compared to urban areas, and higher for any group that was not >75% non-Hispanic White. The majority (51.8%) of dental patients aged <11 years received no amalgam posterior restorations during the study period; however, <11 year old patients had higher odds of higher counts of amalgam posterior restorations than patients aged 35-55 years.

While the data did not allow computing total number of caries restorations, the study concluded that amalgam phase down may currently be unevenly distributed. Achieving further phase down of dental amalgam may require changes to insurance coverage, incentives, provider training, as along with augmented disease prevention and health promotion efforts. Phase down efforts should particularly focus on groups with higher caries risk or higher rates of amalgam placement.

This research was presented as part of the Interactive Talk presentation, “Patterns of posterior dental restorations in privately insured Americans”, which took place on Wednesday, March 15, 2023, at 9 a.m. Pacific Daylight Time (UTC-07:00) during the “Dental Care and Health Service” session taking place from 8 a.m. – 9:30 a.m.

The American Association for Dental, Oral, and Craniofacial Research (AADOCR) is a nonprofit organization with a mission to drive dental, oral, and craniofacial research to advance health and well-being. AADOCR represents the individual scientists, clinician-scientists, dental professionals, and students based in academic, government, non-profit and private-sector institutions who share our mission. AADOCR is the largest division of the International Association for Dental Research. Learn more at