The Nakao Foundation awarded Akimasa Tsujimoto, associate professor of operative dentistry,  and his research team a $92,364 grant to compare outcomes of four restoration materials—glass hybrid, conventional glass ionomer cement, resin-modified glass ionomer cement, and resin composition restorations—among adults age 65 or older.

The Nakao Foundation is a global foundation, based in Switzerland, organized to promote oral health across the world. This award represents the first grant awarded to researchers within the United States.

Restorations for adults age 65 and older are becoming more common as people live longer and retain more of their natural teeth. These restorations are typically used to treat cavities and prevent further tooth decay. Although glass ionomer-based restorations have low costs, studies for adults under the age of 65 have tended to find that resin-based composite restorations performed better than conventional glass ionomer and resin-modified glass ionomer restorations. Challenges associated with early stage setting of the restorative material and poorer physical properties likely accounted for the differences in outcomes.

In 2015, a new “glass hybrid” restoration material was introduced to the United States market. This material is also inexpensive, aesthetically pleasing for many patients, and, at least in theory, addresses the challenges associated with conventional glass ionomer restoration by adding a light curing varnish to protect the material as it sets properly.

This project is investigating not only the longevity of the four restorative materials—glass hybrid, conventional glass ionomer cement, resin modified glass ionomer cement and resin-based composite—but also whether this new glass hybrid material performs better than alternatives, especially for older adults. It will use a retrospective pilot study drawing from the University of Iowa’s patient database, and then further develop this study using the BigMouth Dental Data Repository to broaden the scope of the study.

The project expands on two important aspects of Iowa’s oral health research initiatives—namely, it’s world-class efforts to improve oral health care for older adults and it’s participation in the BigMouth Dental Data Repository,  a comprehensive database of electronic health records provided by eleven major dental schools in a partially de-identified manner.

The research team include Tsujimoto, Daniel Caplan, chair and professor of preventive and community dentistry, and Chandler Pendleton, a statistician in Division of Biostatistics and Computational Biology.