Foundation system

IU College of Dentistry Faculty Member Akimasa Tsujimoto Receives Nakao Foundation Research Grant

Tsujimoto will lead a two-year research project at UI College of Dentistry with the goal of finding the best material for durable restoration of dental fillings for adults ages 65 and older.

Isabelle Cervantes

The University of Iowa College of Dentistry and Dental Clinic building is seen Sunday, February 27, 2022.


A University of Iowa professor will determine which dental filling material is best for adults in terms of longevity and health.

Akimasa Tsujimoto, an associate professor at the University of Iowa College of Dentistry and Dental Clinics, was recently awarded the Foundation’s Nakao Fellowship to conduct research on patients aged 65 and older to find the best restorative material for dental fillings.

The Nakao Foundation for Global Oral Health was founded in 2018, with the grant as a way for dentists to advance dental research.

The grant, which amounts to $92,364, will be used to compare different materials used to restore teeth as people age.

Tsujimoto is the recipient of the third round of grants and is the materials specialist for the project. Important themes of the project are that it is minimally invasive to the patient and focuses on the oral health of the aging population and oral fragility.

The four different materials studied and compared are resin composition, glass hybrid, conventional glass ionomer cement, and resin-modified glass ionomer cement.

Different materials for restorations will last different times depending on the oral health situation, said Daniel Caplan, manager of preventive and community dentistry at IU’s College of Dentistry and Dental Clinics.

“We’re looking to see how many of these fillings had to be redone or how many are in the teeth and ultimately removed,” Caplan said.

He said restoring resin composition is a more common way to finish fillings.

“One is a traditional plastic filler that has been around for many decades,” Caplan said. “The other three materials are different versions of a newer material called glass ionomer.”

Glass ionomer is a material that releases fluoride and can be the color of teeth.

Caplan is also part of the project’s research team. His work on the project involves designing the appropriate research protocols and systematic and logical data collection, he said.

Along with Caplan and Tsujimoto, the team includes Chandler Pendleton, a statistician in UI’s division of biostatistics and computational biology. According to Tsujimoto, several parts of the research have already begun.

“When we checked the case we did at the University of Iowa, dental hospital, we found that we had pulled out 17,000 just for glass ionomer cement since 2015,” Tsujimoto said.

The study, which will take place at UI, will take two years between research and data analysis.

“As a first step, we will check the longevity of glass ionomer cements and composite resin fillings to [patients] over 65s in a university or hospital value using the electric recording system,” Tsujimoto said. “In a second year, we will verify data analysis through this BigMouth data repository.”

The user interface recently joined the BigMouth dental data repository in recent years, he said, which further analyzes the data and compares it with data from other schools across the country.

Tsujimoto said several patient factors will be taken into consideration when conducting the study.

“We will check many variables: age, gender, patient insurance, alcohol consumption, smoking. We will also check the clinic where [the patient was] treaty,” Tsujimoto said. “We can check the longevity of many types of prospects.”

Age is an important variable for research because of changes in saliva production as people age, he said.

Saliva is used for antibacterial repairs in the mouth because it contains fluoride and similar ions, Tsujimoto said, and since saliva production declines with age and people’s mouths become dry, heart risk is higher in adults.

Once the research is complete, he said his team will come to an answer on which filling material is best for older populations.

“If we know what type of material is best for the specific patient,” Tsujimoto said. “We can give [a] good solution for them, [the] best solution for them.