UI College of Dentistry faculty member Akimasa Tsujimoto awarded Nakao Foundation Research Grant

Tsujimoto will lead a two-year research project in the UI College of Dentistry with the goal of finding the best material for long lasting restoration in teeth fillings for adults aged 65 and up.


Isabella Cervantes

The University of Iowa’s College of Dentistry and Dental Clinic building is seen on Sunday, Feb. 27, 2022.

Archie Wagner, News Reporter

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

Akimasa Tsujimoto, a University of Iowa College of Dentistry and Dental Clinics associate professor, was recently awarded the Nakao Foundation Grant to conduct research on patients ages 65 and over to find the best restoration material for tooth fillings.

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

The grant, which is for $92,364, will be used for the comparison of different materials used for the restoration of teeth as people get older.

Tsujimoto is a winner of the third round of grants released and is the material scientist on the project. Important themes of the project are that it is minimally invasive for the patient and focuses on oral health of the aging population and oral frailty.

The four different materials being 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 amounts of time depending on the oral health situation, Daniel Caplan, head of the Preventive and Community Dentistry at UI College of Dentistry and Dental Clinics, said.

“We’re looking to see how many of these fillings either had to be redone or how many of them are in teeth and ultimately got taken out,” Caplan said.

He said resin composition restoration is a more common way of completing fillings.

“One is a traditional plastic filling material that’s 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 serving on the research team for the project. His job on the project is to design the appropriate research protocols and data collection that is systematic and makes sense, he said.

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

“When we checked the case we’ve done in the University of Iowa, in the dental hospital, we saw we pulled out 17,000 alone for the glass ionomer cement since 2015,” Tsujimoto said.

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

“First, we will check the longevity of the glass ionomer cements and resin composite fillings for [patients] more than 65 years old within a university value or the hospital using the electric record system,” Tsujimoto said. “In a second year, we will check the data analysis through this BigMouth data repository.”

The UI recently joined the BigMouth Dental Data Repository within the last few years, he said, which further analyzes data and compares it with data from other schools in the country.

Tsujimoto said several patient factors are going to be taken into consideration while conducting the study.

“We will check lots of variables: age, gender, the insurance the patient has, alcohol use, smoking. We will also check the clinic where [the patient was] treated,” Tsujimoto said. “We can check the longevity for many kinds of perspectives.”

Age is an important variable for the research due to the changes in saliva production as people get older, he said.

Saliva is used for antibacterial repairs in the mouth due to it containing fluoride and similar ions, Tsujimoto said, and since saliva production decreases with age and people’s mouths get drier, there is higher cardiac risk in adults.

Once the research is done, he said his team will reach an answer of which filling material works the for older populations.

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