An “artificial enamel” ingredient in toothpaste has been shown to help restore enamel in teeth, more effectively relieving sensitivity than fluoride while fighting cavities, according to an internationally published study led by a UT Health San Antonio School of Dentistry professor and researcher.
The ingredient, a synthetic version of the natural mineral hydroxyapatite that makes up 97% of healthy enamel in teeth, re-mineralizes teeth affected by a condition called molar incisor hypomineralization (MIH), a widespread developmental defect of enamel, according to the study.
“It is a great concern among dentists and affected children and adults,” said Bennett T. Amaechi, PhD, BDS, MSc, professor in the Department of Comprehensive Dentistry at UT Health San Antonio. He is principal investigator of the study, “Remineralization of molar incisor hypomineralization (MIH) with a hydroxyapatite toothpaste: an in-situ study,” published in the international journal, BDJ Open.
“Permanent teeth affected by MIH are not fully mineralized and as such are referred to as ‘chalky teeth,’ ” he said. “MIH-affected teeth have softer enamel, which makes them weaker and diminishes their ability to function properly during chewing when compared to healthy teeth. The result is porous, often painfully sensitive, and sometimes severely discolored teeth that are more susceptible to dental decay, and that can in the worst case become non-functional.”
Healthy tooth enamel normally is the hardest substance in the body. MIH affects molars most often, but can also affect incisors, said Amaechi, an experienced cariologist and hydroxyapatite specialist. Causes are unclear, although a diet containing lots of acid and sugar aggravates the problem, especially in chalky teeth.
Toothpaste with hydroxyapatite was tested against toothpaste with maximum doses of fluoride, and was found to be “significantly better,” Amaechi said, because unlike fluoride, it helps build back enamel while also fighting tooth decay and providing better sensitivity relief. It is safe if swallowed, he said, making it suitable for both children, including infants, and adults.
The active ingredient hydroxyapatite in the toothpaste used in the study was an engineered form known as biomimetic hydroxyapatite, better known as artificial enamel, inspired by the natural enamel crystallites of teeth. As natural hydroxyapatite wears away in enamel, it cannot be reproduced by the body.
“Active ingredient hydroxyapatite is a new strategy for the oral care of MIH patients,” Amaechi said. “From a clinical perspective, the reduction of MIH-related sensitivity to improve quality of life is also a key advantage of hydroxyapatite.”
His study was performed under in situ conditions – meaning, MIH-affected tooth samples were worn by subjects while brushing with hydroxyapatite toothpaste. The samples were analyzed with microcomputed tomography afterward.
It was a collaborative project with Joachim Enax, Dr. rer. nat., and Frederic Meyer, PhD, both senior oral care scientists with Dr. Wolff Group in Germany, a manufacturer of hydroxyapatite toothpastes and the study sponsor. The study was “double-blinded,” meaning neither the participants nor the researchers knew which treatment the participants were receiving until the process was complete.
Other researchers in the study included Jungyi Alexis Liu, DDS, MS, clinical associate professor of developmental dentistry; and graduate students Rayane Farah, Thais Santiago Phillips, Betty Isabel Perozo and Yuko Kataoka, all of UT Health San Antonio.
Remineralization of molar incisor hypomineralization (MIH) with a hydroxyapatite toothpaste: an in-situ study
Bennett Tochukwu Amaechi, Rayane Farah, Jungyi Alexis Liu, Thais Santiago Phillips, Betty Isabel Perozo, Yuko Kataoka, Frederic Meyer and Joachim Enax
First published: Dec. 10, 2022, BDJ Open