By: Beth Walsh for Dental1
Dentistry may be joining the ranks of regenerative medicine. In an effort to replace natural teeth, researchers from the Tokyo University of Science have developed structurally correct tooth structures from cultured single-cell specimens in mice.
By age 17, seven percent of people in the developed world have lost at least one tooth and after age 50, adults have lost an average of 12 teeth.
Several factors contribute to tooth decay as we age, including recession of the gums and an increased incidence of gum disease. Tooth roots are covered with cementum, a tissue that is softer than enamel. They are susceptible to decay and more sensitive to touch and temperature ranges.
To prevent tooth decay:
Brush your teeth twice a day with fluoride toothpaste.
Eat nutritious and balanced meals and limit snacks.
Drink fluoridated water.
Get professional cleanings and oral examinations regularly.
The ideal replacement is a natural tooth made from the patient's own tissue and grown in its intended location. Synthetic materials used today can elicit an immune-induced host rejection response.
Since teeth are actually small organs, the researchers cultured cells from the mesenchymal and epithelial tissues – the two types of cells that form teeth – of eight-week-old mice. The cells were injected into collagen to form a bioengineered tooth germ. The reconstituted tooth germ was developed over two weeks either by in vitro organ culture or by in vivo transplantation in sub-renal capsules into the adult mice. The bioengineered tooth germ developed with correctly placed mineralized tissue and cell types with both methods.
The researchers also attempted to transplant and redevelop the bioengineered tooth germ in a tooth cavity left after extracting an incisor from an adult mouse. Two weeks after grafting individual bioengineered teeth, the transplants reconstituted into a correct tooth structure with enamel, dentin, root, pulp, and blood vessels.
The authors said that their study “provides the first evidence of a successful reconstitution of an entire organ via the transplantation of bioengineered material.”
This study adds to a growing body of research on tissue bioengineering applications and mechanisms for regenerating dental structures in an animal model. Another study found that transplanting human stem cells into pigs generated a root-periodontal complex that could support a porcelain crown.
Advances in regeneration abound and this method might be applied to re-growing other organs. The researchers actually used similar methods to re-grow a mouse hair follicle that eventually formed a whisker.