Dean Ho, Ph.D.

TIME was when the preferred material for filling superficial dental cavities was gold. Often, it still is, although cheaper materials are frequently used instead. But, for the deepest sort of filling, root-canal treatment, another substance familiar from the jeweller’s shop is about to join the dentists’ armamentarium—diamond.

Root-canal fillings reach, as their name suggests, right to the bottom of a tooth. They are needed when bacterial infection has penetrated both a tooth’s protective enamel and the somewhat softer dentine layer that underlies this, and has got into the nutrient-rich, nerve-containing pulp in a tooth’s centre. Unfortunately, such fillings are complex, painful and tricky to pull off—and it is common for the infection to return, either because the void left when the pulp has been removed has not been cleared properly by the dentist performing the operation or because gutta percha, the gum usually used to fill that void, does not create a good enough seal, permitting bacteria to creep back in. The idea of changing this by mixing diamonds into the gutta percha is the brainchild of Dean Ho, a bioengineer at the University of California, Los Angeles. He outlines it in this month’s edition of ACS Nano.

The diamonds in question are 4-6 nanometres (billionth of a metre) across. Geometrically, they are truncated octahedrons—meaning they have 14 facets. The edges where the facets come together are sharp, and the facets themselves are covered with chemical groups such as amines, carboxyls and hydroxyls. These properties grant nanodiamonds abilities that are desirable from Dr Ho’s point of view.

As the research trio note, significant progress has been made over the past several decades in the development of nano-materials for use in treating cancer and other ailments. The central idea is to use very tiny particles to carry tumor fighting drugs to tumors (they are not as easily repelled as the larger varieties) thereby healing the patient. The list includes metallic particles, nanotubes, polymers and even lipids. More recently, scientists have been looking into using nanodiamonds as more is learned about the electrostatic capabilities of their facet surfaces when they carry chemicals in a biological system, the ways their inert core can be useful in certain applications and as a means to capitalize on their tunable surfaces.

WASHINGTON, D.C.— The American Institute for Medical and Biological Engineering (AIMBE) has announced the pending induction of Dean Ho, Ph.D., Professor, Departments of Bioengineering and Oral Biology and Medicine, UCLA and Co-Director, The Jane and Jerry Weintraub Center for Reconstructive Biotechnology, Departments of Bioengineering and Oral Biology and Medicine, University of California, Los Angeles, to its College of Fellows. Dr. Ho was nominated, reviewed, and elected by peers and members of the College of Fellows For outstanding contributions to the engineering of nanodiamond materials for imaging and therapeutic applications.