[2][3] He obtained his PhD at the University of Groningen in 1968 with a thesis titled:"Photoionization of aromatic hydrocarbons in liquid solutions".

[1] De Groot also worked as a visiting scientist at the UCLA bone research laboratory.

He developed two types of bioceramic, namely bulk ceramics (dense, porous, large and small) for mechanically unloaded bone fillers, and coatings for improving the bone bonding of strong, but less biocompatible, metallic orthopedic and dental implants.

His group also studied the incorporation of drugs and growth factors such as Bone Morphogenetic Proteins (BMP)[4] into such ceramics and coatings,[5] as well as the use of calciumphosphate particles for plastic surgery, i.e. filling and augmenting soft and hard tissues for cosmetic reasons[6]).

Prior to his present appointment he worked at Vrije Universiteit (VU), Amsterdam (until 1988) and Leiden University (until 2001), at both places as head of the department of biomaterials.