The term "Biologic Dentistry" refers to practicing dentistry in a way that is safest for the whole body. Dr. Harju is fully aware of the toxicity of the many dental materials and procedures that can actually poison the human body. For example, this is why he is against the placement of mercury fillings and is concerned about their proper removal. Dr. Harju is also concerned about the overuse of dental x-rays, fluoride, and various other drugs and treatments. Anything that has the possibility of benefit and harm must be used on an individual basis, in which the doctor specifically prescribes them for a very specific purpose.