NGK SPARK PLUG has a wealth of expertise and know-how in combining ceramics, metals, plastics, and other materials, and has merged these together to create many new products. We have applied our past record and entered the medical business, too, with the wish to "put our high function materials to practical use in the medical field.
We are continuing further R&D with a view to improving patients' QOL* and extending our business areas.
In the fields of surgery and orthopedics, alumina ceramics have been in use since 1980 and hydroxyl apatite started to be used in 1985 for artificial joints and as a bone substitute for bone loss areas.
Generally, hydroxyl apatite is said to account for 70 to 75% of human bone components. Although prosthetic hydroxyl apatite had excellent biocompatibility, there was a problem in its use as a bone substitute since its particles were large which made its strength unstable.
For two years from 1976 to 1977, NGK SPARK PLUG began research into hydroxyl apatite, and, in 1978, it succeeded in developing high-strength hydroxyl apatite. Additives were used in the apatite raw materials as a sintering assistant to prevent particles from becoming coarse during sintering. As a result, we were able to obtain a bending strength of 2 tons/1cm2 and strength close to that of human bone at ordinary temperature and normal pressure.
From then on, too, we continued our research into hydroxyl apatite and conducted clinical tests with the cooperation of university medical departments.
In 1990, we began sales of the bone filling material "Ceratight" which brought us one step closer to becoming a manufacturer of medical appliances.
Zirconia Femoral Head
Metal has been used for the bone heads of femoral systems in artificial hips. However, there were the problems of precision and excessive wear due to the surface properties of the material. As a countermeasure, we focused our attention on high-strength partially stabilized zirconia that was developed in house. In 1982, we pushed ahead with fundamental evaluation of this material with the cooperation of medical colleges, national hospitals and faculties of dentistry and with joint development with other companies.
We also conducted mechanical evaluation with the cooperation of the then Ministry of International Trade and Industry (MITI) Mechanical Engineering Laboratory (currently the National Institute of Advanced Industrial Science and Technology (AIST)), and conducted clinical tests at medical schools after having confirmed its outstanding safety. We submitted a pharmaceutical application to the Ministry of Health, Labor and Welfare, and gained manufacturing approval, the first company to do so in Japan, in October, 1993.
In parallel with development of this "zirconia artificial femoral head," we pushed ahead with development of alumina artificial femoral heads which had been problematic in terms of strength, and finally succeeded in developing an artificial femoral head having twice the strength of conventional alumina heads. Although we initially had no knowledge of the medical field and the Pharmaceutical Affairs Law, it was able to bring products to the market with the cooperation of lots of participants inside and outside the company.
In 1999, we began sales of "medical use oxygen concentrators" for home oxygen therapy.
This equipment extracts oxygen of concentration 90% or higher from air by a compressor delivering air to an adsorption column filled with adsorption agent, and alternately repeating the processes of adsorbing nitrogen by high pressurization and desorbing it by low pressurization. Those who undergo oxygen therapy are patients with chronic respiratory failure who suffer from an incomplete oxygen partial pressure in regular breathing.
NGK SPARK PLUG's products feature a low power consumption which places little burden of electrical charges on the patient, silent operation, compact size, and light weight.
The successor model, the 3E series of oxygen concentrators, is highly rated for its power saving performance and for reduced electrical charges, which are borne by home patients. Consequently, this model was awarded the "Energy Conservation Center Japan, Chairman's Award" at the No.16 Energy Conservation Awards in February, 2006.
In 2005, we developed the new medical product "hydroxyapatite cement" and obtained manufacturing approval for this product from the Ministry of Health, Labor and Welfare.
"Bone paste" refers to the material made by mixing powder with a hardening solution for filling bone loss areas and bone fractures.
Because it hardens in the body and changes to hydroxyl apatite, an inorganic component of bones, it has affinity with surrounding bone and promotes bone formation. It is intended for patients with bone fractures from illness or accident and patients suffering from osteoporosis.
Our bone pastes feature high affinity with bone, quick hardening near body temperature (37℃ or, on the other hand, slow hardening near room temperature (25℃), and excellent operability. This is why they are highly rated by doctors and medical personnel.
We will continue to tackle R&D in the medical field so that we can help improve patients' QOL*.