429 Too Many Requests

Kuraray celebrates its 90th anniversary in 2016. We take the opportunity of this occasion to offer you a glimpse of the history of Kuraray from a new perspective. The name Kuraray represents more than 8,300 employees and an annual turnover of approximately 3.7 billion euros. Kuraray was founded in Kurashiki, Japan, in June 1926, by Magosaburo Ohara. Kuraray began with the domestic production of Rayon, a synthetically produced cellulose fibre referred to as artificial silk, a new and innovative product at the time. 

The name KURARAY is derived from the location: Kurashiki and the product manufactured: Rayon. The development of this branch of production developed very quickly in Japan, with many other major manufacturers establishing themselves during this period. Whereas others recruited their technicians and experts from elsewhere, Kuraray established the Kyoko Research Laboratory, which was managed by the University of Kyoto to generate expertise and support for the development of the required technologies. Ohara also committed himself to cultural and social projects. The building of an art gallery and the financing of an orphanage represent only two of his many projects in Kurashiki. The Ohara Museum of Art was the first private museum of Western art in Japan.

Ohara considered the dreadful conditions in which employees commonly worked and lived at the time to be unacceptable; he was not a profit-driven employer, and attempted to solve such issues. He ensured that decent accommodation, fitness facilities and nursery schools were built to provide young employees, or families who had left their homes to work for Kuraray, with everything they needed for education and a healthy and culturally rich lifestyle.
One of the largest general hospitals in the west of Japan, the Kurashiki Central Hospital, was originally founded by Kuraray to promote the well-being of employees and their families. It is still considered to be one of the most famous hospitals in Japan.

With the production of Kuralon in 1950, developed from the in-house manufactured products PVA and vinyl acetate, Kuraray expanded to become the specialist chemical company it is today. Always intent on making a contribution to the good of society, Kuraray addressed the subject of environmental protection very early on. The visionary Ohara was aware of the seriousness of environmental pollution, and made great efforts to prevent it.

Internationally too, Kuraray has remained aware of its social responsibilities. After the war, a production facility was opened in China which helped to improve the poor post-war living conditions of the Chinese population.
Today, Kuraray is a leading global manufacturer of the specialist chemicals used in many aspects of daily life. Kuraray has always viewed its employees as its most important asset, and continues to do so to this day.

During my presentations I am often asked why clinical research into bonding systems is conducted using class V situations.

The non-carious class V lesion is most suitable for this type of research for a number of reasons. Unquestionably, the main reason is the fact that such lesions present little or no macro retention. It must be remembered that if a cavity presents macro retention, loss of adhesive strength in the bonding interface will not automatically lead to loss of retention.

Other major reasons (in no particular order) are that such lesions occur relatively often, but also that in general they are situated in an easily accessible area and do not demand complex restoration technology. The configuration factor is low (ratio between free and bonded areas) and does not therefore cause much shrinkage stress. In addition, both enamel and dentine are involved in the restoration, although in some studies efforts are made to limit bonding to enamel (for example, in Van Dijken et al., Clinical long-term retention of etch-and-rinse and self-etch adhesive systems in non-carious cervical lesions. A 13 year evaluation. Dent Mat 2007).

The restoration is then re-assessed periodically. Obviously, loss of retention is considered, and sometimes restorations are also assessed on marginal integrity, marginal discolouring and aesthetics.

Whenever a restoration goes wrong, this is noted as a failure. The survival/lifetime of restorations is expressed in an Annual Failure Rate; for example, an AFR of 4.6 means that, on an annual basis, 4.6% of the restorations failed in the course of the study.

Phosphoric acid, sometimes also called orthophosphoric acid, is a substance that is used frequently in the practice of dentistry, mostly in concentrations between 30 and 40%. It is a proven substance for the etching of enamel (Buonocore 1955). It also entails hazards, because contact with the eyes and skin may cause severe irritation, blistering and burns.

The substance should only be applied where its use is intended, and proper control is of the essence. The use of a coloured gel is therefore recommended, preferably of a thixotropic type. The application of a cofferdam is also definitely recommended, and the patient should wear protective glasses ( the practitioners should obviously also wear protective glasses). When removing the etching gel, the main volume should first be sucked away using a saliva ejector without a cap. The area should then be rinsed clean with a spray mist suction device under continued suction.

If the etching gel should unintentionally get onto the skin or, even worse, into the eyes, the affected area should be rinsed with plenty of water until the patient no longer feels any pain in the affected area. In such a case, it is recommended that medical assistance be sought.

This article is based on a publication in the British Dental Journal Vol 217 No.2 Jul 25 2014
Link to the publication. 

I would like to refer to a recently conducted study by Garcia et al. to reply to this question, which derives from practice. The study examines the effect of three desensitisers on the bonding strength to dentine of a composite cement.

The study concluded that the effect is dependent on the material. Gluma Desensitizer (Heraeus Kulzer) and Super Seal (Phoenix Dental) decreased the bonding strength, whereas TeethmateTM Desensitizer (Kuraray Noritake) improved the bonding strength. The researchers obviously consider it necessary to conduct further research into the workings of TeethmateTM Desensitizer, a cement that contains calcium phosphate.

Clinical significance:

TeethmateTM Desensitizer, a material containing calcium phosphate, may serve as a useful new generation of desensitisers for use prior to the cementing of indirect restorations.

Click here for the research abstract.