New dental cement

Press, Volume CXIII, Issue 33189, 31 March 1973, Page 12

New dental cement

A new type of dental cement, developed by the Laboratory of the Government Chemist, is now undergoing clinical trials in Britain. It is quick-setting, tough, resistant to staining and acid attack and. unlike traditional dental cements, sticks to tooth material. The strongest material for dental repair was introduced as early as 1903. Although strong, it has serious drawbacks, including its acidity, which is high when it is inserted as a paste into a cavity and remains for some time after setting. It can damage dental pulp, so a protective lining has to be put into the cavity first, which takes time. The L.G.C. set out to find a less irritant cement, the main problem being to discover a better liquid than the phosphoric acid used in the cement as a mixer, which produced the acidity. Success has been achieved by using cement powders

made mostly of alumina, silica and fluorite and mixing them with polyacrylic acid. The performance of these cements is better and, apart from being less acidic, the acid molecules are much bigger than those of phosphoric acid and therefore will not diffuse into dental tissue so easily. The new cement can be used to fill erosion cavities in teeth without drilling. It can be used to seal cracks and prevent tooth decay starting. Sticking power is so good that bacteria cannot get betwen filling material and tooth, so cutting out one possible place- for decay to set in. This sticking power points to other potential uses for the material, such as bonding metals and ceramics and as a base for fibre reinforcement. Patent rights are owned by the National Research Development Corporation.