Zinc phosphate cement structure

Park, C.K., Silsbee, M.R., and Roy, D.M. (1998) Setting reaction and resultant structure of zinc phosphate cement in various orthophosphoric acid cement-forming liquids. Cement and Concrete Research 28,141-150. 

Cartz, L., Servais, G. E. Rossi, F. (1972). Surface structure of zinc phosphate dental cements. Journal of Dental Research, 51, 1668-71. 

One great advantage with phosphate bonded ceramics in biomaterial or dental applications is the phosphate ions in their structure. Bones contain calcium phosphate, and hence phosphate bonded ceramics are generally biocompatible with bones. While chemically bonded calcium phosphate ceramics have been difficult to produce, magnesium and zinc based phosphate bonded ceramics have been more easily synthesized and used as structural and dental cements. 

There is, with acid phosphate reaction cements, a relationship with bond strength and the rate of reaction. The rate of reaction of oxides with phosphoric acid depends on the basicity ofthe oxide. The reaction between aluminum oxide and phosphoric acid is slow enough to permit gradual development of the phosphate bonds. The zinc oxide reaction is so rapid that the structure develops no cohesion. 

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