Vanillate cements

The best formulation proved to be one based on a liquid containing 88 % EBA, 5% n-ethylhexyl syringate and 7% n-hexyl vanillate. Cements prepared from these liquids set in 5-5 to 6-5 minutes with a compressive strength of 66 MPa and tensile strength of 6 to 7 MPa. 

Syringate cements possess similar advantages to the vanillate cements. In addition, syringic acid possesses cariostatic properties, so syringates may inhibit the development of caries (dental decay). Again these advantages need to be confirmed. 

Keller, J. C., Hammond, B. D., Kowlay, K. K. Brauer, G. M. (1988). Biological evaluation of zinc hexyl vanillate cement using two in vivo test methods. Dental Materials, 4, 341-50. 

This type of cement has been further improved by the substitution of -hexyl van ill ate [84375-71-3] and similar esters of vanillic acid [121 -34-6] and/or syringic acid [530-57 ] for eugenol (93—95). These substituted cements are strong, resistant to dissolution, and, unlike ZOE and EBA cements, do not inhibit the polymerization of resin-base materials. Noneugenol cements based on the acid—base reaction of zinc and similar oxides with carboxyhc acids have been investigated, and several promising types have been developed based on dimer and trimer acids (82). 

All cements that contain eugenol inhibit the polymerization of acrylates, and those of EBA-eugenol are no exception. In order to remedy this and other defects, Brauer and his coworkers examined alternatives to eugenol (Figure 9.7). These included the esters of vanillic acid (3-methoxy-4-hydroxybenzoic acid, HV) and syringic acid (3,5-dimethoxy-4-hydroxy-benzoic acid). Both are 3-methoxy-4-hydroxy compounds and are thus chemically related to eugenol and guaiacol. Both are solids and have to be dissolved in EBA where they form satisfactory cements with EBA zinc oxide powder. The vanillate (EBA-HV) cements are the more important. 

All these vanillate and syringate cements are about as strong as those of EBA-eugenol. 

There is little information available on their setting and structure. Bagby Greener (1985) used Fourier transform infrared spectroscopy (FTIR) to examine the cement-forming reaction between zinc oxide and a mixture of EBA and n-hexyl vanillate. Although they found evidence for reaction between zinc oxide and EBA, they were unable to find any for reaction between zinc oxide and n-hexyl vanillate because of peak overlaps, the minor concentration of n-hexyl vanillate and the subtle nature of the spectral changes. 

Bagby, M. Greener, E. H. (1985). Infrared spectral analysis of EBA-hexyl vanillate-ZnO cement. Dental Materials, 1, 86-8. 

Brauer, G. M., Stansbury, J. W. Flowers, D. (1986). Modification of cements containing vanillate or syringate esters. Dental Materials, 2, 21-7. 

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