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2. Deutsches Institut für Normung. Biologische Prüfung von Dentalwerkstoffen;DIN Vornorm 13 930,1990
3. Acid penetration through five calcium hydroxide liners;Garcia-Godoy;Tex Dent J,1986
4. Grützner AE, (1991) Director of Clinical Research, De Trey Dentsply, Konstanz, Germany (personal communication).
5. International Organization for Standardization. Biological testing of medical and dental materials and devices - Part 1: Guidance on selection of tests;ISO Specification 10 993-1,1992