Abstract: A solid fatty polyamide dissolved in a volatile organic solvent has been found effective for preparing cavities of teeth for restoration. For example, when this solution is applied to a cavity in the form of a dental cavity varnish, the organic solvent may be evaporated to leave behind a continuous polyamide film which is compatible with methacrylate resin type restoratives. Solid fatty polyamides are generally derived from the reaction product of partially polymerized unsaturated fatty acids with aliphatic diamines. The present invention relates to methods for preparing cavities with these polyamides as well as to compositions containing these polyamides.