Dental Cements

The manifold uses of dental cements-as (a) luting agents, (b) cavity linings and bases, and (c) restorations for teeth—make them perhaps the most important materials in clinical dentistry. The research of the last 10 years has resulted in four main types, classified by matrix-forming species: (1) phosphate, (2) phenolate, (3) polycarboxylate, and (4) polymethacrylate. The zinc phosphate cements continue to be widely used for luting in an essentially unchanged form. Acidity and oral dissolution remain as problems. The zinc-oxide eugenol cements and their modifications are useful as linings and temporary materials but are susceptible to hydrolytic breakdown. Vanillate cements may be an improvement. Calcium hydroxide-salicylate cements are widely used as cavity linings, especially on exposures, and show improved resistance to acid dissolution. Polycarboxylate cements as both zinc polycarboxylate and glass-ionomer cements show adhesion potential, good physical properties, fluoride release, and, generally, good biological properties. Glass-ionomer cements when correctly manipulated show minimal oral dissolution. Polymethacrylate cements have been used principally for bonding etched cast metal restorations to etched enamel. Recently, adhesive crown-and-bridge cements have been developed. There are no well-established correlations between laboratory measurements of apparently relevant properties and clinical performance. More clinically-based research is needed to facilitate the development of new cements.