Introduction and histort of luting cement:
The word is derived from the latin word latum which mean mud. Dental luting cements provide a link between the restoration and prepared tooth surface, bonding them together through some form of surface attachment, which may be mechanical, micromechanical, chemical or combination. Most cements are formed by an acid-base reaction. Liquids may be phosphoric acid, polyacrylic acid, or eugenol. Powders are either zinc oxide or aluminosilicate glass. Resin cements, however, are not acid-base formed but utilize BIS-GMA or urethane dimethacrylate resins. Cements can be classified into five groups: phosphate bonded, polycarboxylate bonded, phenolate bonded, resin cements, and glass ionomer/hybrid cements(. Lieutenant,2004) Zinc phosphate, zinc oxide eugeno, silicophosphate cements were used from the early twentieth century till 1970s when new cements were developed. At first polycarboxylate cement, next glass ionomer cements and within the last thirty years resin cements and resin modified glass ionomer cements were developed (Ă–nal ;et al 2004). properties of Ideal Cement Basic mechanical, biological, and handling requirements must be met by the cement 1. It should be well biocompatible,it should further have anti cariogenic qualities, 2. It should have very low resolution ratios within the liquids inside the mouth, 3. In order to reach the smallest details between restoration and tooth, it should possess low viscosity and film thickness. 4. It should be resistant against mastication forces and pulling forces formed through the effect of gummy foods. 20