Evaluation of physical properties and surface degradation of self-adhesive resin cements

This study sought to evaluate the pH value, film thickness, filler particle percentage, and morphological changes of self-adhesive resin luting cements. Products tested were G-Cem, Maxcem, Smart Cem, and RelyX Unicem. Cement pH was measured with pH test paper. Filler particle percentage was calculated after cement samples were incinerated at 750 degrees C. To test film thickness, mixed cements were placed between two glass plates and compressed using a loading device. For morphological changes, specimen surfaces were observed by SEM after treatment with various media. There were significant differences among the cement pH values measured at 20 seconds after light curing, and at 90 seconds and 48 hours after mixing. Filler particle percentage was directly proportional to film thickness. Degradation of cement surfaces was also detected after surface polishing and immersion in water, acetic acid, and acetone. In conclusion, significant differences were found in the surface properties of the materials tested, and these differences might lead to differences in their clinical performance.