title: Hardening of new resin cements cured through a ceramic inlay.
abstract: This study investigated the degree of hardening achieved through self-curing only and through dual-curing a group of eight new resin-based cements. In addition, the effect of ceramic inlay thickness on cement hardness was determined. Disk specimens measuring 6 mm in diameter and 2.5 mm thick were prepared from eight cements: Adherence, Choice, Duolink, Enforce, Lute-It, Nexus, Resinomer, and Variolink. Eight specimens were prepared from each material; half were self-cured, while the remainder were dual-cured. Knoop hardness measurements were then made at 1-hour, 1-day, and 1-week intervals. In addition 12 specimens of the same dimensions were prepared from each cement and were dual-cured through ceramic spacers of varying thickness (1-6 mm). Hardness measurements were made as above. ANOVA showed significant differences in hardness of self-cured versus dual-cured specimens for all cements (P < 0.0001). Significant differences were also found in the hardness of specimens dual-cured through ceramic spacers 2-3 mm in thickness or more compared with those that were dual-cured without spacer. It is concluded that for some materials self-curing alone was not adequate to achieve sufficient hardening; cement hardness was significantly reduced when ceramic inlay thickness was 2-3 mm or more.
authors.affiliation: University of Toronto, Faculty of Dentistry, Department of Restorative Dentistry, Ontario, Canada.
authors.forename: O M
authors.initials: OM
authors.lastname: el-Mowafy
authors.forename: M H
authors.initials: MH
authors.lastname: Rubo
authors.forename: W A
authors.initials: WA
authors.lastname: el-Badrawy
mesh_terms: D000704:Analysis of Variance; D002516:Ceramics; D003776:Dental Porcelain / Q000737:chemistry; D006244:Hardness; D007284:Inlays; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*
chemical_list: D011108:Polymers; D019279:Resin Cements; D003776:Dental Porcelain; C074543:Cerec