title: Effect of overglazed and polished surface finishes on the compressive fracture strength of machinable ceramic materials.
abstract: Controversy prevails over the effect of overglazing on the fracture strength of ceramic materials. Therefore, the effects of different surface finishes on the compressive fracture strength of machinable ceramic materials were investigated in this study. Plates prepared from four commercial brands of ceramic materials were either surface-polished or overglazed (n=10 per ceramic material for each surface finish), and bonded to flat surfaces of human dentin using a resin cement. Loads at failure were determined and statistically analyzed using two-way ANOVA and Bonferroni test. Although no statistical differences in load value were detected between polished and overglazed groups (p>0.05), the fracture load of Vita Mark II was significantly lower than those of ProCAD and IPS Empress CAD, whereas that of IPS e.max CAD was significantly higher than the latter two ceramic materials (p<0.05). It was concluded that overglazed and polished surfaces produced similar compressive fracture strengths irrespective of the machinable ceramic material tested, and that fracture strength was material-dependent.
authors.affiliation: Division of Cariology, Operative Dentistry and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Japan. tetsu@dent.niigata-u.ac.jp
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Asai
authors.forename: Ryunosuke
authors.initials: R
authors.lastname: Kazama
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Fukushima
authors.forename: Takashi
authors.initials: T
authors.lastname: Okiji
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D002484:Cementation / Q000379:methods; D002516:Ceramics / Q000737:chemistry*; D019245:Compressive Strength; D017076:Computer-Aided Design; D001840:Dental Bonding / Q000379:methods; D003775:Dental Polishing / Q000379:methods*; D003776:Dental Porcelain / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D017680:Potassium Compounds / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties
chemical_list: D000538:Aluminum Silicates; C500742:ED Primer II; C520133:IPS e.max CAD LT; C075815:IPS-Empress ceramic; D008689:Methacrylates; D017680:Potassium Compounds; C454801:ProCAD Ceramic; D019279:Resin Cements; C082340:Vita Mark II; C530542:clearfil esthetic cement; C493120:lithia disilicate; D003776:Dental Porcelain; C016447:feldspar; C078519:leucite; C023506:Glass ceramics