title: Effect of an occlusal screw-access hole on the fracture resistance of permanently cemented implant crowns: a laboratory study.
abstract: This study aimed to evaluate the fracture resistance of cement-retained metal-ceramic implant-supported posterior crowns. Three groups of 10 restorations each were tested: group A (cement-retained using zinc phosphate), group B (cement-retained using zinc oxide-eugenol), and group C (cement-retained using zinc phosphate but with an occlusal screw-access hole). All specimens were thermocycled and vertically loaded in a universal testing machine. Mean values of fracture loads were calculated and analyzed statistically. The cement-retained restorations without an occlusal screw-access hole showed significantly higher mean fracture loads than those having one. The type of cement did not affect the porcelain fracture resistance significantly.
authors.affiliation: Department of Prothodontics, Faculty of Dentistry, Arab American University, Jenin, Palestinian, Territory. rola_shadeed@yahoo.com
authors.forename: Rola M
authors.initials: RM
authors.lastname: Shadid
authors.forename: Layla
authors.initials: L
authors.lastname: Abu-Naba'a
authors.forename: Wael M
authors.initials: WM
authors.lastname: Al-Omari
authors.forename: Khaled R
authors.initials: KR
authors.lastname: Asfar
authors.forename: Bilal M
authors.initials: BM
authors.lastname: El Masoud
mesh_terms: D000704:Analysis of Variance; D003442:Crowns; D000044:Dental Abutments; D001840:Dental Bonding / Q000379:methods; D003738:Dental Cements / Q000737:chemistry*; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing; D016876:Metal Ceramic Alloys; D018709:Statistics, Nonparametric
chemical_list: D003738:Dental Cements; D016876:Metal Ceramic Alloys