title: Effect of cooling rate on shear bond strength of veneering porcelain to a zirconia ceramic material.
abstract: The purpose of the present study was to evaluate the effect of cooling rates after firing procedures of veneering porcelain on shear bond strength between veneering porcelain and a zirconium dioxide (zirconia; ZrO₂) ceramic material. A total of 48 ZrO₂ disks were divided equally into three groups. Two veneering porcelains that are recommended for ZrO₂ material - Cerabien ZR (CZR), IPS e.max Ceram (EMX) - and one that is recommended for metal ceramics - Super Porcelain AAA (AAA) were assessed. Each group was then further divided into two subgroups (n = 8) according to cooling time (0 or 4 min) after porcelain firing. Specimens were fabricated by veneering the porcelain on the ZrO₂ disks, after which shear bond testing was conducted. Bond strength differed significantly by cooling time in ZrO₂-AAA (P < 0.001) and ZrO₂-EMX (P = 0.001) specimens. There was no significant difference in shear bond strength with respect to cooling time in ZrO₂-CZR specimens (P = 0.382). The duration of cooling from firing temperature to room temperature may affect the shear bond strength of veneering porcelain to a zirconia material depending on porcelain material used.
authors.affiliation: Department of Fixed Prosthodontics, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan. komine@dent.nihon-u.ac.jp
authors.forename: Futoshi
authors.initials: F
authors.lastname: Komine
authors.forename: Ayako
authors.initials: A
authors.lastname: Saito
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Mai
authors.initials: M
authors.lastname: Koizuka
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Koizumi
authors.forename: Hideo
authors.initials: H
authors.lastname: Matsumura
mesh_terms: D003080:Cold Temperature; D001840:Dental Bonding; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D003801:Dental Veneers; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D033081:Shear Strength; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013997:Time Factors; D015040:Zirconium
chemical_list: D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide