title: Effects of metal surface grinding at the porcelain try-in stage of fixed dental prostheses.
abstract: OBJECTIVE
  This study was to evaluate the effect of grinding of the inner metal surface during the porcelain try-in stage on metal-porcelain bonding considering the maximum temperature and the vibration of samples.
  
  
  METHODS
  Ninety-one square prism-shaped (1 × 1 × 1.5 mm) nickel-chrome cast frameworks 0.3 mm thick were prepared. Porcelain was applied on two opposite outer axial surfaces of the frameworks. The grinding was performed from the opposite axial sides of the inner metal surfaces with a low-speed handpiece with two types of burs (diamond, tungsten-carbide) under three grinding forces (3.5 N, 7 N, 14 N) and at two durations (5 seconds, 10 seconds). The shear bond strength (SBS) test was performed with universal testing machine. Statistical analyzes were performed at 5% significance level.
  
  
  RESULTS
  The samples subjected to grinding under 3.5 N showed higher SBS values than those exposed to grinding under 7 N and 14 N (P<.05). SBS values of none of the groups differed from those of the control group (P>.05). The types of bur (P=.965) and the duration (P=.679) did not affect the SBS values. On the other hand, type of bur, force applied, and duration of the grinding affected the maximum temperatures of the samples, whereas the maximum vibration was affected only by the type of bur (P<.05).
  
  
  CONCLUSIONS
  Grinding the inner metal surface did not affect the metal-porcelain bond strength. Although the grinding affected the maximum temperature and the vibration values of the samples, these did not influence the bonding strength.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Halil İbrahim
authors.initials: Hİ
authors.lastname: Kılınç
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Bülent
authors.initials: B
authors.lastname: Kesim
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Hasan Önder
authors.initials: HÖ
authors.lastname: Gümüş
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Dinçel
authors.affiliation: Department of Mechatronics Engineering, Faculty of Engineering, Erciyes University, Kayseri, Turkey.
authors.forename: Selçuk
authors.initials: S
authors.lastname: Erkaya
keywords: Fixed dental prosthesis; Grinding; Metal-porcelain; Shear bond strength