title: Light transmittance and surface roughness of a feldspathic ceramic CAD-CAM material as a function of different surface treatments.
abstract: BACKGROUND
  The aim of the present study was to determine the effect of different surface treatments on light transmission of aesthetic feldspathic ceramics used in CAD-CAM chairside restorations.
  
  
  METHODS
  Forty eight feldspatic ceramic test specimens were prepared from prefabricated CAD-CAM blocks by using a slow speed diamond saw. Test specimens were prepared and divided into 4 groups (n = 12). In the control group, no surface treatments were applied on the feldspathic ceramic surfaces. In the hydrofluoric acid group, the bonding surfaces of feldspathic ceramics were etched with 9.5 % hydrofluoric acid. In the sandblasting group the feldspathic ceramic surfaces were air-abraded with 30-μm alumium oxide (Al2O3) particles and Er:YAG laser was used to irradiate the ceramic surfaces. The incident light power given by the LED device and the transmitted light power through each ceramic sample was registered using a digital LED radiometer device. Each polymerization light had a light guide with 8-mm-diameter tips. Light transmission of feldspathic ceramic samples was determined by placing it on the radiometer and irradiating the specimen for 10 s at the highest setting for each light polymerization. All specimens were coated with gold using a sputter coater and examined under a field emission scanning electron microscope. Surface roughness measurement each group were evaluated with 3D optical surface and tactile profilometers.
  
  
  RESULTS
  One-way ANOVA test results revealed that both surface conditioning method significantly affect the light transmittance (F:412.437; p < 0.001) and the surface roughness values (F:16.386; p < 0.001). Al2O3 and Er-YAG laser application reduced the light transmission significantly (p < 0.05).
  
  
  CONCLUSIONS
  The laser and Al2O3 applications reduced the light transmission of 1.5 mm thickness feldspathic ceramic material below the value of 400 mW/cm(2) which is critical limit for safe polymerization.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
authors.forename: Çağrı
authors.initials: Ç
authors.lastname: Ural
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
authors.forename: İbrahim
authors.initials: İ
authors.lastname: Duran
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
authors.forename: Betül
authors.initials: B
authors.lastname: Evmek
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Ondokuz Mayıs University, Samsun, Turkey.
authors.forename: İdris
authors.initials: İ
authors.lastname: Kavut
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey.
authors.forename: Seda
authors.initials: S
authors.lastname: Cengiz
authors.affiliation: Department of Prosthodontics, School of Dentistry, Istanbul Medipol University, Ataturk Bulvari, No:27, 34083, Unkapani, Fatih, Istanbul, Turkey. eyuzbasioglu@medipol.edu.tr.|Biomaterials and Translational Dental Research Laboratory, Regenerative and Restorative Medicine Research Center (REMER), Istanbul Medipol University, Istanbul, Turkey. eyuzbasioglu@medipol.edu.tr.
authors.forename: Emir
authors.identifier: http://orcid.org/0000-0001-5348-6954
authors.initials: E
authors.lastname: Yuzbasioglu
mesh_terms: D002516:Ceramics; D017076:Computer-Aided Design; D001840:Dental Bonding; D003776:Dental Porcelain; D004955:Esthetics, Dental; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements; D013499:Surface Properties
chemical_list: D019279:Resin Cements; D003776:Dental Porcelain
keywords: CAD-CAM blocks; Feldspathic ceramic; Laser treatment; Light-transmission