title: Cutting efficiency of diamond burs operated with electric high-speed dental handpiece on zirconia.
abstract: Zirconia-based dental restorations are becoming used more commonly. However, limited attention has been given to the difficulties experienced, concerning cutting, in removing the restorations when needed. The aim of the present study was to compare the cutting efficiency of diamond burs, operated using an electric high-speed dental handpiece, on zirconia (Zir) with those on lithium disilicate glass-ceramic (LD) and leucite glass-ceramic (L). In addition, evaluation of the cutting efficiency of diamond burs on Zir of different thicknesses was performed. Specimens of Zir were prepared with thicknesses of 0.5, 1.0, 2.0, and 4.0 mm, and specimens of LD and L were prepared with a thickness of 1.0 mm. Cutting tests were performed using diamond burs with super coarse (SC) and coarse (C) grains. The handpiece was operated at 150,000 rpm with a cutting force of 0.9 N. The results demonstrated that cutting of Zir took about 1.5- and 7-fold longer than cutting of LD and L, respectively. The SC grains showed significantly higher cutting efficiency on Zir than the C grains. However, when the thickness of Zir increased, the cutting depth was significantly decreased. As it is suggested that cutting of zirconia is time consuming, this should be taken into consideration in advance when working with zirconia restorations.
authors: Department of Prosthetic Dentistry/Dental Materials Science, Institute of Odontology, University of Gothenburg, Gothenburg, Sweden.|Laboratory for Redox Regulation, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Keisuke
authors: K
authors: Nakamura
authors: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Yusuke
authors: Y
authors: Katsuda
authors: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Shuhei
authors: S
authors: Ankyu
authors: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Akio
authors: A
authors: Harada
authors: Liaison Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Taichi
authors: T
authors: Tenkumo
authors: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Taro
authors: T
authors: Kanno
authors: Laboratory for Redox Regulation, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Yoshimi
authors: Y
authors: Niwano
authors: Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors: Hiroshi
authors: H
authors: Egusa
authors: Department of Prosthetic Dentistry/Dental Materials Science, Institute of Odontology, University of Gothenburg, Gothenburg, Sweden.
authors: Percy
authors: P
authors: Milleding
authors: Department of Prosthetic Dentistry/Dental Materials Science, Institute of Odontology, University of Gothenburg, Gothenburg, Sweden.|Department of Clinical Dentistry/Faculty of Health Sciences, The Arctic University of Norway, Tromsø, Norway.
authors: Ulf
authors: U
authors: Örtengren
keywords: cutting efficiency; diamond burs; leucite; lithium disilicate; zirconia