title: Effect of different grinding burs on the physical properties of zirconia.
abstract: OBJECTIVE
  Grinding with less stress on 3Y-TZP through proper selection of methods and instruments can lead to a long-term success of prosthesis. The purpose of this study was to compare the phase transformation and physical properties after zirconia surface grinding with 3 different grinding burs.
  
  
  METHODS
  Forty disc-shaped zirconia specimens were fabricated. Each Ten specimens were ground with AllCeramic SuperMax (NTI, Kahla, Germany), Dura-Green DIA (Shofu Inc., Kyoto, Japan), and Dura-Green (Shofu Inc., Kyoto, Japan). Ten specimens were not ground and used as a control group. After the specimen grinding, XRD analysis, surface roughness test, FE-SEM imaging, and biaxial flexural strength test were performed.
  
  
  RESULTS
  After surface grinding, small amount of monoclinic phase in all experimental groups was observed. The phase change was higher in specimens, which were ground with Dura-Green DIA and AllCeramic SuperMax burs. The roughness of surfaces increased in specimens, which were ground with Dura-Green DIA and AllCeramic SuperMax burs than control groups and ground with Dura-Green. All experimental groups showed lower flexural strength than control group, but there was no statistically significant difference between control group and ground with Dura-Green DIA and AllCeramic SuperMax burs. The specimens, which were ground with Dura- Green showed the lowest strength.
  
  
  CONCLUSIONS
  The use of dedicated zirconia-specific grinding burs such as Dura-Green DIA and AllCeramic SuperMax burs decreases the grinding time and did not significantly affect the flexural strength of zirconia, and therefore, they may be recommended. However, a fine polishing process should be accompanied to reduce the surface roughness after grinding.
authors.affiliation: Department of Prosthodontics, School of Dentistry, Chosun University, Gwangju, Republic of Korea.
authors.forename: Kyung-Rok
authors.identifier: 0000-0002-4826-9821
authors.initials: KR
authors.lastname: Lee
authors.affiliation: Department of Dental Materials, School of Dentistry, Chosun University, Gwangju, Republic of Korea.
authors.forename: Han-Cheol
authors.identifier: 0000-0003-1966-781X
authors.initials: HC
authors.lastname: Choe
authors.affiliation: Department of Prosthodontics, School of Dentistry, Chosun University, Gwangju, Republic of Korea.
authors.forename: Yu-Ri
authors.identifier: 0000-0002-1806-3822
authors.initials: YR
authors.lastname: Heo
authors.affiliation: Department of Computer Science and Statistics, College of Natural Sciences, Chosun University, Gwangju, Republic of Korea.
authors.forename: Jang-Jae
authors.identifier: 0000-0001-8787-9940
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Prosthodontics, School of Dentistry, Chosun University, Gwangju, Republic of Korea.
authors.forename: Mee-Kyoung
authors.identifier: 0000-0001-9225-1744
authors.initials: MK
authors.lastname: Son
keywords: 3Y-TZP; Biaxial flexural strength; Phase transformation; Roughness; XRD