title: Modified tricalcium silicate cement formulations with added zirconium oxide.
abstract: OBJECTIVE
  This study aims to investigate the effect of modifying tricalcium silicate (TCS) cements on three key properties by adding ZrO2.
  
  
  METHODS
  TCS powders were prepared by adding ZrO2at six different concentrations. The powders were mixed with 1 M CaCl2solution at a 3:1 weight ratio. Biodentine (contains 5 wt.% ZrO2) served as control. To evaluate the potential effect on mechanical properties, the mini-fracture toughness (mini-FT) was measured. Regarding bioactivity, Ca release was assessed using ICP-AES. The component distribution within the cement matrix was evaluated by Feg-SEM/EPMA. Cytotoxicity was assessed using an XTT assay.
  
  
  RESULTS
  Adding ZrO2to TCS did not alter the mini-FT (p = 0.52), which remained in range of that of Biodentine (p = 0.31). Ca release from TSC cements was slightly lower than that from Biodentine at 1 day (p > 0.05). After 1 week, Ca release from TCS 30 and TCS 50 increased to a level that was significantly higher than that from Biodentine (p < 0.05). After 1 month, Ca release all decreased (p < 0.05), yet TCS 0 and TCS 50 released comparable amounts of Ca as at 1 day (p > 0.05). EPMA revealed a more even distribution of ZrO2within the TCS cements. Particles with an un-reacted core were surrounded by a hydration zone. The 24-, 48-, and 72-h extracts of TCS 50 were the least cytotoxic.
  
  
  CONCLUSIONS
  ZrO2can be added to TCS without affecting the mini-FT; Ca release was reduced initially, to reach a prolonged release thereafter; adding ZrO2made TCS cements more biocompatible.
  
  
  CONCLUSIONS
  TCS 50 is a promising cement formulation to serve as a biocompatible hydraulic calcium silicate cement.
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium.|Wuhan University, School and Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Okayama University Hospital, Center for Innovative Clinical Medicine, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Yoshihara
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: De Munck
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium.
authors.forename: Stevan
authors.initials: S
authors.lastname: Cokic
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium.
authors.forename: Pong
authors.initials: P
authors.lastname: Pongprueksa
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium.
authors.forename: Eveline
authors.initials: E
authors.lastname: Putzeys
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium.
authors.forename: Mariano
authors.initials: M
authors.lastname: Pedano
authors.affiliation: Wuhan University, School and Hospital of Stomatology, The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, Wuhan, People's Republic of China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Van Landuyt
authors.affiliation: KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven, Dentistry, Kapucijnenvoer 7, blok A-box 7001, 3000, Leuven, Belgium. bart.vanmeerbeek@med.kuleuven.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
mesh_terms: D001672:Biocompatible Materials; D017610:Calcium Compounds / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D008422:Materials Testing; D017640:Silicates / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D003738:Dental Cements; D017640:Silicates; C506393:tricalcium silicate; D015040:Zirconium; C028541:zirconium oxide
keywords: Ca release; Component distribution; Cytotoxicity; Mini-fracture toughness; Tricalcium silicate; Zirconium oxide