title: The effect of working time on the displacement of Biodentine™beneath prefabricated stainless steel crown: a laboratory study.
abstract: OBJECTIVE
  To investigate the displacement of Biodentine™following cementation of stainless steel crowns (SSC) with glass-ionomer cement (GIC) on plastic deciduous teeth prepared for pulpotomy.
  
  
  METHODS
  Twenty plastic teeth with prepared occlusal cavities were divided into four groups and had Biodentine™placed as a mock pulpotomy agent. The pulp chamber was filled with freshly mixed Biodentine™then a GIC-loaded SSC was seated on the tooth using a standardized seating force for periods of: 1 min (Group 1); 2 min (Group 2), 3 min (Group 3) and 6 min (Group 4) after mixing. After 24 h at 37°C and 90% humidity, the crowns were sectioned mesio-distally and standardized digital photographs taken. Image analysis software was used to determine the ratio of the surface area of displaced Biodentine™relative to the surface area of the pulp chamber. The thinnest section of the remaining Biodentine™was measured.
  
  
  RESULTS
  The lowest values of Biodentine™displacement and the highest values of remaining Biodentine™thickness were associated with Group 4. There were no significant differences between the results in Group 3 and Group 4.
  
  
  CONCLUSIONS
  Within the limitations of this in vitro study, a GIC-loaded SSC can be seated on Biodentine™placed into a pulp chamber 3 min after mixing.
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic., Australia.
authors.forename: Alaa E
authors.initials: AE
authors.lastname: Dawood
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic., Australia. djmanton@unimelb.edu.au.
authors.forename: David J
authors.initials: DJ
authors.lastname: Manton
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic., Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Parashos
authors.affiliation: Melbourne Dental School, Oral Health CRC, The University of Melbourne, Melbourne, Vic., Australia.
authors.forename: Rebecca H K
authors.initials: RH
authors.lastname: Wong
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry*; D002484:Cementation / Q000379:methods*; D003442:Crowns; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003782:Dental Pulp; D003786:Dental Pulp Cavity; D003793:Dental Restoration, Permanent; D005899:Glass Ionomer Cements / Q000737:chemistry; D008422:Materials Testing; D008963:Molar; D011672:Pulpotomy / Q000295:instrumentation; D012387:Root Canal Filling Materials / Q000737:chemistry*; D018915:Root Canal Preparation; D017640:Silicates / Q000737:chemistry*; D013193:Stainless Steel / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D019231:Tooth Preparation, Prosthodontic; D014094:Tooth, Deciduous
chemical_list: D017610:Calcium Compounds; D003722:Dental Alloys; D003738:Dental Cements; D005899:Glass Ionomer Cements; D012387:Root Canal Filling Materials; D017640:Silicates; D013193:Stainless Steel; C506393:tricalcium silicate
keywords: biodentine; glass-ionomer cement; pulpotomy; setting time; stainless steel crown