title: Evaluation of a newly developed polymethyl methacrylate powder for brush-dip technique.
abstract: OBJECTIVE
  The aim of this study is to evaluate a newly developed polymethyl methacrylate (PMMA) powder.
  
  
  METHODS
  The particle size distribution, surface area, and particle shape of both new and traditional powders were compared. The shear bond strength of the resin cement with the new powder to a silver-palladium-copper-gold alloy was determined and compared to that for a cement with the traditional powder. Also, the weight of mixture held by the brush at one time of both powders was also calculated and compared as an index of mixability.
  
  
  RESULTS
  The surface area of the new powder was smaller than that of the traditional powder, while the particles size distributions were similar. The new powder included various-sized spherical particles as well as irregular particles, while the traditional powder consisted of only irregular particles. The new powder showed significantly higher mixability, although its bond strength was not significantly different from that of traditional powder.
  
  
  CONCLUSIONS
  The results of this study show that the interminglement of spherical and irregular particles cannot influence the bond strength to the alloy but is helpful to improve the working properties.
authors.affiliation: Division of General Dentistry, Nagasaki University Hospital, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. t-naomi@nagasaki-u.ac.jp
authors.forename: Naomi
authors.initials: N
authors.lastname: Tanoue
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yanagida
authors.forename: Takashi
authors.initials: T
authors.lastname: Sawase
mesh_terms: D003722:Dental Alloys; D001840:Dental Bonding / Q000379:methods*; D010316:Particle Size; D019904:Polymethyl Methacrylate; D011208:Powders; D019279:Resin Cements; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: C120982:Ag-Pd-Cu-Au alloy; D003722:Dental Alloys; D011208:Powders; D019279:Resin Cements; D019904:Polymethyl Methacrylate