title: Reducing the surface roughness of dental acrylic resins by using an eggshell abrasive material.
abstract: BACKGROUND
  Excessive surface roughness of denture base resins adversely impacts oral health.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to examine the abrasive potential of eggshell powder in reducing the surface roughness of denture base resins.
  
  
  METHODS
  Thirty poly(methyl methacrylate) specimens were fabricated and polished with eggshell powders of different particle sizes and with pumice. The average surface roughness (Ra) after polishing was measured with a profilometer. Scanning electron microscope and optical electron microscope techniques were used to assess the surface roughness morphology of the specimens. ANOVA was used to analyze the Ravalues. The Tukey honest significant differences and Bonferroni tests were used to identify differences between the 2 abrasive materials (α=.05).
  
  
  RESULTS
  Significant differences in the Ravalues were observed between the fine and medium eggshell powder abrasives (P<.05). Similarly, significant differences were found between pumice and the fine eggshell powder abrasives (P<.001). No significant differences were found between pumice and the medium eggshell powder abrasive (P>.05). Specimens polished with pumice had the highest Ravalues, whereas specimens polished with the fine eggshell powder abrasive had the lowest Ravalues.
  
  
  CONCLUSIONS
  By connecting the Ravalues to the threshold limit value of 0.2 μm, eggshell powder abrasive finished denture acrylic resin surfaces better than pumice.
authors.affiliation: Postgraduate student, Dental Sciences Department, Dental Technology Programme, Durban University of Technology, Durban, South Africa.
authors.forename: Stanley C
authors.initials: SC
authors.lastname: Onwubu
authors.affiliation: Lecturer, Dental Sciences Department, Dental Technology Programme, Durban University of Technology, Durban, South Africa. Electronic address: anisav@dut.ac.za.
authors.forename: Anisa
authors.initials: A
authors.lastname: Vahed
authors.affiliation: Lecturer, Operations and Quality Management Department, Durban University of Technology, Durban, South Africa.
authors.forename: Shalini
authors.initials: S
authors.lastname: Singh
authors.affiliation: Professor, Department of Mechanical Engineering, Durban University of Technology, Durban, South Africa.
authors.forename: Krishnan M
authors.initials: KM
authors.lastname: Kanny
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry* / Q000627:therapeutic use; D000818:Animals; D003775:Dental Polishing / Q000379:methods*; D003802:Dentifrices / Q000627:therapeutic use*; D003819:Denture Bases; D004528:Egg Shell; D006801:Humans; D066298:In Vitro Techniques; D013499:Surface Properties
chemical_list: D000180:Acrylic Resins; D003802:Dentifrices