title: Biomechanical degradation of the nano-filled resin-modified glass-ionomer surface.
abstract: OBJECTIVE
  To evaluate in the laboratory the roughness (Ra) and micromorphology surface of the nanofilled resin-modified glass-ionomer (Ketac N100) subjected to biomechanical degradation, compared to Vitremer, Ketac Molar Easymix and Fuji IX.
  
  
  METHODS
  Specimens obtained from the ionomers were divided into two storage groups (n = 10): relative humidity and S. mutans biofilm (biodegradation). After 7 days, Ra values and micrographs were obtained. Then, the brushing abrasion test (mechanical degradation) was conducted with dentifrice slurry (three-body) and the specimens were reassessed. Data were submitted to repeated measures three-way ANOVA and Tukey tests (P < 0.05).
  
  
  RESULTS
  There was significant interaction among the factors: material, storage and abrasion (before/after). Vitremer showed similar Ra values between storage groups, while the other materials presented higher Ra values after biodegradation test. Concerning biomechanical challenge, Ketac N100 presented the lowest Ra values. Ketac Molar Easymix and Fuji IX presented undesirable roughening of their surfaces under the detrimental conditions tested. The eroded aspect after biodegradation with filler exposure after mechanical degradation was evident.
authors: Department of Social and Public Health, University of Campinas, Piracicaha, São Paulo, Brazil.
authors: Suzana Beatriz Portugal
authors: SB
authors: de Fúcio
authors: Andréia Bolzan
authors: AB
authors: de Paula
authors: Fabíola Galbiatti
authors: FG
authors: de Carvalho
authors: Victor Pinheiro
authors: VP
authors: Feitosa
authors: Glaucia Maria B
authors: GM
authors: Ambrosano
authors: Regina Maria
authors: RM
authors: Puppin-Rontani
mesh_terms: D001696:Biomechanical Phenomena; D005898:Glass; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D013499:Surface Properties