title: Effect of toothbrushing on titanium surface: an approach to understanding surface properties of brushed titanium.
abstract: OBJECTIVE
  This in vitro study aimed to characterize the surface morphology and composition of tooth-brushed titanium casting and thereby to elucidate interactions between the metal and abrasive material in dentifrice.
  
  
  METHODS
  Specimens were cast from CP Ti ingots and then mirror-finished. Two fluoride-free toothpastes containing crystalline CaHPO4.2H2O and amorphous SiO2 particles as abrasive were slurried with distilled water (15 g/30 mL). While toothbrushes were reciprocated at 120 strokes/min for 350,400 strokes, the specimens were brushed with the respective slurries under a load of 2.45 N. The brushed and non-brushed surfaces were characterized by means of SPM, EPMA, and XPS. SPM data were analyzed using one-way ANOVA, followed by post hoc Tukey test (p<0.01).
  
  
  RESULTS
  Irrespective of toothpastes, toothbrushing had a significant influence on surface roughness. The CaHPO4.2H2O-containing paste produced much rougher surface than the SiO2-containing paste. Both the surfaces were chemically altered due to reactions with the respective abrasive materials. Abrading chips had dimensions of micron to submicron order. A number of chips were attached to abrasive particles.
  
  
  CONCLUSIONS
  The alterations of surface morphology and composition may affect biological responses of titanium in the oral environment. Dentifrice with lower abrasivity might be advisable for daily oral hygiene practice of patients with dental titanium devices.
authors.affiliation: Division of Dental Biomaterial Science, Graduate School of Medical and Dental Sciences, Niigata University, Gakkoucho-dori 2-5274, Niigata 951-8514, Japan.
authors.forename: Awlad
authors.initials: A
authors.lastname: Hossain
authors.forename: Seigo
authors.initials: S
authors.lastname: Okawa
authors.forename: Osamu
authors.initials: O
authors.lastname: Miyakawa
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D004577:Electron Probe Microanalysis; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014099:Toothbrushing / Q000295:instrumentation*; D014100:Toothpastes / Q000737:chemistry
chemical_list: D002130:Calcium Phosphates; D003764:Dental Materials; D014100:Toothpastes; D012822:Silicon Dioxide; C020243:calcium phosphate; D014025:Titanium