title: Effects of daily topical fluoride gels on resin composite degradation and wear.
abstract: OBJECTIVE
  This in vitro study compares the effects of professional and consumer-applied topical fluorides on the weight, wear resistance and surface appearance of a resin composite containing barium boroaluminosilicate glass filler particles.
  
  
  METHODS
  Prior to wear studies with a pin and disc apparatus, specimens were immersed for 6 min 10 times in water, three consumer-applied topical fluorides (1.1% NaF, 0.4% SnF2, or 0.5% APF gel) or a professionally applied topical fluoride (1.23% APF gel). Specimens were weighed before and after each immersion. Following wear studies, the specimen surfaces were visually evaluated using scanning electron microscopy. Weight changes were analyzed for significant differences using one-way ANOVA and Duncan's multiple range test (p = 0.01). Values of wear parameters were ranked and tested for significance using one-way ANOVA with least squares mean contrast (p = 0.05).
  
  
  RESULTS
  Significant differences were found in the weight loss of specimens treated with different fluoride agents: 1.23% APF = 0.5% APF > 0.4% SnF2 > 1.1% NaF = water (p < or = 0.0001). Significant differences in initial wear depth (S(i)) occurred in the following samples: 1.23% APF > 1.1% NaF = 0.5% APF (p = 0.04). Scanning electron micrographs showed variable wear tracks on the specimen surfaces. The specimen surfaces outside the wear track were smooth for those treated with water or with NaF; the surfaces outside the wear track of specimens treated with APF showed extensive loss of filler particles.
  
  
  CONCLUSIONS
  Topical APF agents caused extensive loss of filler from the resin composite specimens whereas 1.1% NaF caused the least damage. Although significant differences in surface wear resistance were detected, clinical studies are needed to determine the effect of topical fluorides on the properties of this resin composite.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, University of Missouri-Kansas City Dental School, USA. kulak@smtpgate.umkc.edu
authors.forename: K
authors.initials: K
authors.lastname: Kula
authors.forename: J E
authors.initials: JE
authors.lastname: McKinney
authors.forename: T J
authors.initials: TJ
authors.lastname: Kula
mesh_terms: D000149:Acidulated Phosphate Fluoride / Q000737:chemistry; D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D019554:Dental Restoration Wear; D005460:Fluorides, Topical / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011140:Polyurethanes / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D018709:Statistics, Nonparametric; D014002:Tin Fluorides / Q000737:chemistry
chemical_list: D003188:Composite Resins; D005460:Fluorides, Topical; D005782:Gels; D011140:Polyurethanes; D014002:Tin Fluorides; D000149:Acidulated Phosphate Fluoride; D017438:Bisphenol A-Glycidyl Methacrylate; D012969:Sodium Fluoride; C046503:formula F 70