title: Relative wear of flowable and highly filled composite.
abstract: BACKGROUND
  By decreasing the proportion of filler, flowable composites are easy to adapt to small cavity preparations. However, the wear resistance of flowable composites is a clinical concern, as improved wear has been related to increased filler percentage.
  
  
  OBJECTIVE
  The purpose of this study was to compare wear for flowable composites and comparable heavily filled materials.
  
  
  METHODS
  Wear by attrition and abrasion (microm) of microfilled flowable (Heliomolar Flow) and heavily filled microfill (Heliomolar HB) was measured and compared to a microhybrid flowable (Tetric Flow) and a heavily filled microhybrid (Tetric HB). There were 5 specimens, 2 mm thick and 15 mm in diameter, in each group. The Oregon Health Sciences University oral wear simulator was used to produce abrasive wear and attrition for all specimens. Abrasion and attrition of the substrates were measured using a profilometer. Data were subjected to a 3-way analysis of variance for the 3 main factors: composite type, filler load, and wear type (alpha=.05)
  
  
  RESULTS
  Composite wear rates were significantly influenced (P <.01) by both the type of wear and the filler amount. Abrasive wear occurred less than wear by attrition, and the heavily filled composites experienced less wear than the flowable composites.
  
  
  CONCLUSIONS
  Results of this in vitro study suggest that highly filled microhybrid composites may have greater wear resistance for contact-supporting posterior restorations. However, in small noncontact restorations where longevity may be dictated by abrasion, flowable microfilled resins may be adequate.
authors.affiliation: The Ohio State University, College of Dentistry, Columbus, Ohio, USA. clelland.1@osu.edu
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Clelland
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Pagnotto
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Kerby
authors.forename: Robert R
authors.initials: RR
authors.lastname: Seghi
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D019554:Dental Restoration Wear / Q000706:statistics & numerical data*; D011140:Polyurethanes / Q000737:chemistry*; D014072:Tooth Abrasion; D019217:Tooth Attrition
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; C513708:Heliomolar; C470818:Heliomolar Flow; C478050:Heliomolar HB; D011140:Polyurethanes; C121818:Tetric ceram; C452226:tetric flow composite resin