title: Surface characteristics of orthodontic materials and their effects on adhesion of mutans streptococci.
abstract: OBJECTIVE
  To test the hypothesis that there are no significant differences in the adhesion of mutans streptococci (MS) to various orthodontic materials based on their surface characteristics.
  
  
  METHODS
  Surface roughness (SR) and surface free energy (SFE) characteristics were investigated for nine different orthodontic materials (four orthodontic adhesives, three bracket raw materials, hydroxyapatite blocks, and bovine incisors) using confocal laser scanning microscopy and sessile drop method. Each material, except the bovine incisors, was incubated with whole saliva or phosphate-buffered saline for 2 hours. Adhesion assays were performed by incubating tritium-labeled MS with each material for 3 or 6 hours.
  
  
  RESULTS
  Orthodontic adhesives had higher SFE characteristics and lower SR than bracket materials. Orthodontic adhesives showed a higher MS retaining capacity than bracket materials, and MS adhesion to resin-modified glass ionomer and hydroxyapatite was highest. Extended incubation time increased MS adhesion, while saliva coating did not significantly influence MS adhesion. SFE, specifically its dispersive and polar components, was positively correlated with MS adhesion, irrespective of saliva coating.
  
  
  CONCLUSIONS
  The hypothesis is rejected. This study suggests that SFE characteristics play an important role in the initial MS adhesion to orthodontic materials.
authors.affiliation: Department of Oral Anatomy, Seoul National University, Seoul, Korea.
authors.forename: Seung-Pyo
authors.initials: SP
authors.lastname: Lee
authors.forename: Shin-Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Bum-Soon
authors.initials: BS
authors.lastname: Lim
authors.forename: Sug-Joon
authors.initials: SJ
authors.lastname: Ahn
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D001672:Biocompatible Materials / Q000737:chemistry; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry; D003738:Dental Cements / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D044622:Dental Pellicle / Q000502:physiology; D017886:Durapatite / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D007180:Incisor / Q000382:microbiology; D008422:Materials Testing; D018613:Microscopy, Confocal; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry; D012463:Saliva / Q000502:physiology; D012965:Sodium Chloride / Q000737:chemistry; D013193:Stainless Steel / Q000737:chemistry; D013295:Streptococcus mutans / Q000502:physiology*; D013499:Surface Properties; D013500:Surface Tension; D013997:Time Factors; D017155:Wettability
chemical_list: D001672:Biocompatible Materials; D003188:Composite Resins; D003722:Dental Alloys; D003738:Dental Cements; D003764:Dental Materials; D005899:Glass Ionomer Cements; D019279:Resin Cements; D013193:Stainless Steel; D012965:Sodium Chloride; D017886:Durapatite; D000537:Aluminum Oxide