title: Amorphous calcium phosphate-containing orthodontic composites. Do they prevent demineralisation around orthodontic brackets?
abstract: BACKGROUND
  A preliminary study using laser fluorescence suggested that amorphous phosphate-containing orthodontic composites may prevent demineralisation around bonded orthodontic brackets.
  
  
  OBJECTIVE
  To compare the microhardness of the enamel around brackets bonded with an amorphous calcium phosphate-containing orthodontic composite (ACP-containing) with the microhardness of the enamel around brackets bonded with a conventional composite resin.
  
  
  METHODS
  Forty extracted upper premolars were used. Orthodontic brackets were bonded to the teeth with either an ACP-containing composite resin (N = 20) or a conventional composite resin (N = 20). The latter were used as the control. The crowns of all teeth were painted with an acid resistant varnish, leaving a 2 mm ring of exposed enamel around the brackets. The teeth were then subjected to a daily cycle of demineralisation for 6 hours and remineralisation for 18 hours for 21 days. Each tooth was sectioned and the microhardness of the enamel determined 25, 50, 75, 100 and 150 microm from the surface.
  
  
  RESULTS
  The enamel was significantly harder 25 microm (p = 0.000) and 50 microm (p = 0.001) from the enamel surface in the teeth with brackets bonded with the ACP-containing composite resin as compared with the control teeth.
  
  
  CONCLUSIONS
  ACP-containing orthodontic composite resins may reduce the enamel decalcification found in patients with poor oral hygiene.
authors.affiliation: Department of Orthodontics, Erciyes University, Kayseri, Turkey. tancanuysal@yahoo.com
authors.forename: Tancan
authors.initials: T
authors.lastname: Uysal
authors.forename: Mihri
authors.initials: M
authors.lastname: Amasyali
authors.forename: Alp Erdin
authors.initials: AE
authors.lastname: Koyuturk
authors.forename: Suat
authors.initials: S
authors.lastname: Ozcan
authors.forename: Deniz
authors.initials: D
authors.lastname: Sagdic
mesh_terms: D000134:Acid Etching, Dental; D002130:Calcium Phosphates / Q000737:chemistry*; D002327:Cariostatic Agents / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003743:Dental Enamel / Q000648:ultrastructure; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry*; D013997:Time Factors; D017001:Tooth Demineralization / Q000517:prevention & control*; D014089:Tooth Remineralization
chemical_list: C528777:Aegis Ortho adhesive; D002130:Calcium Phosphates; D002327:Cariostatic Agents; D003188:Composite Resins; D003738:Dental Cements; D019279:Resin Cements; C516047:Transbond XT Light Cure Adhesive Primer; C519480:amorphous calcium phosphate