title: Placement and replacement of restorations by selected practitioners.
abstract: BACKGROUND
  There are few Australian data on the reasons for placement and replacement of restorations, and the extent to which these are carried out in general practice.
  
  
  METHODS
  A survey was carried out of approximately 100 consecutive restorations placed by each of 28 general dental practitioners. The data were coded and statistically analyzed for various associations.
  
  
  RESULTS
  Resin composite was used twice as frequently as amalgam as a restorative material, and nearly four times as often as glass-ionomer cement. Secondary caries was the principal reason for replacing restorations, affecting predominantly amalgam restorations in Class I and Class V cavities. Teeth restored with amalgam fractured nearly twice as often as teeth restored with resin composite. The average ages of amalgam, resin composite and glass-ionomers at replacement were 13.6, 7.1 and 5.7 years respectively.
  
  
  CONCLUSIONS
  Amalgam has the longest clinical service life, but is associated with more tooth fracture. Secondary caries is the main reason for replacing restorations. The anti-cariogenic effect of glass-ionomer cement is equivocal.
authors.affiliation: School of Dental Science, The University of Melbourne. m.tyas@unimelb.edu.au
authors.forename: M J
authors.initials: MJ
authors.lastname: Tyas
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003731:Dental Caries / Q000628:therapy; D003733:Dental Caries Susceptibility; D003737:Dental Cavity Preparation / Q000145:classification; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D005260:Female; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D019233:Retreatment; D012737:Sex Factors; D014082:Tooth Fractures / Q000209:etiology
chemical_list: D020770:Compomers; D003188:Composite Resins; D005899:Glass Ionomer Cements; D003723:Dental Amalgam