title: Reasons for the placement and replacement of restorations in vocational training practices.
abstract: OBJECTIVE
  The reasons for placement and replacement of restorations are central to clinical practice. It is the purpose of this paper to assess the reasons for placement and replacement of restorations in the practices of vocational dental practitioners (VDPs) and their trainers.
  
  
  METHODS
  VDPs and their trainers were invited to take part in the study. VDPs were asked to record the principal reason for the placement or replacement of all restorations which they provided for a one-month period and, also, to record the age, Class and materials used for each restoration replaced (if known). Trainers were also asked to participate. The data thereby collected were analysed statistically.
  
  
  RESULTS
  56 VDPs and 17 trainers participated. Data were obtained on a total of 9031 restorations, 4423 (49%) being initial placements and 4608 (51%) replacements. Of the total number of restorations assessed, 54% were amalgam, 30% composite and 16% glass ionomer. Principal reasons for placement/replacement of the restorations were primary caries (41%), secondary caries (22%), tooth fracture (6%), margin fracture/degradation (6%), non-carious defects (6%) and bulk fracture (5%). The type of existing restorative material was recorded for 4196 restorations: secondary caries was the most common reason for the replacement of restorations--for 46.0%, 39.6% and 39.8% of amalgam, composite and glass-ionomer restorations respectively. VDPs placed more restorations as a consequence of caries than their trainers.
  
  
  CONCLUSIONS
  Primary caries is the most common reason for the placement of restorations by the participating dentists, and secondary caries is the most common reason for the replacement of restorations of amalgam, composite and glass ionomer. VDPs placed more restorations as a consequence of caries than their trainers.
authors.affiliation: Glasgow Dental School. f.j.t.burke@dental.gla.uk
authors.forename: F J
authors.initials: FJ
authors.lastname: Burke
authors.forename: S W
authors.initials: SW
authors.lastname: Cheung
authors.forename: I A
authors.initials: IA
authors.lastname: Mjör
authors.forename: N H
authors.initials: NH
authors.lastname: Wilson
mesh_terms: D003731:Dental Caries / Q000628:therapy; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data*; D004497:Education, Dental / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D011231:Preceptorship / Q000706:statistics & numerical data; D019233:Retreatment; D011795:Surveys and Questionnaires; D014082:Tooth Fractures / Q000628:therapy; D006113:United Kingdom