title: Influence of patient factors on age of restorations at failure and reasons for their placement and replacement.
abstract: OBJECTIVE
  This study examined the reasons given by a selected group of dental practitioners for placement and replacement of restorations and correlated the data provided with patient factors, such as patients' age and gender, caries risk, occlusal function and oral hygiene, with restoration longevity.
  
  
  METHODS
  A group of general dental practitioners (GDPs) were recruited to take part in the study. Each participant was asked to record the reason for placement or replacement of restorations from a list of potential reasons. The age and Class of the restoration being replaced was also recorded, as also was the material being used and the material being replaced.
  
  
  RESULTS
  Details of reason for placement/replacement was received on 3196 restorations from 32 GDPs. Of the restorations placed, 54% were amalgam, 32% composite, 8% compomer and 7% glass ionomer. The reasons for placement/replacement of the restorations were principally primary caries (28%), secondary caries (29%), margin fracture (10%), tooth fracture (7%), and non-carious defects (6%). Overall, the mean age of restorations at failure was 7.1 years. Of the patients who received glass ionomer restorations, 29% were rated as having poor oral hygiene, compared with 18% of the patients who received amalgam restorations, 18% of the patients who received composite restorations and 23% of the patients who received compomer restorations. Of the patients who received glass ionomer restorations, 35% were rated as having high caries susceptibility, compared with 27% of those receiving amalgam restorations, 21% of those receiving composite restorations and 30% of those receiving compomer restorations.
  
  
  CONCLUSIONS
  Primary caries was the principal reason for initial restorations. Secondary caries was the most prevalent reason for replacement of restorations. The results also indicate a selective application of different materials for different patients.
authors.affiliation: University of Birmingham School of Dentistry, St. Chad's Queensway, Birmingham B4 6NN, UK. f.j.t.burke@bham.ac.uk
authors.forename: F J
authors.initials: FJ
authors.lastname: Burke
authors.forename: N H
authors.initials: NH
authors.lastname: Wilson
authors.forename: S W
authors.initials: SW
authors.lastname: Cheung
authors.forename: I A
authors.initials: IA
authors.lastname: Mjör
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002648:Child; D003731:Dental Caries / Q000453:epidemiology / Q000628:therapy; D003733:Dental Caries Susceptibility; D003766:Dental Occlusion; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009910:Oral Hygiene; D019233:Retreatment; D012737:Sex Factors; D018709:Statistics, Nonparametric; D006113:United Kingdom / Q000453:epidemiology