title: Outcome of direct restorations placed within the general dental services in England and Wales (Part 1): variation by type of restoration and re-intervention.
abstract: OBJECTIVE
  It is the aim of this paper to consider the dental factors associated with the need for re-intervention on a restoration, such as the tooth position, size of cavity, and restoration material.
  
  
  METHODS
  Patients whose data were included in this study were those whose birthdays were included within a set of randomly selected dates, one of which was chosen in each possible year of birth. The restoration records consisted of all those records containing directly placed restorations which related to courses of treatment of patients 18 years or older with last date on the claim form after 31st December 1990, and with date of acceptance after September 1990 and before January 2002. For each tooth treated with a direct restoration the subsequent history of intervention on that tooth was consulted, and the next date of intervention, if any could be found in the extended data set, was obtained. Thus a data set was created of direct restorations with their dates of placement and their dates, if any, of re-intervention.
  
  
  RESULTS
  Data for over 80,000 different adult patients were analyzed, of whom 46% were male and 54% female. A total of 503,965 tooth restoration occasions were obtained from the data over a period of eleven years. Single surface amalgam restorations were found to have the longest survival --58% at 10 years, and glass ionomer the shortest 38% at 10 years. Factors which were found to reduce restoration outcome included involvement of the incisal angle in composite restorations--this resulted in a reduction in median survival of around two years--and the placement of pins in a restoration. The presence of a root filling was also found to reduce the survival of restorations in the crown of the root filled tooth.
  
  
  CONCLUSIONS
  Small amalgam restorations have longer survival times before re-intervention than large amalgam restorations such as MOD. Composite and glass ionomer restorations perform less well than amalgam restorations. Pin placement and root filling reduce the survival time of restorations.
authors.affiliation: Dental Practice Board, Eastbourne, Sussex BN20 8AD, UK.
authors.forename: P S K
authors.initials: PS
authors.lastname: Lucarotti
authors.forename: R L
authors.initials: RL
authors.lastname: Holder
authors.forename: F J T
authors.initials: FJ
authors.lastname: Burke
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000293:Adolescent; D000328:Adult; D003188:Composite Resins; D003723:Dental Amalgam; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D011140:Polyurethanes; D012044:Regression Analysis; D019233:Retreatment; D012822:Silicon Dioxide / Q000737:chemistry*; D016019:Survival Analysis; D013997:Time Factors; D014852:Wales
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D011140:Polyurethanes; C015897:glass ionomer; D012822:Silicon Dioxide; D003723:Dental Amalgam