title: Changes in the provision of implant-supported prostheses at the Academic Centre for Dentistry Amsterdam (ACTA) from 1989 to 1995.
abstract: OBJECTIVE
  Over the last decade, oral implantology has become a major treatment modality to aid the restoration of reduced dentitions. The present study monitored and quantified changes within a 5-year interval (1989-1991 [denoted as 1990*] to 1995) in the provision of different types of implant-supported superstructures and characteristics of recipient patients at the Academic Centre for Dentistry Amsterdam (ACTA).
  
  
  METHODS
  All patients who received oral implants in 1990* and in 1995 were selected, and their files (95 and 105, respectively) were consulted. Data of interest were retrieved retrospectively, compared, and statistically analyzed using Chi-squared tests.
  
  
  RESULTS
  A number of statistically significant differences was apparent between these 2 periods. By 1995 there was a threefold increase in both the number of patients and the number of implants placed per year. The patient group of < or = 40 years of age had significantly increased, from 7% to 23%. Also, in 1995 more maxillae were implanted than in 1990* (44% vs 26%). Whereas the majority of implanted patients was edentulous in 1990* (64%), the majority in 1995 was partially edentulous (60%). By 1995, the new technique of guided bone regeneration (GBR) using membranes was evidenced (no GBR in 1990* vs 33% of all patients in 1995 receiving some form of local GBR therapy). With respect to the type of superstructures, there was a strong increase in the number of single-tooth replacements (from 4% to 23%). In the edentulous group, the majority of superstructures in 1990 was fixed prostheses (64%), whereas in 1995 the majority was overdentures (71%).
  
  
  CONCLUSIONS
  Major changes in oral implantology treatments were noticed between the 1990* and 1995 periods at ACTA. There is a trend toward implanting younger patients for partial implant-supported reconstructions using more regenerative procedures and with a more equal distribution in the maxilla and mandible.
authors.affiliation: Oral Implantology Group, Department of Oral Function, Academic Centre for Dentistry Amsterdam (ACTA), Louwesweg 1, 1068 EA Amsterdam, The Netherlands. E.vd.Zee@acta.nl
authors.forename: E
authors.initials: E
authors.lastname: Van der Zee
authors.forename: M
authors.initials: M
authors.lastname: Van Waas
authors.forename: M
authors.initials: M
authors.lastname: Broek
authors.forename: R
authors.initials: R
authors.lastname: Van der Mieden van Opmeer
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D000328:Adult; D017677:Age Distribution; D000540:Alveolar Ridge Augmentation / Q000706:statistics & numerical data; D016009:Chi-Square Distribution; D015921:Dental Implants / Q000706:statistics & numerical data*; D019250:Dental Implants, Single-Tooth / Q000706:statistics & numerical data; D017267:Dental Prosthesis Design / Q000706:statistics & numerical data*; D019094:Dental Prosthesis, Implant-Supported / Q000706:statistics & numerical data*; D003829:Denture, Partial / Q000706:statistics & numerical data; D005260:Female; D016557:Guided Tissue Regeneration, Periodontal / Q000706:statistics & numerical data; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000453:epidemiology* / Q000534:rehabilitation; D008297:Male; D008334:Mandible; D008437:Maxilla; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012189:Retrospective Studies; D017678:Sex Distribution
chemical_list: D015921:Dental Implants