title: Clinical experiences of computer numeric control-milled titanium frameworks supported by implants in the edentulous jaw: a 5-year prospective study.
abstract: BACKGROUND
  Few long-term follow-up studies on treatment concepts using computer numeric control-milled titanium frameworks have been conducted.
  
  
  OBJECTIVE
  To evaluate the clinical and radiographic performance of implant-supported prostheses provided with computer numeric control-milled titanium frameworks in the edentulous jaw and to compare their performance during the first 5 years of function with that of prostheses provided with conventional cast gold alloy frameworks.
  
  
  METHODS
  A consecutive group of 126 edentulous patients were randomly provided with 67 prostheses with titanium frameworks (test group) in 23 upper jaws and 44 lower jaws and with 62 conventional prostheses with gold alloy castings (control group) in 31 upper jaws and 31 lower jaws. Clinical and radiographic 5-year data were collected for the test and control groups.
  
  
  RESULTS
  The frequency of problems was low, and clinical and radiologic performances were similar in both groups. In the test group, the 5-year cumulative survival rates (CSRs) were 94.9% and 98.3% for implants and titanium prostheses, respectively. The respective corresponding CSRs for the control group were 97.9% and 98.2%. More loaded implants were lost in the maxillas in the test group (p < .01), but this difference was not significant on the patient/prosthesis level (p > .05). Smokers lost more implants than nonsmokers lost (p < .01). Similar survival rates were observed for implants in the mandible. One prosthesis was lost in each group because of the loss of implants. Metal fractures were seen only in the control group, and resin veneer fractures were more frequent in the maxilla in the gold alloy group (p < .05). In the test group, the mean marginal bone loss was 0.5 mm (SD, 0.44) in the maxilla and 0.4 mm (SD, 0.50) in the mandible. A similar pattern of bone reaction was observed in the control group. Mean marginal bone loss was similar for smokers and nonsmokers (p > .05).
  
  
  CONCLUSIONS
  Computer numeric control-milled titanium frameworks are a viable alternative to gold alloy castings in the edentulous jaw and present clinical and radiologic performances similar to those of conventional gold alloy frameworks during the first 5 years of function.
authors.affiliation: The Brånemark Clinic, Public Dental Health, Göteborg, Sweden. anders.ortorp@vgregion.se
authors.forename: Anders
authors.initials: A
authors.lastname: Ortorp
authors.forename: Torsten
authors.initials: T
authors.lastname: Jemt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology; D017076:Computer-Aided Design; D003758:Dental Implantation, Endosseous; D015921:Dental Implants / Q000009:adverse effects; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported / Q000009:adverse effects; D019232:Dental Restoration Failure; D005260:Female; D005500:Follow-Up Studies; D006047:Gold Alloys; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation*; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D018709:Statistics, Nonparametric; D014025:Titanium
chemical_list: D015921:Dental Implants; D006047:Gold Alloys; D014025:Titanium