title: Survival of splinted mini-implants after contamination with stainless steel.
abstract: OBJECTIVE
  Dental practitioners are instructed to avoid any type of contact with implant surfaces prior to their insertion. However, the probability of contaminating the surface is high, especially when placement of implants necessitates the use of precise surgical guides. The aim of this study was to evaluate the 2-year survival rate of splinted mini-implants that came into contact with stainless steel prior to their insertion.
  
  
  METHODS
  During the clinical portion of the study, initiated over a 3-day period, 90 mini-implants were inserted into the anterior mandible of 45 totally edentulous patients; 46 were inserted using a prefabricated stainless steel guide (group 1, bar) and 44 were placed without a guide (group 2, ball). A flapless surgical protocol was used. All implants were immediately loaded with mandibular overdentures, and follow-up was conducted for up to 2 years. The Kaplan-Meier method was used to analyze implant survival in each group, with a confidence level of 95%. In the in vitro phase of the study, five mini-implants were contaminated for 20 seconds with a stainless steel surgical guide. They were then observed using scanning electron microscopy and energy dispersive spectroscopy to identify contaminants and to determine qualitatively the chemical composition of the surface. As a control, five mini-implants recently extracted from their original containers were analyzed.
  
  
  RESULTS
  During the 2-year follow-up, one implant failed (97.8% survival rate) in group 1 and four failed in group 2 (90.9% survival rate). The in vitro analysis revealed carbon and oxygen on all implants. On the implants that were in contact with stainless steel, additional elements were identified, including silica, calcium, iron, and chromium.
  
  
  CONCLUSIONS
  Contact between mini-implants and stainless steel surgical guides does not seem to generate contamination that compromises the survival of splinted mini-implants.
authors.affiliation: Center for Advanced Prosthodontics and implant Dentistry, Universtity of Concepción, Concepción, Chile. jjofre@udec.cl
authors.forename: Jorge
authors.initials: J
authors.lastname: Jofré
authors.forename: Yuri
authors.initials: Y
authors.lastname: Conrady
authors.forename: Claudia
authors.initials: C
authors.lastname: Carrasco
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D002118:Calcium / Q000032:analysis; D002244:Carbon / Q000032:analysis; D002857:Chromium / Q000032:analysis; D003722:Dental Alloys / Q000737:chemistry*; D003758:Dental Implantation, Endosseous / Q000295:instrumentation; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003828:Denture, Overlay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007501:Iron / Q000032:analysis; D007575:Jaw, Edentulous / Q000601:surgery; D008297:Male; D008334:Mandible / Q000601:surgery; D008422:Materials Testing; D008875:Middle Aged; D010100:Oxygen / Q000032:analysis; D012822:Silicon Dioxide / Q000032:analysis; D013193:Stainless Steel / Q000737:chemistry*; D013499:Surface Properties; D016019:Survival Analysis; D014025:Titanium / Q000737:chemistry*; D016896:Treatment Outcome
chemical_list: D000497:Alloys; D003722:Dental Alloys; D015921:Dental Implants; D002857:Chromium; D013193:Stainless Steel; C031462:titanium alloy (TiAl6V4); D002244:Carbon; D012822:Silicon Dioxide; D014025:Titanium; D007501:Iron; D010100:Oxygen; D002118:Calcium