title: Effects of installation depth on survival of an hydroxyapatite-coated Bicon implant for single-tooth restoration.
abstract: OBJECTIVE
  The present retrospective study evaluated various implant surface factors associated with Bicon implant survival for single-tooth restoration in the healthy individual.
  
  
  METHODS
  A retrospective cohort study design was used. A total of 613 Bicon (Bicon System, Boston, MA) implants (272 patients) were included. Because the use of hydroxyapatite (HA) coating has been controversial, the surface type was chosen according to the patient's preference. A total of 308 HA-coated implants and 305 titanium plasma-sprayed (TPS) implants were used. The macroanatomy of both implant types was identical. Patients who had systemic disease, poor quality bone, or removable prosthetics were excluded from the present study. A chart review was conducted to record age, gender, implant diameter, implant length, installation depth, installation location, and the use of bone grafting. Implant failure was recorded, and the data were analyzed using the chi(2) test and logistic regression analysis.
  
  
  RESULTS
  The installation depth was an important prognostic factor in the HA-coated implants. The failure rate for the HA-coated implants installed at margin level and 2 mm below level was 10.29% and 3.01%, respectively (chi(2) = 6.035, P = .014). The implant length was an important prognostic factor for the TPS-treated implants. The failure rate recorded for the TPS-treated implants installed with a length of less than 10 mm and 10 mm or longer was 15.46% and 2.40%, respectively (chi(2) = 18.414, P < .001).
  
  
  CONCLUSIONS
  Many factors can influence the failure rate of TPS and HA-coated Bicon implants. Among these, installation depth played an especially significant role in the success of HA-coated Bicon implants in the present study.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Sacred Heart Hospital, Hallym University, Gangwon-Do, Republic of Korea.
authors.forename: Eui-Hee
authors.initials: EH
authors.lastname: Lee
authors.forename: Sun-Mi
authors.initials: SM
authors.lastname: Ryu
authors.forename: Jwa-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Byoung-Ouck
authors.initials: BO
authors.lastname: Cho
authors.forename: Yong-Chan
authors.initials: YC
authors.lastname: Lee
authors.forename: Young-Ju
authors.initials: YJ
authors.lastname: Park
authors.forename: Seong-Gon
authors.initials: SG
authors.lastname: Kim
mesh_terms: D016025:Bone Transplantation; D016009:Chi-Square Distribution; D020099:Coated Materials, Biocompatible; D015331:Cohort Studies; D003442:Crowns; D003758:Dental Implantation, Endosseous / Q000379:methods*; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D017886:Durapatite; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D012307:Risk Factors; D013499:Surface Properties; D014025:Titanium
chemical_list: D020099:Coated Materials, Biocompatible; D017886:Durapatite; D014025:Titanium