title: Influence of Fixture Thread Exposure on Marginal Bone Level Around Different Implant Systems: A Preliminary Study in Dogs.
abstract: OBJECTIVE
  To evaluate the influence of implant neck structures on marginal bone loss around intentionally exposed implant fixtures by histomorphometric analysis.
  
  
  METHODS
  Twenty-four implants representing 3 implant systems were placed in three dogs; an implant system with SLA surface without microthreads (group A); one with SLA + calcium surface without microthreads (group B); and one with SLA surface with microthreads (group C). The histomorphometric analyses for vertical defect length (VDL), infrabony defect height (IDH), and defect depth (DD) were performed at the buccal and lingual sides of each fixture.
  
  
  RESULTS
  The VDL was lower in group A relative to groups B and C on the buccal and lingual sides. The IDH and DD were higher in group A than group C on the buccal and lingual sides; however, no statistically significant differences were noted between the groups in VDL, IDH, and DD on the buccal and lingual sides of the fixtures.
  
  
  CONCLUSIONS
  In this preliminary study, marginal bone resorption pattern in the canine mandible varied according to the neck design of each implant fixture. Further studies with larger sample size are needed to confirm the effect of microthreads and surface roughness on the marginal bone loss at the exposed implant fixture.
authors.affiliation: Department of Prosthodontics, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Bohm
authors.initials: B
authors.lastname: Choi
authors.affiliation: Department of Oral and Maxillofacial Surgery, Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, Republic of Korea.
authors.forename: Hyun-Joong
authors.initials: HJ
authors.lastname: Yoon
authors.affiliation: Practice private clinic, Busan, Republic of Korea.
authors.forename: Won-Suk
authors.initials: WS
authors.lastname: Ha
authors.affiliation: DIO, Busan, Republic of Korea.
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Park
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology*; D000818:Animals; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D008297:Male; D008334:Mandible / Q000601:surgery; D013499:Surface Properties
chemical_list: D015921:Dental Implants
keywords: Dental implant; microthread; surface roughness