title: Influence of abutment materials on the implant-abutment joint stability in internal conical connection type implant systems.
abstract: OBJECTIVE
  This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems.
  
  
  METHODS
  Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess the amount of settlement after abutment fixation, a 30-Ncm tightening torque was applied, then the change in length before and after tightening the abutment screw was measured, and the preload exerted was recorded. The compressive bending strength was measured under the ISO14801 conditions. In order to determine whether there were significant changes in settlement, preload, and compressive bending strength before and after abutment fixation depending on abutment materials, one-way ANOVA and Tukey's HSD post-hoc test was performed.
  
  
  RESULTS
  Group TA exhibited the smallest mean change in the combined length of the implant and abutment before and after fixation, and no difference was observed between groups T3 and T4 (P>.05). Group TA exhibited the highest preload and compressive bending strength values, followed by T4, then T3 (P<.001).
  
  
  CONCLUSIONS
  The abutment material can influence the stability of the interface in internal conical connection type implant systems. The strength of the abutment material was inversely correlated with settlement, and positively correlated with compressive bending strength. Preload was inversely proportional to the frictional coefficient of the abutment material.
authors.affiliation: Department of Prosthodontics, School of Dentisty, Pusan National University, Yangsan, Republic of Korea.
authors.forename: Jae-Young
authors.initials: JY
authors.lastname: Jo
authors.affiliation: Department of Prosthodontics, School of Dentisty, Pusan National University, Yangsan, Republic of Korea.
authors.forename: Dong-Seok
authors.initials: DS
authors.lastname: Yang
authors.affiliation: Department of Prosthodontics, School of Dentisty, Pusan National University, Yangsan, Republic of Korea.
authors.forename: Jung-Bo
authors.initials: JB
authors.lastname: Huh
authors.affiliation: Osstem Dental Implant Research Center (Osstem Implant), Busan, Republic of Korea.
authors.forename: Jae-Chan
authors.initials: JC
authors.lastname: Heo
authors.affiliation: Department of Prosthodontics, School of Dentisty, Pusan National University, Yangsan, Republic of Korea.
authors.forename: Mi-Jung
authors.initials: MJ
authors.lastname: Yun
authors.affiliation: Department of Prosthodontics, School of Dentisty, Pusan National University, Yangsan, Republic of Korea.
authors.forename: Chang-Mo
authors.initials: CM
authors.lastname: Jeong
keywords: Abutment material; Compressive bending strength; Implant; Interface stability; Preload