title: A biomechanical effect of wide implant placement and offset placement of three implants in the posterior partially edentulous region.
abstract: To prevent loosening or fracture of screws retaining the prosthesis to the implants in the posterior partially edentulous region, the use of staggered buccal and lingual offset placement or wide implants is suggested. However, it is not known how this usage compensates for the torque produced by lateral occlusal forces. This study evaluated the effectiveness of offset placement of three implants and a wide implant placement at the most posterior site. Three-dimensional geometric analysis was used to calculate the tensile force applied to gold screws in clinical situations with buccal or lingual loading perpendicular to cuspal inclination (10 or 20 degrees ). Four variations of the placement of three implants (3.75 mm) are: (1) straight; (2) buccal offset of the second implant; (3) lingual offset of the second implant; (4) a wide implant (5 mm) placement at most posterior site. The offset placement did not always decrease tensile force at the gold screw, but wide implant placement and decrease in cuspal inclination did.
authors.affiliation: Department of Removable Prosthodontics, Hiroshima University School of Dentistry, Hiroshima, Japan. sato@ipc.hiroshima-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Sato
authors.forename: N
authors.initials: N
authors.lastname: Shindoi
authors.forename: R
authors.initials: R
authors.lastname: Hosokawa
authors.forename: K
authors.initials: K
authors.lastname: Tsuga
authors.forename: Y
authors.initials: Y
authors.lastname: Akagawa
mesh_terms: D001641:Bicuspid; D001696:Biomechanical Phenomena; D000044:Dental Abutments / Q000706:statistics & numerical data; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D017267:Dental Prosthesis Design / Q000379:methods* / Q000706:statistics & numerical data; D017268:Dental Prosthesis Retention / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D003799:Dental Stress Analysis / Q000379:methods / Q000706:statistics & numerical data; D020342:Finite Element Analysis / Q000706:statistics & numerical data; D006047:Gold Alloys; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000503:physiopathology / Q000534:rehabilitation*; D008334:Mandible; D008963:Molar
chemical_list: D006047:Gold Alloys