title: Primary implant stability in a bone model simulating clinical situations for the posterior maxilla: an in vitro study.
abstract: OBJECTIVE
  The aim of this study was to determine the influence of anatomical conditions on primary stability in the models simulating posterior maxilla.
  
  
  METHODS
  Polyurethane blocks were designed to simulate monocortical (M) and bicortical (B) conditions. Each condition had four subgroups measuring 3 mm (M3, B3), 5 mm (M5, B5), 8 mm (M8, B8), and 12 mm (M12, B12) in residual bone height (RBH). After implant placement, the implant stability quotient (ISQ), Periotest value (PTV), insertion torque (IT), and reverse torque (RT) were measured. Two-factor ANOVA (two cortical conditions×four RBHs) and additional analyses for simple main effects were performed.
  
  
  RESULTS
  A significant interaction between cortical condition and RBH was demonstrated for all methods measuring stability with two-factor ANOVA. In the analyses for simple main effects, ISQ and PTV were statistically higher in the bicortical groups than the corresponding monocortical groups, respectively. In the monocortical group, ISQ and PTV showed a statistically significant rise with increasing RBH. Measurements of IT and RT showed a similar tendency, measuring highest in the M3 group, followed by the M8, the M5, and the M12 groups. In the bicortical group, all variables showed a similar tendency, with different degrees of rise and decline. The B8 group showed the highest values, followed by the B12, the B5, and the B3 groups. The highest coefficient was demonstrated between ISQ and PTV.
  
  
  CONCLUSIONS
  Primary stability was enhanced by the presence of bicortex and increased RBH, which may be better demonstrated by ISQ and PTV than by IT and RT.
authors: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea.; Department of Periodontology, Periodontal-Implant Clinical Research Institute, Kyung Hee University Dental Hospital, Seoul, Korea.
authors: Ho-Chyul
authors: 0000-0001-9746-583X
authors: HC
authors: Han
authors: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea.; Department of Periodontology, Periodontal-Implant Clinical Research Institute, Kyung Hee University Dental Hospital, Seoul, Korea.
authors: Hyun-Chang
authors: 0000-0001-7695-1708
authors: HC
authors: Lim
authors: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea.; Department of Periodontology, Periodontal-Implant Clinical Research Institute, Kyung Hee University Dental Hospital, Seoul, Korea.
authors: Ji-Youn
authors: 0000-0003-1040-7077
authors: JY
authors: Hong
authors: Department of Biomaterials & Prosthodontics, Institute of Oral Biology, Kyung Hee University School of Dentistry, Seoul, Korea.
authors: Su-Jin
authors: 0000-0003-2128-1561
authors: SJ
authors: Ahn
authors: Department of Dentistry & Periodontology, Hanyang University College of Medicine, Seoul, Korea.
authors: Ji-Young
authors: 0000-0002-2364-8366
authors: JY
authors: Han
authors: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea.; Department of Periodontology, Periodontal-Implant Clinical Research Institute, Kyung Hee University Dental Hospital, Seoul, Korea.
authors: Seung-Il
authors: 0000-0001-8762-6169
authors: SI
authors: Shin
authors: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea.; Department of Periodontology, Periodontal-Implant Clinical Research Institute, Kyung Hee University Dental Hospital, Seoul, Korea.
authors: Jong-Hyuk
authors: 0000-0002-2678-1525
authors: JH
authors: Chung
authors: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea.; Department of Periodontology, Periodontal-Implant Clinical Research Institute, Kyung Hee University Dental Hospital, Seoul, Korea.
authors: Yeek
authors: 0000-0001-9243-7119
authors: Y
authors: Herr
authors: Department of Periodontology, Kyung Hee University School of Dentistry, Seoul, Korea.; Department of Periodontology, Periodontal-Implant Clinical Research Institute, Kyung Hee University Dental Hospital, Seoul, Korea.
authors: Seung-Yun
authors: 0000-0001-6980-7556
authors: SY
authors: Shin
keywords: Anatomic models; Dental implants; Maxilla; Maxillary sinus