title: Relationship between the CT Value and Cortical Bone Thickness at Implant Recipient Sites and Primary Implant Stability with Comparison of Different Implant Types.
abstract: BACKGROUND
  Studies have shown that bone quality at the implant recipient site can influence primary stability.
  
  
  OBJECTIVE
  The aims of this study were to explore the quantitative estimation of the primary stability of implants preoperatively using CT values and to examine the effect of different implant designs with recommended socket preparation on primary stability.
  
  
  METHODS
  Forty-four fresh porcine femoral heads were prepared. The bone surrounding implant sockets was preoperatively evaluated by helical CT. Forty-four implants (φ 4.3 × 10 mm), 22 straight and 22 tapered, were placed according to the manufacturer's instructions. The insertion torque value (ITV), implant stability quotient (ISQ), and removal torque value (RTV) were recorded as indicators of primary implant stability.
  
  
  RESULTS
  Significant correlations and linear relationships were found between the CT value and ITV, ISQ, and RTV for both straight and tapered implants (Spearman's correlation coefficient, p < .001; linear regression analysis, p < .01). Tapered implants had a significantly higher ITV than straight implants (analysis of covariance, p < .01).
  
  
  CONCLUSIONS
  Obtained results suggest that the primary stability of implants could be quantitatively estimated using the CT value preoperatively, indicating the CT value of bone surrounding an implant can contribute considerably to implant planning and design choice in clinical situations.
authors.affiliation: Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Miori
authors.initials: M
authors.lastname: Howashi
authors.affiliation: Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tsukiyama
authors.affiliation: Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Ayukawa
authors.affiliation: Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Isoda-Akizuki
authors.affiliation: Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kihara
authors.affiliation: Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Imai
authors.affiliation: Division of Prosthodontics and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Osaka, Japan.
authors.forename: Motofumi
authors.initials: M
authors.lastname: Sogo
authors.affiliation: Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Koyano
mesh_terms: D000818:Animals; D015519:Bone Density; D000071538:Cortical Bone / Q000000981:diagnostic imaging* / Q000601:surgery*; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D005270:Femur Head / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D020007:Implants, Experimental; D013552:Swine; D014057:Tomography, X-Ray Computed; D019415:Torque
chemical_list: D015921:Dental Implants
keywords: CT value; bone density; cortical bone thickness; dental implant; primary stability