title: Accuracy of a direct drill-guiding system with minimal tolerance of surgical instruments used for implant surgery: a prospective clinical study.
abstract: OBJECTIVE
  A recently introduced direct drill-guiding implant surgery system features minimal tolerance of surgical instruments in the metal sleeve by using shank-modified drills and a sleeve-incorporated stereolithographic guide template. The purpose of this study was to evaluate the accuracy of this new guided surgery system in partially edentulous patients using geometric analyses.
  
  
  METHODS
  For the study, 21 implants were placed in 11 consecutive patients using the direct drill-guiding implant surgery system. The stereolithographic surgical guide was fabricated using cone-beam computed tomography, digital scanning, computer-aided design and computer-assisted manufacturing, and additive manufacturing processes. After surgery, the positional and angular deviations between planned and placed implants were measured at the abutment level using implant-planning software. The Kruskal-Wallis test and Mann-Whitney U test were used to compare the deviations (α=.05).
  
  
  RESULTS
  The mean horizontal deviations were 0.593 mm (SD 0.238) mesiodistally and 0.691 mm (SD 0.344) buccolingually. The mean vertical deviation was 0.925 mm (SD 0.376) occlusogingivally. The vertical deviation was significantly larger than the horizontal deviation (P=.018). The mean angular deviation was 2.024 degrees (SD 0.942) mesiodistally and 2.390 degrees (SD 1.142) buccolingually.
  
  
  CONCLUSIONS
  The direct drill-guiding implant surgery system demonstrates high accuracy in placing implants. Use of the drill shank as the guiding component is an effective way for reducing tolerance.
authors.affiliation: Department of Prosthodontics, School of Dentistry, A3DI, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Du-Hyeong
authors.identifier: 0000-0003-2803-7457
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Seo-Young
authors.identifier: 0000-0001-6711-5986
authors.initials: SY
authors.lastname: An
authors.affiliation: Department of Bio-medical Research Institute, A3DI, Kyungpook National University Hospital, Daegu, Republic of Korea.
authors.forename: Min-Ho
authors.identifier: 0000-0002-6456-2200
authors.initials: MH
authors.lastname: Hong
authors.affiliation: Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Kyoung-Bae
authors.identifier: 0000-0002-5289-4179
authors.initials: KB
authors.lastname: Jeon
authors.affiliation: Department of Prosthodontics, School of Dentistry, A3DI, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Kyu-Bok
authors.identifier: 0000-0002-1838-7229
authors.initials: KB
authors.lastname: Lee
keywords: Accuracy; Dental implants; Guided surgery; Surgical drills; Tolerance