title: Retrospective study to determine the accuracy of template-guided implant placement using a novel nonradiologic evaluation method.
abstract: OBJECTIVE
  With a novel, noninvasive method for determining three-dimensional accuracy, the realized implant position relative to the planned implant position was analyzed retrospectively. Additional postoperative cone beam computed tomography was thus dispensable.
  
  
  METHODS
  Twelve cases with distal extension situations (DESs) or single tooth gaps (STGs) were evaluated. The data sets of the planned implant position were superimposed on the actually achieved implant position, retrieved from digitizing the implant impression. The deviations were measured and statistically analyzed.
  
  
  RESULTS
  The mean deviation was 5° in the DES group and 4° in the STG group for the implant axes, 1 mm (DES) and 0.9 mm (STG) at the implant neck, and 1.6 mm (DES) and 1.5 mm (STG) at the implant apex. The mean height discrepancy was 0.5 mm (DES) and 0.5 mm (STG). No significant differences (P > .05) were found between the DES and STG groups.
  
  
  CONCLUSIONS
  The innovative, noninvasive evaluation method is suitable and sufficiently accurate for the assessment of larger cohorts. The results of our study showed a sufficiently high degree of accuracy when using a virtual planning program for which no radiopaque template is needed when performing cone beam computed tomography.
authors.affiliation: Clinic of Prosthetic Dentistry, Ulm University Hospital, Department of Dentistry, Ulm, Germany; Private practice, Hilzingen, Germany. Electronic address: Sigmar.schnutenhaus@uni-ulm.de.
authors.forename: Sigmar
authors.initials: S
authors.lastname: Schnutenhaus
authors.affiliation: Private practice, Hilzingen, Germany.
authors.forename: Cornelia
authors.initials: C
authors.lastname: Edelmann
authors.affiliation: Clinic of Prosthetic Dentistry, Ulm University Hospital, Department of Dentistry, Ulm, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Rudolph
authors.affiliation: Clinic of Prosthetic Dentistry, Ulm University Hospital, Department of Dentistry, Ulm, Germany.
authors.forename: Ralph G
authors.initials: RG
authors.lastname: Luthardt
mesh_terms: D000328:Adult; D000368:Aged; D017076:Computer-Aided Design; D054893:Cone-Beam Computed Tomography; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D003761:Dental Impression Technique; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D003765:Models, Dental; D010347:Patient Care Planning; D012189:Retrospective Studies; D012984:Software; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014584:User-Computer Interface
chemical_list: D015921:Dental Implants