A new 3D-method to assess the inter implant dimensions in patients-A pilot study

Abstract

Background: Complex implant treatments have steadily increased within implant prosthodontics. Based on the lower implant mobility, implant impressions need high accuracy in the model transfer to receive a high passive fit within the final prosthodontic restoration. To analyze the accurate 3-dimensional (3D) inter-implant-positions, a reference point is indispensable. However, there is no reference in the patients mouth, so the aim of the present study was to develop a new method based on a custom-made-measuring-aid (CMA) to assess the inter implant dimensions (InID) in patients. Material and Methods: Initially an implant master model (IMM/patient equivalent) was digitized by computed tomography. A CMA was fixed on the impression posts and the inter implant dimensions (InID) were recorded with a coordinate measurement machine (CMM). For comparison to conventional and digital impression techniques, 10 impressions per technique were taken. InIDs for the IMM, the CMA and the two impression techniques were compared. To give a proof of principle, the new 3D-method was applied to three patients as pilot cases. Results for trueness and precision were analyzed by pairwise comparisons (p