Comparison of 3D positional accuracy of implant analogs in printed resin models versus conventional stone casts: Effect of implant angulation

Abstract

PurposeTo study the effect of implant angulation on 3D linear and absolute angular distortions of implant analogs in printed resin models and conventional stone casts. Materials and methodsThree sectional master models with two implants with total inter-implant angulations of 0 degrees, 10 degrees, and 20 degrees were fabricated. For each master model, five conventional stone casts (CS) and printed resin models (PM) were fabricated (n = 5). Test models were made with nonsplinted impression copings and open tray polyether impressions for the CS groups and scan bodies scanned using an intraoral scanner for the PM groups. The physical positions of the implants and implant analogs were measured with a coordinate measuring machine. 3D linear distortion (Delta R) and absolute angular distortion (Absd theta) defined the 3D positional accuracy of the analogs in the test models. Univariate ANOVA was used to analyze data followed by post hoc tests (Tukey HSD, alpha = 0.05). ResultsMean Delta R was significantly greater for PM10 (73.5 +/- 8.9 mu m) and PM20 (65.5 +/- 33.3 mu m) compared to CS0 (16.8 +/- 14.1 mu m), CS10 (22.2 +/- 13.0 mu m), CS20 (15.6 +/- 19.9 mu m), and PM0 (23.9 +/- 16.1 mu m). For Absd theta, there were no significant differences between test groups. ConclusionsWith conventional stone casts, implant angulation had no significant effect on 3D linear and absolute angular distortions. Amongst printed resin models test groups, angulated implants had significantly greater Delta R. Amongst angulated implants test groups, printed resin models had significantly greater Delta R than conventional stone casts. Compared to the master model, all test groups, regardless of inter-implant angulation, produced greater inter-analog distances.