“Comparing the Accuracy of Direct and Indirect Completely Limiting Design of Computer Guided Surgical Stents in Implant Supported Mandibular Partial Overdentures”

Abstract

This study was conducted to compare the accuracy of both direct (intraoral scan based) and indirect (cast scan based) completely limiting CAD/CAM-based surgical guide for locating dental implants in implant supported mandibular partial overdenture. Ten patients exhibiting mandibular bilateral distal extension edentulous area (Kennedy class I) were selected to participate in this study. Pre-operative CBCT scanning were made for the patients; and the DDS Pro software was used for implant planning. Two implants were placed in the area of first molar using either intraoral scan or cast scan based surgical guide. Evaluation of implant accuracy was done by comparing the superimposition of the pre and post CBCT image of each patient and calculating the angular, coronal and apical deviation for each implant. The results of this study showed, the mean angular deviations of the placed implants in group A and B were 3.3° ± 0.51° and 2.9° ± 0.34° respectively. The mean coronal and apical deviations in distance between the planned and placed implants were 1.02 ± 0.07 mm and 1.26 ± 0.08 mm for Group A; 0.95 ± 0.08 mm and 1.13 ± 0.17 mm for Group B respectively. Mean apical, coronal and angular deviations in Group B were smaller than that of Group A although it did not reach a significant level (p > 0.05).