The Accuracy of Different Types of Silicone Impression Materials and Technique of Implant Supported Restoration

Background the techniques of impression taking can be made by either a close or open tray impression procedures or by implant level impression technique, this can be achieved by Snap-on procedure which is best described as a hybrid between the two techniques mentioned previously. The aim of the study was to evaluate the accuracy of implant impressions obtained from different types and viscosity of silicone impression materials. (Addition silicone monophase, addition silicone (heavy/light body) and condensation silicone (putty/light body). Materials and methods Two dental implants holes were drilled in the lower lateral incisor in both sides in the lower edentulous cast, two implants fixtures size 12mm/4 of Dentium Company inserted in the drilled holes. Three types of impression technique used and the evaluation of the accuracy of the impression technique with different impression materials were tested. Impression copings were removed and parallelism gauges attached to the implant then CBCT is taken for all casts using SOREDEX CBCT machine. A demand system software measuring the distances between the parallelism gauges in 4 points, the measurements compared by one way ANOVA Table with multiple comparison LSD tests applied. Results Descriptive statistical analysis show that the best result of the dimensional accuracy obtained with monophase A-silicone type impression material when compared with the other types of materials used in the study. Conclusions For impression materials, monophase addition silicone impression material produce more accurate impression than condensation silicone impression material Addition silicone impression material is recommended for implant impression. For impression technique Snap-On impression technique exhibited better three-dimensional transfer compared to open and closed impression technique. The three-dimensional accuracy of Snap-On impression technique was comparable to that of the open-tray technique. The open-tray impression technique exhibited higher accuracy in comparison to closed-tray technique with monophase and heavy bodytype A.