Int J Oral Maxillofac Implants 25 (2010), No. 4 15. July 2010
Int J Oral Maxillofac Implants 25 (2010), No. 4 (15.07.2010)
Page 715-721, PubMed:20657866
Accuracy of Impression Techniques for an Implant-Supported Prosthesis
Del'Acqua, Marcelo Antonialli / Chávez, Alejandro Muñoz / Compagnoni, Marco Antonio / De Assis Mollo jr., Francisco
Purpose: This in vitro study compared the dimensional accuracy of a stone index and of two impression techniques (squared impression copings and modified squared impression copings) for implant-supported prostheses.
Materials and Methods: A master cast with four parallel implant-abutment analogs and a passive framework were fabricated. Vinyl polysiloxane impression material was used for all impressions with a metal stock tray. Three groups of impressions were tested (n = 5): index (I), squared (S), and modified squared (MS). The measurement method employed was just one titanium screw tightened to the framework. The measurements (60 gap values) were analyzed using software that received the images from a video camera coupled to a stereomicroscope at 3100 magnification. The results were evaluated statistically (analysis of variance, Holm-Sidak method, a = .05).
Results: The mean abutment/framework interface gaps were: master cast = 31.63 µm; group I = 45.25 µm; group S = 96.14 µm; group MS = 51.20 µm. No significant difference was detected among the index and modified squared techniques (P = .05).
Conclusion: Under the limitations of this study, the techniques modified squared and index generated more accurate casts than the squared technique.
Keywords: dental implants, dental impression technique, dental models