Assessment of accuracy of open tray and closed tray dental implant impression techniques: A comparative study

Abstract
Background: A dental impression is a negative imprint of an oral structure utilized to produce a positive replica of the structure that can be used as a permanent record or in the production process of a dental restoration. Hence; the present study was undertaken for assessing the accuracy of two different dental implant impression techniques. Materials & methods: For reference model, an edentulous mandibular cast with four implant analogues in the anterior region was used. For the present study, two different types of impression trays were used as follows: Closed custom tray, and Open custom tray. The impressions were allowed to set for 10 minutes under a standard load of 500 gm. All the impressions were poured using the same quantity of Type IV dental stone. The casts were subjected to measurement after 24 hours to simulate clinical situation. All the results were recorded in Microsoft excel sheet and were analysed by SPSS software.Results: Mean error obtained in closed custom tray technique was 0.028 while mean error obtained in open custom tray technique was 0.23. While analysing statistically, significant results were obtained. Conclusion: Better results are obtained when open custom trays were used.