Study of the interocclusal distortion in impressions taken with different types of closed-mouth trays and two types of impression materials.

The aim of this study was to compare different types of impression trays for the closed-mouth impression technique, using two different types of impression material. For this study, five different types of impression trays were used with two different types of impression materials, one of addition silicone and the other of polyether. We designed a model used for taking the impressions and for measuring interocclusal distortion. The results obtained show that the impression trays COE (GC (R) GC America INC. Alsip) and Premier (Premier (R), Premier Dental Products Co. Canada) show a lesser degree of interocclusal distortion when taking closed-mouth impressions. In terms of impression materials, the polyether was the one that produced the best results. From a clinical point of view, our study shows that the use of these types of trays is absolutely recommendable when used according to the clinical indications for which they have been designed; that said, we must not fail to consider that selecting the proper type of tray is also important.