Objectives: The aim of this study was to investigate two different shapes of impression trays by comparing the number of flow defects in the final impression. A low number of defects indicates a better impression which, in turn, indicates a better clinical end product. The new shape includes a dorsal block and a palatal spoiler. Six patients were selected based on their specific oral clinical characteristics, such as the amount of undercuts, crooked teeth and different palatal heights. Each subject took a total of 40 impressions, 20 standard and 20 final impressions. For the standard impressions, ten were taken using Position Penta (3M ESPE) (PP) in the newly shaped Position Trays (3M ESPE) (PT) and ten using PP in rim-locked, metal trays (MT). For the final impressions, ten using Impregum Penta Soft (3M ESPE) (IPS) in an experimental tray shaped comparable to PT (3M ESPE) (ET) and ten using IPS in the MT were taken. Methods: All impressions were evaluated with regard to the number of flow defects which were divided into three groups (0–1mm; 1–2mm; >2mm) according to their length. The number of flow defects in each impression were measured using the same standards for all 240 samples. Results: The average number of flow defects in group 1 (0–1mm) detected e.g. for PP in the PT was 1.5 ± 0.4 and for PP in the MT was 2.6 ± 0.4. Conclusion: ANOVA (p<0.001) showed a significant decrease in the number of flow defects in the PT as opposed to the MT. In conclusion, the PT showed the least amount of defects in the impressions taken as compared to the defects from the MT.

Back to the Dental Materials: VIII - Others-Non-metallic Program
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