1. Alginate impressions are not suitable for fabricating crowns, bridges, and inlays because the material shrinks as the water evaporates, compromising accuracy. Nearly all impression materials can be used for full denture impressions. 2. Vacuum mixed stone models have higher strength because less water is required, resulting in less porosity. Less porous models are stronger. 3. Ceramometal pontics should provide adequate embrasure spaces between teeth for proper cleaning, as covering too much mucosa can lead to issues.