Dental Materials NBDHE STUDY GUIDE 2025/2026 COMPREHENSIVE EXAM QUESTIONS WITH DETAILED CORRECT SOLUTIONS || ALREADY GRADED A+||100% GUARANTEED PASSBRAND NEW VERSION

Dental Materials NBDHE STUDY GUIDE 2025/2026 COMPREHENSIVE EXAM QUESTIONS WITH DETAILED CORRECT SOLUTIONS || ALREADY GRADED A+||100% GUARANTEED PASSBRAND NEW VERSION 1. Elasticity - ANSWER Material's ability to recover its initial shape after undergoing a force 2. Galvanism - ANSWER An electrical current generated by dissimilar metals in an acidic environment 3. Gelation - ANSWER The process of gelling (solidification by cold) 4. Imbibition - ANSWER Absorption of a solvent by a gel 5. Malleability - ANSWER A material's capacity to be shaped by force or pressure 6. Adhesion - ANSWER The chemical attraction between unlike molecules 7. Cohesion - ANSWER The chemical attraction between like molecules 8. Coefficient of thermal expansion - ANSWER An index which indicated how one material reacts to temperature extremes in relation to another 9. Compressive Strength - ANSWER The force at which a material breaks under pressure 10. Creep - ANSWER Slow dimensional change caused by compression 11. Ductility - ANSWER The ability to undergo change of form without breaking 12. Microleakage (percolation) - ANSWER Passage of oral fluids/bacteria into and out of tooth structure due to marginal gap or failure of marginal (restorative) seal 13. Polymerization - ANSWER The linking, branching, or cross-linking of smaller molecules 14. Gypsum Products; more water needed, the... - ANSWER ...greater the setting expansion (dimensional change) and lower the compressive strength of the final product 15. Gypsum products; between Alpha-Calcium Sulfate HemiHydrate and Beta-Calcium Sulfate Hemi-Hydrate, which one requires more water to reconstitute? - ANSWER Beta-Calcium Sulfate Hemi-Hydrate (plaster) requires more water to reconstitute; because of this it undergoes a greater setting expansion and therefore has a lower compressive strength compared to the Alpha Calcium Sulfate Hemi-Hydrate (stone) 16. Gypsum Product; Alpha is ____ to Beta - ANSWER Alpha (stone) is superior to Beta (Plaster) as a material; A B 17. Quality of product (gypsum grade) is determined by its - ANSWER Refinement 18. Plaster, Type II Gypsum - ANSWER Beta-Calcium Sulfate Hemi-Hydrate 19. Stone, Type III Gypsum - ANSWER Alpha-Calcium Sulfate Hemi-Hydrate 20. Diestone,* Type IV Gypsum - ANSWER Alpha-Calcium Sulfate Hemi-Hydrate - contains additive to make more durable and wear resistant 21. *also called improved stone 22. Gypsum material selection dependent upon strength and dimensional accuracy desired - ANSWER Orthodontic model: plaster (easy to polish) 23. Study model/working model: stone (more accurate and wear resistant) 24. Crown and bridge die or model: improved stone or diestone (accurate and most wear resistant)