Answer The Following Dental Materials Midterms Of 2020 Quiz

Alginate is a water-based elastomeric impression material composed of sodium alginate and water. Sodium alginate forms a gel when combined with water, making it suitable for dental impressions.

The correct answer outlines the advantages and disadvantages of Alginate, including its ability to 'wet' tooth structure and be easily poured in gypsum material, as well as drawbacks such as irreversible hydrocolloid and loss of accuracy due to shrinking. The three incorrect answers provide contrasting information which does not align with the characteristics of Alginate.

Covalent bonds involve the sharing of electrons between atoms, resulting in a strong bond. Ionic bonds involve the transfer of electrons, metallic bonds involve a sea of electrons shared between atoms, and hydrogen bonds are relatively weaker interactions between a hydrogen atom and an electronegative atom.

Metallic bonds are formed between positive metal ions and delocalized electrons, leading to a sea of electrons within the structure. This allows for electrical conductivity and unique properties seen in metals.

Secondary bonds, also known as Van der Waals forces, are weaker than primary bonds and are considered to be more physical than chemical interactions. These forces are due to the formation of a dipole, which can be fluctuating or permanent.

Ceramics are primarily held together by ionic bonds, metals by metallic bonds, and molecular solids (polymers) by a combination of covalent and secondary bonds.

Cross-linking refers to the linking of one coil or polymer chain to another via wire or covalent bond, resulting in increased stiffness.

Polymerization is a process where monomers join together to form long chains. The correct answer refers to free radicals adding to double bonds, which is a common method of polymerization. The incorrect answers do not accurately describe the process of polymerization.

The linear coefficient specifically refers to the coefficient of thermal expansion, which measures how a material's volume changes in response to temperature variations. This term is distinct from other mathematical interpretations of 'coefficient,' as it pertains to thermal properties.

The modulus of elasticity is a measure of a material's stiffness, which is determined by the characteristics of the material and its atomic bonds. A higher modulus of elasticity indicates a stiffer material.

Paris is the capital city of France and is known for its cultural landmarks, fashion, and cuisine.

Yield strength is the point on the stress-strain curve where plastic deformation begins, while ultimate strength refers to the maximum stress a material can withstand before failure. Tensile strength is the maximum stress a material can withstand while being pulled before breaking. The fracture point is where the material breaks completely.

The plastic deformation limit is the point where the material undergoes permanent stretching or deformation without breaking.

Metals are known for their high thermal conductivity, making them ideal for conducting heat efficiently. Conversely, polymers, ceramics, and porcelain are poor thermal conductors, which is why they are not suitable for applications where heat conduction is required.

In mechanics, stress is broadly categorized into compression, tension, shear, torsion, and bending. Each type of stress exerts different forces on objects based on their applications.

In dentistry, ORTHOPHOSPHORIC ACID 37% is commonly used as an adhesive due to its ability to etch enamel and provide micromechanical retention for dental restorations.

Enamel etching is a dental procedure that involves using an acidic solution to create surface irregularities on the enamel, allowing low viscosity adhesive to flow into these irregularities for better adhesion. This process does not involve removal of enamel, it does not increase the viscosity of adhesive, nor does it aim to smooth out the enamel surface.

Dentinal bonding typically involves the use of polycarboxylate cement followed by glass ionomer cements due to their compatibility with the acid etching process used for bonding.