CDC CDC Dental Materials & Technology 2 — Questions and Answers
Question 1: Which restorative material both releases fluoride over time and chemically bonds to tooth structure through ion exchange?
- Composite resin
- Dental amalgam
- Glass ionomer cement (Correct answer)
- Feldspathic porcelain
Correct answer: Glass ionomer cement
Glass ionomer cement releases fluoride ions that help prevent secondary caries and forms a chemical adhesive bond to enamel and dentin through ion exchange.
Question 2: What is the primary function of a dental bonding (adhesive) agent?
- To permanently cement cast restorations to prepared teeth
- To create micromechanical and chemical retention between composite resin and tooth structure (Correct answer)
- To bond orthodontic brackets to enamel
- To adhere complete dentures to the oral mucosa
Correct answer: To create micromechanical and chemical retention between composite resin and tooth structure
A dental bonding agent infiltrates the micro-porosities created by acid etching and forms both micromechanical retention in enamel and a hybrid layer in dentin, bonding composite resin to the tooth.
Question 3: What property of dental materials does the Vickers Hardness Number (VHN) measure?
- Elastic flexibility of impression materials
- Surface resistance to indentation, correlating with wear resistance (Correct answer)
- Solubility of cements in oral fluids
- Coefficient of thermal expansion for metal alloys
Correct answer: Surface resistance to indentation, correlating with wear resistance
The Vickers Hardness Number quantifies a material's resistance to surface indentation by a diamond pyramid indenter, which correlates with its abrasion and wear behavior.
Question 4: Which implant design is the most widely used in contemporary implant dentistry?
- Subperiosteal implant
- Transosteal (staple) implant
- Endosseous (root-form) implant (Correct answer)
- Ramus frame implant
Correct answer: Endosseous (root-form) implant
Endosseous root-form implants are placed directly into the jawbone and have become the dominant design due to high long-term success rates and favorable biomechanical integration.
Question 5: How is the term 'osseointegration' best defined in dental implantology?
- The process of bone graft incorporation into a recipient site
- The direct structural and functional bond between living bone and the surface of a load-bearing implant (Correct answer)
- The integration of gingival soft tissue around the implant collar
- The hardening of implant cement beneath a crown
Correct answer: The direct structural and functional bond between living bone and the surface of a load-bearing implant
Osseointegration, as defined by Brånemark, is the direct structural and functional connection between organized living bone and the surface of a load-bearing endosseous implant.
Question 6: Which ceramic material is preferred for posterior crowns and implant-supported restorations due to its exceptional flexural strength?
- Feldspathic porcelain
- Leucite-reinforced ceramic
- Zirconia (zirconium oxide) (Correct answer)
- Lithium disilicate
Correct answer: Zirconia (zirconium oxide)
Zirconia's flexural strength exceeding 900 MPa makes it the material of choice for high-stress posterior restorations and implant-supported prostheses.
CDC CDC Dental Materials & Technology 2
Which restorative material both releases fluoride over time and chemically bonds to tooth structure through ion exchange?