By Prof.Dr/Mona Hussein

1. Dental biomaterials By Prof.Dr/Mona Hussein

2. Dental biomaterials • The science of dental biomaterials involves the study of the composition and properties of materials and the way in which they interact with the oral environment in which they are placed.

3. Dental biomaterials may be classified according to nature into, ceramics, metals, polymers and composites or according to use into restorative and auxiliary materials

4. Materials used in dentistry are confined within the three known groups: metals, ceramics and polymers.

5. I- Metals • Metals are used for making restorations of the lost tooth structure, prosthetic devices, orthodontic appliances, and many other applications where strength and elasticity are required. • A mixture of two or more metallic elements is called alloy (Gold alloy &Cobalt chromium alloy)

6. Metallic restoration

7. II- Ceramics Ceramics include a wide variety of substances such as glass, cement, refractory (high temp), and many other materials.

8. Types of dental ceramics: • Dental porcelain. • Dental cements. • Gypsum products. • Casting investment

9. Ceramic restoration

10. Ceramo-metal system Bridge

11. III- Polymers Polymers are synthetic resins. Types of dental polymers: • Polymeric impression materials. • Denture base materials. • Tooth colored restorative materials.

12. Polymeric denture base

13. Esthetic restoration (dental composite)

14. Oral Environment

15. 1-Enamel. 2-Dentine. 3-Gingiva (Gum). 4-Gingival Sulcus. 5-Periodontal Ligaments. 6-Pulp Chamber. 7-Root Canal. 8-Apical Foramen. 9-Bone. 10-Cementum.

16. 1. Enamel: • Is the hardest structure in the human body. • It forms the outer layer of the crown • It’s the only visible portion of the crown.

17. 2. Dentine: • Is the main substance of the crown & the root. • Is yellowish-white in color. • Is sensitive.

18. 3. Gingiva(Gum): • Is the soft tissue covering the bone encircling the tooth near the junction of the crown & the root.

19. 4. Gingival sulcus: • Surrounds the tooth. • It has a normal depth of 0.5-2mm.

20. 5. Periodontal ligaments: • Attaches the tooth to the bone by means of thin fibers. • Act as a shock absorber for the tooth.

21. 6. Pulp chamber: • This cavity contains bloods vessels for nutrition&nerves for the sensitivity of the tooth. • Is extremely sensitive.

22. 7. Root canals: • Are small canals through which blood vessels& nerves pass through the roots on their way to the pulp chamber.

23. 8. Apical foramen: • Is the only normal opening of the root canal. • The nerves & the blood vessels pass from it to the root canal.

24. 9. Bone: • The tooth is anchored in the bone. • The bone forms part of the jaw.

25. 10. Cementum: • A thin layer covering the root. • The ligaments attaches to this.

26. Saliva Contents: 1- Water. 2- Electrolytes. 3- Mucus. 4- Enzymes.

27. Functions: • Helps in creating the bolus of the food. • Amylase enzyme that converts starch into dextrin. • Prevent tooth decay& tooth erosion due to its buffering properties. • Saliva carries ions as calcium,fluoride…. That helps in remineralization. • Antibacterial.

28. The restorative material present in the oral environment is subjected to: • Changes in temperature.(Thermal properties) • Variation in pH.(Corrosion) • Occlusal stresses. • Solubility and disintegration. • Change in color(Optical properties)

29. TMJ Functions: • The first function is rotation around a horizontal axis. • The second function is translation where the condyle & the disc move together anteriorly beneath the articular eminence.

33. DENTALBIOMATERIALS I -Basic science of biomaterials • Physical properties Thermal properties Optical properties Surface chemistry Corrosion • Mechanical properties

34. Basic structure of metals. • Basic structure of polymers. • Basic structure of ceramics. II APPLIED BIOMATERIALS

35. Thank you