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By Prof.Dr/Mona Hussein 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. Dental biomaterials may be classified according to nature into, ceramics, metals, polymers and composites or according to use into restorative and auxiliary materials WHAT is the THIRD CLASSIFICATION? 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) Metallic restoration II- Ceramics Ceramics include a wide variety of substances such as glass, cement, refractory (high temp), and many other materials. Types of dental ceramics: Dental porcelain. Dental cements. Gypsum products. Casting investment Ceramic restoration Ceramo-metal system Bridge III- Polymers Polymers are synthetic resins. Types of dental polymers: Polymeric impression materials. Denture base materials. Tooth colored restorative materials. Polymeric denture base Esthetic restoration (dental composite) 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. 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. 2. Dentine: Is the main substance of the crown & the root. Is yellowish-white in color. Is sensitive. Saliva Contents: 1- Water. 2- Electrolytes. 3- Mucus. 4- Enzymes. Functions: 1. Helps in creating the bolus of the food. 2. Amylase enzyme that converts starch into dextrin. 3. Prevent tooth decay& tooth erosion due to its buffering properties. 4. Saliva carries ions as calcium,fluoride…. That helps in remineralization. 5. Antibacterial. The restorative material present in the oral environment is subjected to: 1. Changes in temperature.(Thermal properties) 2. Variation in pH.(Corrosion) 3. Occlusal stresses. 4. Solubility and disintegration. 5. Change in color(Optical properties) Tempromandibular Joint Functions: 1. The first function is rotation around a horizontal axis. 2. The second function is translation where the condyle & the disc move together anteriorly beneath the articular eminence. DENTAL BIOMATERIALS I -Basic science of biomaterials • Physical properties Thermal properties Optical properties Surface chemistry Corrosion • Mechanical properties • Basic structure of metals. • Basic structure of polymers. • Basic structure of ceramics. II APPLIED BIOMATERIALS