口腔學(xué)英文課件：introduction

1、Oral Materials (口腔材料學(xué)),Bai hua Lecturer Department of Oral Medicine,Introduction (總論),Part I:Summary,Time line,1. 1530: Paper pulp、cotton & linen、leather used for mask. 2. 1756: Wax used for impression and molding materials. 3. 1826: Amalgam(銀汞合金) epoch-making event 4. 1936: Methyl methacrylate(甲基丙烯

2、酸甲酯) simplified oral repair process. 5. 1970s: Resin composite(復(fù)合樹脂) New epoch 6. 1980s: Implant materials 7. 1990s: Porcelain materials, titanium 8. Future: nanomaterials and so on.,Classification,(一) By property,1. Nonmetal material (非金屬材料) (1) Organic Polymer Materials (有機(jī)高分子材料) (2) Inorganic non

3、-metallic materials (無機(jī)非金屬材料) 2. Metal material (金屬材料),1.Impression materials (印模材料) 2.Molding materials (模型材料) 3.Denture materials (義齒材料) 4.Filling materials (充填材料) 5.Bonding materials (粘接材料) 6.Implant materials (種植材料) 7.Materials for dental preventive health care (齒科預(yù)防保健材料),Classification,(二) By a

4、pplication,Classification,(三) By type of contact to oral tissue,1. Direct and long-term contact 2. Direct and temporary contact 3. Indirect contact,Classification,(四) By application site,1. Implanted to body 2. Non-implanted to body,standardization,Organizations of Standardization for oral materials

5、,1. FDI (Federation Dentaire Internationale) 2. (ISO):ISO/TC106-dentistry 國際標(biāo)準(zhǔn)化組織 3. TC99 中國口腔材料和器械設(shè)備標(biāo)準(zhǔn)化技術(shù)委員會 4. ADA美國牙科材料標(biāo)準(zhǔn) 5. Other countries: BSI (Britain) 、NF (France)、JIS (Japan)、DIN(Germany)、SSA(Australia)、NIOM (Northern Europe).,Part II: Property of oral materials,- Physical properties (物理性能)

6、 - Mechanical properties (機(jī)械性能) - Chemical properties (化學(xué)性能) - Biological properties (生物性能),Physical properties (物理性能),(一) Dimensional change (尺寸改變),In the oral environment and in the process of making repair body, deformation degree of filling materials, repair materials and auxiliary materials cha

7、nged because of the influence of physical and chemical factors, called dimensional change.,Physical properties (物理性能),L- L0 = 100% L0 : dimensional change L0: original dimension L: dimension after change,Formula, The clinical significance of dimensional stability of oral materials,We must try to red

8、uce the dimensional change of this kind of material in the process of using,(二) Linear expansion coefficient (線脹系數(shù)),Physical properties (物理性能),It means the characterization of the length of an object (or volume) physical quantity changing with temperature.,1 dL L= L dT (constant pressure ) L : LEC (

9、K-1) when temperature is T L: length (mm) when temperature is T dL: change of length dT: change of temperature,Linear expansion coefficient of Tooth and oral materials (10-6k-1), The clinical significance of linear expansion coefficient of oral materials,1. The embedding material coefficient of ther

10、mal expansion for compensation of metal casting shrinkage. 包埋材料的熱膨脹系數(shù)對于補(bǔ)償金屬鑄造收縮有意義。 2. Filling and tooth difference of thermal expansion coefficient has an effect on treatment effect. 充填體與牙體熱膨脹系數(shù)的差別對于治療效果有影響。,(三) Thermal conductivity (熱導(dǎo)率),Physical properties (物理性能),- A form of energy transfer in he

11、at. - Thermal conductivity is a physical quantity measuring the thermal conductivity of composites., The clinical significance of thermal conductivity of oral materials,We must choose low thermal conductivity material using near to dental pulp, in order to isolate the temperature change on pulp stim

12、ulation.,(四) Galvanism (流電性),Physical properties (物理性能),There are dissimilar in the electrolyte solution, the potential of different metal contact between different, there will be potential difference, causing microcurrent.,唾液,鋁冠,金冠,金冠和鋁冠伽尼電流產(chǎn)生示意圖,Aluminium crown,Gold crown,Saliva, The clinical sign

13、ificance of galvanism of oral materials,In saliva, different metals will react and generate electrical current and then stimulate the pulp and corrode denture materials.,- Avoid using different mental materials. Denture base of removable partial avoid setting on metal filling body.,(五) Wettability (

14、潤濕性),Physical properties (物理性能),The diffusion trend of liquid on the solid surface is called liquid wettability of solid, is a necessary condition for bonding.,(六) Color (色彩性),Physical properties (物理性能),The harmony of color is demanded by requirement of appreciation of the beauty. - Hue (色調(diào)或色相): nam

15、e of color - Chroma (彩度或飽和度): purity of color - Value (明度或亮度): reflective objects to light, The clinical significance of color of oral materials,Aesthetic denture materials must have light transmission performance. Color must be considered when the color of the surrounding environment.,Tokyo Medical

16、 and Dental University,Mechanical properties (機(jī)械性能),(一) Stress (應(yīng)力),Stress is the description of the mechanical state of objects in each direction. = F / S F：Force 外力（N） S：Area 受力面積（mm2） ：Stress 應(yīng)力（MPa）,Mechanical properties (機(jī)械性能),(二) Strain (應(yīng)變),The strain is to describe the shape change materials

17、 under external force quantity. =L/L0 ： Strain 應(yīng)變 L：Incremental length 長度增量 L0 ：Length of the specified reference conditions 指定參考狀況下的長度(mm),Mechanical properties (機(jī)械性能),(三) Modulus of elasticity (彈性模量),The modulus of elasticity is a measure of the amount of material rigidity, elastic state under the

18、 strain and stress ratio. 彈性模量是量度材料剛性的量,即彈性狀態(tài)下應(yīng)力與應(yīng)變的比值。 modulus of elasticity stiffness,Mechanical properties (機(jī)械性能),Modulus of elasticity of Tooth and oral materials,(四) Impact strength (沖擊強(qiáng)度),Mechanical properties (機(jī)械性能),Impact strength is the ability of a material to resist impact damage. It exam

19、ines the brittleness (脆性) and toughness （韌性） of the materials.,(五) Hardness (硬度),Mechanical properties (機(jī)械性能),Hardness is the resistance ability of solid material elastic deformation, plastic deformation or damage, or the ability to resist the two or three occur simultaneously. 硬度是固體材料抵抗彈性變形、塑性變形或破壞

20、的能力，或抵抗其中兩種或三種情況同時(shí)發(fā)生的能力。,(六) Stress concentration (應(yīng)力集中),Mechanical properties (機(jī)械性能),(七) Thermal stress (熱應(yīng)力),(八) Flexural strength (撓曲強(qiáng)度),Sakura,Chemical properties (化學(xué)性能),(一) Corrosion (腐蝕),Corrosion means materials occur deterioration or breakage due to biological and chemical erosion.,Chemical

21、properties (化學(xué)性能),(二) Adsorption & Dissolution (吸附和溶解),Adsorption: sorption phenomena generated by means of electrostatic and intermolecular by Van der Waals force between ions, atoms or molecules. Dissolution: materials process stably dispersed in a solvent.,Chemical properties (化學(xué)性能),Some dental m

22、aterials will be adsorbed saliva, then partially dissolved.,There are certain requirements for water absorption and solubility. Resin: absorption50ug/mm3, solubility5ug/mm3.,(三) Aging (老化),Deterioration of physical, chemical properties and mechanical properties in the processing, storage and use, called aging.,Chemical properties (化學(xué)性能),(四) Chemical bonding (化學(xué)性粘接),The combination between atoms or ions of bonding surface and adhesived to