口腔学英文课件：introduction

1、Oral Materials (口腔材料学),Bai hua Lecturer Department of Oral Medicine,Introduction (总论),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(银汞合金) epoch-making event 4. 1936: Methyl methacrylate(甲基丙烯

2、酸甲酯) simplified oral repair process. 5. 1970s: Resin composite(复合树脂) New epoch 6. 1980s: Implant materials 7. 1990s: Porcelain materials, titanium 8. Future: nanomaterials and so on.,Classification,(一) By property,1. Nonmetal material (非金属材料) (1) Organic Polymer Materials (有机高分子材料) (2) Inorganic non

3、-metallic materials (无机非金属材料) 2. Metal material (金属材料),1.Impression materials (印模材料) 2.Molding materials (模型材料) 3.Denture materials (义齿材料) 4.Filling materials (充填材料) 5.Bonding materials (粘接材料) 6.Implant materials (种植材料) 7.Materials for dental preventive health care (齿科预防保健材料),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 国际标准化组织 3. TC99 中国口腔材料和器械设备标准化技术委员会 4. ADA美国牙科材料标准 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 (机械性能) - Chemical properties (化学性能) - Biological properties (生物性能),Physical properties (物理性能),(一) Dimensional change (尺寸改变),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 (线胀系数),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. 包埋材料的热膨胀系数对于补偿金属铸造收缩有意义。 2. Filling and tooth difference of thermal expansion coefficient has an effect on treatment effect. 充填体与牙体热膨胀系数的差别对于治疗效果有影响。,(三) Thermal conductivity (热导率),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 (流电性),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,铝冠,金冠,金冠和铝冠伽尼电流产生示意图,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、润湿性),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 (色调或色相): nam

15、e of color - Chroma (彩度或饱和度): 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 (机械性能),(一) Stress (应力),Stress is the description of the mechanical state of objects in each direction. = F / S F：Force 外力（N） S：Area 受力面积（mm2） ：Stress 应力（MPa）,Mechanical properties (机械性能),(二) Strain (应变),The strain is to describe the shape change materials

17、 under external force quantity. =L/L0 ： Strain 应变 L：Incremental length 长度增量 L0 ：Length of the specified reference conditions 指定参考状况下的长度(mm),Mechanical properties (机械性能),(三) Modulus of elasticity (弹性模量),The modulus of elasticity is a measure of the amount of material rigidity, elastic state under the

18、 strain and stress ratio. 弹性模量是量度材料刚性的量,即弹性状态下应力与应变的比值。 modulus of elasticity stiffness,Mechanical properties (机械性能),Modulus of elasticity of Tooth and oral materials,(四) Impact strength (冲击强度),Mechanical properties (机械性能),Impact strength is the ability of a material to resist impact damage. It exam

19、ines the brittleness (脆性) and toughness （韧性） of the materials.,(五) Hardness (硬度),Mechanical properties (机械性能),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. 硬度是固体材料抵抗弹性变形、塑性变形或破坏

20、的能力，或抵抗其中两种或三种情况同时发生的能力。,(六) Stress concentration (应力集中),Mechanical properties (机械性能),(七) Thermal stress (热应力),(八) Flexural strength (挠曲强度),Sakura,Chemical properties (化学性能),(一) Corrosion (腐蚀),Corrosion means materials occur deterioration or breakage due to biological and chemical erosion.,Chemical

21、properties (化学性能),(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 (化学性能),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 (化学性能),(四) Chemical bonding (化学性粘接),The combination between atoms or ions of bonding surface and adhesived to