Biocramics refers to a type of ceramic materials used for specific biological or physiological functions. In other words, bioceramics refer to ceramic materials directly used in the human body or biological, medical, biochemical, etc. related to the human body. Broadly speaking, all engineering ceramic materials are collectively referred to as bioceramics.
As a bioceramic material, it should have the following functions: to replace the diseased or damaged part of the human body; as a substitute for the congenital defect part of the human body; to help the recovery of human body tissues. Bioceramic materials can be divided into:
① Artificial bone or artificial joint;
②Materials for artificial organs (such as heart valves) of the motor system;
③Materials for morphological restoration and plastic surgery;
④ Artificial tooth roots and dentures;
③Adsorption material (activated carbon) in artificial liver;
⑥ Immobilized enzyme carrier (porous glass);
⑦The temperature, gas, ion sensor and other materials of the diagnostic instrument.
In addition to measurement, diagnosis, and treatment, bioceramics are mainly used as substitute materials for biological hard tissues. They can be used in orthopedics, plastic surgery, oral surgery, cardiovascular surgery, ophthalmology, ENT and general surgery. Since it is mainly used for special repair functions or for artificial organs, bioceramics must have a series of excellent properties:
①It is harmless to the human body (non-toxic, no tissue irritation, no carcinogenic effect, no thrombosis, etc.);
②Good biocompatibility with human body (good affinity for biological tissues);
③Strong combination with surrounding bones and other tissues;
④The tensile, flexural, compressive and shear strengths are higher than those of natural bone, and the strength is not significantly reduced in body fluids (corrosion resistance);
⑤ Wear resistance;
⑥The hardness and elastic modulus are close to those of natural bone;
⑦Easy to shape and process, convenient for clinical operation.
The above items ①~③ are to meet the conditions of biology, the items ④ to ⑥ are to meet the conditions of mechanics, and the item ⑦ is the conditions for easy operation and promotion and application.
As a substitute for human hard tissues, bioceramics are mainly divided into two categories: bio-inert ceramics and bioactive ceramics. The bioactive ceramics can be divided into surface bioactive ceramics and bioabsorbable ceramics (which are decomposed and absorbed in the organism and replaced by biological tissues).
Bio-inert ceramic materials mainly refer to ceramic materials with stable chemical properties and good biocompatibility. That is, after the ceramic material is implanted in the human body, it will not produce toxic and side effects on the body, and the body will not repel the material. That is to say, the material will not be swallowed by tissue cells nor rejected out of the body, and finally surrounded by human tissues. Such materials mainly include α-Al2O3, glassy carbon, pyrolytic carbon and so on.
Bioactive ceramic material refers to a bioceramic material in which a part or all of the material is dissolved or absorbed through cell activity in a biological environment, and replaced with bone to form a firm bond. Such materials mainly include: calcium phosphate glass, hydroxyapatite and tricalcium phosphate.
As a biological material used in the human body, ceramics have received extensive attention for nearly 30 years. Bioceramics, a new material with a series of excellent properties and harmless to the human body, has promoted the development of medical science through continuous application in the medical field, and has shown infinite and broad application prospects.
my country began to study bioceramics in the early 1970s and used them in clinical practice. In 1974, the research on the use of microglass in artificial joints was carried out; in 1977, alumina ceramics were used in clinical practice; in 1979, high-purity alumina single products were used in clinical practice, and new bioceramic materials continued to appear and applied in clinical practice. .
In addition, with the development of ceramic materials and other basic sciences, functional ceramic materials that have developed simultaneously with bioceramic implant materials have also been developed in the medical field, promoting the rapid development of physiotherapy equipment, diagnostic medical equipment, and medical measurement equipment.
It can be expected that with the increasing living standards of the people in our country, people put forward higher requirements for medical and rehabilitation medicine, and ceramic materials, as key materials in bio-implant materials and medical physiotherapy, diagnostics, and measurement equipment, will be extremely With great development, ceramic materials will occupy an increasingly important position in the field of bioengineering.