Composite resins are generally divided into two types: thermoplastic and thermosetting. Thermoplastic resin has the characteristics of softening by heating and hardening by cooling, and no chemical reaction occurs. Common thermoplastic resins include polycarbonate, polyamide, polypropylene and polyethylene.
Thermosetting resin reacts chemically under the action of heat, pressure, curing agent and ultraviolet light. Once cured, it is impossible to soften or flow again after heating under pressure. Common thermosetting resins are epoxy resin, phenolic resin, polyurethane and aminoplast.
Composite resin has the advantages of light weight, strong plasticity, short production time, environmental protection, corrosion resistance and long service life. , widely used in tooth beauty, and also has a good effect on the restoration and filling of anterior teeth and posterior cavities.
Extended data
Common filling materials generally include amalgam, composite resin, cast gold, ceramics, glass ions and so on.
1, amalgam: a mixture of silver, tin, zinc, copper and mercury, with a mercury content close to 50%.
Advantages: good compressive strength and resistance to chewing pressure; The most economical; Treatment can be completed in one visit; Compared with composite resin, the requirements for moisture resistance in the filling process are lower.
Disadvantages: it does not match the color of teeth; Over time, amalgam will be corroded and lose its luster, and it will also cause discoloration of tooth tissue in contact with it; Traditional amalgam can't bond with teeth; In order to fill the amalgam, it is necessary to prepare a box-shaped hole. For this reason, dentists may have to grind more tooth tissue.
2. Casting gold: gold alloy, that is, the mixture of gold and other metals.
Advantages: no corrosion; It has good durability and lasts longer than other filling materials.
Disadvantages: at least two treatments are needed; Because gold is more expensive and production also consumes technology, the cost is more expensive; If two adjacent teeth are filled with gold alloy and amalgam, an electric current may be generated between them, which makes people feel uncomfortable; It doesn't match the color of the teeth.
3. Ceramics: porcelain.
Advantages: close to the color of teeth; Not easy to color and wear.
Disadvantages: it is more fragile than composite resin material; Ceramic inlays or high inlays need more volume to avoid cracking, which means that teeth need to wear more.
4. Glass ions: acrylic acid, glass and fluoride.
Advantages: close to the color of teeth; Glass ions can release fluorine, which can prevent further dental caries; Glass ions can be combined with teeth, which helps to prevent gaps between fillings and tooth tissues and further dental caries.
Disadvantages: traditional glass ionic materials are obviously weaker than resin materials and are more prone to wear or crack; Traditional glass ionomer materials are not as good as composite resin in color matching with teeth; Resin-modified glass ions need to be filled in layers, and each layer needs illumination or curing, which has stronger strength, but also prolongs the operation time.
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