The resin used for fillings is a composite resin, which is based on acrylic resin, with glass, quartz and other particles added for reinforcement.
Composite resins are generally categorized into two types: thermoplastic and thermosetting. Thermoplastic resins have the ability to soften with heat and harden with cooling, and do not react chemically. Common thermoplastic resins include polycarbonate, polyamide, polypropylene and polyethylene.
Thermosetting resins in the heating, pressure, or in the curing agent, ultraviolet light under the action of chemical reaction, once cured, and then pressurized and heated again can not be softened again or flow. Common thermosetting resins are epoxy resins, phenolic resins, polyurethane and aminoplastics.
Composite resin has the advantages of light weight, plasticity, short production time, environmental protection, corrosion resistance, long service life, etc. It is widely used in dental aesthetics, and also has a good effect on the filling of anterior and posterior cavities.
Expanded
The common filling materials are amalgam, composite resin, cast gold, ceramic, glass ionomer and so on.
1, silver amalgam: a mixture of silver, tin, zinc, copper and mercury, the mercury content is close to 50%.
Advantages: good compressive strength, able to resist the pressure of chewing; the most economical; can be completed in a single visit to the treatment; compared with composite resin, in the filling process, the requirement for moisture barrier is low.
Disadvantages: does not match the color of the teeth; amalgam can corrode and lose its luster over time, and can also cause discoloration of the tooth tissue with which it comes in contact; traditional amalgam cannot be bonded to the teeth; box-shaped cavities need to be prepared in order to fill amalgam, and for this reason the dentist may have to grind away more tooth tissue.
2, cast gold: gold alloy, that is, gold and other metals mixed composition.
Advantages: does not corrode; has a better durability and lasts longer than any other filling material.
Disadvantages: requires at least two treatments; more expensive because gold is more expensive and craftsmanship is consumed in making it; if there are gold-alloy and silver-mercury fillings on two adjacent teeth, there is a possibility that an electric current could be generated between them, which would make the body feel uncomfortable; doesn't match the color of the teeth.
3, ceramic: porcelain.
Advantages: close to the color of the teeth; not easy to stain and wear.
Disadvantages: more fragile than composite resin materials; ceramic inlays or high inlays need more volume to avoid fracture, which means more teeth need to be ground away.
4. Glass ions: acrylic and glass and fluoride.
Advantages: close to the color of the tooth; glass ions release fluoride, which prevents further decay; glass ions can bond to the tooth, which helps prevent gaps from forming between the filling and tooth tissue and further decay.
Disadvantages: traditional glass ionomer materials are significantly weaker than resin materials and are more prone to wear and tear or fracture; traditional glass ionomer materials are not as good as composite resins in terms of color matching to the teeth; resin-modified glass ionomer needs to be filled in layers, with each layer needing to be lighted or cured, which makes it stronger but also extends the time of operation.
Baidu Encyclopedia - Dental Fillings
Baidu Encyclopedia - Composite Resin