Written and maintained by CASRAI Editorial Board
Last updated
General product information for laboratory and clinic staff; not medical or dental advice.
Short answer
Dental composite resin is a tooth-coloured restorative material made of an organic polymerizable resin matrix, inorganic filler and a coupling agent. In US device regulation it is called “tooth shade resin material” (21 CFR 872.3690), a Class II device with product code EBF, which is the term to search under in regulatory records.
What is dental composite resin?
The American Dental Association (ADA) describes resin composite restorative materials as “generally made up of an organic polymerizable resin matrix, inorganic filler material and a coupling agent”, developed as an esthetic alternative to amalgam by providing a tooth-colored filling. Since 2003 the ADA Council on Scientific Affairs has sorted materials for direct restorations into four categories: amalgam, resin-based composites, glass ionomer and resin-modified glass ionomer. The NIDCR notes that composite resin materials are increasingly used by dentists to fill teeth.
How the material is built and cured
Resin matrix
The ADA page traces bisphenol A glycidyl methacrylate (BisGMA) as a matrix monomer from the early 1960s and urethane dimethacrylate from the 1970s, with other monomers such as TEGDMA added to reduce viscosity. It notes that methacrylate polymerization naturally results in shrinkage, which can lead to marginal gaps.
Filler
Silica was introduced as a filler in the 1950s. Micro-fillers (0.01 to 0.1 µm) improved polishability; hybrid composites combine macro- and micro-fillers; nano-fillers followed in the 2000s.
Curing
Traditional composites were self-cured by hand-mixing. Light-curing was introduced in the 1970s, and the ADA notes that light-cured composites have limits on light penetration. Dual-cure resins combine light-curing with a chemical reaction for deeper applications where light penetration may be limited.
Classification checklist
The ADA states that composites are a heterogeneous group, “often classified by resin type, particle filler size or curing type”, and that these classifications are nonexclusive and often overlap. A product record can therefore be read along three axes at once:
| Axis | What to look for in a product record | Source |
|---|---|---|
| Resin type | Matrix monomers, for example BisGMA, urethane dimethacrylate, TEGDMA | ADA, Materials for Direct Restorations |
| Filler particle size | Macro-, micro-, hybrid or nano-filled | ADA, Materials for Direct Restorations |
| Curing type | Self-cure, light-cure or dual-cure | ADA, Materials for Direct Restorations |
| Regulatory identity | Device name “tooth shade resin material”, 21 CFR 872.3690, Class II, product code EBF | eCFR 21 CFR 872.3690; FDA product classification database, code EBF |
Where it matters for labs, clinics and supply decisions
Regulatory name differs from the trade name
The regulation (eCFR, checked 2026-10-30) defines a tooth shade resin material as a device composed of materials such as BisGMA, intended to restore carious lesions or structural defects in teeth, and classifies it as Class II. A catalogue or database entry may list a composite under that device name or product code rather than “composite resin”, so searching all three terms avoids missing records.
Specification properties
ADA Specification No. 27 sets requirements for resin-based filling materials, with shade, color stability, flexural strength and radiopacity among the properties covered. Staff reading a product’s documentation can look for those properties by name. Shade is expressed against a reference scale; see our VITA shade guide.
Equipment that comes with the material
The ADA notes that many resin materials need to be light-cured, that adhesion to tooth structure requires intermediary agents containing highly reactive chemicals, and that curing relies on curing devices that require protective equipment. Records for a composite therefore often sit alongside curing-light and adhesive records. The ADA also states that durability, strength and cost issues have prevented composites from entirely replacing amalgam.
Related material families
Composites are one of four ADA direct-restoration categories. For the glass ionomer family, read what glass ionomer cement is; for the older mercury-based alternative, see amalgam versus composite.
Common misunderstandings
- “Composite” and “resin” are different products. In the ADA’s usage they are the same family: resin-based composites.
- One category fits every product. The ADA says the resin, filler and cure classifications overlap, so a single label is incomplete.
FAQ
What is dental composite resin made of?
An organic polymerizable resin matrix, inorganic filler material and a coupling agent (ADA).
How does FDA classify it?
As a “tooth shade resin material” under 21 CFR 872.3690, Class II, product code EBF.
How is it hardened?
By self-curing, light-curing or dual-curing, depending on the product (ADA).
Sources
- American Dental Association, Materials for Direct Restorations, checked 2026-10-30.
- eCFR, 21 CFR 872.3690 Tooth shade resin material, checked 2026-10-30.
- FDA, Product Classification database, product code EBF (device name “Material, Tooth Shade, Resin”, Class II, 21 CFR 872.3690), checked 2026-10-30.
- NIDCR, Dental Fillings, checked 2026-10-30.
