Written and maintained by CASRAI Editorial Board
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This page describes products and general use; it is not medical advice.
Who uses them: dental and oral surgery practitioners work with dental sutures, and buyers and students read the same product class when comparing materials and sizes. After reading, you should be able to name the thread materials used in oral surgery, read a 3-0, 4-0 or 5-0 size label against measured breaking-force data, and know which questions a test table cannot answer.
What dental sutures are
Dental sutures are surgical threads, usually supplied with an attached needle, used to hold soft tissue together in oral surgery. They are the same device class described in what a suture is; the dental difference is the setting, where the thread sits in a wet mouth and the study discussed below tested it in artificial saliva at 37 °C.
How they are built
A suture is a thread plus, optionally, a needle. In the US, the regulation for a nonabsorbable polyester suture (21 CFR 878.5000) describes it as a multifilament, nonabsorbable, sterile, flexible thread made of long-chain polyester fibers, coated or uncoated, with or without a needle, meeting the USP monograph for nonabsorbable sutures. The same regulation classes it as Class II with special controls.
The threads tested in a 2022 in vitro study of sutures used in oral surgery differ in structure: polypropylene and polyvinylidene fluoride are monofilament, polyamide and polyglycolide-co-caprolactone are pseudo-monofilament, and the polyester/polyethylene (PE), polyglycolide and rapid polyglycolide threads are multifilament. Needle shapes and sizes are covered separately in suture needle types and suture needle sizes.
Materials and sizes: what a bench test measured
Eight materials were each tested in three sizes (3-0, 4-0, 5-0): silk, PGCL, polypropylene, rapid polyglycolide, polyglycolide, polyamide, PE and PVDF. Thread samples were soaked in artificial saliva at 37 °C and pulled on a uniaxial testing machine. The table gives the breaking force in newtons (mean ± standard deviation, five tests per thread).
| Material | 3-0 (N) | 4-0 (N) | 5-0 (N) |
|---|---|---|---|
| Silk (S) | 13.75 ± 1.21 | 13.13 ± 0.49 | 6.57 ± 0.29 |
| Polyglycolide-co-caprolactone (PGCL) | 14.4 ± 3.57 | 9.83 ± 0.51 | 2.62 ± 1.06 |
| Polypropylene (PP) | 10.6 ± 1.37 | 8.56 ± 1.75 | 4.83 ± 2.03 |
| Rapid polyglycolide (rPGA) | 16.81 ± 2.18 | 9.72 ± 1.78 | 8.69 ± 0.63 |
| Polyglycolide (PGA) | 15.52 ± 2.84 | 10.93 ± 0.83 | 10.19 ± 5.45 |
| Polyamide (PA) | 13.32 ± 1.02 | 10.17 ± 0.56 | 3.25 ± 0.68 |
| PE (multifilament) | 9.5 ± 0.78 | 7.07 ± 0.43 | 6.47 ± 2.12 |
| Polyvinylidene fluoride (PVDF) | 12.74 ± 0.39 | 9 ± 1.07 | 7.45 ± 0.84 |
Source: Materials 2022, “Evaluation of Breaking Force of Different Suture Materials Used in Dentistry: An In Vitro Mechanical Comparison”, Table 1 (PMC8840186).
What the numbers show
- The highest breaking force was 3-0 rapid polyglycolide (16.81 N); the lowest was 5-0 PGCL (2.62 N).
- The 3-0 size showed the highest breaking force overall. For seven of the eight materials the 3-0 versus 5-0 difference was statistically significant; for polyglycolide it was not.
- Polyamide and PVDF fell significantly at each step down in size. Polyglycolide at 5-0 had a wide spread (10.19 ± 5.45 N), so its mean should be read with care.
- Needle-to-thread detachment was also measured: the highest value was 3-0 polyglycolide (14.29 ± 3.57 N) and the lowest was 5-0 PGCL (1.78 ± 0.62 N). After a forward-reverse-forward knot, 3-0 silk resisted tension best and 5-0 silk least.
Why this page gives no selection rule
The study’s authors say that the main goal of their work was not to classify the best suture but to give clinicians information on the behavior of different materials. This page therefore ranks nothing and gives no selection rule. Absorbable and nonabsorbable thread types are compared in absorbable vs non-absorbable sutures; individual materials have their own pages, such as polyglycolic acid and polyglactin.
Safe use and handling basics
Sutures are regulated medical devices (Class II for the polyester example above), supplied sterile, and used by trained clinicians following the manufacturer’s instructions for use. Use, placement and removal are clinical decisions that belong to the treating clinician and are not described here.
Common mistakes when reading suture data
- Treating breaking force as clinical performance. The study was in vitro only, on samples about 20 mm long in artificial saliva.
- Comparing sizes across materials by label alone. The same size label produced very different breaking forces between materials in the table.
- Reading a mean without its spread. Several 5-0 results have large standard deviations relative to the mean.
Frequently asked questions
Which materials were compared in the oral surgery study?
Silk, polyglycolide-co-caprolactone, polypropylene, rapid polyglycolide, polyglycolide, polyamide, a multifilament polyethylene/polyester thread and polyvinylidene fluoride, each in 3-0, 4-0 and 5-0.
Does a thinner size always break at a lower force?
In the study, breaking force generally fell as the size got thinner (3-0 to 5-0), with polyglycolide the exception, where the differences were not statistically significant.
Is the polyester suture regulated in the US?
Yes. 21 CFR 878.5000 identifies the nonabsorbable polyester suture and classes it as Class II with special controls.
Sources
- “Evaluation of Breaking Force of Different Suture Materials Used in Dentistry: An In Vitro Mechanical Comparison”, Materials 2022: https://pmc.ncbi.nlm.nih.gov/articles/PMC8840186 (checked 2026-10-30).
- 21 CFR 878.5000, Nonabsorbable poly(ethylene terephthalate) surgical suture, eCFR: https://www.ecfr.gov/current/title-21/section-878.5000 (checked 2026-10-30).
