Dental suture glossary

Sizing

USP size

United States Pharmacopeia designation of suture diameter, expressed as a count of zeros (USP 6-0 is finer than USP 2). The metric equivalent is approximately 0.7 metric for USP 6-0 and 5 metric for USP 2, per ISO 10304.

Metric sizing

European suture diameter in millimetres × 10 (e.g. metric 1 = 0.1 mm). Used alongside USP in the EU per European Pharmacopoeia monographs 3.0.4 and 3.0.5.

Thread length

The suture strand length in centimetres, typically 30, 45, 60, 75, 90 or 150 cm. Longer threads reduce the number of knots needed for long closures.

Absorption

Absorbable suture

A suture that loses tensile strength in tissue over weeks to months and is eventually broken down by hydrolysis or enzymatic action. Examples: polyglactin 910 (Vicryl), polydioxanone (PDS), polyglycolide (PGA), poliglecaprone 25 (Monocryl), catgut.

Non-absorbable suture

A suture that resists absorption and either remains encapsulated or is removed. Examples: silk, polypropylene (Prolene), polyester (Ethibond), polyamide / nylon (Ethilon), PTFE.

Tensile strength retention

The percentage of original strength a suture retains at a given day post-implant. Polyglycolide retains about 50% at 14 days and 0% at 90 days; polydioxanone retains about 50% at 28 days and 25% at 56 days.

Construction

Monofilament

A single-strand suture. Lower tissue drag, lower knot security, lower infection risk. Examples: polydioxanone, polypropylene, polyamide.

Polyfilament (braided)

A multi-strand suture twisted or braided together. Higher knot security, higher tissue drag, slightly higher infection risk. Examples: polyglactin 910, polyester, silk.

Coated suture

A braided suture with a polymer coating (e.g. polyglactin 370 + calcium stearate) to reduce tissue drag while keeping knot security. Example: coated Vicryl.

Materials (synthetic)

Polyglycolide (PGA)

Synthetic absorbable braid. Loses 50% tensile strength at 14 days; fully absorbed by 90 days. Used for mucosal and subcutaneous closures.

Polyglactin 910 (Vicryl)

Synthetic absorbable braid (copolymer of glycolide and lactide). 50% strength at 21 days; absorbed by 90 days. The workhorse for oral mucosa and subcutaneous tissue.

Polydioxanone (PDS)

Synthetic absorbable monofilament. 50% strength at 28 days; absorbed by 180 days. Used where prolonged support is needed.

Poliglecaprone 25 (Monocryl)

Synthetic absorbable monofilament. 50% strength at 7 days; absorbed by 90-120 days. Common in plastic surgery and skin closure.

Polypropylene (Prolene)

Synthetic non-absorbable monofilament. Used for skin, vascular, and long-term support closures.

Polyester (Ethibond)

Synthetic non-absorbable braid (often coated). High tensile strength and knot security; common in cardiac and dental bone work.

Polyamide / nylon (Ethilon)

Synthetic non-absorbable monofilament. Used in skin closure; slowly hydrolyses over years.

Materials (natural)

Catgut (plain)

Natural absorbable monofilament made from purified collagen. Loses tensile strength in 7-10 days. Largely phased out in Europe in favour of synthetic absorbables.

Silk

Natural non-absorbable braid. Soft handling, high knot security; can wick bacteria and is not used intra-orally where infection risk is high.

Needles

Needle shape: taper point (TP)

Round-bodied needle that pushes tissue aside without cutting. Default for soft tissue and mucosa.

Needle shape: reverse cutting (CR)

Triangular needle with the cutting edge on the outer curve. Used for tough tissue like skin and oral mucosa. Preferred over conventional cutting because the inside curve is flat, reducing tissue cut-out.

Needle shape: conventional cutting (CP)

Triangular needle with the cutting edge on the inner curve. Less common than reverse cutting in dentistry; used in some periodontal and plastic surgery applications.

Needle shape: tapercut

Hybrid: round body at the tip transitions to a cutting edge near the swage. Useful for tough fibrous tissue like oral mucosa overlying bone.

Needle circle (3/8, 1/2, 5/8)

The fraction of a full circle the needle sweeps. 3/8 (most common in dentistry), 1/2 (deeper cavities), 5/8 (deepest).

Needle length (mm)

The straight-line chord length of the needle in millimetres, typically 11, 13, 16, 19, 24, 30 mm for dental use. Longer needles reach further but require more dexterity.