All you need to know about Sutures

Surgeons have important decisions to make regarding the type and method of suturing. This article deals with the suture needle and the choice of materials and types.

–Choosing THE RIGHT SUTURE–

Multiple material thread types and needle designs are available for dental use, each with significantly differing characteristics. It is important to understand the different options and their impact on recovery.

The appropriate choice of suture depends on the procedure’s objective and the material’s physical characteristics. Key factors to consider include the suture’s strength, knot security, and wicking properties, (see below) if a follow-up appointment is necessary for removal, if an absorbable material can be used, and if so, the duration of its effectiveness.

This article addresses all these considerations. For an online tutorial covering suturing instruments and techniques for oral surgery see the end of this piece.

Suture FUNCTION

Surgical procedures often require a clinician to create a wound for access, as seen in dental procedures such as complex extractions, bone graft placements, or dental implant insertions. After the procedure, clinicians must close the wound to prevent infection and promote healing.

Sutures serve several functions, with the most crucial being to hold the tissue in place and bring the opposing wound edges together. A sharper incision causes less trauma to the wound margins, which increases the likelihood of healing by primary intention, where the wound edges are cleanly aligned and close together, leading to faster and more efficient healing with minimal scarring. If the space between the two wound edges is minimal, rapid and complete wound healing will be possible. If the wound edges experience tears or significant trauma, healing may need to occur by secondary intention. In secondary intention, the wound is left open and heals from the bottom up, with new tissue gradually filling the wound. This process takes longer, often resulting in more scarring compared to healing by primary intention, where the edges are directly aligned and closed.

–Suture CONSTRUCTION–

Suture SIZING

Historically, suture materials were available in sizes 1-7, with 1 being 0.4mm in diameter and 7 being 0.9mm. Very thick by today’s standards. Later, a thinner 0.35mm suture was designated as size 0.  As finer materials were developed, more zeroes needed to be added to the numbering.  Today, the United States Pharmacopeia (USP) standard uses a number, and zeros separated by a hyphen. 

For example, 4-0 means 4 x 0, i.e. 0000, and 5-0 means 5 x 0, i.e. 00000. The more zeros a suture has, the smaller its diameter so 5-0 is smaller than 4-0.

Size in mm	Metric Gauge	USP Gauge
0.05mm	0.7	6-0
0.1mm	1	5-0
0.15mm	1.5	4-0
0.2mm	2	3-0

Suture NEEDLES

Suture needles are produced from surgical-grade stainless steel alloys and have three parts:

1. • A narrow point that is passed into the tissue.

1. • A body which is grasped by the needle holder.

1. • A swage where the needle joins the thread.

Needles come in various shapes and sizes. In oral surgery, the most commonly used needles are either half-circle or three-eighths circle (3/8). The curve of the needle allows it to pass through tight spaces and be guided smoothly with wrist rotation.

Sutures with cutting NEEDLE

A cutting needle with a sharp point is favoured, typically with a triangular cross-section, with the cutting edge on the inner or outer curve, while the opposite side remains flat. In oral surgery, the preferred choice is a reverse cutting (R/C) needle, which has the cutting edge on the outer curve. This design reduces the risk of the needle cutting through and damaging the tissue. A non-cutting needle is rarely used with abdominal surgery one of the few disciplines where it is preferred,

Sutures – Thread TYPE.

Oral suture threads can be monofilament (single) or multifilament (sometimes known as braided). It is important to appreciate the key features and weaknesses of each type.

—Suture MATERIALS—

Historically, sutures made from animal sources, commonly known as catgut, were widely used. These absorbable sutures were produced from the collagen fibres of sheep and cow intestines. Despite being technically braided, the gut fibres are so fine that they resemble and function much like monofilament sutures. Gut sutures came in 3 types:

1. • Plain gut – simple collagen with a glycerol-wetted surface.

1. • Chromic gut – treated with a chromium salt solution to reduce enzyme action and prolong the adsorption time.

1. • Heat-treated for faster absorption.

Catgut is superseded: Many countries banned gut sutures after the BSE (bovine spongiform encephalopathy) scare and today, they have been superseded by synthetic materials of both nonadsorbing and fully adsorbing types. Today, most oral surgery procedures are completed with a synthetic suture material in either monofilament or multi-filament with the characteristics attributable to the filament type chosen – better healing and less bacterial harbouring against packaging memory, more knot throes and sharpness/stiffness.

NON ADSORBING SUTURES

->PTFE Sutures

Polytetrafluoroethylene or PTFE for short is an un-coated monofilament suture recognised as the most ideal for bone graft and dental implant procedures.

PTFE monofilament Dental Sutures are available in 3-0, 4-0, 5-0 and 6-0 sizes and present the following key features:

• • Easy to see without the need for a dye (white colour).

• • Easy pull-through and low tissue reaction.

• • Prevent bacteria from wicking into the surgical site.

• • Good knot hold.

• • High patient comfort.

• • Limited memory effect.

->POLYAMID Sutures

Polyamid is a monofilament nylon-type suture made from a copolymer of Polyamid 6 and available in 3-0, 4-0,5-0 and 6-0 sizes.

Polyamid Dental Sutures are often chosen for their premium features at significant cost savings compared to PTFE albeit with a slight increase in memory effect.

• • Blue dye for easy visualisation.

• • Easy pull-through and low tissue reaction.

• • Prevents bacteria from wicking into the surgical site.

• • Good knot hold and patient comfort.

->SUPRAMID Sutures

Supramid is a unique material referred to as a pseudo monofilament due to its dual features.

Composed of a polyamid 6.6 core within a sheath of polyamide 6 .  this emerging material offers the benefits of monofilament i.e. low bacterial retention with low memory of multifilament. Available in 3-0 and 4-0.

ADSORBING SUTURES

->POLYGLACTIN 910 Sutures.

Polyglactin 910, often known as Vicryl or Neosorb is an absorbable multifilament suture that looks and feels like fine cotton and is dyed purple to make it easier to see.  

Polyglactin 910 sutures are often coated to improve tissue pull-through and reduce wicking. Polyglactin 910 is available in 3-0, 4-0, 5-0 and 6-0 sizes.

Adsorption: Polyglactin 910 loses 50% tensile strength at 21 and is 100% adsorbed by day 70.  

->POLYGLACTIN RAPID Sutures.

Polyglactin Rapid (Vicryl Rapid / Neosorb Rapid) is a polyglactin 910 multifilament with a low molecular weight coating for quicker adsorption than standard polyglactin 910.  

A coated Polyglactin Rapid suture offers good pull-through and low tissue reaction with good knot hold and is available in 3-0, 4-0, 5-0 and 6-0 sizes.

Polyglactin Rapid adsorption: Demonstrates 50% loss at day 5 and 100% at 10 days.

->PGA Sutures.

Poly Glycolic Acid or P.G.A. is a multifilament alternative to Polyglactin 910 with a slightly longer adsorption time and lower packaging memory.

P.G.A. demonstrates excellent handling and good tensile strength. PGA is available in 3-0, 4-0, 5-0 and 6-0 sizes.

P.G.A adsorption: P.G.A. retains 65% tensile strength at day 14 and more than 35% at day 70.

->PGCL Sutures

P.G.C.L (Monofast, Monocryl) is one of the only absorbable monofilament materials available.

P.G.C.L is a copolymer of PGA and caprolactone with a high initial tensile strength.

As an adsorbing monofilament suture P.G.C.L ‘pulls-through’ tissues well and is less likely to absorb fluids than adsorbing multifilament types. It may present a memory effect from the package and a stiffer knot to the patient.

PGCL Adsorption: Retains good strength for 7 days, loses 30% at 14 and is complete at 100.

Summary

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SUTURING TECHNIQUES

Online lectures covering the techniques to undertake a suture procedure can be found at https://www.youtube.com/@restore-surgical. 

A short video tutorial on tools and knots can be seen at https://youtu.be/jVVzY524tSw

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MORE INFORMATION, SAMPLES AND PURCHASING

Products featured in this article are manufactured in Europe by Medipac SA and available from Restore Surgical Limited. You can rread more about each SUTURE and browse the best deals HERE 

To test a suture, write to ask@implant-store.co.uk letting us know your regular type and gauge.

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TRADE NAME DISCLAIMER: Prolene, Dacron, GoreTex, Cytoplast, Teflon, Dexon, Vicryl, Vicryl Rapide and Monofast are registered trademarks and unconnected with Restore Surgical Limited.

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