Dental sutures, commonly known as stitches, are medical devices used after oral procedures like tooth extractions, implant placements, or gum surgery. Their primary purpose is to hold soft tissues together, securing wound edges and stabilizing the blood clot to promote proper healing. Suture materials are broadly categorized into two types: those the body can break down (absorbable) and those that must be manually removed (non-absorbable). The material’s composition dictates its strength, how the body interacts with the body, and the required duration of wound support.
Absorbable Sutures: Materials That Dissolve
Absorbable sutures are constructed from materials designed to be broken down and eliminated by the body over a predictable period. These materials fall into natural or synthetic categories, each with distinct mechanisms of degradation. Synthetic absorbable materials, such as Polyglycolic Acid (PGA) and Polyglactin 910 (PGLA), dissolve through hydrolysis. Water molecules penetrate the material and break the polymer chains into smaller, dissolvable components.
Natural absorbable sutures, such as Plain Catgut and Chromic Gut, are derived from purified collagen. These materials are broken down by the body’s own proteolytic enzymes. Plain Catgut loses strength quickly and is absorbed rapidly, while Chromic Gut is treated with chromium salts to slow degradation, allowing it to maintain strength longer.
The predictable breakdown of synthetic materials through hydrolysis generally makes them preferred for many modern dental procedures. Polyglactin 910, for example, offers a balance of tensile strength and a reliable absorption rate over several weeks. The speed of enzymatic absorption for natural materials can vary depending on the patient’s metabolism and local tissue conditions.
Non-Absorbable Sutures: Materials Requiring Removal
Non-absorbable sutures are composed of inert materials that the body cannot break down, requiring manual removal after the wound has healed. Historically, natural fibers like Silk have been the most common choice in dentistry. Silk is a proteinaceous material known for its excellent handling and knot security, but as a braided thread, it can harbor bacteria and provoke a significant tissue reaction.
The most frequently used synthetic non-absorbable materials are Nylon (polyamide) and Polypropylene (Prolene). These are manufactured as monofilaments, meaning they are a single, smooth strand. This monofilament structure results in very low tissue drag and minimal tissue reaction compared to braided silk. Nylon offers high tensile strength, while Polypropylene is highly inert and resistant to infection, making it a popular choice for long-term, stable support.
Specialty materials like Polytetrafluoroethylene (PTFE) are used, particularly in complex implant or grafting procedures. PTFE is prized for its extreme biocompatibility and low adherence to bacteria. Because these materials retain their full strength indefinitely, they are selected when the surgical site requires prolonged mechanical support.
Material Properties and Dentist Selection
The chemical composition of a dental suture directly influences its physical and biological properties. One property is the material’s handling characteristic, which describes how easily the thread can be manipulated and tied into a secure knot. Silk is often considered superior for this, while stiff monofilaments like nylon can be more difficult to manage. Another property is tensile strength, which is the material’s resistance to breaking when pulled, and the duration it maintains this strength in the oral environment.
The body’s tissue reaction to the material is a significant consideration, as the oral cavity presents a high risk for bacterial contamination and inflammation. Synthetic monofilaments, such as Polypropylene and Nylon, are generally favored for their low tissue reactivity and smooth surface, which resists bacterial accumulation. Conversely, braided materials like silk, while strong and easy to knot, can act as a wick for oral fluids and bacteria, potentially increasing the risk of local irritation.
Ultimately, the choice of material is dictated by the procedure’s needs, particularly the required duration of wound support. Fast-healing wounds, such as those following a simple tooth extraction, may use rapidly absorbing catgut to eliminate the need for a return visit. Procedures involving bone grafts or implants, which require extended stabilization, often necessitate the use of slower-absorbing synthetic polymers or non-absorbable materials like PTFE to ensure the tissues are held securely throughout the critical healing phase.