Review of Hemostatic Agents Used In Dentistry

  Dentists perform a variety of surgical procedures frequently requiring the need for a hemostatic agent. Exodontia, tissue biopsies, placement of endosseous implants, and periodontal surgery are just some examples where hemostatic agents may be beneficial.

 Not only are these agents useful for specific procedures, but they also are valuable for certain patient groups, specifically those with coagulation defects. These defects may be genetic or acquired . 

A comprehensive review of this topic is beyond the scope of this article. Nevertheless, dentists performing surgery should be familiar with these defects and their clinical manifestations.

PERIOPERATIVE HEMORRHAGE

The best management of perioperative hemorrhage is prevention. This includes a thorough preoperative patient history, necessary medical consults, familiarity with managing patients with possible bleeding diathesis, meticulous intraoperative technique, and appropriate postoperative instructions, care, and follow-up. Although these are easily listed, application in practice can be challenging. Multiple obstacles may prevent the implementation of the management steps listed. Some of these hurdles include treating patients with an undisclosed or undiagnosed medical condition, improper information retrieval, or difficult surgical conditions. Poor patient compliance with medication or postoperative instructions also are factors to be considered.

If an intraoperative bleeding episode is encountered, the clinician should consider several steps. A quick mental review of the patient’s medical history is first. If the hemorrhagic episode is difficult to manage, injection of 1/50,000 solution of epinephrine into the area may be needed. This will likely provide temporary reduction of bleeding as a result of local vasoconstriction. The site may need to be packed, and the clinician will need to consider the seriousness of the event. If very serious, a call to an emergency service may be necessary.

One of the more common methods of intraoperative hemorrhage control involves the use of a topical hemostatic agent. This article reviews some of the more common hemostatic agents and introduces ActCel (MedSpring Group), a hemostatic agent that has recently become available.

TOPICAL HEMOSTATIC AGENTS

Hemostatic Collagen

These products (eg, CollaPlug, CollaTape, and Helistat [Integra LifeSciences]) are soft, white, pliable, nonfriable, coherent, sponge-like structures. They are fabricated from bovine collagen (usually from deep flexor tendons) and are nontoxic and nonpyrogenic. The products are highly absorbent and able to hold many times their own weight of fluid. Their indications are for wound protection and for control of oozing or bleeding from clean oral wounds. As for application, these products should be held in place for approximately 2 to 5 minutes to achieve hemostasis and then may be removed, replaced, or left in situ. 

All of these collagen materials are completely resorbed within 14 to 56 days.

In addition to serving as a mechanical obstruction to bleeding, these materials affect the coagulation process. In contact with blood, collagen causes aggregation of platelets, which bind in large numbers to the collagen fibrils. The aggregated platelets degranulate, releasing factors such as thromboxane A22 that assist in the formation of a clot. The sponge also provides a 3-D matrix for strengthening the blood clot.

As with most hemostatic agents, collagens are not to be used in infected or contaminated wounds. The agents may serve as a nidus for abscess formation and may potentiate bacterial growth. Possible adverse reactions are formation of adhesions, allergic reactions, foreign body reactions, and subgaleal seroma formation (subgaleal seroma is an accumulation of blood serum beneath the scalp). 

Gelatin

(eg, Gelfoam)

Gelfoam (Pharmacia) is one of the more commonly employed agents for the control of minor bleeding. It is a porous, pliable sponge made from dried and sterilized porcine skin gelatin. Gelfoam’s mode of action is not completely understood, but unlike collagen, it is believed to be related to formation of a mechanical matrix that facilitates clotting rather than affecting the blood-clotting mechanism. This agent can retain in its interstices 45 times its weight in blood.  Gelfoam liquefies in one week and is completely resorbed in 4 to 6 weeks.

Its use is not associated with excessive scar formation. Reported adverse reactions are giant cell granuloma and hematoma formation, foreign body reactions, excessive fibrosis, toxic shock syndrome, fever, and failure of absorption. 

Cellulose (eg, Surgicel, ActCel)

Surgicel (Johnson & Johnson) is a resorbable oxidized cellulose material and is an expensive but useful option in oral surgery. It is prepared as a sterile fabric meshwork. Its mechanism of action is not completely understood, but appears to be physical rather than involve an alteration of the clotting mechanism. After it is fully absorbed with blood, it swells into a brownish/black gelatinous mass that aids in clotting. Excessive amounts of the material should be removed if possible to prevent delayed healing.

Specific dental indications include use as an adjunct to control bleeding in exodontia and other oral surgical procedures.This material may be more useful in soft-tissue procedures due to its shape, consistency, and interference with osteogenesis.

Surgicel has been found to be bacteriocidal in vitro against many organisms, and it does not enhance infection under experimental conditions.Nevertheless, it is still recommended to avoid its use in contaminated wounds where persistent drainage is desired. Encapsulation of fluid and foreign body reactions have been reported, and a burning sensation has been noted when the product is placed in unanesthetized nasal passages.

ActCel is a new topical hemostatic agent that is made from treated and sterilized cellulose and available in similar fabric meshwork as Surgicel, although it is slightly more friable. It is an FDA-approved material indicated for the control of bleeding from open wounds and body cavities (eg, mouth, ears, nose, throat, and vagina). The material does not contain chemical additives, thrombin, or collagen, and is hypoallergenic. In contact with blood, it expands to 3 to 4 times its original size and is almost immediately converted to a gel. Complete dissolution of the product takes place within 1 to 2 weeks.  Because of its purity and the fact that it degrades rapidly into biocompatible end products (glucose, water), it does not adversely affect wound healing. ActCel’s mechanisms of action are multiple, enhancing the coagulation process biochemically by en-hancing platelet aggregation and physically by 3-D clot stabilization .

After an injury, platelets are activated, changing from a discoid to spherical shape and extending pseudopodia. Platelets release factors such as thromboxane A22 that stimulate other platelets to activate. Platelets have receptors that promote their adhesion to blood vessel linings, collagen, and other platelets.2 It has been demonstrated that the fabric-like and solid texture of ActCel slows blood flow and reduces the time for thrombin to be released into the wound.24 This increases platelet adhesion (similar to platelet aggregation at a damaged blood vessel wall or at exposed collagen), thereby reducing the time to establish the clot.

Dry Socket Prevention

Localized alveolar osteitis is the most common complication in extractions, with a prevalence of 1.9% to 31.2% following removal of mandibular third molar teeth.26-28 A variety of theories exist as to its etiology, although it certainly involves an interruption of the healing process. This condition is a significant problem for both the clinician and the patient, as 45% of patients who develop alveolar osteitis require at least 4 additional postoperative visits.29 Several methods have been found to reduce the incidence of alveolar osteitis, including the use of both topical30-32 and systemic agents.33-35 Preliminary results examining the use of ActCel and tetracycline in mandibular impacted extraction sites have reduced alveolar osteitis (personal observation). Randomized controlled trials are needed to substantiate these observations.

Indications for the use of ActCel are the control of bleeding or protection of a wound in the oral cavity. This includes minor oozing that may require additional hemostatic assistance, routine use in mandibular third molar extraction sites to decrease the occurrence of alveolar osteitis, or as an adjunct for control of arterial bleeding (first stopping the arterial bleed with other methods and then assisting in stabilizing the clot by placement of ActCel). ActCel, as previously noted, should not be placed in areas that are not in communication with the external environment or placed in infected sites .

Bone Wax

Bone Wax (Ethicon) is a sterile mixture of beeswax, paraffin, and isopropyl palmitate (a softening agent) that is packaged in individual foil envelopes. It is useful when bleeding is from a visualized local vascular channel within bone, commonly referred to as a “bone bleeder,” at the surgical site. This occurs commonly during the extraction of mandibular third molars, and if not adequately addressed during surgery can be a reason for postoperative bleeding. The wax is pliable enough to be placed within a vascular channel, immediately tamponading the vascular source.

Bone Wax is nonresorbable, and due to its possible adverse effect on osteogenesis, caution should be used where regeneration of bone is expected (eg, a future implant site). Mild inflammatory reactions have been reported in tissues adjacent to the site of Bone Wax implantation, and this agent may prevent the clearing of bacteria from infected sites.

Bone wax benefits and drawbacks