Comparative Evaluation of Clinical and Radiographic Success of Oxymetazoline Versus Sodium Hypochlorite as Hemostatic Agents in MTA Pulpotomy of Primary Molars in a Group of Egyptian Children: A Randomized Controlled Trial

The rationale for pulpotomy procedure is based on the healing capacity of the remaining pulp tissue following surgical amputation of the affected or infected coronal pulp. After achieving hemostasis, the exposed pulp stumps are covered either with a pulp-capping agent that promotes healing or with an agent that fixes the underlying tissue. MTA has been established as the gold standard medicament for pulpotomy owing to its several desirable properties such as biocompatibility, bioactivity, hydrophilicity, radiopacity, sealing ability and low solubility.

Besides the type of the pulp dressing material, one of the crucial parameters influencing the success of the pulpotomy procedure is the ability to control bleeding from the amputated pulp tissue. Selection of a hemostatic agent during pulpotomy has been a subject of extensive research and debate with respect to its influence on clinical and radiographic outcomes. The hemostatic agent provides not only hemostasis but also a sterile environment which is essential for pulp healing. Failure to achieve proper hemostasis means that blood will be continuously oozing out resulting in dislodgment of the placed medicament which will form a thick fibro purulent membrane over the pulpal tissue creating a dead space paving way for secondary infection and subsequent failure of the procedure. Furthermore, blood clot formation after hemostasis is undesirable because the fibrin present in the clot can act as a chemoattractant for polymorphonuclear leukocytes leading to prolonged pulpal inflammation.

Sodium hypochlorite (NaOCl) is one of the most popular hemostatic agents. It has tissue dissolution capacity by interfering with the cytoplasmic membrane integrity leading to irreversible enzymatic inhibition, biosynthetic change in cell metabolism, and phospholipid destruction in lipid peroxidation. It also helps in the formation of dentinal bridge. NaOCl has unique properties of simultaneous disinfection of dentine-pulp interface and chemical amputation of necrotic cells and blood clot. This ensures direct contact between pulp tissue and the capping material facilitating wound healing. In spite of its favorable antibacterial and hemostatic properties, NaOCl is considered cytotoxic. A histological study demonstrated that irrigating the tooth with 5.25% NaOCl after access opening resulted in damage to pre-dentine and dissolution of up to 4-5 layers of odontoblasts in the pulp tissue, consequently increasing the risk of internal root resorption after exposure of calcified tissue.

Furthermore, NaOCl was found to be hazardous to dental pulp stem cells (DPSCs) and hence it may theoretically cause a disturbance in pulp healing and negatively influence the outcome of the pulpotomy procedure. Moreover, NaOCl is believed to cause damage to the surrounding tissues, and alter the properties of the remaining tooth structure as it is associated with a significant decrease in dentin elastic modulus and flexural strength. Unpleasant taste and odor could also be added to the list of drawbacks of NaOCl.

Dental pulp tissue is innervated mainly by the autonomic nervous system, and activation of α-1 receptors causes vasoconstriction. Oxymetazoline (OXY) is a highly effective α -1 receptors agonist and can initiate hemostasis by vasoconstricting the smooth muscles associated with arterioles and venules in pulp tissue.