Enamel matrix derivative

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In dentistry, enamel matrix derivative (EMD) is an extract of porcine fetal tooth material used to biomimetically stimulate the soft and hard tissues surrounding teeth to regrow (in a process known as regeneration) following tissue destruction.

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Discovery of EMP's role in cementogenesis

There are three hard tissues that comprise human teeth: enamel, dentin and cementum. The majority of the tooth structure is formed from dentin, and the enamel serves as the superficial layer of the crown while the cementum serves to cover the root. In the mid-1990s, however, it was discovered that a very thin layer of enamel actually exists between the dentin and cementum on the roots of adult human teeth. This led researchers to conclude that enamel matrix proteins (or EMPs) laid down by Hertwig's epithelial root sheath serve as precursors to acellular cementum during its formation, known as cementogenesis. [1] The presence of acellular cementum acts to signal the development of periodontal ligament (PDL) fibers, followed by new alveolar bone, thus leading to the formation of the tissues of the periodontium. [2]

Enamel matrix protein and its derivative

Making use of this finding, enamel matrix derivative (EMD) was introduced in 1996. A commercially prepared and purified extract of enamel matrix proteins, EMD is composed primarily of amelogenin and has been shown to promote PDL fibroblast proliferation and growth. [3] Based on the high degree of homology between porcine and human enamel proteins, it was decided to produce the EMD from fetal pigs. [4]

It was marketed as Emdogain by the Swedish company Biora, until Straumann acquired Biora in 2003 and began producing it under the Straumann name.

Mechanism of action

It is still unclear exactly how EMD participates in the regeneration process. [5] But it has been demonstrated that EMD serves to promote periodontal ligament fibroblast proliferation and growth and inhibit epithelial cell proliferation and growth; [3] this is a key feature in EMD-promoted periodontal tissue regeneration, because the faster-growing epithelium will ordinarily compete very successfully for the space once occupied by the periodontal ligament and alveolar bone, leading to tissue repair as opposed to regeneration.

EMD mimics normal root development by stimulating release of autocrine growth factors from periodontal ligament undifferentiated mesenchymal cells. [6] EMD also stimulates osteoprotegerin, serving to trigger osteoblasts and indirectly inhibit both osteoclastogenesis and osteoclastic function, both of which are important in attaining alveolar bone growth in the area of desired regeneration. [7]

Related Research Articles

Human tooth Calcified whitish structure in humans mouths used to break down food

The human teeth function to mechanically break down items of food by cutting and crushing them in preparation for swallowing and digesting. Humans have four types of teeth: incisors, canines, premolars, and molars, which each have a specific function. The incisors cut the food, the canines tear the food and the molars and premolars crush the food. The roots of teeth are embedded in the maxilla or the mandible and are covered by gums. Teeth are made of multiple tissues of varying density and hardness.

Cementum Specialized calcified substance covering the root of a tooth

Cementum is a specialized calcified substance covering the root of a tooth. The cementum is the part of the periodontium that attaches the teeth to the alveolar bone by anchoring the periodontal ligament.

Tooth enamel Major tissue that makes up part of the tooth in humans and many other animals

Tooth enamel is one of the four major tissues that make up the tooth in humans and many other animals, including some species of fish. It makes up the normally visible part of the tooth, covering the crown. The other major tissues are dentin, cementum, and dental pulp. It is a very hard, white to off-white, highly mineralised substance that acts as a barrier to protect the tooth but can become susceptible to degradation, especially by acids from food and drink. Calcium hardens the tooth enamel. In rare circumstances enamel fails to form, leaving the underlying dentin exposed on the surface.

Periodontal fiber Group of specialized connective tissue fibers

The periodontal ligament, commonly abbreviated as the PDL, is a group of specialized connective tissue fibers that essentially attach a tooth to the alveolar bone within which it sits. It inserts into root cementum one side and onto alveolar bone on the other.

Enamel organ

The enamel organ, also known as the dental organ, is a cellular aggregation seen in a developing tooth and it lies above the dental papilla. The enamel organ is responsible for the formation of enamel, initiation of dentine formation, establishment of the shape of a tooth's crown, and establishment of the dentoenamel junction.

Human tooth development Process by which teeth form

Tooth development or odontogenesis is the complex process by which teeth form from embryonic cells, grow, and erupt into the mouth. For human teeth to have a healthy oral environment, all parts of the tooth must develop during appropriate stages of fetal development. Primary (baby) teeth start to form between the sixth and eighth week of prenatal development, and permanent teeth begin to form in the twentieth week. If teeth do not start to develop at or near these times, they will not develop at all, resulting in hypodontia or anodontia.

Dental papilla

In embryology and prenatal development, the dental papilla is a condensation of ectomesenchymal cells called odontoblasts, seen in histologic sections of a developing tooth. It lies below a cellular aggregation known as the enamel organ. The dental papilla appears after 8–10 weeks intra uteral life. The dental papilla gives rise to the dentin and pulp of a tooth.

Periodontology or periodontics is the specialty of dentistry that studies supporting structures of teeth, as well as diseases and conditions that affect them. The supporting tissues are known as the periodontium, which includes the gingiva (gums), alveolar bone, cementum, and the periodontal ligament. A periodontist is a dentist that specializes in the prevention, diagnosis and treatment of periodontal disease and in the placement of dental implants.

Dental follicle

The dental follicle, also known as dental sac, is made up of mesenchymal cells and fibres surrounding the enamel organ and dental papilla of a developing tooth. It is a vascular fibrous sac containing the developing tooth and its odontogenic organ. The dental follicle (DF) differentiates into the periodontal ligament. In addition, it may be the precursor of other cells of the periodontium, including osteoblasts, cementoblasts and fibroblasts. They develop into the alveolar bone, the cementum with Sharpey's fibers and the periodontal ligament fibers respectively. Similar to dental papilla, the dental follicle provides nutrition to the enamel organ and dental papilla and also have an extremely rich blood supply.

Bone grafting Bone transplant

Bone grafting is a surgical procedure that replaces missing bone in order to repair bone fractures that are extremely complex, pose a significant health risk to the patient, or fail to heal properly. Some small or acute fractures can be cured without bone grafting, but the risk is greater for large fractures like compound fractures.

Epithelial root sheath

The Hertwig epithelial root sheath (HERS) or epithelial root sheath is a proliferation of epithelial cells located at the cervical loop of the enamel organ in a developing tooth. Hertwig epithelial root sheath initiates the formation of dentin in the root of a tooth by causing the differentiation of odontoblasts from the dental papilla. The root sheath eventually disintegrates with the periodontal ligament, but residual pieces that do not completely disappear are seen as epithelial cell rests of Malassez (ERM). These rests can become cystic, presenting future periodontal infections.

Cementogenesis is the formation of cementum, one of the three mineralized substances of a tooth. Cementum covers the roots of teeth and serves to anchor gingival and periodontal fibers of the periodontal ligament by the fibers to the alveolar bone.

Gingival recession

Gingival recession, also known as receding gums, is the exposure in the roots of the teeth caused by a loss of gum tissue and/or retraction of the gingival margin from the crown of the teeth. Gum recession is a common problem in adults over the age of 40, but it may also occur starting from the age of a teenager, or around the age of 10. It may exist with or without concomitant decrease in crown-to-root ratio.

Sharpeys fibres

Sharpey's fibres are a matrix of connective tissue consisting of bundles of strong predominantly type I collagen fibres connecting periosteum to bone. They are part of the outer fibrous layer of periosteum, entering into the outer circumferential and interstitial lamellae of bone tissue.

Resorption of the root of the tooth, or root resorption, is the progressive loss of dentin and cementum by the action of osteoclasts. Root resorption is a normal physiological process that occurs in the exfoliation of the primary dentition. However, pathological root resorption occurs in the permanent or secondary dentition and sometimes in the primary dentition.

In tooth development, the hyaline layer of Hopewell-Smith is the most peripheral layer of initially unmineralized dentin that forms immediately subjacent to the cementodentinal junction (CDJ). It eventually mineralizes, but not before the rest of the dentin is already mineralized. It is 0.5-0.8 µm thick and contains enamel matrix-like protein as well as the proteins one would expect to find in dentin. It is into this hyaline layer that the initial fibers of the periodontal ligament embed themselves.

Osteopromotive describes a material that promotes the de novo formation of bone.

Host modulatory therapy is an emerging treatment concept in the management of periodontitis that aims to reduce tissue destruction and stabilise or even regenerate the periodontium by modifying the host response. Historically treatment of periodontitis has been focused on reducing the bacterial challenge. However the outcomes of the conventional treatment procedures like scaling and root planning (SRP) are not always stable or predictable. Periodontal disease is seen as a balance between (1) a persisting bacterial challenge and the proinflammatory destructive events in the tissue and (2) resolution of inflammation and downregulation of destructive processes. The goal is to maximize treatment response by reducing inflammation and inhibiting destructive processes in the tissues which will result in enhanced periodontal stability after conventional periodontal treatments like SRP.

Hard tissue is tissue which is mineralized and has a firm intercellular matrix. The hard tissues of humans are bone, tooth enamel, dentin, and cementum. The term is in contrast to soft tissue.

Gingival grafting

Gingival grafting, also called gum grafting or periodontal plastic surgery, is a generic term for the performance of any of a number of periodontal surgical procedures in which the gum tissue is grafted. The aim may be to cover exposed root surfaces or merely to augment the band of keratinized tissue.

References

  1. ↑ Hammarström, L. Enamel matrix, cementum development and regeneration. J Clin Perio 1997;24:658-68.
  2. ↑ Beertsen W,et al.The periodontal ligament: A unique, multifunctional, connective tissue. Perio 2000 1997;13:20-40.
  3. 1 2 Sculean A, et al.The application of an enamel matrix protein derivative (Emdogain) in regenerative periodontal therapy: A review. Med Princ Pract 2007;16:167-80.
  4. ↑ Brooks, SJ, et al.Biochemistry and molecular biology of amelogenin proteins of developing dental enamel. Arch Oral Bio 1995;40:1-14
  5. ↑ Boyan, BD, et al.Porcine fetal enamel matrix derivative enhances bone formation induced by demineralized freeze dried bone allograft in vivo. J Perio 2000;71:1278–1286
  6. ↑ Lyngstadaas SP, et al.Autocrine growth factors in human periodontal ligament cells cultured on enamel matrix derivative. J Clin Perio 2001;28:181-8.
  7. ↑ He J, et al.Emdogain promotes osteoblast proliferation and differentiation and stimulates osteoprotegerin expression. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;97:239-45
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