Enamel matrix derivative
Encyclopedia
In dentistry
, enamel matrix derivative (EMD) is an extract of porcine fetal
tooth material used to biomimetically stimulate the soft and hard tissue
s surrounding teeth to regrow (in a process known as regeneration) following tissue destruction.
, 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
. The presence of acellular cementum acts to signal the development of periodontal ligament
fibers, followed by new alveolar bone, thus leading to the formation of the tissues of the periodontium
.
and has been shown to promote PDL fibroblast proliferation and growth. Based on the high degree of homology
between porcine and human enamel proteins, it was decided to produce the EMD from fetal pigs.
It was marketed as Emdogain by the Swedish
company Biora, until Straumann
acquired Biora in 2003 and began producing it under the Straumann name.
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 factor
s from periodontal ligament undifferentiated mesenchymal cell
s. EMD also stimulates osteoprotegerin
, serving to trigger osteoblast
s and indirectly inhibit both osteoclastogenesis and osteoclastic
function, both of which are important in attaining alveolar bone growth in the area of desired regeneration.
Dentistry
Dentistry is the branch of medicine that is involved in the study, diagnosis, prevention, and treatment of diseases, disorders and conditions of the oral cavity, maxillofacial area and the adjacent and associated structures and their impact on the human body. Dentistry is widely considered...
, enamel matrix derivative (EMD) is an extract of porcine fetal
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...
tooth material used to biomimetically stimulate the soft and hard tissue
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
s surrounding teeth to regrow (in a process known as regeneration) following tissue destruction.
Discovery of EMP's role in cementogenesis
There are three hard tissues that comprise human teeth: enamelTooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
, dentin
Dentin
Dentine is a calcified tissue of the body, and along with enamel, cementum, and pulp is one of the four major components of teeth. Usually, it is covered by enamel on the crown and cementum on the root and surrounds the entire pulp...
and cementum
Cementum
Cementum is a specialized calcified substance covering the root of a tooth. Cementum is excreted by cells called cementoblasts within the root of the tooth and is thickest at the root apex. These cementoblasts develop from undifferentiated mesenchymal cells in the connective tissue of the dental...
. The majority of the tooth structure is formed from dentin, and the enamel serves as the superficial layer of the crown
Crown (tooth)
In dentistry, crown refers to the anatomical area of teeth, usually covered by enamel. The crown is usually visible in the mouth after developing below the gingiva and then erupting into place.-References:...
while the cementum serves to cover the root. In the mid-1990s, however, it was discovered that a very thin layer of enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
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
Hertwig's epithelial root sheath
The Hertwig's epithelial root sheath is a proliferation of epithelial cells located at the cervical loop of the enamel organ in a developing tooth. Hertwig's epithelial root sheath initiates the formation of dentin in the root of a tooth by causing the differentiation of odontoblasts from the...
serve as precursors to acellular cementum during its formation, known as cementogenesis
Cementogenesis
Cementogenesis is the formation of cementum, one of the three mineralized substances of a tooth. For cementogenesis to begin, Hertwig's epithelial root sheath must fragment. Once the root sheath fragments, the dentin that later forms the tooth's root, comes in contact with the dental sac...
. The presence of acellular cementum acts to signal the development of periodontal ligament
Periodontal ligament
The periodontal fiber or 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...
fibers, followed by new alveolar bone, thus leading to the formation of the tissues of the periodontium
Periodontium
Periodontium refers to the specialized tissues that both surround and support the teeth, maintaining them in the maxillary and mandibular bones. The word comes from the Greek terms peri-, meaning "around" and -odons, meaning "tooth." Literally taken, it means that which is "around the tooth"...
.
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 amelogeninAmelogenin
Amelogenin is a protein found in developing tooth enamel, and it belongs to a family of extracellular matrix proteins. Developing enamel contains about 30% protein, and 90% of this is amelogenins...
and has been shown to promote PDL fibroblast proliferation and growth. Based on the high degree of homology
Homology (biology)
Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...
between porcine and human enamel proteins, it was decided to produce the EMD from fetal pigs.
It was marketed as Emdogain by the Swedish
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
company Biora, until Straumann
Straumann
Headquartered in Basel, Switzerland, the Straumann Group acts in implant and restorative dentistry and oral tissue regeneration.Recently, Straumann entered the fast-growing field of restorative dentistry through the acquisition of etkon, an emerging force in CAD/CAM based tooth replacement...
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. But it has been demonstrated that EMD serves to promote periodontal ligament fibroblast proliferation and growth and inhibit epithelial cell proliferation and growth; this is a key feature in EMD-promoted periodontal tissue regeneration, because the faster growing epitheliumEpithelium
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...
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 factor
Growth factor
A growth factor is a naturally occurring substance capable of stimulating cellular growth, proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors are important for regulating a variety of cellular processes....
s from periodontal ligament undifferentiated mesenchymal cell
Mesenchymal stem cell
Mesenchymal stem cells, or MSCs, are multipotent stem cells that can differentiate into a variety of cell types, including: osteoblasts , chondrocytes and adipocytes...
s. EMD also stimulates osteoprotegerin
Osteoprotegerin
Osteoprotegerin , also known as osteoclastogenesis inhibitory factor , or tumor necrosis factor receptor superfamily member 11B , is a protein that in humans is encoded by the TNFRSF11B gene...
, serving to trigger osteoblast
Osteoblast
Osteoblasts are mononucleate cells that are responsible for bone formation; in essence, osteoblasts are specialized fibroblasts that in addition to fibroblastic products, express bone sialoprotein and osteocalcin.Osteoblasts produce a matrix of osteoid, which is composed mainly of Type I collagen...
s and indirectly inhibit both osteoclastogenesis and osteoclastic
Osteoclast
An osteoclast is a type of bone cell that removes bone tissue by removing its mineralized matrix and breaking up the organic bone . This process is known as bone resorption. Osteoclasts were discovered by Kolliker in 1873...
function, both of which are important in attaining alveolar bone growth in the area of desired regeneration.