Matrix

matrix /ma·trix/ (ma´triks) pl. ma´trices   [L.]

1. the intercellular substance of a tissue or the tissue from which a structure develops.

2. groundwork; the base in which or from which a thing develops.

3. a mold or form for casting.

4. a metal or plastic strip used to provide form to a dental restoration.

5. the continuous phase of a composite dental restoration.

---

bone matrix  the intercellular substance of bone, consisting of collagenous fibers, ground substance, and inorganic salts.

cartilage matrix  the intercellular substance of cartilage, consisting of cells and extracellular fibers embedded in an amorphous ground substance.

extracellular matrix  (ECM) any substance produced by cells and excreted to the extracellular space within the tissues, serving as a scaffolding to hold tissues together and helping to determine their characteristics.

interterritorial matrix  a paler staining region among the darker territorial matrices.

nail matrix  m. unguis.

territorial matrix  basophilic matrix around groups of cartilage cells.

matrix un´guis  nail bed; also, the proximal part of the nail bed where growth occurs.

---

ma·trix (mtrks)

n. pl. ma·trix·es or ma·tri·ces (mtr-sz, mtr-)

1. A surrounding substance within which something else originates, develops, or is contained.

2. The womb.

3. The formative cells or tissue of a fingernail, toenail, or tooth.

4. See ground substance.

5. A specially shaped instrument, plastic material, or metal strip for holding and shaping the material used in filling a tooth cavity.

---

Matrix

The tissue at the base of the nail, from which the nail grows.

Mentioned in: Nail Removal

---

matrix (mā´triks),

n 1. an intergranular substance that acts somewhat as a cementing material for other particles; e.g., zinc phosphate cement is made of undissolved zinc oxide particles, surrounded and held or cemented together by phosphate compounds. The phosphate compounds make up the matrix.
n 2. a mechanical or artificial wall that completes the mold into which plastic material is inserted.
n 3. a mold into which something is formed. See also bone; splint.

matrix, amalgam,

n a metal form, usually of stainless steel, about 0.0015 to 0.002 inch thick, adapted to a prepared cavity to supply the missing wall so that the plastic amalgam will be confined when it is condensed into the cavity.

matrix, celluloid,

n a strip of celluloid used to mold cement into the desired shape. See also strip, plastic.

matrix, custom,

n a matrix made especially for a given location, tooth, or preparation.

matrix, fibrous, of alveolar bone,

n collagen fibers in the alveolar bone, calcified by the accumulation of hydroxyapatite, a calcium salt.

matrix, fibrous, of bone,

n a component of bone tissue consisting of collagen fibers.

matrix, fibrous, of periodontal ligament,

n major component consisting of collagen and oxytalan fibers whose function is to provide support to the tooth.

matrix holder,

n See retainer, matrix.

matrix, intermicrobial

(in´turmīkrō´bēl),
n an intercellular substance found in plaque, which is made from derivatives of saliva, gingival fluids, and microorganisms.

matrix, mechanical,

n (proprietary matrix), a patented or manufactured type of matrix.

matrix, plastic,

n a matrix of resin or plastic for use with cold-curing resin or cement.

matrix, platinum,

n a matrix of wrought platinum foil, usually 0.001 inch or thinner, adapted to a die of a preparation for a fired porcelain restoration; serves as a vehicle to carry and maintain the applications of porcelain when they are placed in a furnace for firing.

matrix, proprietary,

n See matrix, mechanical.

matrix retainer,

n a mechanical device used to secure the ends of metal or plastic bands around a tooth to provide a form into which a restorative material can be condensed to replace a portion of tooth substance removed in cavity preparation. See also retainer, matrix.

matrix, T-band,

n a matrix material cut with a T-shaped projection at one end; the lugs are bent over to engage the band as it encircles the tooth.

---

matrix

pl. matrices [L.]

1. the intercellular substance of a tissue, such as bone matrix.

2. the tissue from which a structure develops, such as hair or nail matrix.

3. a rectangular arrangement of quantities or symbols.

---

bone matrix (1)

see bone matrix.

cartilage matrix (1)

the intercellular substance of cartilage, consisting of cells and extracellular fibers embedded in an amorphous ground substance.

claw matrix (2)

the claw bed. Called also matrix unguis.

correlation matrix (3)

a square table giving a correlation between each pair of a set of variables. The diagonal elements give the correlation of a variable with itself, namely 1.

covariance matrix

similar to the correlation matrix but gives the variances and covariances.

matrix Gla protein

part of the organic phase of bones; found tightly bound to the bone morphogenetic protein of Urist.

transition matrix (3)

a table of values used in a markov chain mathematical model, giving the probability of a transition from one state to another in a specified time interval.

matrix unguis

see claw matrix (above).