gutta-percha point

gutta-percha point

n.

A cone of a gutta percha compound used for filling root canals in conjunction with a cement, paste, or plastic.

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gutta-percha point,

a small cone of gutta-percha, which, along with endodontic sealer, may be used to fill a root canal. The radiopacity of gutta-percha points permits them to be used also as probes for determining the depth and topographic characteristics of periodontal pockets and fistulas by means of radiography.

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point [point]

1. a small area or spot; the sharp end of an object.

2. to approach the surface, like the pus of an abscess, at a definite spot or place.

3. a tapered, pointed endodontic instrument used for exploring the depth of the root canal in root canal therapy; called also root canal point.

point A a radiographic, cephalometric landmark, determined on the lateral head film; it is the most retruded part of the curved bony outline from the anterior nasal spine to the crest of the maxillary alveolar process.

absorbent point in root canal therapy, a cone of variable width and taper, usually made of paper or a paper product, used to dry or maintain a liquid disinfectant in the canal. Called also paper point.

point B a radiographic, cephalometric landmark, determined on the lateral head film; it is the most posterior midline point in the concavity between the infradentale and pogonion.

boiling point the temperature at which a liquid will boil; at sea level the boiling point of water is 100°C (212°F).

cardinal p's

1. the points on the different refracting media of the eye that determine the direction of the entering or emerging light rays.

2. four points within the pelvic inlet— the two sacroiliac articulations and the two iliopectineal eminences.

craniometric p's the established points of reference for measurement of the skull.

dew point the temperature at which moisture in the atmosphere is deposited as dew.

far point the most remote point at which an object is clearly seen when the eye is at rest.

point of fixation

1. the point or object on which one's sight is fixed and through which the axis opticus passes.

2. the point on the retina, usually the fovea, on which are focused the rays coming from an object directly regarded.

freezing point the temperature at which a liquid begins to freeze, for water, 0°C (32°F); it is often used interchangeably with melting point, but should be used for substances being cooled while melting point is reserved for substances being heated.

gutta-percha point gutta-percha cone.

ice point the true melting point of ice, being the temperature of equilibrium between ice and air-saturated water under one atmosphere pressure.

isoelectric point (pI) the pH of a solution in which molecules of a specific substance, such as a protein, have equal numbers of positively and negatively charged groups and therefore do not migrate in an electric field.

J point on an electrocardiogram, the junction between the end of the QRS segment and the beginning of the ST segment.

jugal point the point at the angle formed by the masseteric and maxillary edges of the zygomatic bone; called also jugale.

lacrimal point a small aperture on a slight elevation at the medial end of the eyelid margin, through which tears from the lacrimal lake enter the lacrimal canaliculi. See also lacrimal apparatus.

point of maximal impulse the point on the chest where the impulse of the left ventricle is sometimes felt or seen most strongly, normally in the fifth costal interspace inside the mammillary line.

McBurney point a point of special tenderness in appendicitis, about 4 to 5 cm from the right anterior iliac spine on a line between the spine and the navel; it corresponds to the normal position of the appendix.

McBurney's point is located midway between the anterior iliac crest and the umbilicus in the right lower quadrant. From Ignatavicius and Workman, 2002.

melting point (mp) the minimum temperature at which a solid begins to liquefy; see also freezing point.

near point the nearest point of clear vision, the absolute near point being that for either eye alone with accommodation relaxed, and the relative near point being that for the two eyes together with employment of accommodation.

nodal p's two points on the axis of an optical system situated so that a ray falling on one will produce a parallel ray emerging through the other.

paper point absorbent point.

pressure point

1. a point of extreme sensitivity to pressure.

2. one of various locations on the body at which digital pressure may be applied for the control of hemorrhage.

Locations of pressure points. Shaded areas show the regions in which hemorrhage may be controlled by pressure at the points indicated.

root canal point point (def. 3).

silver point in root canal therapy, a tapered and elongated silver plug that is cemented into the canal as a filling. Called also silver cone.

trigger point a spot on the body at which pressure or other stimulus gives rise to specific sensations or symptoms.

triple point the temperature and pressure at which the solid, liquid, and gas phases of a substance are in equilibrium.

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point,

n 1. a small spot or a small area.
n 2. a rotating instrument having a small cutting end or surface.

point A,

n the deepest point in the bony concavity in the midline at the base of the anterior nasal spine, in the region of the incisor roots. A landmark on the lateral cephalometric view.

point, abrasive, rotary,

n small abrasive instruments used in straight or contraangle handpieces. Also called
mounted carborundum, diamond.

point angle,

n See angle, point.

point B,

n a mandibular point comparable to point A.

point, bleeding,

n See bleeding points.

point, Bolton,

n the highest point of the curvature between the occipital condyle and the basilar part of the occipital bone and located behind the occipital condyle. A substitute for the basion point when it cannot be ascertained on cephalometric headplates.

point, central-bearing,

n the contact point of a central-bearing device. See also central-bearing device.

point, condenser,

n the nib of a condensing instrument, which is a short instrument for condensing foil or amalgam that is inserted into a mechanical condenser or into a cone socket handle.

point, contact,

n the area of contact of approximating surfaces of two adjacent teeth. The areas of contact are located at the line of junction between the occlusal and middle thirds of the posterior teeth and the incisal and middle thirds of the anterior teeth. Also called
contact area. See also open contact.

point, convenience,

n a small undercut in the cavity wall convenient for placing and retaining the first portion of a filling material. It is generally one of the retention points placed in a cavity preparation that provides the best access to the operator.

point D,

n the center of the body of the symphysis.

point, faulty contact,

n a defective contact between the proximal surfaces of adjacent teeth, produced by wearing of the contact areas, dental caries, improper restoration, or altered tooth position. See also open contact.

point, gutta-percha,

n See gutta-percha points.

point, hinge axis,

n a point placed on the skin corresponding with the opening axis of the mandible.

point, Hirschfeld's silver,

n.pr a calibrated silver rod used to record the clinical depth of periodontal pockets radiographically for the purpose of diagnosis.

point, incisor,

n the intersection of the mandibular occlusal and midsagittal planes. The point at the mesioincisal angles of the two mandibular central incisors.

point, loss of contact,

n the failure of contact of convex proximal surfaces of adjacent teeth; produced by tooth migration, dental caries, or improper restoration.

point, median mandibular,

n a point on the anteroposterior center of the mandibular ridge in the median sagittal plane.

point of centricity,

n if the point of the buccal cusp of the mandibular right molar, put in lateral position, arcs around the upright axis of the right condyle, it will reach a station where further muscular efforts leftward will change the cusp's direction so that it will arc around the left condyle. The station where the right arc ends and the left arc begins is a point of mandibular centricity. While the right cusp point orbits (arcs) around the near vertical axis, all other points in the jaw join in orbiting (arcing). The left condyle arcs rearward until it reaches a cranial backstop; then the muscles start rotating it and carrying it leftward, and the right condyle begins arcing forward, downward, and medially. In the right and left swings of the jaw, a condyle reciprocally alternates between being a rotator and an orbiter. The point of centricity of the mandible is demonstrated usually on a horizontal plane, but it can be demonstrated on all three planes of projection. The point of centricity is rearmost, midmost (between the arcs of motion), and uppermost. See also face-bow and relation, centric.

point, paper,

n See paper point.

point, registration,

n a point considered as fixed for a particular pattern of analysis. Also, the midpoint of a perpendicular line from the sella turcica to the Bolton-nasion plane.

point, transition,

n See Tg value.

point, treatment,

n a piece of paper point, selected for the root canal being treated, that carries or holds the medication in place.

point, trial,

n a cone of filling material placed in a canal and radiographed to check on the length and fit of the filling.

point, trigger,

n the point from which referred pain initiates. In the myofascial pain syndrome, usually a localized, deep tenderness in a taut bundle of muscle fibers from which pain is referred to other sites.

point, yield,

n 1. the place on the stress-strain curve where marked permanent deformation occurs. It is just beyond the proportional limit.
n 2. the point where permanent deformation starts in a metal.