Dental Cements 1 (copy)

Vocabulary flashcards based on dental cements lecture notes.

Acid-base reaction

Chemical reaction between a compound with replaceable hydrogen ions (acid) and a substance with replaceable hydroxide ions (base) that yields a salt and water; for aqueous cements, the liquid is an acid and the powder is a base.

Anticariogenic

Capable of inhibiting or preventing dental caries.

Appliance

A dental device that is made extraorally and affixed intraorally, such as a crown, a fixed prosthesis, or an orthodontic bracket.

Atraumatic Restorative Treatment (ART)

A clinical procedure performed without dental burs, air/water spray, or anesthesia that consists of manual excavation of carious tissue in a cavitated lesion and restoration of the tooth cavity with a fluoride-releasing cement.

Base

A material that is used to protect the pulp in a prepared cavity by providing thermal insulation; a may also serve as a medicament.

Calcium phosphate cement

A cement used for bone regeneration usually comprising a powder (di-, tri-, or tetra-calcium phosphate) that dissolves in an aqueous solution from which hydroxyapatite is precipitated.

Cavity liner

A material that coats the bottom of a prepared cavity to protect the pulp; it is applied in a thin layer and usually contains calcium hydroxide or mineral trioxide aggregate (MTA); also, includes certain glass ionomer cements used as intermediate layers between tooth structure and composite restorative material.

Cement

Substance that hardens from a viscous state to a solid state to join two surfaces; for dental applications, cements act as a base, liner, filling material, or adhesive to bind devices and prostheses to tooth structures or to each other.

Cement thickness

Distance between the abutment tooth and cemented prosthesis. This dimension is influenced by the design of the prosthesis and the viscosity of the cement during seating.

Cermet

A glass ionomer cement that is reinforced with filler particles prepared by fusing silver particles to glass.

Compomer

Resin-based composite consisting of a silicate glass filler phase and a methacrylate-based matrix with carboxylic acid functional groups; also known as polyacid-modified glass ionomer cement, a term derived from composite and ionomer; a secondary setting mechanism is related to acid-base reactions of the glass filler.

Craze

A network of fine cracks or lines that are formed in the surface of aqueous-based cements because of rapid dehydration.

Demineralization

The loss of mineral, typically calcium and phosphate ions, from tooth structure caused by exposure to organic acids produced by oral microorganisms.

Dew point

The temperature at which moisture in air begins to condense such as the temperature at which dew condenses on a cool glass mixing slab.

Di- and tricalcium silicate

The main phases present in MTA cement, which are hydraulically active (set with water). (Monocalcium silicate is not hydraulically active.)

Film thickness

Per ANSI/ADA Specification No. 96 (ISO 9917-1), the thickness in micrometers of set cement 10 minutes after a load of 150 N has been applied by a flat plate against another flat surface. The thickness should be less than 25 μm for luting cements.

Fluoride recharging

The process by which a restorative material, specifically glass ionomer cement, absorbs fluoride from a solution with a high fluoride concentration.

Formocresol

A compound consisting of formaldehyde, cresol, glycerin, and water.

Glass

A hard, stiff, amorphous material made by fusing silicates with one or more types of metal oxides, usually an alkali or alkaline earth oxide, boron oxide, or alumina. Radiopaque glass contains strontium oxide, barium oxide, or other high-atomic-mass metal oxides that are dissolved in the silicate glass. Fluoride or phosphate compounds may also be incorporated in a glass matrix.

Glass ionomer cement (conventional GIC)

A cement that hardens following an acid-base reaction between fluoroaluminosilicate glass powder and an aqueous-based polyacrylic acid solution.

Gutta-percha

A material composed of trans-polyisoprene rubber with various additives, usually including zinc oxide powder, barium sulfate, and modifiers to adjust the rheology for filling (obturating) a root canal after pulp extirpation and canal preparation; gutta-percha must be used with a root canal sealer to seal the canal from bacterial penetration.

HEMA

2-hydroxyethylmethacrylate.

High-viscosity glass ionomer cement

A conventional GIC that contains finer glass particles and a higher powder/liquid ratio for increased packability and strength.

Hybrid ionomer

Also called resin-modified glass ionomer.

Intermediate restoration

A tooth filling placed or prosthesis that is cemented for a limited time, from several days to months, which is designed to seal a tooth and maintain its position until a long-term restoration is produced; also called a temporary restoration.

Luting agent

A viscous cement-like material that fills a gap between bonded materials.

Maturation (cement)

The process of hardening a cement matrix through hydration with oral fluids to achieve greater mechanical strength.

Metal-reinforced glass ionomer cement

A glass ionomer cement that incorporates metal particles to improve certain mechanical properties.

Mineral trioxide aggregate (MTA)

A tri- and dicalcium silicate−based cement used for vital pulp therapy and endodontic indications including apexification, iatrogenic perforation repair, resorption repair, root-end filling, and sealing.

Permanent restoration

A long-lasting replacement or restoration for missing, damaged, or dis- colored teeth. Because of the tendency of materials to degrade or fracture over time, the termpermanent does not signify an unlimited life expectancy.

P/L ratio

Powder-to-liquid ratio by weight or volume.

Polyacid-modified composite

See compomer.

Pulp capping

A procedure for treating a pulp that has been exposed through carious tissue removal by the application of a medicament; indirect pulp capping is the term used when the pulpal expo- sure is incipient, as when dentinal tubules are visible in a prepared tooth.

Remineralization

Process of restoring mineral content (calcium phosphate) in demineralized tooth structure.

Resin cement

A resin-based material containing fillers that are cured to form a composite material used for attaching orthodontic brackets and fixed prostheses. Such cements are applied following the application of an etchant and an enamel or a dentin bonding agent to bond to tooth structure. Generally, these cements are less viscous than resin-based composite restorative materials.

Resin-modified glass ionomer cement (hybrid ionomer cement)

A hybrid cement that combines a glass powder, such as used in glass ionomers, and a liquid that contains polymerizable groups attached to the polyacrylic acid, such as HEMA, and catalysts, such as diphenyliodonium chloride. This type of cement has a longer working time and is less sensitive to water contamination than conventional glass ionomer cement.

Root canal sealer

A material used in conjunction with an obturation material for root canal therapy such as gutta-percha, to prevent the ingress of fluid or bacteria within the tooth root.

Sandwich technique

Technique of placing glass ionomer cement as an intermediate layer between the tooth structure and a resin-based composite restorative material; this restoration design com- bines the adhesion and fluoride-releasing nature of a glass ionomer cement with the esthetic quality and durability of a resin-based composite.

Self-adhesive

Ability of a material to adhere to tooth structure without the aid of a dentin or enamel bonding agent.

Setting time

The elapsed time from the start of mixing to the time at which the setting reaction essentially stops as measured by reaching a desired hardness or consistency; setting time can be measured with a 1-mm-diameter needle indenter at a load of 400 g at a temperature of 37 °C and a relative humidity greater than 90%. Setting time is the elapsed time from the start of mixing to the point at which the needle no longer makes a discernible circular indentation in the cement.

Silicate cement (silicophosphate)

Traditional restorative material made from the mixture of a liquid (phosphoric acid) and a fluoride-containing silicate glass powder.

Temporary restoration

Same as intermediate restoration.

Varnish

A material for application to the floor of a prepared cavity; a solution of natural gum, synthetic resins, or resins dissolved in volatile solvent, such as acetone, ether, or chloroform; not necessarily a cement.

Vital pulp therapy

The placement of a material in a prepared tooth over an injured pulp to induce the formation of secondary dentin. Pulp capping, cavity lining, and pulpotomies are all vital pulp therapy treatments. MTA and calcium hydroxide have been used for this therapy.

Working time

Elapsed time from the start of mixing to the time at which the consistency of a material is no longer suitable for its intended use or a rapid rise in viscosity occurs.

Zinc oxide−eugenol (ZOE) cement

A cement that is based on the reaction between zinc oxide and eugenol, formulated for use as a temporary material (type I), a long-term luting agent for fixed prostheses (type II), a base or a temporary filling (type III), or an intermediate restoration (type IV).

Zinc phosphate cement

A substance that is formed by the reaction between zinc oxide powder and phosphoric acid liquid, which can be used either as a base or as a luting agent.

Zinc polycarboxylate cement

A dental cement based on the reaction between zinc oxide powder and a liquid of polycarboxylic acid. Dental cements are materials that set intraorally and that are commonly used to join a tooth and a prosthesis.

Luting agent

A luting agent must exhibit a sufficiently low viscosity to flow readily along the interfaces between hard tissue and a fixed prosthesis, and they must be capable of wetting both surfaces to retain the prosthesis in place.

Varnish coats

Applied at the margins of fresh GICs facilitate maturation.

Mechanical retention

Microscopically the tooth and prosthesis surfaces are rough and the cement fills the irregular crevices between both surfaces to form a void-free continuum that microscopically locks one surface against another to resist shear stresses that might dislodge the appliance.

Glass ionomer cements (GICs)

Based on polyacrylic acids, bond to teeth by chelating acrylic acids to both organic and inorganic tooth components, and continue to cure after the defined setting time.

Excess cement

Should be present at the margin of a crown just after seating, but its removal depends on the properties of the cement used.

Debonding

May be caused by cement fracture, dissolution or erosion, secondary caries, or excessive shear forces.

Coefficient of thermal expansion

The coefficient of thermal expansion between the tooth, the prosthesis, and the cement should be similar over the range of temperature associated with consumed foods and beverages.

Cavity varnishes

Composed of natural gums—such as copal, rosins, or synthetic resins—dissolved in an organic solvent (acetone, chloroform, or ether). The varnish forms a thin coating on the tooth as the solvent evaporates.

Cavity liners

Calcium hydroxide is the chief ingredient in many cavity- liners and cement-base materials because calcium hydroxide is antimicrobial, has an elevated pH (basic, alkaline), and stimulates the formation of secondary dentin over an injured pulp to protect it over the long term.

Film thickness

Refers to the thickness of a continuous cement after setting under pressure, according to ANSI/ADA Specification No. 96 (ISO 9917-1).

Cement thickness

Refers to the thickness of the cement between the tooth structure and a cemented cast crown, inlay, onlay, or veneer. It plays a significant role in the retention of prostheses.

Cement bases

Applied in thicker layers (greater than 0.75 mm) beneath restorative materials to protect the pulp against thermal injury, galvanic shock, and chemical irritation.

Zinc phosphate cement

Is an effective base for thermal insulation, but its low pH (acidity) may require a cavity liner under the cement to protect the pulp.

Amalgam restorations

calcium hydroxide and ZOE materials are effective base cements.

Direct filling gold restorations

A stronger base cement—such as zinc phosphate, polycarboxylate, or GIC—is indicated.

Zinc phosphate cement

The oldest luting cement and its long clinical record of success serves as a standard by which newer cements are compared.

Zinc phosphate cement

When mixed, phosphoric acid dissolves the zinc oxide, which reacts with the aluminum phosphate and forms zinc aluminophosphate gel on the remaining undissolved zinc oxide particles.

Zinc phosphate cement

The reaction between zinc oxide and phosphoric acid is exothermic and requires a careful mixing procedure to minimize the effect of heat generation.