Zinc Oxide Eugenol
Encyclopedia
Zinc oxide eugenol is a material created by the combination of zinc oxide
and eugenol
contained in oil of cloves
. An acid-base reaction takes place with the formation of zinc eugenolate chelate. The reaction is catalysed by water and is accelerated by the presence metal salts. ZOE can be used as a filling or cement material in dentistry
. It is often used in dentistry when the decay is very deep or very close to the nerve or pulp chamber. Because the tissue inside the tooth, i. e. the pulp
, reacts badly to the drilling stimulus (heat and vibration), it frequently becomes severely inflamed and precipitates a condition called acute or chronic pulpitis. This condition usually leads to severe chronic tooth sensitivity or actual toothache and can then only be treated with the removal of the nerve (pulp) called root canal therapy. The placement of a ZOE "temporary" for a few to several days prior to the placement of the final filling usually prevents the sensitivity or toothache and therefore, most times, precludes the need for the expensive and time consuming root canal procedure. It is classified as an intermediate restorative material and has anaesthetic and antibacterial properties. It is sometimes used in the management of dental caries
as a "temporary filling
". ZOE cements were introduced in the 1890s.
Zinc oxide eugenol is also used as an impression material during construction of complete dentures
and are used in the mucostatic technique of taking impressions.
Zinc oxide eugenol is also used as an antimicrobial additive in paint.
ZOE impression pastes are dispensed as two separate pastes. One tube contains zinc oxide and vegetable or mineral oil; the other contains eugenol
and rosin
. The vegetable or mineral oil acts as a plasticizer and aids in offsetting the action of the eugenol as an irritant.
Oil of cloves
, which contains 70% to 85% eugenol, is sometimes used in preference to eugenol because it produces less burning sensation for patients when it contacts the soft tissues. The addition of rosin to the paste in the second tube facilitates the speed of the reaction and yields a smoother, more homogenous product.
Canada balsam
and Peru balsam are often used to increase flow and improve mixing properties. If the mixed paste is too thin or lacks body before it sets, a filler (such as a wax) or an inert powder (such as kaolin, talc, or diatomaceous earth) may be added to one or both of the original pastes.
Zinc oxide
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
and eugenol
Eugenol
Eugenol is a phenylpropene, an allyl chain-substituted guaiacol. Eugenol is a member of the phenylpropanoids class of chemical compounds. It is a clear to pale yellow oily liquid extracted from certain essential oils especially from clove oil, nutmeg, cinnamon, basil and bay leaf. It is slightly...
contained in oil of cloves
Oil of cloves
Oil of cloves, also known as clove oil, is an essential oil from the clove plant, Syzygium aromaticum.* CAS number: 8000-34-8It is a natural analgaesic and antiseptic used primarily in dentistry for its main ingredient eugenol...
. An acid-base reaction takes place with the formation of zinc eugenolate chelate. The reaction is catalysed by water and is accelerated by the presence metal salts. ZOE can be used as a filling or cement material in dentistry
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...
. It is often used in dentistry when the decay is very deep or very close to the nerve or pulp chamber. Because the tissue inside the tooth, i. e. the pulp
Pulp (tooth)
The dental pulp is the part in the center of a tooth made up of living connective tissue and cells called odontoblasts.- Anatomy :Each person can have a total of up to 52 pulp organs, 32 in the permanent and 20 in the primary teeth....
, reacts badly to the drilling stimulus (heat and vibration), it frequently becomes severely inflamed and precipitates a condition called acute or chronic pulpitis. This condition usually leads to severe chronic tooth sensitivity or actual toothache and can then only be treated with the removal of the nerve (pulp) called root canal therapy. The placement of a ZOE "temporary" for a few to several days prior to the placement of the final filling usually prevents the sensitivity or toothache and therefore, most times, precludes the need for the expensive and time consuming root canal procedure. It is classified as an intermediate restorative material and has anaesthetic and antibacterial properties. It is sometimes used in the management of dental caries
Dental caries
Dental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...
as a "temporary filling
Dental fillings
This page is about types of dental restorative materials. For dental fillings see dental restorationsDental restorative materials are specially fabricated materials, designed for use as dental restorations , which are used to restore tooth structure loss, usually resulting from but not limited to...
". ZOE cements were introduced in the 1890s.
Zinc oxide eugenol is also used as an impression material during construction of complete dentures
Dentures
Dentures are prosthetic devices constructed to replace missing teeth, and which are supported by surrounding soft and hard tissues of the oral cavity. Conventional dentures are removable, however there are many different denture designs, some which rely on bonding or clasping onto teeth or dental...
and are used in the mucostatic technique of taking impressions.
Zinc oxide eugenol is also used as an antimicrobial additive in paint.
Composition
The chemical composition of ZOE is typically:- Zinc oxideZinc oxideZinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
, ~69.0% - White rosin, ~29.3%
- Zinc acetateZinc acetateZinc acetate is the chemical compound with the formula Zn2, which commonly occurs as a dihydrate Zn22. Both the hydrate and the anhydrous forms are colorless solids that are commonly used in chemical synthesis and as dietary supplements. Zinc acetates are prepared by the action of acetic acid on...
, ~1.0% (improves strength) - Zinc stearateZinc stearateZinc stearate is a zinc soap that repels water. It is insoluble in polar solvents such as alcohol and ether but soluble in aromatic hydrocarbons when heated. It is the most powerful mold release agent among all metal soaps. It contains no electrolyte and has a hydrophobic effect...
, ~0.7% (acts as accelerator) - Liquid (EugenolEugenolEugenol is a phenylpropene, an allyl chain-substituted guaiacol. Eugenol is a member of the phenylpropanoids class of chemical compounds. It is a clear to pale yellow oily liquid extracted from certain essential oils especially from clove oil, nutmeg, cinnamon, basil and bay leaf. It is slightly...
, ~85%, Olive oil ~15%)
ZOE impression pastes are dispensed as two separate pastes. One tube contains zinc oxide and vegetable or mineral oil; the other contains eugenol
Eugenol
Eugenol is a phenylpropene, an allyl chain-substituted guaiacol. Eugenol is a member of the phenylpropanoids class of chemical compounds. It is a clear to pale yellow oily liquid extracted from certain essential oils especially from clove oil, nutmeg, cinnamon, basil and bay leaf. It is slightly...
and rosin
Rosin
.Rosin, also called colophony or Greek pitch , is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black...
. The vegetable or mineral oil acts as a plasticizer and aids in offsetting the action of the eugenol as an irritant.
Oil of cloves
Oil of cloves
Oil of cloves, also known as clove oil, is an essential oil from the clove plant, Syzygium aromaticum.* CAS number: 8000-34-8It is a natural analgaesic and antiseptic used primarily in dentistry for its main ingredient eugenol...
, which contains 70% to 85% eugenol, is sometimes used in preference to eugenol because it produces less burning sensation for patients when it contacts the soft tissues. The addition of rosin to the paste in the second tube facilitates the speed of the reaction and yields a smoother, more homogenous product.
Canada balsam
Canada balsam
Canada balsam, also called Canada turpentine or balsam of fir, is a turpentine which is made from the resin of the balsam fir tree of boreal North America...
and Peru balsam are often used to increase flow and improve mixing properties. If the mixed paste is too thin or lacks body before it sets, a filler (such as a wax) or an inert powder (such as kaolin, talc, or diatomaceous earth) may be added to one or both of the original pastes.