{{Short description|Dental cement material}} {{More citations needed|date=June 2009}} '''Zinc oxide eugenol''' ('''ZOE''') is a material created by the combination of [[zinc oxide]] and [[eugenol]] contained in [[clove oil]]. 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 of metal salts. ZOE can be used as a dental filling material or [[dental cement]] in [[dentistry]].<ref name="Ferracane">Jack L. Ferracane, ''Materials in Dentistry: Principles and Applications'', 2001, 2d Edition, Lippincott Williams & Wilkins, {{ISBN|0-7817-2733-2}}</ref><ref name="van Noort">Richard van Noort, 2002, ''Introduction to Dental Materials'', 2d Edition, Elsevier Health Sciences, {{ISBN|0-7234-3215-5}}</ref> 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 (tooth)|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 [[Endodontic therapy|root canal therapy]]. For persons with a [[dry socket]] as a complication of tooth extraction, packing the dry socket with a eugenol-zinc oxide paste on iodoform gauze is effective for reducing acute pain.<ref>{{cite journal |vauthors=Tarakji B, Saleh LA, Umair A, Azzeghaiby SN, Hanouneh S |title=Systemic review of dry socket: aetiology, treatment, and prevention |journal=J Clin Diagn Res |volume=9 |issue=4 |pages=ZE10–3 |date=April 2015 |pmid=26023661 |pmc=4437177 |doi=10.7860/JCDR/2015/12422.5840 }}</ref> The placement of a ZOE "temporary" for a few to several days prior to the placement of the final filling can help to sedate the pulp. But, ZOE had in vitro cytotoxicity majorly due to release of Zn ions, not eugenol.<ref>{{Cite journal|last1=Lee|first1=Jung-Hwan|last2=Lee|first2=Hae-Hyoung|last3=Kim|first3=Kyoung-Nam|last4=Kim|first4=Kwang-Mahn|date=2016-05-01|title=Cytotoxicity and anti-inflammatory effects of zinc ions and eugenol during setting of ZOE in immortalized human oral keratinocytes grown as three-dimensional spheroids|url=http://www.sciencedirect.com/science/article/pii/S0109564116000208|journal=Dental Materials|language=en|volume=32|issue=5|pages=e93–e104|doi=10.1016/j.dental.2016.01.003|pmid=26960744 |issn=0109-5641|url-access=subscription}}</ref> In spite of severe in vitro [[cytotoxicity]], ZOE showed relatively good [[biocompatibility]] in animal study when ZOE was applied on dentin.<ref>{{Cite journal|last1=Sabir|first1=Ardo|last2=Tabbu|first2=Charles R.|last3=Agustiono|first3=Purwanto|last4=Sosroseno|first4=Wihaskoro|date=2005|title=Histological analysis of rat dental pulp tissue capped with propolis|url=http://joi.jlc.jst.go.jp/JST.JSTAGE/josnusd/47.135?from=CrossRef|journal=Journal of Oral Science|language=en|volume=47|issue=3|pages=135–138|doi=10.2334/josnusd.47.135|pmid=16313091 |issn=1343-4934|doi-access=free}}</ref> When ZOE was used as dentin-protective based materials, use of dental composite resin on ZOE was strongly prevented due to its inhibition of resin polymerization through radical scavenging effect.<ref>{{Cite journal|last1=Carvalho|first1=Ceci Nunes|last2=Bauer|first2=José roberto De Oliveira|last3=Loguercio|first3=Alessandro Dourado|last4=Reis|first4=Alessandra|date=2007|title=Effect of Zoe Temporary Restoration on Resin-Dentin Bond Strength Using Different Adhesive Strategies|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1708-8240.2007.00087.x|journal=Journal of Esthetic and Restorative Dentistry|language=en|volume=19|issue=3|pages=144–152|doi=10.1111/j.1708-8240.2007.00087.x|pmid=17518904 |issn=1708-8240|url-access=subscription}}</ref> It is classified as an intermediate restorative material and has [[anaesthetic]] and [[antibacterial]] properties. The exact mechanism of anesthetic effect from ZOE was not revealed perfectly, but possibly through [[anti-inflammatory]] effect, modulating immune cells to less inflamed status.<ref>{{Cite journal|last1=Lee|first1=Jung-Hwan|last2=Lee|first2=Hae-Hyoung|last3=Kim|first3=Hae-Won|last4=Yu|first4=Je-Wook|last5=Kim|first5=Kyoung-Nam|last6=Kim|first6=Kwang-Mahn|date=2017-01-01|title=Immunomodulatory/anti-inflammatory effect of ZOE-based dental materials|url=http://www.sciencedirect.com/science/article/pii/S0109564116303943|journal=Dental Materials|language=en|volume=33|issue=1|pages=e1–e12|doi=10.1016/j.dental.2016.09.012|pmid=27726970 |issn=0109-5641|url-access=subscription}}</ref>
It is sometimes used in the management of [[dental caries]] as a "temporary [[Dental fillings|filling]]". ZOE cements were introduced in the 1890s.
Zinc oxide eugenol is also used as an impression material during construction of complete [[dentures]] and is used in the mucostatic technique of taking [[Dental impression|impressions]], usually in a special tray, (acrylic) produced after primary alginate impressions. However, ZOE is not usually used if the patient has large undercuts or tuberosities, whereby silicone impression materials would be better suited.
Zinc oxide eugenol is also used as an [[antimicrobial]] additive in paint.
==Types== According to ANSI/ADA Specification no:30 (ISO 3107) and depending on intended use and individual formulation designed for each specific purpose. ==Composition== The chemical composition of ZOE is typically:<ref>[https://docs.google.com/viewer?a=v&q=cache:iJDZrlhjZwMJ:journal.kap.or.kr/inc/download.php%3Fpubyear%3D1960%26volume%3D1%26issue%3D2%26f_name%3Dkap1-2-6.pdf%26convert%3DY+Zinc+oxide+white+rosin+zinc+stearate+Zinc+acetate+Eugenol&hl=ro&gl=ro&pid=bl&srcid=ADGEESh-m3x__e4fSeWes7xSdsjOSeKL0cX1hjcPDrM5QFjuEOl5KYeGIndEUD8-JvZ0myRhQclgOUF8a5pXL4zp8QxFzbCesbZTWGoO9R8ZzPw6z8srSplbRkQ7yzRl7YB1DUdMUuSJ&sig=AHIEtbTYSV4u8AmNYxlcNXlco_lFIiMkfQ Zinc Oxide Eugenol Impression Pastes -A Study of an impression material- Chung Suck Lee, D.D.S.]</ref> * [[Zinc oxide]], ~69.0% * [[rosin|White (bleached) rosin]], ~29.3% * [[Zinc acetate]], ~1.0% (improves strength) * [[Zinc stearate]], ~0.7% (acts as accelerator) * Liquid ([[eugenol]], ~85%, [[olive oil]] ~15%)
ZOE impression pastes are sold in two separate tubes. The first tube contains zinc oxide and vegetable or mineral oil, while the second tube contains eugenol and rosin. The vegetable or mineral oil acts as a [[plasticizer]] and helps to counteract the irritant action of eugenol.
Clove oil, which contains 70% to 85% eugenol, is sometimes used instead of eugenol because it causes less burning sensation in patients when it comes into contact with soft tissues. Rosin added to the paste in the second tube speeds up the reaction and produces a smoother, more homogeneous product.
[[Canada balsam]] and [[Balsam of Peru]] 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.
==References== {{reflist}} A D Wilson and J W Nicholson, Acid-Base Cements, 1993, {{ISBN|0-521-37222-4}}, Chapter 9
[[Category:Dental materials]] [[Category:Zinc oxide|oxide eugenol]] [[Category:Impression material]]