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- Essential Oils
- Dentistry
- Therapeutic Properties
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Date:
06-30-2016 | HC# 121544-547
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Re: Essential Oils in Oral Health
Dagli N, Dagli R, Mahmoud RS, Baroudi K.
Essential oils, their therapeutic properties, and implication in dentistry: a
review. J Int Soc Prev Community Dent.
September-October 2015;5(5):335-340.
Plant essential oils (EOs) are secondary
metabolites, complex mixtures of terpenic hydrocarbons, especially mono- and
sesquiterpenes, and oxygenated derivatives like aldehydes, ketones, epoxides,
alcohols, and esters. Differing greatly in composition from species to species,
even EOs from the same species harvested in different regions may vary. Plant maturity
at time of extraction also affects composition. About 3000 EOs have been
described so far. Many of them have been used medicinally, including in dentistry,
since ancient times. EOs are well known to possess antibacterial, antifungal,
and antioxidant properties. The mechanisms of antimicrobial effect differ according
to chemical composition and the location of functional groups on bioactive molecules;
membrane damage to microbes is thought to be the main mechanism of action, due
to the solubility of EOs in the phospholipid bilayer of cell membranes. In
addition, EOs' terpenoids have the ability to interfere with enzymatic
reactions of energy metabolism of microorganisms.
This review focuses on EOs with regard to
their potential application in dentistry. Oral health problems, especially dental
caries and periodontal disease, persist despite improvements in oral health in
some countries, particularly among underprivileged groups. Several antimicrobial
agents classically used to treat oral infections may cause adverse effects
(AEs) and promote the development of resistance. Therefore, there is a need to
identify alternative antimicrobial agents. The authors searched the PubMed
database for clinical trials and reviews of specific EOs, published up to
February 2015. A total of 70 articles were found; 52 were included in this
review. Inclusion criteria are not specified.
Lavender (Lavandula
spp., Lamiaceae) oil includes
linalool, linalyl acetate, lavandulol, 1,8-cineole, and other constituents
varying by species and extraction method. The activity of whole EOs is
reflected by the activity of linalool, indicating that it is likely the active
compound. EOs from various lavenders are active against bacteria, filamentous
fungi, and yeasts. Interestingly, one species has been reported to be active
against antibiotic-resistant bacteria. Lavender EOs are anxiolytic, reducing
stress and improving mood. Given this property, lavender oil may be used to
reduce anxiety before dental procedures and lessen the pain of needle
insertion.
Eucalyptus (Eucalyptus spp., Myrtaceae) oil contains as major constituents 1,8-cineole,
cryptone, α-pinene, p-cymene, and
α-terpineol. Its antimicrobial effects are likely to involve several components
acting in synergy rather than a single molecule component. Several species of Eucalyptus have antibacterial effects
towards both Gram+ and Gram− bacteria, including oral pathogens, thus
supporting their use as an anticariogenic agent. Moreover, eucalyptus EO possesses
anti-inflammatory effects and can stimulate the innate cell-mediated immune
response.
The widely used peppermint (Mentha × piperita, Lamiaceae) oil has menthol as its major compound, along
with menthyl acetate and menthofuran. It inhibits the proliferation of Staphylococcus spp., as well as both
azole-resistant and azole-susceptible Candida
spp. strains. Peppermint EO possesses a fungal anti-biofilm effect and
dose-dependently inhibits Candida
albicans biofilm formation.
Tea tree (Melaleuca
alternifolia, Myrtaceae) oil (TTO) contains terpinen-4-ol, γ-terpinene, p-cymene, α-terpinene, 1,8-cineole,
α-terpineol, and α-pinene. It is active against dental biofilm and was found to
be strongly antibacterial against oral pathogens. It is also antimycotic, with
terpinen-4-ol being mostly responsible for this effect. TTO can be used to
treat oral candidiasis, although one study found terpinen-4-ol safer and more
effective.
Lemon (Citrus
× limon, Rutaceae) oil is made up
almost entirely of terpenes and oxygenated terpenes. It has been found
effective against three Candida spp.
and has been suggested for the treatment of Candida
albicans infections.
Constituents of clove (Syzygium aromaticum, Myrtaceae) bud oil include the phenylpropanoids
eugenol, eugenyl acetate, carvacrol, thymol, cinnamaldehyde, β-caryophyllene,
and 2-heptanone. It possesses antioxidant, antifungal, and antibacterial
properties, and is even active against multi-resistant strains of Staphylococcus spp. Eugenol is well
known for its therapeutic properties, being effective against pathogens
associated with tooth decay and gum disease, and is thus widely used in
dentistry.
Oils from the bark, leaf, and root of various
cinnamons (Cinnamomum spp., Lauraceae)
differ widely in composition. In Ceylon cinnamon (C. verum syn. C. zeylanicum)
bark oil, trans-cinnamaldehyde,
eugenol, and linalool make up 82.5% of the total compounds. Cinnamaldehyde is
the most active constituent. Cinnamon EO inhibits both Gram+ and Gram− bacteria,
as well as many fungi. It is known to possess antimutagenic properties in vitro
and in vivo and has been found to have significant anti-melanoma activity.
Ceylon cinnamon EO is also known to have antiparasitic and antioxidant effects,
with free radical scavenging activity. A phase I clinical study found cinnamon
EO safe and effective for treating patients with denture-associated oral
candidiasis.
Combining EOs with other antibacterial agents
can lower resistance in multidrug-resistant bacteria. In this regard, peppermint,
cinnamon bark, and lavender EOs can potentiate the effect of piperacillin against
antibiotic-resistant bacterial strains.
Not all the studies reviewed support the use
of EOs. A study comparing an EO mouthwash with 0.2% chlorhexidine found EOs
effective for two to three hours only, thus suggesting that the use of chlorhexidine
may be preferable. Another study found no benefit over water in using EOs as a
coolant in ultrasonic root debridement. Some AEs have been reported in regard
to the use of EOs, ranging from dermatitis to tonic-clonic seizures.
Nonetheless, although additional clinical trials are required, there is
considerable evidence that EOs may be useful in dental therapy to improve the
quality of dental treatments.
—Mariann
Garner-Wizard
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