- Abstract: The major objective in root canal treatment is to
disinfect the entire root canal system. Cleaning, shaping, and use of
antimicrobial medicaments are effective in reducing the bacterial load to some
extent, but some bacteria do remain behind and multiply, causing reinfection.
Taking into consideration the ineffectiveness, potential side-effects and
safety concerns of synthetic drugs, the herbal alternatives for endodontic
usage might prove to be advantageous. Over the past decade, interest in drugs
derived from medicinal plants has markedly increased. Phytomedicine has been
used in dentistry as anti-inflammatory, antibiotic, analgesic, sedative and
also as endodontic irrigant. Herbal preparations can be derived from the root,
leaves, seeds, stem, and flowers. The PubMed database search revealed that the
reference list for natural medicaments featured 1480 articles and in dentistry
173 articles. A forward search was undertaken on the selected articles and
author names. This review focuses on various natural drugs and products as well
as their therapeutic applications when used as phytomedicine in dentistry.
Introduction
Natural products have been used since ancient times in folk
medicine. In dentistry, phytomedicines have been widely used. Herbs with
medicinal properties are useful and effective source for treatment of various
disease processes. Even though chemo-mechanical preparation of root canal is
able to reduce the number of bacteria, the intracanal medicament with
antibacterial action is required to maximize the disinfection of root canal
system. [1] Sodium hypochlorite (NaOCl), 2%
chlorhexidine (CHX) and calcium hydroxide possess varying degree of
antibacterial activity. [2]Although NaOCl has been widely used as root
canal irrigating solution, it has several undesirable characteristics such as
tissue toxicity, risk of emphysema when overfilled, allergic potential,
disagreeable smell and taste and inability to remove the smear layer. [3],[4],[5] The use of
CHX as an irrigant is generally restricted because it can discolor the teeth
and tongue can cause loss of taste, burning sensation of the oral mucosa and
subjective dryness of the oral cavity. The effectiveness of CHX to clean the
root canal walls is generally found to be inferior to NaOCl. [3] Ca (OH) 2 is
not effective in eliminating bacteria from the dentinal tubules. It was
reported that Enterococcus faecalis present in the dentinal
tubules was resistant to Ca (OH) 2 over 10 days. [6]
In endodontics because of the cytotoxic
reactions of the most of the commercial intracanal medicaments used and their
inability to eliminate bacteria from dentinal tubules, trend of recent medicine
is to use biologic medication extracted from natural plants. [7] The herbal products are also being
increasingly used as sedatives, or plaque reduction and healthy gums.
a. Phytotherapeutic substances are generally
classified into three groups [8]
- Plant products
- Animal products
- Mineral origin.
b. In dentistry,
they are used as [9]
- Antimicrobial agents
- Anti-inflammatory agents
- Sedative and anxiolytics.
c. Miscellaneous endodontic irrigants, medicaments and
endodontic retreatment.
Materials and Methods
A PubMed search was made with the keywords; herbal,
dentistry, phytomedicines and from the relevant articles medicaments found
closest to these three keywords were selected for this review.
Acacia nilotica Linn. (Babool - Indian gun Arabic)
It has long been used for the treatment of skin, sexual,
stomach, and tooth problems. It has been proved as an effective medicine in the
treatment of malaria, sore throat (aerial part) and toothache (bark). Babool has
shown to possess antibacterial activity against Streptococcus mutans and E.
faecalis.[10] Antimicrobial function is believed to be
due to tannins, phenolic compounds, essential oil, and flavonoids. [11]
Aloe barbadensis Miller (Kumari - Aloe)
Aloe leaves
contain a clear gel and green part of the leaf that surrounds the gel is used
to produce juice or dried substance. It contains alloins and barbadoins as main
chemical constituents. In dentistry, A. vera is used in cases
of apthous ulcers, lichen planus, alveolar osteitis. [12] A. vera gel has inhibitory
effects on Streptococcus pyogens and E. faecalis because
of anthraquinone. [13] Its bactericidal activity is found to be
less than Ca (OH) 2. [14]
Arctium lappa Linn.
It has antibacterial and antifungal activity, diuretic,
anti-oxidant and anxiolytic action, platelet anti-aggregating effect, and HIV
inhibitory action. In dentistry, A. lappa has been
investigated due to its antimicrobial potential against oral microorganisms,
specifically those associated with endodontic infections. An in vitro evaluation
of antimicrobial activity of A. lappa against microorganisms
specifically found in endodontic infections showed a great microbial inhibition
of A. lappa against the tested endodontic pathogens. The
microbial inhibition potential of A. lappa observed in this
study opens the perspective for its use as an intracanal medication. [15]
Azadirachta indica A. Juss
(Nimba - Nimtree)
Each part of the Neem tree has some
medicinal property and is thus commercially exploitable. [16] This product has been proved to be
effective against E. faecalis and Candida albicans.[17] A study was conducted to evaluate the
efficacy of Neem extract dental gel with commercially
available CHX gluconate mouthwash as a positive control. Microbial evaluation
of S. mutans and Lactobacilli species was
carried out to determine the total decrease in the salivary bacterial count
over a period of treatment. The results of the study suggested that the dental
gel containing Neem extract had significantly reduced the
plaque index and bacterial count than that of the control group. [18]
Carvacrol
Carvacrol (thymol isomer) is present in the
essential oil of Origanum vulgare, which is edible plant oil used
in food products. It has a broad spectrum of antibacterial activity; it works
by inhibiting ATPase activity and increasing the nonselective permeability of
bacterial cell membranes. Therefore, it not only inhibits microbial
colonization, but also makes microbes more sensitive to antibacterial agents.
It has an antibacterial effect against Enterobacteriaceae family
including Escherichia More
Details coli, Salmonella More
Details enteritidis and Salmonella essen.
Antibacterial effect of carvacrol and its isomer thymol against six ATCC
standard bacterial strains including E. faecalis has been
proved. Carvacrol also has anti-inflammatory effects. It can restrain neutrophilic
elastase enzyme and suppress prostaglandin production. [19] Carvacrol has inhibitory action on E.
coli and Pseudomonas aeruginosa. The cause of
antimicrobial property is attributed to action on several targets in bacterial
cell and disruption of bacterial cell membrane. It also helps in repair of
periapical tissues. This property is due to the presence of phenolic component,
which stimulates pulpal fibers, phenomena known as hormesis. [20],[21]
Casearia sylvestris Sw. (Gulkhair - Wild coffee)
Alcoholic extract of C. sylvestris constitutes
a rich source of phospholipase A2 inhibitors, which reduce the acute phase of
the inflammatory process and prolongs the regenerative phase. It offers a wide
range of uses: Healing, antiseptic, antiulcerative, diuretic, tonic, stimulant,
and antimicrobial. It is shown as an alternative intracanal medicament. [2]
Allium sativum Linn. (Rason - Garlic)
Garlic contains sulfur containing compound allin, which is converted to active ingredient "allicin" when the garlic bulb is crushed. This compound has an inhibitory effect upon the key enzymes involved in cholesterol biosynthesis, such as 3-hydroxy-3-methyl-glutaryl-CoA reductase. Hypocholesterolemic effect of garlic is exerted by a decrease in hepatic cholesterogenesis, whereas the triacylglycerol lowering effect appears to be due to inhibition of fatty acid synthesis, by mallic enzymes, fatty acid synthatase and glucose-6-phosphate dehydrogenase. Garlic helps to prevent lipid implantation on the arterial wall. Allicin destroys cell wall and cell membrane of root canal bacteria. [22] This is used as irrigant alternative to
NaOCl. [23]
Marticaria recutitia Linn. (German chamomile)
The German chamomile has been used for centuries as a
medicinal plant mostly for its anti-inflammatory, analgesic, antimicrobial,
antispasmic, and sedative properties. Chamomile was also found to be effective when
used as a mouthwash to treat irritations and minor infections of the mouth and
gingivae and is also used in some toothpaste. [24
Camellia sinensis (Chai - Tea)
The antioxidative properties of
unfermented tea can be attributed to the ability of the polyphenols contained
in the leaves of Thea chinensis, especially the gallocatechins, to
inactive free radicals. [25],[26] Green and black teas both contain
flavonoids that inhibit the growth and activity of the bacteria associated with
tooth decay. Tea also contains natural fluoride, which may be helpful in
preventing dental caries. An in vitro study conducted to
evaluate the antimicrobial efficacy of Triphala (one of the
well-known Indian Ayurvedic herbal formulation consisting of dried and powdered
fruits of three medicinal plants namely Terminalia bellerica,
Terminalia chebula and Emblica officinalis),[4] green tea polyphenols (GTPs), MTAD
and 5% NaOCl against E. faecalis biofilm formed on
tooth substrate showed maximum antibacterial activity with NaOCl and
statistically significant antibacterial activity with Triphala,
GTPs and MTAD. [27]
Citrus limonum Risso. (Nimbuka - Lemon)
Fresh
lemon solution is used as root canal medicament due to its wide antibacterial
efficiency including E. faecalis. Oil of lemon is topically used
for the treatment of oral thrush and stomatitis. [28]
Morinda citrifolia Linn. (Ashyuka - Indian mulberry)
A number of major components have been identified in the Noni plant such as scopoletin, octoanoic acid, potassium, vitamin C, terpenoids, alkaloids, anthraquinones (such as nordamnacanthal, morindone, rubiadin, and rubiadin-1-methyl ether, anthraquinone glycoside), β-sitosterol, carotene, vitamin A, flavone glycosides, linoleic acid, Alizarin, amino acids, acubin, L-asperuloside, caproic acid, caprylic acid, ursolic acid, rutin, and a putative proxeronine. [29] These compounds have been shown to
fight against infectious bacteria strains such as P. aeruginosa,
Proteus morgaii, Staphylococcus aureus, Baciillis
subtilis, E. coli, Salmonella,
and Shigela. [30] Its juice has a broad range of
therapeutic effects including antibacterial, antiinflammatory, antiviral,
antitumor, antihelmenthic, analgesic, hypotensive, and immune enhancing
effects.
The antimicrobial activity of 2% CHX gel,
propolis, Morinda citrifolia juice and Ca (OH)2 has
been compared on E. faecalis infected root canal dentin at two
different depths and three intervals. It was concluded that propolis and M.
citrifolia were effective against E. faecalis in
dentin on extracted teeth. [31]
Orange
Oil (Narangah)
This is composed mostly of d-limonene. It
also has a long chain aliphatic hydrocarbon alcohols, aldehydes like octanal.
It is suggested as an alternative to chloroform or xylene for gutta-percha
softening and also in dissolving endodontic sealers. [32]
Propolis
(Propolis resin)
Pharmacologically active constituents in
propolis are flavonoids, phenolics, and aromatics. It exhibits various biologic
activities, including antimicrobial, anti-inflammatory, antioxidant, anesthetic
and cytotoxic properties. [33] The anti-inflammatory property of
propolis is due to the presence of caffeic acid and phenethyl ester in
propolis. In dental practice it is used as a pulp capping agent, intracanal
irrigant, mouth rinse, cariostatic agent, treatment of periodontitis and
denture stomatitis, etc. [34] The antimicrobial activity of
propolis with Ca (OH) 2 as intracanal medicament
against E. faecalis found that propolis was
effective in eliminating the microorganisms. [35]
Study showed less pain, less incidence of
postoperative complications and less swelling in the honey treated wounds after
surgical removal of impacted third molars than in the untreated control
group. [36] It has been reported in another
study [37] that natural honey showed
antibacterial action against anaerobic bacteroides present in dental abscess
and osteomyelitis. [38] It has also been proposed that
antioxidants be used to protect the periodontal tissues from the damaging free
radicals formed in the inflammatory response. Honey contains a substantial
level of antioxidants. [39],[40],[41] In a study, eight honeys and three
types of propolis were tested and the result proved them effective as an
anticalculus agent in toothpastes and mouthwashes. [42] Recent studies indicated that honey
possessed moderate antitumor and pronounced anti-metastatic effects in five
different strains of rat and mouse tumors. Furthermore, honey potentiated the
antitumor activity of chemotherapeutic drug s such as
5-fluorouracil and cyclophosphamide. [43] Studies suggested that chewing "honey leather" can reduce inflammation of the gingiva. [44],[45],[46]Candy made with honey may be useful for
prevention of halitosis. [47] It was found that the minimum inhibitory
concentrations of honey for Streptococcus mitis, Streptococcus sobrinus and Lactobacillus
caseii were 7%, 7.5-8.5%, and 8-12%, respectively. The production of
acid by these bacteria was also inhibited. [48],[49] Direct pulp capping with propolis in
rats may delay dental pulp inflammation and stimulate reparative dentin. [50] Another study conducted on premolars
for direct pulp capping also showed that propolis is equally efficacious as
calcium hydroxide. [51],[52]
Psidium guajava Linn. (Perukam - Guava)
The fruits and leaves of this shrub
contain essential oil rich in cineol, tannins, tripentnes and flavonoids.
Ethanol extracts of it has higher antimicrobial activity, especially
against E. faecalis. [53] The leaf extracts of P.
guajava have some pharmacological activities, such as
anti-inflammatory, antidiarrheal besides antimicrobial activities. It has also
been used extensively as a hypoglycaemic agent. The active flavonoid compound
gujaverin isolated from the methanol leaf extract of P. guajava has
been demonstrated by one of the researcher to be a potential antiplaque agent
by inhibiting the growth of S. mutans. [54]
Psoralea corylifolia Linn. (Bakuchi - Psoralea seeds)
P. corylifolia extract contains a number of
bioactive compounds including flavonoids, coumarins, meroterpenes and
benzofuran glycosides that are the molecular basis of its action.
Neobavaisoflavone is isolated from fruits and seeds of P. corylifolia.[55] This is found to be effective
against E. faecalis. It acts by causing injury to the cell membrane
and inhibiting DNA polymerase. [25]
Rhus lancia (L.f.) F.A. Barkley (African Sumac)
It contains gallic tannins and gallic
acid. Tannins exhibit antibacterial and antifungal properties. Gallic acid is
antioxidant and bactericidal. Gallic acid has been found to reduce periapical
inflammation. Water extract of Rhus plants help in the opening of blocked
dentinal tubules. [24]
Salavadora persica Linn. (Peelu - Mustard tree)
Many studies have demonstrated that
extracts of S. persica possess various antiplaque, antiperiopathic,
anticaries, anti-inflammatory and antimycotic effects. Its chewing sticks
contain trimethyl amine, salvadorime chloride and fluoride in large
amounts. [56] Tests have shown that these sticks
contain natural antibiotics, fluoride, and other anti-cavity components. 15%
alcoholic extracts of it has maximum antimicrobial action. It can be used as a
substitute for NaOCl and chlorhexidine as root canal irrigant. [57],[58]
Syzigium aromaticum (L.) Merrill and Perry (Lavanga - Clove)
Essential oil shows antioxidant,
antibacterial, and anodyne effects. [9],[24]
Melaleuca alternifolia (Maiden and Betche) Cheel (Tea Tree Oil)
Tea tree oil's major active component is terpinen-4-ol (typically 30-40%). [24],[25] In order to avoid the undesirable
effects of NaOCl, a scanning electron microscopy study was conducted using two
medicinal plants that is German chamomile extract and tea tree oil which might
disinfect the root canal system with less toxicity when used as irrigants. It
was concluded that the efficacy of chamomile to remove the smear layer was
superior to NaOCl alone, but less than NaOCl combined with ethylene di-amine
tetra acetic acid. [59]
Triphala (Haritaki, Bibhitaki and Amalaki)
Triphala is one of the well-known Indian Ayurvedic herbal
formulation consisting of dried and powdered fruits of three medicinal plants
namely Terminalia Bellerica (Gaertn.) Roxb., Terminalia
chebula Retz. and Embellica officinalis Gaertn. [4] It can be used as an
effective antiplaque agent due to its antioxidant properties and it can
effectively inhibit the biofilm formation. [60] Its fruit is rich in citric acid,
which may aid in removal of smear layer thereby acting as chelating agent and
also found to be alternative to NaOCl for root canal irrigation. [4]
Curcuma longa Linn. (Haridra - Turmeric)
The active constituents of turmeric are the
flavonoid curcumin (diferuloylmethane) and various volatile oils, including
tumerone, atlantone, and zingiberone. It possess good antioxidant,
hepatoprotective, antimicrobial, and anticancer activity. [31]
A researcher conducted an in vitro study
to evaluate the antimicrobial efficacy of curcumin against E. faecalis considering
NaOCl (3%) as reference for comparison. The result of his study revealed that
curcumin had significant antibacterial activity against E. faecalis and
thus can be used in endodontics for root canal failures. [61],[62] Curcumin in surfactant preparations
showed its potential as a photosensitizer in antibacterial photodynamic
therapy in vitro. [63]
Glycyrrhiza glabra Linn. (Yashtimadhu - Liquorice)
A number of pharmaceutical effects of liquorice are known
anti-inflammatory, antiviral and anticarcinogenic. [64],[65] It has been evaluated for the management
of oral lichen planus. The study reported that liquorice extract was as
effective as triamcinolone acetonide, but safer and may be used as an
alternative treatment for lichen planus. [66] Glycyrrhizin, a triterpenoid compound,
accounts for the sweet taste of liquorice root. The antibacterial activity of
liquorice and glycyrrhizin on different strains of S. mutans was
also studied and their effects on the adherence of S. mutans to
glass. Liquorice extract exhibited a more profound activity in both adherence
and anti-bacterial assays than that of glycyrrhizin. [67]Liquorice has also shown greater
biocompatibility with fibroblasts cells compared to calcium hydroxide, which
was severely toxic to the cells. A mixture of liquorice and calcium hydroxide
showed moderate cytotoxicity. [68]
Discussions
Over the past decade, interest in drugs derived from
medicinal plants has markedly increased. Literature has addressed many plants
with a potential source for new therapies in endodontics. In dentistry,
phytomedicine has been used as anti-inflammatory, antibiotic, analgesic,
sedative, and also as endodontic irrigant [Table 1].
Table 1: Classification of herbal drugs used in dentistry based
on their actions.
The major drawbacks of the many antimicrobial and pulp
therapeutic agents used in dentistry since long have been immune suppression,
hypersensitivity, allergic reactions and resistance of microorganisms to these
drugs; also some are mutagenic and cytotoxic. Therefore, there is a need to
conduct extensive researches to find plant based alternatives for the
conventional drugs. [69] Studies have found herbal agents such as A.
nilotica, A. barbadensis, A. lappa, A. indica, carvacrol, C.
sylvestris, A. sativum, M. recutitia L, C. sinensis, C.
limonum, M. citrifolia, propolis, P. guajava, P. corylifolia,
R. lancia, S. persica, S. aromaticum, M. alternifolia, C. longa, G.
glabra can be used as an alternative intracanal medicament and can be
used as potential root canal irrigants because of their anti-inflammatory,
antimicrobial and immune-modulating activity. Propolis and M.
citrifolia were found to be effective against E. faecalis (most
common bacteria isolated from recurrent and failed root canal cases) in dentin
on extracted teeth. [31] In our study too, the
results indicated that propolis had an effective antifungal action on C.
albicans(which is the most common fungus seen in root canals) similar to
that of NaOCl. [70]
Herbal agents like propolis, A. vera have
healing potential thus making them good pulp therapeutic agents. [50],[69] Propolis, GTPs have shown to preserve periodontal cell
viability and thus used as storage media for avulsed tooth. [39],[40],[41],[42],[69]
Triphala has free radical scavenging property thus aiding
in the protection of gum cells effectively from free radicals produced by the microorganisms. [71] Some essential oils like orange have
endodontic filling material dissolving capacity thus making them readily useful
in endodontic retreatments. [32],[69] Herbal agents
like German chamomile is used in mouthwashes to reduce gingival inflammation
and plaque formation. [24]
Conclusion
The major advantages of using natural alternatives are easy
availability, cost-effectiveness, increased shelf life, low toxicity and lack
of microbial resistance reported so far. Herbal agents have been used in
dentistry for reducing inflammation, as antimicrobial plaque agents,
antiseptics, antioxidants, antimicrobials, antifungals, antibacterials,
antivirals, and analgesics. They also aid in healing and are effective in
controlling microbial plaque in gingivitis and periodontitis and thereby
improving immunity. Though the in vitro results appear
promising, many clinical trials are warranted to evaluate biocompatibility and
safety factor before they can be recommended for clinical use conclusively.
References
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About
Authors and Address for Correspondence: Dakshita J Sinha and Ashish A Sinha. Department of Conservative Dentistry Endodontics, Kothiwal Dental College Research Centre and Hospital, Moradabad, Uttar Pradesh, India AND Department of Pedodontics, Kothiwal Dental College Research Centre and Hospital, Moradabad, Uttar Pradesh, India. Dakshita J Sinha, Department of Conservative Dentistry Endodontics, Kothiwal Dental College Research Centre and Hospital, Moradabad - 244 001, Uttar Pradesh India.
Article available online/offline on: AYU, Vol. 35, Issue-2, April-June
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