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INTRODUCTION
Oral diseases, including dental caries, gingivitis, and periodontal diseases, are major public health problems. They affect people of different age groups. Dental plaque is a structured microbial biofilm that develops on tooth surfaces. Poor plaque control can lead to gingival inflammation and may contribute to periodontal disease (Marsh, 2006; Palombo, 2011; Cowan, 1999).
The burden of oral diseases is high worldwide. Periodontal diseases and untreated dental caries are among the most common oral conditions (Petersen and Ogawa, 2005; Nazir, 2017). Gingivitis is an inflammatory response to dental plaque. It is generally reversible when effective plaque control is maintained. If inflammation persists, it may progress to periodontitis. This can cause loss of periodontal attachment and, in severe cases, tooth loss (Pihlstrom et al., 2005; Kinane et al., 2017).
Dental plaque contains many microbial species within an extracellular matrix. Its formation begins with the development of an acquired salivary pellicle on the tooth surface. Bacteria then attach to the pellicle and form a mature biofilm (Marsh, 2006; Hannig and Joiner, 2006). The interaction between oral microorganisms and host immune responses plays an important role in gingival inflammation. Bacterial products can stimulate inflammatory mediators such as cytokines and prostaglandins. These mediators may contribute to tissue damage (Haffajee and Socransky, 1994; Preshaw and Taylor, 2011). Mechanical plaque control is the main approach to maintaining oral hygiene. Mouthwashes are often used as an adjunct to brushing and interdental cleaning. Conventional mouthwashes may contain chlorhexidine, cetylpyridinium chloride, or alcohol. Chlorhexidine has strong antimicrobial activity. However, prolonged use may cause tooth staining, altered taste, and mucosal irritation (Jones, 1997; Fine, 1995). Alcohol-containing products may also cause oral dryness (McCullough and Farah, 2008). These limitations have increased interest in plant-based oral-care products.
Herbal mouthwashes contain extracts or bioactive constituents obtained from medicinal plants. Important phytochemical groups include flavonoids, tannins, alkaloids, polyphenols, terpenoids, and essential oils. These compounds may act against oral microorganisms through different mechanisms. They may interfere with microbial growth, adhesion, biofilm formation, and quorum sensing. Some phytochemicals may also reduce inflammatory and oxidative responses (Daglia, 2012; Niazy, 2021; Kumar et al., 2013).
Several medicinal plants have been studied for oral healthcare. These include Azadirachta indica (neem), Ocimum sanctum (tulsi), Camellia sinensis (green tea), Syzygium aromaticum (clove), Psidium guajava (guava), Aloe barbadensis (aloe vera), and Triphala. Their reported activities include antimicrobial, antibiofilm, anti-inflammatory, and antioxidant effects. However, their activity can vary with plant species, plant part, extraction method, phytochemical content, and formulation.
Despite growing interest in herbal mouthwashes, several challenges remain. Differences in raw materials and extraction methods can affect product quality and activity. Laboratory findings may also differ from clinical outcomes. Therefore, proper standardization and quality control are essential. Well-designed clinical studies are also needed to establish their effectiveness and safety.
LITERATURE SEARCH STRATEGY
Relevant scientific literature was examined to identify evidence on herbal mouthwashes, oral biofilm, gingival inflammation, medicinal plants, and bioactive phytochemicals. The search focused on studies related to antimicrobial, antibiofilm, anti-inflammatory, and antioxidant activities.
Major scientific databases, including PubMed, Scopus, Web of Science, ScienceDirect, and Google Scholar, were considered. Search terms included herbal mouthwash, herbal mouthrinse, oral biofilm, dental plaque, gingivitis, periodontal disease, phytochemicals, medicinal plants, antibiofilm activity, antimicrobial activity, and clinical trial.
Recent publications were given greater emphasis. Earlier studies were included when they provided important background information or established evidence. Clinical trials, systematic reviews, experimental studies, and relevant mechanistic studies were considered.
The literature was assessed with particular attention to the major themes of this review. These included phytochemical mechanisms, clinical effectiveness, standardization, safety, and future applications. Studies comparing herbal mouthwashes with chlorhexidine and other conventional mouthwashes were also considered.
Previous evidence indicates that some herbal mouthwashes may reduce plaque and gingival inflammation. A systematic review and meta-analysis of 13 randomized controlled trials reported potential benefits of herbal mouthwashes for plaque and inflammation control. However, the authors also highlighted the need for better-quality clinical trials (Cai et al., 2020; Santi et al., 2021; Shukla et al., 2026; Araujo et al., 2026). Differences in plant materials, formulations, treatment duration, study populations, and outcome measures can affect the reported results. Therefore, the present review considers both the potential benefits and the limitations of the available evidence.
Oral Biofilm and Gingival Inflammation
Formation and Development of Oral Biofilm
Oral biofilm is a complex microbial community that develops on teeth and other surfaces of the oral cavity. It is commonly known as dental plaque. The biofilm contains bacteria, extracellular polymers, proteins, and other components. Its structure allows microorganisms to attach to surfaces and survive under changing oral conditions (Flemming and Wingender, 2010).
Microbial Composition of Dental Plaque
Dental plaque contains a diverse group of microorganisms. These microorganisms exist as a mixed community within the biofilm. The composition of plaque can change with oral conditions and the stage of biofilm development. Early colonizers attach to the acquired pellicle and provide surfaces for the attachment of other microorganisms. This process increases the microbial diversity of the developing biofilm (Kolenbrander et al., 2010; Marsh and Zaura, 2017).
Both Gram-positive and Gram-negative bacteria can be present in dental plaque. Early plaque communities are often dominated by Gram-positive organisms. As the biofilm matures, the microbial community becomes more diverse. Gram-negative anaerobic bacteria become more prominent in disease-associated plaque. Species such as Streptococcus, Actinomyces, Fusobacterium, and Porphyromonas have been associated with different stages of oral biofilm development and periodontal disease (Socransky et al., 1998).
The microbial composition of plaque is not identical in all individuals. Oral hygiene, saliva, diet, smoking, systemic conditions, and local environmental factors can influence the microbial community. Changes in the microbial balance may favour organisms associated with inflammation and periodontal disease (Cekici et al., 2014).
The polymicrobial nature of dental plaque is important when considering mouthwash activity. An agent that acts against only one bacterial species may have limited effects on an established biofilm. Therefore, compounds with activity against several microorganisms or different stages of biofilm development may have greater potential for oral biofilm control.
Biofilm-Associated Gingival Inflammation
Accumulation of dental plaque near the gingival margin can initiate an inflammatory response in gingival tissues. Microbial components and their metabolic products can stimulate host cells. This process results in the release of inflammatory mediators. The clinical features may include redness, swelling, and bleeding of the gingiva (Cekici et al., 2014).
Gingivitis is generally a reversible condition when effective plaque control is achieved. Regular mechanical plaque removal can reduce the microbial challenge and allow the gingival tissues to recover. However, persistent plaque accumulation can maintain the inflammatory response. In susceptible individuals, prolonged inflammation may contribute to the development of periodontitis (Cekici et al., 2014).
The severity of inflammation is influenced by both microbial and host factors. The composition of the biofilm can affect the intensity of the inflammatory response. At the same time, the host response can influence the local oral environment. This interaction makes gingival inflammation a complex process rather than a response to a single microorganism.
Inflammatory mediators such as cytokines and prostaglandins have an important role in this process. Excessive or prolonged inflammatory activity can contribute to damage of periodontal tissues. Therefore, effective oral-care strategies should aim to control both microbial biofilm and the associated inflammatory response.
Role of Host-Microbe Interactions
The development of gingival inflammation results from continuous interaction between oral microorganisms and the host. A healthy oral cavity can support a diverse microbial community without causing significant tissue damage. The host immune system also helps maintain this balance. Changes in the microbial community may disturb this relationship and increase inflammatory activity (Cekici et al., 2014).
Microorganisms within dental plaque can release bacterial components and other products that are recognized by host immune cells. These signals can activate inflammatory pathways. The resulting response helps control microbial challenge but may also cause tissue damage when it becomes excessive or prolonged (Jakubovics and Kolenbrander, 2010).
Host factors can also influence the behaviour of the oral microbial community. Saliva, immune responses, oral hygiene, and local environmental conditions can affect microbial growth and biofilm development. Thus, oral health depends on a dynamic relationship between the microbial community and host tissues (Mehta et al., 2024).
This interaction is important for the development of herbal mouthwashes. Phytochemicals may influence more than microbial growth alone. Some compounds may reduce bacterial adhesion and biofilm formation. Others may modulate inflammatory or oxidative pathways. This multitarget activity provides a basis for further evaluation of herbal mouthwashes in oral healthcare (Figure 1) (Guimarães et al., 2021).
Phytochemical Classes Relevant to Herbal Mouthwashes
Medicinal plants contain several bioactive phytochemicals. These compounds may contribute to antimicrobial, antibiofilm, anti-inflammatory, and antioxidant effects. Their activity depends on the plant source, chemical composition, extraction method, and concentration (Table 1) (Kovac et al., 2023; Riaz et al., 2023).
Flavonoids
are important plant polyphenols. They may inhibit bacterial growth, adhesion, and biofilm formation. Some flavonoids can also interfere with bacterial enzymes involved in oral biofilm development (Milho et al., 2021).
Tannins and Other Polyphenols
Tannins can interact with microbial proteins and may reduce bacterial adhesion and growth. Other polyphenols, such as catechins and proanthocyanidins, have also shown activity against oral microorganisms (Milho et al., 2021).
Alkaloids
are nitrogen-containing plant compounds with diverse biological activities. Some alkaloids show antimicrobial effects against oral microorganisms. Their actions may involve interference with microbial enzymes, membranes, or cellular processes (Milho et al., 2021).
Terpenoids and Essential Oils
Terpenoids are major constituents of many essential oils. They may affect microbial membranes and reduce microbial viability. Compounds such as eugenol, thymol, and carvacrol have been investigated for their activity against oral microorganisms (Milho et al., 2021).
Saponins and Other Bioactive Constituents
Saponins and other plant metabolites may provide additional antimicrobial and anti-inflammatory effects. Their activity may complement that of polyphenols, alkaloids, and terpenoids. However, the overall effect of a plant extract may result from several constituents acting together rather than from a single compound (Milhoet al., 2021).
Major Medicinal Plants Used in Herbal Mouthwashes
Several medicinal plants have been investigated as ingredients of herbal mouthwashes. Their reported effects are mainly related to antimicrobial, antibiofilm, anti-inflammatory, and antioxidant properties. However, clinical evidence varies among plants and formulations (Freires and Rosalen, 2016).
Azadirachta indica
(neem) is widely used in traditional oral care. Neem contains bioactive compounds such as nimbidin and azadirachtin. Clinical studies suggest that neem mouthwash may reduce plaque and gingival inflammation. However, available trials are limited and show methodological variation (Dhingra and Vandana, 2017; Chatterjee et al., 2011).
Ocimum sanctum (tulsi)
contain phenolics, flavonoids, and volatile constituents. These compounds may contribute to antimicrobial and anti-inflammatory effects. Experimental evidence supports their potential against oral microorganisms, but clinical evidence for mouthwash formulations remains limited (Chatterjee et al., 2011).
Camellia sinensis
(Camellia sinensis ( green tea) is one of the better-studied medicinal plants for oral care. Catechins, particularly epigallocatechin gallate, are associated with antimicrobial and anti-inflammatory effects. Clinical studies have reported reductions in plaque and gingival indices with green tea preparations (Tafazoli and Tafazoli, 2020).
Syzygium aromaticum
(clove) is rich in eugenol. Eugenol has antimicrobial and anti-inflammatory properties and may interfere with microbial growth. Clove-based preparations therefore have potential as oral-care agents, although more controlled clinical studies are needed (Tafazoli and Tafazoli, 2020).
Psidium guajava
leaves contain flavonoids, tannins, and other phenolic compounds. Extracts have demonstrated antimicrobial activity against oral microorganisms. Their potential use in mouthwash formulations requires further clinical validation (Tafazoli and Tafazoli, 2020).
Phytochemical class | Major constituents (examples) | Key biological activities relevant to oral health | Representative plant sources |
|---|---|---|---|
Flavonoids | Quercetin, kaempferol, catechins, apigenin, luteolin | Antimicrobial; inhibition of biofilm formation; anti-inflammatory; antioxidant activity. | Camellia sinensis (green tea), Ocimum sanctum (tulsi), Psidium guajava (guava), Triphala. |
Tannins | Gallic acid, ellagic acid, proanthocyanidins, tannic acid | Inhibition of bacterial adhesion; antibiofilm activity; astringent effects. | Terminalia chebula, Terminalia bellirica, Emblica officinalis (Triphala), Psidium guajava. |
Alkaloids | Berberine, piperine, magnoflorine | Antimicrobial activity; possible inhibition of microbial signalling; anti-inflammatory effects. | Azadirachta indica (neem), Berberis spp., Piper nigrum. |
Terpenoids and terpenes | Eugenol, thymol, carvacrol, limonene, menthol | Antimicrobial and antibiofilm activity; disruption of microbial membranes; anti-inflammatory effects. | Syzygium aromaticum (clove), Ocimum sanctum, Mentha piperita, Cinnamomum spp. |
Phenolic acids and polyphenols | Caffeic acid, ferulic acid, chlorogenic acid, curcumin, resveratrol | Antimicrobial; antioxidant; modulation of inflammatory mediators; protection against oxidative stress. | Curcuma longa (turmeric), Camellia sinensis, Psidium guajava. |
Essential oils | Eugenol, thymol, eucalyptol, menthol, citral | Broad antimicrobial activity; inhibition of biofilm formation; anti-inflammatory effects; reduction of oral malodour. | Syzygium aromaticum, Ocimum sanctum, Mentha spp., Cymbopogon citratus, Eucalyptus spp. |
Saponins | Asiaticoside, glycyrrhizin, quillaic acid | Antimicrobial and antibiofilm activity; anti-inflammatory effects; possible support for mucosal repair. | Aloe spp., Glycyrrhiza glabra, Quillaja saponaria. |
Aloe barbadensis
contains polysaccharides, phenolic compounds, and other bioactive constituents. Aloe-based oral-care preparations have been investigated for their possible anti-inflammatory and plaque-control effects. However, clinical findings are not yet sufficient to establish consistent superiority over conventional agents (Tafazoli and Tafazoli, 2020).
Triphala
is a traditional combination of three fruits: Emblica officinalis, Terminalia chebula, and Terminalia bellirica. It contains several polyphenolic constituents. Studies have reported antimicrobial and plaque-control effects, but differences in preparation and concentration make direct comparison difficult (Tafazoli and Tafazoli, 2020).
Other Promising Medicinal Plants
Other plants, including Calendula officinalis, Melaleuca alternifolia, Curcuma longa, and Cinnamomum species, have also been investigated for oral biofilm control. Systematic reviews indicate promising results for several of these plants. However, differences in formulation, dosage, study duration, and clinical outcomes limit direct comparison (Table 2) (Arumugam et al., 2020).
Phytochemical Mechanisms of Action
Herbal mouthwashes may act through several complementary mechanisms. Their effects include antimicrobial activity, inhibition of biofilm formation, modulation of inflammation, and reduction of oxidative stress. These effects depend on the phytochemical composition and formulation (Figure 2) (Diaz and Valm, 2020).
Antimicrobial Activity
Plant-derived compounds can inhibit the growth of oral microorganisms. Phenolics, flavonoids, terpenoids, and essential oils may affect microbial membranes, enzymes, and cellular functions (Diaz and Valm, 2020; Slobodníková et al., 2016).
Antibiofilm and Anti-Adhesion Activity
Some phytochemicals can interfere with the attachment of microorganisms to tooth surfaces. They may also affect biofilm development and reduce the stability of established biofilms. This mechanism is particularly relevant because oral biofilms contain multiple interacting microbial species (Slobodníková et al., 2016).
Inhibition of Quorum Sensing and Biofilm Signaling
Microorganisms use chemical signals to coordinate activities within biofilms. Certain plant compounds may interfere with these signaling pathways. This could reduce microbial communication and biofilm development. However, evidence for quorum-sensing inhibition in oral applications is still mainly experimental (Slobodníková et al., 2016).
Anti-Inflammatory Activity
Several phytochemicals can influence inflammatory pathways. They may reduce the production or activity of inflammatory mediators associated with gingival inflammation. This provides a possible mechanism for the reduction in gingival bleeding and inflammation reported with some herbal preparations (Daglia, 2012).
Antioxidant Activity
Oxidative stress can contribute to periodontal tissue damage. Polyphenols and other antioxidant compounds can scavenge reactive oxygen species and may support the antioxidant defence system. This activity may complement their antimicrobial and anti-inflammatory effects (Daglia, 2012).
Modulation of Host-Microbial Interactions
Herbal compounds may influence both microorganisms and host responses. Their potential effects include reduction of microbial adhesion, modulation of inflammatory signalling, and protection against oxidative damage. However, these mechanisms should not be considered equivalent to proven clinical efficacy. Clinical evidence remains variable among different herbal preparations (Daglia, 2012; Hajishengallis and Lamont, 2014).
Clinical Evidence of Herbal Mouthwashes
Evidence from Randomized Controlled Trial
Randomized controlled trials have reported reductions in plaque and gingival inflammation with several herbal mouthwashes. A systematic review of 13 RCTs found that herbal mouthwashes performed better than placebo for several plaque and gingival indices. However, no significant difference was found when compared with chlorhexidine in the selected studies (Janakiram et al., 2020).
Effects on Plaque and Gingival Indices
Herbal mouthwashes have shown reductions in plaque and gingival scores in several clinical studies. Green tea, neem, Triphala, and other plant-based preparations have demonstrated potential benefits. However, the magnitude of improvement differs between formulations (Chen et al., 2014; Deshpande et al., 2021).
Effects on Periodontal Microorganisms
Some clinical studies have reported reductions in bacterial counts following the use of herbal preparations. These effects may result from direct antimicrobial activity and interference with biofilm formation. However, evidence for specific periodontal pathogens remains less consistent than evidence for plaque and gingival indices (Deshpande et al., 2021).
Comparative Clinical Evidence
Herbal mouthwashes have been compared with placebo and conventional agents, particularly chlorhexidine. Current evidence suggests that some herbal formulations may provide plaque and gingival control comparable to conventional products. However, this does not establish that all herbal mouthwashes are equally effective (Chen et al., 2014).
Medicinal plant | Major phytochemicals | Reported oral-health activities | Main area of evidence |
|---|---|---|---|
Azadirachta indica (neem) | Limonoids, nimbidin, flavonoids, tannins | Antimicrobial; Antiplaque; Antigingivitis | Clinical and experimental |
Ocimum sanctum (tulsi) | Eugenol, rosmarinic acid, flavonoids, terpenoids | Antimicrobial; Antibiofilm; Anti-inflammatory | Experimental and clinical |
Camellia sinensis (green tea) | Catechins, epigallocatechin gallate, polyphenols | Antimicrobial; Antibiofilm; Anti-Inflammatory; Antioxidant | Clinical and experimental |
Syzygium aromaticum (clove) | Eugenol, eugenyl acetate, β-caryophyllene | Antimicrobial; Antibiofilm; Anti-Inflammatory | Mainly experimental |
Aloe spp. | Polysaccharides, anthraquinones, phenolics | Anti-inflammatory; Antimicrobial; Possible Gingival Benefits | Clinical and experimental |
Psidium guajava (guava) | Flavonoids, tannins, phenolic compounds | Antimicrobial; Antiplaque; Anti-Inflammatory | Experimental and clinical |
Triphala | Tannins, gallic acid, ellagic acid, flavonoids | Antimicrobial; Antibiofilm; Antiplaque; Antigingivitis | Clinical and experimental |
Curcuma longa (turmeric) | Curcuminoids, volatile oils | Anti-inflammatory; Antioxidant; Antimicrobial | Experimental and clinical |
Cinnamomum spp. | Cinnamaldehyde, eugenol, polyphenols | Antimicrobial; Antibiofilm; Anti-Inflammatory | Mainly experimental |
Limitations of Current Clinical Evidence
Several limitations affect interpretation of the available evidence. Many trials are short in duration and use different formulations and outcome measures. An umbrella review also reported possible publication bias and noted that many trials lasted less than four weeks (Chen et al., 2014). Therefore, longer and well-designed clinical trials using standardized formulations are required (Table 3).
Comparison with Conventional Mouthwashes
Conventional mouthwashes have stronger clinical evidence and more standardized formulations than many herbal products. Chlorhexidine remains an important reference agent, while Cetylpyridinium Chloride (CPC) and essential-oil formulations are commonly used for daily plaque control. Herbal products may offer additional options, but their efficacy depends on the specific plant and formulation (James et al., 2017).
Chlorhexidine
(CHX) has strong antiplaque and antigingivitis activity. However, prolonged use may cause tooth staining, taste alteration, and other local adverse effects. These limitations restrict its use as a long-term daily mouthwash (James et al., 2017; Windhorst et al., 2025).
Cetylpyridinium Chloride
(CPC) is a cationic antimicrobial agent used in several mouthwashes. Recent evidence suggests that CPC can provide effective plaque and gingivitis control. Its clinical performance may approach that of CHX in some brushing conditions, with generally fewer staining concerns (Swaaij et al., 2025).
Essential-Oil-Based Mouthwashes
Essential-oil mouthwashes can reduce plaque and gingival inflammation. Recent evidence indicates that their effectiveness is influenced by formulation. Alcohol-containing and alcohol-free formulations may show differences in plaque control, although gingival outcomes can be similar (Swaaij et al., 2025).
Herbal versus Conventional Mouthwashes: Evidence-Based Comparison
Evidence-Based Comparison
Herbal mouthwashes have shown promising results in clinical studies, but evidence is less consistent across products. Conventional agents generally have better-established efficacy and quality standards. Herbal preparations may therefore be considered useful adjuncts rather than universal replacements for conventional mouthwashes. Direct comparisons should consider the specific formulation, concentration, treatment duration, safety, and clinical outcome (Table 4) (Swaaijet al., 2025).
Formulation, Standardization and Quality Control
The quality of a herbal mouthwash depends on the identity and quality of the plant material, extraction process, formulation, and storage conditions. Variations in these factors can produce differences in chemical composition and biological activity (Gupta et al., 2014).
Selection and Authentication of Plant Materials
Plant materials should be correctly identified and authenticated before formulation. The plant part, geographical source, harvesting stage, and storage conditions should be documented. Pharmacognostic evaluation and suitable botanical reference standards can help reduce substitution and adulteration (Gupta et al., 2014).
Extraction and Phytochemical Standardization
Extraction conditions can influence the concentration of active constituents. Solvent type, extraction time, temperature, and plant-to-solvent ratio should therefore be controlled. Chromatographic techniques such as HPLC and HPTLC can be used for marker-compound analysis and chemical fingerprinting (Edo et al., 2024; Jindal, 2026).
Formulation Variables
An herbal mouthwash should have acceptable pH, clarity, taste, odour, and physical stability. The concentration of plant extracts and other excipients should be optimized to maintain efficacy and patient acceptability. Preservatives may be required when the formulation is susceptible to microbial contamination (Lalchandani et al., 2025).
Quality Control and Stability
Quality control should include physicochemical, microbiological, and phytochemical evaluation. Stability studies should assess changes in appearance, pH, microbial quality, and marker compounds during storage. Appropriate packaging is also important because light, temperature, oxygen, and moisture can affect product stability (Figure 3) (Lalchandani et al., 2025).
Herbal mouthwash / intervention | Clinical evidence | Main outcomes assessed | Overall findings | Key limitation |
|---|---|---|---|---|
Neem (Azadirachta indica) | Randomized clinical studies and systematic reviews | Plaque index, gingival index | Reduction in plaque accumulation and gingival inflammation has been reported | Limited number of well-designed long-term trials |
Green tea (Camellia sinensis) | Clinical studies and systematic reviews | Plaque, gingival inflammation, microbial parameters | Promising plaque-control and anti-inflammatory effects | Variation in extract concentration and formulation |
Triphala | Randomized clinical studies | Plaque index, gingival index | Reported reduction in plaque and gingival inflammation | Different preparations and concentrations |
Aloe vera | Clinical studies | Plaque and gingival indices | Potential benefit in controlling gingival inflammation | Clinical evidence remains limited |
Polyherbal mouthwashes | Randomized controlled trials | Plaque and gingival indices | Some formulations showed beneficial effects compared with placebo or conventional products | Formulations are not standardized |
Clove (Syzygium aromaticum) | Mainly experimental evidence with limited clinical data | Microbial growth and biofilm-related outcomes | Antimicrobial and antibiofilm potential has been reported | More clinical trials are required |
Guava (Psidium guajava) | Experimental and limited clinical evidence | Plaque, gingival inflammation, microbial outcomes | Promising antimicrobial and antiplaque activity | Limited standardized clinical evidence |
Other herbal formulations | Clinical studies with different plant combinations | Plaque and gingival indices | Results are generally promising but heterogeneous | Differences in formulation, duration, and study design |
Good Manufacturing Practices and Reproducibility
Good manufacturing practices are important for achieving consistent herbal products. Raw materials, extraction procedures, manufacturing conditions, and finished products should be documented and controlled. Standardization is particularly important because natural variation can cause batch-to-batch differences (Lalchandani et al., 2025).
Safety and Regulatory Considerations
Herbal mouthwashes should not be considered automatically safe because they are plant-based. Safety depends on the plant, dose, extraction method, formulation, and duration of use. Variation in composition and quality can also affect product safety (Sahoo et al., 2010; Indrayanto, 2024).
Oral Safety and Tolerability
Most herbal mouthwashes studied clinically have shown acceptable short-term tolerability. However, some users may experience burning, dryness, unpleasant taste, mucosal irritation, or hypersensitivity. Long-term safety data are limited for many formulations (Leeuwen et al., 2014).
Potential Adverse Effects and Drug Interactions
Plant constituents can produce adverse effects at higher concentrations or with prolonged exposure. Interactions with medicines are also possible for some botanicals. Therefore, safety assessment should consider the complete formulation rather than only individual phytochemicals (Leeuwen et al., 2014).
Quality and Contamination Concerns
Contamination with microorganisms, pesticides, heavy metals, or other unwanted substances can compromise herbal products. Incorrect plant identification and adulteration are additional concerns. Appropriate authentication, quality testing, and batch control are therefore essential (World Health Organization, 2018).
Regulatory Considerations for Herbal Oral-Care Products
Regulatory requirements differ between countries. Product classification, permitted claims, quality standards, safety evaluation, and clinical evidence requirements may vary considerably. In India, herbal products may fall under different regulatory pathways depending on their composition, intended use, and claims. Harmonized standards and stronger post-market surveillance could improve product consistency and consumer safety (European Medicines Agency, 2022).
Emerging Delivery Systems and Recent Advances
Recent research is moving beyond conventional herbal mouthwash formulations. Nanoformulations, encapsulation, mucoadhesive systems, and combinations of phytochemicals may improve stability, biofilm penetration, and retention in the oral cavity (Nehavarshini et al., 2023).
Nanoformulations and Encapsulation
Nanoemulsions and other nanocarriers can improve the dispersion and delivery of poorly water-soluble plant compounds. An herbal nanoemulsion has shown antibiofilm and anti-adhesion activity against oral microorganisms in experimental models (Nehavarshini et al., 2023). Recent reviews also indicate growing interest in herbal nanoemulsions for oral biofilm control (Ahmed et al., 2026).
Sustained and Controlled Delivery
Conventional mouthwashes have relatively short contact times in the oral cavity. Mucoadhesive and controlled-release systems may increase the retention of active compounds and provide prolonged exposure. However, clinical evidence for these advanced herbal systems remains limited (Ahmed et al., 2026).
Combination of Phytochemicals
Combining extracts from different plants may provide complementary antimicrobial and anti-inflammatory effects. Recent formulation studies have investigated polyherbal combinations against multiple oral pathogens and biofilms (Sakthivel et al., 2024). However, possible interactions between phytochemicals should be evaluated rather than assuming that combinations will always produce synergistic effects.
Personalized and Precision Oral Care
Future oral-care products may consider individual differences in oral microbiota, disease risk, diet, and treatment response. Such approaches could support more targeted use of antimicrobial or anti-inflammatory phytochemicals. At present, personalized herbal mouthwash remains an emerging concept and requires substantial clinical validation (Arif et al., 2024).
RESEARCH GAPS AND FUTURE PERSPECTIVES
Herbal mouthwashes show potential for controlling oral biofilm and gingival inflammation. However, important gaps remain in clinical validation, standardization, safety assessment, and formulation development (Dalir et al., 2023).
Need for Better Clinical Evidence
Many clinical studies are short and use different formulations and outcome measures. Larger, well-designed trials with longer follow-up are needed. Direct comparisons with established mouthwashes should also use standardized protocols (Dalir et al., 2023; Duane et al., 2023).
Standardization of Herbal Formulations
Variation in plant species, growing conditions, extraction methods, and phytochemical content can affect efficacy. Standardized extracts and validated marker compounds are therefore needed to improve reproducibility between batches (Duane et al., 2023).
Understanding the Oral Microbiome
Future research should examine whether herbal mouthwashes selectively control harmful microorganisms while preserving beneficial oral microbes. This is important because broad antimicrobial activity may also disturb the oral microbial ecosystem. Recent studies have increased interest in microbiome-friendly mouthwash development (Wattanawongwan et al., 2025).
Parameter | Herbal mouthwashes | Chlorhexidine | Cetylpyridinium chloride | Essential-oil mouthwashes |
|---|---|---|---|---|
Main active components | Plant extracts and phytochemicals | Chlorhexidine | Cetylpyridinium chloride | Essential oils such as thymol, eucalyptol, menthol and related compounds |
Antimicrobial activity | Depends on plant and formulation | Strong | Established | Established |
Antibiofilm activity | Reported for several formulations | Strong | Good | Good |
Plaque control | Promising but variable | Strong | Good | Good |
Gingival inflammation | Promising | Strong | Good | Good |
Long-term evidence | Limited for many products | Better established | Better established | Better established |
Common limitations | Variation in phytochemical content and formulation | Tooth staining and taste alteration with prolonged use | Effect varies with formulation | Possible taste or tolerability issues |
Standardization | Major challenge | Highly standardized | Highly standardized | Generally standardized |
Potential role | Adjunctive oral-care option | Short-term therapeutic plaque control | Daily plaque and gingivitis control | Daily plaque and gingivitis control |
Advanced Formulation Approaches
Nanoformulations, encapsulation, and controlled-release systems may improve the stability and delivery of phytochemicals. However, their safety, scalability, and clinical effectiveness require further evaluation before routine use (Jayanandan et al., 2026).
Future Research Priorities
Future studies should focus on standardized plant extracts, validated clinical outcomes, long-term safety, microbiome effects, and well-characterized formulations. Greater collaboration between pharmacognosy, pharmaceutical sciences, microbiology, and clinical dentistry could accelerate the development of evidence-based herbal mouthwashes (Jayanandan et al., 2026).
CONCLUSION
Herbal mouthwashes have considerable potential as adjuncts for controlling oral biofilm and gingival inflammation. Their activity is associated with multiple phytochemicals, including flavonoids, polyphenols, alkaloids, terpenoids, and essential oils. These compounds may provide antimicrobial, antibiofilm, anti-inflammatory, and antioxidant effects.
Clinical evidence suggests that some herbal mouthwashes can reduce plaque and gingival inflammation. However, the evidence is not equally strong for all plants and formulations. Differences in extract composition, concentration, treatment duration, and study design limit direct comparison. Recent reviews also highlight the short duration and methodological limitations of many clinical trials.
Standardization remains a major requirement for the development of reliable herbal oral-care products. Proper plant authentication, phytochemical characterization, quality control, stability testing, and safety evaluation are essential. Advanced approaches such as nanoformulations and controlled delivery systems may further improve the performance of selected phytochemicals, but their clinical value requires further validation.
Overall, herbal mouthwashes should be considered evidence-based adjuncts to routine mechanical oral hygiene rather than automatic replacements for conventional products. Future research should focus on standardized formulations, longer clinical trials, long-term safety, and effects on the oral microbiome. These efforts may help translate promising phytochemical research into consistent and clinically useful herbal oral-care products.
