Dental and Medical Problems

Dent Med Probl
Index Copernicus (ICV 2021) – 132.50
MEiN – 70 pts
CiteScore (2021) – 2.0
JCI (2021) – 0.5
Average rejection rate (2021) – 82%
ISSN 1644-387X (print)
ISSN 2300-9020 (online)
Periodicity – quarterly

Download original text (EN)

Dental and Medical Problems

2022, vol. 59, nr 3, July-September, p. 461–474

doi: 10.17219/dmp/146133

Publication type: review

Language: English

License: Creative Commons Attribution 3.0 Unported (CC BY 3.0)

Download citation:

  • BIBTEX (JabRef, Mendeley)
  • RIS (Papers, Reference Manager, RefWorks, Zotero)

Cite as:


Mazur M, Ndokaj A, Bietolini S, Nisii V, Duś-Ilnicka I, Ottolenghi L. Green dentistry: Organic toothpaste formulations. A literature review. Dent Med Probl. 2022;59(3):461–474. doi:10.17219/dmp/146133

Green dentistry: Organic toothpaste formulations. A literature review

Marta Mazur1,A,D, Artnora Ndokaj1,B,C, Sabina Bietolini2,A,E, Veronica Nisii3,A,B, Irena Duś-Ilnicka4,B,C, Livia Ottolenghi1,E,F

1 Department of Oral and Maxillofacial Sciences, Sapienza University of Rome, Italy

2 Niccolò Cusano University (UNICUSANO), Rome, Italy

3 Chirurgien Dentiste Centre Publique Mairie de Paris 18ème, Paris, France

4 Department of Oral Pathology, Wroclaw Medical University, Poland

Abstract

Dentistry as a profession should take into account the goals of sustainable development in daily practice and encourage the transition to a green economy. Consumers are becoming more conscious about the impact of self-care products, including toothpastes, on the environment. Organic toothpastes are considered very safe. A broad literature review was conducted to: (i) identify the ingredients in available organic toothpastes; (ii) classify them into active and inactive; and (iii) evaluate each ingredient’s purpose and the adverse events that may be associated with its use. A comprehensive list of available organic toothpastes and their ingredients was compiled based on the products from the largest Italian organic supermarket chain (NaturaSì®) that is representative of the European market. Then, PubMed, Scopus and Google Scholar databases were searched to identify, classify and evaluate each ingredient. The final sample consisted of 46 organic toothpastes that included 156 ingredients; 139 (89.1%) and 17 (10.9%) were classified as active and inactive, respectively. Overall, 32 (20.5%) ingredients were associated with known adverse events. The results of this study indicate that organic toothpastes are highly biocompatible with oral cavity tissues. Careful product selection may help consumers avoid potential adverse effects that can be caused by ingredients such as polymers (e.g., polyethylene glycol) and carbomers, detergent agents (e.g., sodium lauryl sulfate), and triclosan. The lack of clinical studies should encourage the development of sufficient evidence to provide consumers with recommendations for daily use, based on both efficacy and biocompatibility.

Keywords: natural, toxicology, ingredients, organic toothpaste, plant/herbal extracts

Introduction

In August 2017, the FDI World Dental Federation published a document titled “Sustainability in Dentistry”1 that was based on the United Nations “Transforming our world: The 2030 Agenda for Sustainable Development”.2 It is recommended that dentistry as a profession takes into account the goals of sustainable development in daily practice and encourages the transition to a green economy.3 Oral health professionals are responsible for reducing their impact on natural resources while promoting optimal oral health for all people and ensuring patient safety.4 As a result, toothpaste formulations have dramatically improved over the last decade by incorporating safer active ingredients, higher fluoride bioavailability and better stain removal with fewer abrasives.5 These products are supposed to simultaneously improve many oral diseases and conditions, such as caries, tooth discoloration, hypersensitivity, halitosis, and gingivitis, while also satisfying the expectations of more conscious and demanding consumers.5

The development of toothpastes, however, is far from complete. Over the last 20 years, the organic personal care market – of which the oral care subset represents a huge driving force – has grown exponentially and will presumably be nearly doubled by 2022 as compared to 2000.6

The requirements to be considered an “organic” product include: (i) the use of substances of natural origin characterized by ecological and skin compatibility and good aquatic toxicity performance; (ii) no genetically modified organisms in either the finished product or its individual ingredients; (iii) the use of natural fragrances (e.g., essential oils); (iv) the use of biodegradable detergents and surfactants; (v) no ionizing radiation; and (vi) the use of natural substances coming from controlled organic farming certified by a recognized accredited independent body.7

An attempt has been made to differentiate between active and inactive ingredients in widely marketed non-organic toothpaste formulations.8 Active ingredients are expected to contribute to improved oral health, while inactive ingredients are added merely to enhance the appeal of the product. Unfortunately, a substantial proportion of inactive ingredients has been associated with adverse events (AEs), including enamel demineralization.8 A previous review detailing the composition of non-organic toothpaste formulations found that 75.6% of the ingredients were associated with possible AEs.8 In addition, nearly 30% of the ingredients were inactive.8 Notably, most individuals were not aware of the risks associated with particular ingredients.9

Until now, no data about the content of active and inactive ingredients and the risks associated with organic toothpaste formulations is available in Europe.

Thus, this study aimed to: (i) identify the ingredients in available organic toothpastes; (ii) classify the ingredients into active and inactive; and (iii) evaluate each ingredient’s purpose and the known risks associated with its long-term use.

Material and methods

Selection criteria for the organic toothpaste database

The products included in this study were analyzed based on the database from the largest Italian organic supermarket chain, NaturaSì®, which has more than 240 shops in the country. They were considered representative of the European market due to the international distribution of most of the products in this field.

We accessed the online database of their dental products (https://www.naturasi.it/prodotti/cura-della-persona/igiene-orale) and extracted a list of available toothpastes. As this chain is restricted to organic products, all of the toothpastes surveyed had some European organic certifications. The first coder (MM) compiled the list of ingredients, and the second coder (AN) created a coding sheet to register all the ingredients of each toothpaste.

Identification of active and inactive ingredients

The authors developed an Excel (Microsoft Corp., Redmond, USA) database that included each ingredient for every selected formulation. Subsequently, each ingredient was classified as active or inactive, according to literature data obtained from PubMed, Scopus and Google Scholar databases from March 2021 to July 2021. In general, active ingredients are considered those typically present in toothpastes, such as emulsifying, buffering, preserving, and wetting agents, as well as thickeners, abrasives, solvents, absorbents, and antibacterial agents. Inactive ingredients include substances such as sweeteners, flavorings, colorants, and fragrance additives.

Ingredient toxicity

All AEs associated with each ingredient were collected by searching PubMed, Scopus and Google Scholar databases. Adverse events included the following: burning sensation/irritation/swelling/sensitivity of the cheek, tongue, lips, gum, palate, or papillae; tooth sensitivity; peeling/exfoliation/roughness of the cheek, tongue, lips, or gum; presence of aphthous ulcer/wounds; itching/tingling/taste changes of the cheek, tongue or lips; gastrointestinal signs and symptoms; and eye irritation. Since AEs may be individual in nature, the scope of the analyzed literature included not only randomized controlled trials and case-control studies on human and animal subjects but also case reports.

Database availability

The supplementary research database associated with this article (Excel database including each ingredient for every selected toothpaste formulation) can be obtained from the corresponding author on reasonable request.

Results

Organic toothpaste database

A total of 46 all-natural organic toothpastes sold by NaturaSì® were identified. They were classified according to different countries’ certifications; 44 of the 46 toothpastes (95.7%) were marketed in more than 6 European countries. The certificates attesting to the organic nature of the analyzed toothpastes were NATRUE label, Biorganic DE, ICEA Eco Bio Cosmesi, BDIH, AIAB Bio Eco Cosmesi, Cosmebio, Ecocert, and Demeter. The Italian companies included Ecor, Natyr, Bioearth, Ecosì-Pierpaoli s.r.l., Victor Philippe, Lycon Cosmetics, and Argital. The German companies included Sante Naturkosmetik, Lavera Naturkosmetik, Logona Naturkosmetik, and Neobio. There was one product from each of the following countries: Switzerland (Weleda), England (Dr. Hauschka), the Netherlands (Ecodenta), and France (Cattier).

Identification of overall ingredients

A total of 156 unique ingredients were coded: 139 (89.1%) and 17 (10.9%) ingredients were classified as active and inactive, respectively. Overall, 32 (20.5%) ingredients were associated with known AEs; 23 were in the active group and 9 were in the inactive group.

The calculated mean number of ingredients per toothpaste was 16.0 ±3.8. The mean number of ingredients originating from plant extracts was 6.4 ±3.1.

Only 8 toothpastes (17.4%) were fluoridated; 6 (13.0%) contained sodium fluoride, and 2 (4.3%) had monofluorophosphate.

A total of 21 (45.7%) formulations contained xylitol, which was always among the first 10 ingredients.

Identification of active ingredients

One hundred thirty-nine of the 156 ingredients were classified as active. They were subdivided into fluorides, emulsifiers, emollients, buffering agents, wetting agents, preserving agents, thickening agents, abrasives, whitening and plaque removal agents, solvents, absorbents, antibacterials, and active plant/herbal extracts. Among the 139 active ingredients, 23 (16.5%) were reported to have had possible AEs and 82 (59.0%) were organic plant/herbal extract ingredients. According to the literature search for each individual ingredient, none appeared to be related to any AEs.

Table 1 presents the classification of active ingredients according to their purpose and known AEs. Adverse events are listed in the table, when appropriate.

Identification of inactive ingredients

Seventeen of the 156 ingredients were classified as inactive. They were subdivided into sweeteners, flavorings, natural colorants, and fragrances. Of these, 9 (52.9%) were reportedly associated with a known AE, while 8 (47.1%) were not.

Among the inactive ingredients, 14 (82.4%) were natural ingredients, including organic essential oils (n = 8), natural colorants (n = 3; natural red, Carbo vegetabilis and natural green (chlorophyll) – CI 75810), natural flavoring agents (n = 2), and one natural sweetener (Stevia rebaudiana).

The reported AEs were skin and eye irritations (coumarin, citronella, geraniol, linalool, cinnamaldehyde, and limonene) and gastrointestinal symptoms (sorbitol).

Table 2 presents the inactive ingredients with their purposes and known AEs. Adverse events are listed in the table, when appropriate.

Table 3 presents the classification of the ingredients and the percentage of AEs among the groups.

The research dataset is available from the corresponding author on reasonable request. All the ingredients are classified and listed in the table according to each of the examined formulations. Moreover, the International Nomenclature of Cosmetic Ingredients (INCI) for each of the examined formulations is reported.

Discussion

This study identified for the first time the ingredients of 46 all-natural organic toothpastes currently marketed in Europe and classified them into active and inactive compounds. The study also evaluated, through a broad literature review, the purpose of the ingredients, as well as their known toxicity risks. In total, 156 unique ingredients were analyzed: 89.1% (n = 139) and 10.9% (n = 17) were classified as active and inactive, respectively.

According to our study, only 20.5% of the ingredients found in the organic toothpastes were associated with AEs, reassuring the safety of these products for oral care. In detail, the study determined that most of the potential toxicity of the products was in the inactive ingredients.

The findings of this study are relevant to the following issues:

1. Compared with the results of the Basch and Kernan study on the composition of non-organic toothpastes for children, the percentage of ingredients associated with possible AEs in this study was much lower (75.6% compared to 20.5%). The Basch and Kernan study identified 71.1% and 28.9% of all components as active and inactive ingredients, respectively, while they were 89.1% and 10.9%, respectively, in this study.8

2. Most of the possible AEs associated with non-organic products do not occur with organic toothpastes. In particular, only 2 of the toothpaste formulations evaluated in this study contained the 2 classes of ingredients most frequently associated with toxicity, namely, synthetic polymers (e.g., polyethylene glycol (PEG), carbomers and Triclosan) and detergent agents (e.g., sodium lauryl sulfate (SLS)). This indicates favorable biocompatibility for the other 44 products. Synthetic polymers and detergent agents were present in only 2 formulations by one manufacturer (Cattier). The literature reports that non-ionic surfactants (e.g., PEG) act as penetration enhancers by decreasing surface tension and conditioning the stratum corneum, which may increase the diffusion of other molecules through the skin.10 Moreover, there is evidence on the side effects of detergent agents (e.g., SLS) that can cause irritation and soft tissue peeling.11, 12, 13 Sodium lauryl sulfate is reported to be the most toxic agent on mucosal cells; it causes epithelial desquamation,14, 15 as shown by studies on the cytotoxicity and genotoxicity of commercial toothpastes.16, 17, 18

This study did not identify any artificial colorings, such as FD&C Blue No. 1 Lake, D&C Red No. 30 Lake, D&C Red No. 28, and Red No. 40, which are associated with allergic reactions, neurotoxicity, carcinogenicity, and skin discoloration.19, 20, 21 In addition, there were no foam or flavor boosters, such as cocamidopropyl betaine, in the organic toothpaste formulations. Although rare, these compounds can cause allergic reactions.22, 23

3. Most potential AEs associated with organic products are due to inactive ingredients, such as fragrances that can cause skin and eye irritations. In addition, the authors need to highlight that the study searched for any potential toxicity, regardless of the dose. This results in the conclusion that the very low absolute dose in these toothpastes is unlikely to cause such AEs. Furthermore, detailed information on the concentration (%) of each ingredient is missing, which is challenging for researchers.

Twenty-seven (58.7%) formulations contained a sweetening agent, including 25 (92.6%) with sorbitol, one (3.7%) with sodium saccharine, and one (3.7%) with Stevia rebaudiana. Stevia rebaudiana is a sweetening agent that has no reported AEs, so it meets the safety standards of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Recent research suggests that sodium saccharine, although safe for consumption,24 contributes to enamel demineralization.25 Sorbitol has been shown to cause abdominal discomfort and diarrhea.26 Conversely, a recent review by de Cock et al.27 highlights the extensive research on the safety of erythritol, a polyol produced by the natural process of fermentation. Erythritol has sweetness and calorific reduction compared to sucrose, no cariogenic potential, a low glycemic index, a relatively high stability in acidic and alkaline environments, a high stability against heat, and suitability as a bulking agent in food manufacturing. Furthermore, there is a significant number of toxicology and safety studies that report a lack of AEs associated with small amounts of erythritol.9, 28, 29 Analogous characteristics of safety and health effects are valid for xylitol. Considering this evidence, the authors propose the use of Stevia rebaudiana, erythritol or xylitol in toothpaste formulations instead of other components that have been linked to AEs.

Regarding fragrances, the authors suggest focusing on 100% naturally sourced, plant-based essential oils to avoid possible AEs. Moreover, they recommend that as small a quantity as possible should be used to avoid potential AEs.

Essential oils should have 3 major characteristics: safe to consume, pure food grade, and organic certification. Alternatively, naturally derived flowers, spices and fruit flavors are suitable options, especially for children’s toothpaste.

In the past, the risk of bioaccumulation had been correlated with the amount of toothpaste inadvertently swallowed during brushing.30 Consequently, the American Dental Association (ADA) recommendations stated that no amount of toothpaste should ever be swallowed intentionally.31 Therefore, based on the results of a recent randomized placebo-controlled study that evaluated the effect of a vitamin B12-fortified toothpaste on vitamin status markers in vegans, manufacturers should be cautious when selecting toothpaste ingredients. This is because each toothpaste ingredient, when in contact with the oral cavity, can also enter the systemic blood circulation via the sublingual blood system route. The study demonstrated that, compared to the placebo, the vitamin B12-fortified toothpaste resulted in a significant increase in serum vitamin B12 concentration after 12 weeks. Although the authors specified that the mechanism of vitamin B12 absorption via the mucosal barrier is currently not known, the toothpaste-based strategy may be a promising approach for delivering vitamins.32

While there are few existing trials evaluating the clinical effectiveness of organic toothpastes, there appears to be a rising trend. It is necessary to obtain scientific evidence of abrasive action, removal of external discoloration, and remineralizing effects on enamel. Interestingly, only 8 (17.4%) of the toothpastes analyzed in this study were fluoridated: 6 (13%) with sodium fluoride and 2 (4.3%) with monofluorophosphate. The remineralizing effect of fluoride on International Caries Detection and Asessment System (ICDAS)-II codes 1 and 2 early carious lesions is well understood.33 Considering this data, many questions and doubts arise about the remineralizing effects of organic toothpastes; answering them as soon as possible is fundamental to promote their use and provide both clinicians and patients with clinical recommendations based on evidence.

A recent systematic review highlighted the efficacy of Camellia sinensis extracts on gingivitis and periodontitis.34 Thus, it is surprising that it was present in only 2 of the 46 toothpaste formulations analyzed in this study. A recent clinical study found that scaling and root planing with the aid of ozonated olive oil mouthwash were more effective on salivary matrix metalloproteinase-8 (MMP-8) reduction than scaling and root planing alone.35 None of the examined formulations contained ozonated olive oil. The supplementary research database is available from the corresponding author on reasonable request. All of the listed single ingredients can be searched.

In the light of the above, the authors of this article emphasize the need for direct comparisons between manufacturers and researchers. It is only through constant dialogue and inclusive cooperation between the manufacturers and those conducting the research that products requested by patients can be obtained. In fact, patients are increasingly oriented toward ecological transition and sustainability, given the development of dentistry itself toward less invasive procedures that also consider the patient’s quality of life.36, 37, 38

Limitations

The main limitation of this study is that it only included one supermarket chain in one country. However, the authors showed that most products are marketed in more than 6 European countries, which diminishes the impact of this limitation. Another limitation is that the toxicity evaluation was based on evidence emerging from our literature search, which did not assess the actual quantity (see above) or possible combinations; these could be considered worst-case scenarios. Third, the authors did not conduct a direct comparison between organic and non-organic toothpaste formulations. However, the difference between the analysis in this study and previous analyses is sufficient to minimize this bias. Finally, the efficacy was not assessed. Future research is warranted to further evaluate organic toothpastes and address these limitations.

Conclusions

Based on the results of this study, the organic toothpaste formulations showed adequate safety when each ingredient was analyzed. However, the clinical efficacy of the organic toothpastes still needs to be assessed to support their daily use for maintaining oral health and preventing diseases. This analysis provides important information for consumers who are concerned with ecological and environmental issues.

Ethics approval and consent to participate

Not applicaple.

Data availability

The datasets generated and/or analyzed during the current study are available from the corresponding author on reasonable request.

Consent for publication

Not applicable.

Tables


Table 1. Characteristics of the selected studies

Purpose and known adverse events of active toothpaste ingredients

Type of ingredient

Ingredient

Purpose

Known adverse events

Active ingredient

sodium fluoride

anti-caries activity, whitening effects, halitosis control1

excess ingestion of sodium fluoride was linked with dehydration and with the possibility of dental and skeletal fluorosis2–4

sodium monofluorophosphate

not found

not found

Emulsifiers

sodium lauryl sulfate

thickening and foaming agent5

skin, eyes, oral mucosa, and gastrointestinal irritant6–8

sodium carboxymethyl cellulose

emulsion stabilizing agent9

no known contamination risks9

poloxamer 407

emulsifying agent10,11

eye and renal irritant12,13; in animal studies and with parenteral administration, it was linked to hyperlipidemia and engorgement of Kupffer cells14

tetrasodium pyrophosphate

anti-biofilm action by reducing saliva calcium and magnesium15,16

nose, skin, eye, throat, and respiratory tract irritant17

sodium hexametaphosphate

extrinsic stain removal18

skin, eye, respiratory tract irritant; can cause gastrointestinal symptoms and lethargy, when ingested19

sodium cocoyl glutamate

surfactant

not found

Emulsifiers

disodium cocoyl glutamate

surfactant

not found

disodium cocoamphodiacetate

surfactant

not found

algin

thickener

not found

sodium chloride

moisturizer

not found

pistacia lentiscus gum

antibacterial activity20

not found

Cyamopsis tetragonoloba (guar) gum

natural thickener

not found

sodium lauroyl glutamate

surfactant

not found

lauryl glucoside

foaming agent

allergic dermatitis reported in case studies21

sodium lauroyl sarcosinate

pH buffering agent

non-irritating and non-sensitizing to animal and human skin; can increase the penetration of other ingredients through the skin; low oral toxicity in rats, not mutagenic; no data on carcinogenicity22

betaine

moisturizer and foam stabilizer23

not found

hectorite (natural clay)

excellent absorption capacity23,24

not found

magnesium aluminum silicate

excellent absorption capacity

not found

sucrose laurate

solubilization properties25

not found

Emollients

Triticum vulgare (wheat) germ oil

emollient and antioxidant agent; often mixed with other oils, and used as a base for many creams for mature skin, owing to the high content of tocopherols (vitamin E) which also makes it an excellent antioxidant23

not found

esculin

emollient; glucoside extracted from
Aesculus hippocastanum, Aesculus californica
and Daphne mezereum23

not found

Helianthus annuus oil (sunflower)

rich in linoleic acid, vitamin E, vitamin A, a powerful antioxidant, helps to maintain the right cholesterol level and protects against cardiovascular diseases by keeping the blood flowing26,27

not found

potassium nitrate

desensitizing agent 28

not found

Buffering agents

disodium pyrophosphate

remineralizing agent

not found

sodium hydroxide

buffering agent

unclear toxicity; at high concentrations sodium hydroxide has been shown to affect the viability of esophageal cells29

calcium citrate

remineralizing agent

not found

sodium silicate

remineralizing agent

extremely toxic in purity to contact30

Preserving agents

sodium benzoate

preserving agent

excess consumption could decrease the functioning of the immune system and cause other irritations31,32

potassium sorbate

preserving agent

dangerous in case of ingestion and inhalation; skin and eye irritant33

sodium dehydroacetate

preserving agent

allergic dermatitis reported in case studies34

ethylhexylglycerin

preserving, antibacterial, surfactant,
skin-conditioning, emollient agent

a low-risk but relevant sensitizer in ‘hypoallergenic’ formulations35

salicylic acid

preserving agent

salicylic acid toxicity (salicylism) can occur after topical use of 6% salicylic acid over as little as 40% of body surface area36

sorbic acid

preserving agent

contact urticaria after the use of synthetic cassia oil and sorbic acid limited to the face37

Thickening agents

cellulose gum

thickening agent9

skin and eye irritant38

xanthan gum

thickening and stabilizing agent39

pure xanthan gum could cause bloating,
cold and flu-like symptoms40,41

carrageenan

thickening agent9

gastrointestinal issues42–44

Abrasives

calcium carbonate

active in extrinsic stain and plaque removal45

eye and respiratory tract irritant 46

silica

abrasive agent47

not found

diatomaceous earth
(solum diatomeae)

abrasive agent

not found

illite

abrasive agent

not found

Whitening/plaque removal agents

citric acid

active in dental plaque removal9

the developmental toxicity associated with chronic consumption of citric acid is not known48; gastrointestinal symptoms are reported to be associated with citric acid consumption9

hydrated silica

active in extrinsic stain and plaque removal49

use of silica nanoparticles in-vivo poses risks of bioaccumulation50

mica

not found

not found

sodium bicarbonate

active in extrinsic stain and plaque removal51

rare reactions such as dizziness, confusion, irritability, memory problems, muscle pain or aches, vomiting, or weakness are reported to be associated with its excess consumption52

titanium dioxide

active in extrinsic stain removal53

mixed findings; recent work suggested that titanium dioxide in higher concentrations may be dangerous53; particularly, chronic health effects include possible harm to the upper respiratory tract and lungs54

trisodium phosphate

not found

not found

xylitol

active in caries prevention55

no carcinogenicity55

Wetting agents

glycerin

used to prevent toothpaste from drying out56

generally used with low toxicity, but at high concentrations, it could impair blood circulation57

hydrogenated starch hydrolysate

used also as a sweetener (polyol (sugar alcohol))

not found

lactose

used also as a sweetener

not found

calcium lactate

used also as an enamel remineralizer

not found

Solvents

aqua

solvent

not found

denatured alcohol

solvent

not found

alcohol

solvent

not found

Absorbents

kaolin

cleaning and polishing agent

not found

solum fullonum

absorbent

not found

maltodextrin

used also as a sweetener

not found

charcoal powder

buffering agent

not found

Antibacterials

Copaifera officinalis resin

antibacterial agent

not found

honey (Manuka honey IAA15+)

antibacterial agent

not found

Anthemis nobilis extract (chamomile)

antibacterial, antifungal, insecticidal, hypotensive, anti- platelet aggregation, anti-inflammatory, hypoglycemic, and antioxidant agent58

the US Food And Drug Administration (FDA) classified the oil and extract of Roman chamomiles as safe58

bisabolol

antibacterial and thickening agent

not found

carvone

antibacterial agent

not found

Other ingredients

Aloe vera

antioxidant and antibacterial properties

not found

Vegetable-based ingredients

Mentha arvensis oil

analgesic counterirritant

not found

Mentha arvensis flower/leaf/stem extract

analgesic counterirritant

sensitizer; case reports on allergic contact cheilitis caused by toothpaste menthol59

Mentha viridis (spearmint) leaf oil

analgesic counterirritant

sensitizer and allergenic59

Melissa officinalis flower/leaf/stem water

antimicrobial and antioxidant agent

case reports on contact dermatitis60

Aloe barbadensis leaf juice

emollient and antimicrobial agent; used to treat aphthous ulcers and to reduce the incidence of alveolar osteitis after third molar extraction surgeries61; a mouthrinse containing A. vera was found to reduce gingival inflammation and gingival bleeding62 and was more effective than Listerine® in reducing the count of aerobic, microaerophilic and anaerobic bacteria63

not found

Vegetable-based ingredients

Aloe barbadensis gel

emollient, antimicrobial

not found

Mentha piperita oil

analgesic, antiseptic and anti-inflammatory properties64

not found

Myrtus communis leaf water

antibacterial activity on oral pathogens: Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Streptococcus pyogenes and Candida albicans65

not found

Echinacea purpurea extract

immunostimulant, increases interferon production66

not found

Salvia officinalis (sage) leaf extract

antioxidant

not found

Salvia officinalis oil

antioxidant

not found

Salvia sclarea (clary) oil

antioxidant

not found

Salvia triloba (sage) leaf oil

antioxidant

not found

Mentha piperita (peppermint) leaf extract

analgesic counterirritant

not found

Glycyrrhiza glabra root extract

anti-inflammatory activity

not found

Camellia sinensis leaf water

antimicrobial

not found

Camellia oleifera leaf extract

antimicrobial

not found

Mentha spicata herb oil

analgesic counterirritant

not found

Krameria triandra extract

astringent

not found

Elettaria cardamomum seed oil

active on oral cavity disinfection and halitosis; regulates inflammatory and immune function67

not found

Citrus limon peel oil

antibacterial agent

not found

Achillea millefolium extract

hydrating agent

not found

Echinacea angustifolia root extract

immunostimulant agent: increases interferon production

not found

Echinacea pallida extract

immunostimulant agent: increases interferon production

not found

Arnica montana flower extract

antimicrobial, anti-inflammatory, antibiotic and antifungal agent

not found

Melaleuca alternifolia leaf oil

antimicrobial agent

not found

Fragaria chiloensis fruit extract

astringent effect

not found

Rubus idaeus fruit extract

anti-biofilm formation

not found

Rosmarinus officinalis (rosemary) leaf extract

anti-biofilm formation

not found

Rosmarinus officinalis oil

anti-biofilm formation

not found

Citrus aurantium bergamia (bergamot) peel oil

fragrance agent

not found

Citrus grandis (grapefruit) peel oil

antimicrobial activity: inhibits metabolism of and kill plaque bacteria

not found

Citrus aurantium dulcis (orange) peel oil

fragrance agent

not found

Thymus vulgaris oil

antimicrobial activity comparable to clorexidine or triclosan against S. mutans68

not found

Eugenia caryophyllus (clove) leaf oil

antimicrobial agent

not found

Chamomilla recutita flower extract

anti-inflammatory agent

not found

Pimpinella anisum oil

antioxidant and antimicrobial agent69

not found

Foeniculum vulgare fruit extract (fennel)

antibacterial agent active on S. mutans70

not found

Hamamelis virginiana flower water

antioxidant and anti-inflammatory agent

not found

Malva sylvestris (mallow) extract

active against S. mutans and S. aureus71

not found

Vegetable-based ingredients

Commiphora abyssinica resin extract

antiseptic agent

not found

Commiphora myrrha extract

antiseptic agent

not found

Malva officinalis flower extract

active against S. mutans, S. aureus71

not found

Calendula officinalis flower extract

active in preventing gingivitis, periodontal disease, stomatitis, and halitosis72

not found

Illicium verum fruit/seed oil (star anise)

antibacterial and antifungal activity, especially active on Staphylococcus aureus73

not found

Rosa canina fruit extract

antibacterial, antioxidant, astringent agent

not found

Avena sativa extract

humectant agent

not found

Chondrus crispus (carrageenan) extract

antimicrobial agent

not found

Aesculus hippocastanum (horse chestnut) seed extract

matrix metalloproteinase inhibitor74

not found

Carbon of beech and Betulla

whitening efficacy

not found

Aesculus hippocastanum (horse chestnut) bark extract

matrix metalloproteinase inhibitor74

not found

Arum maculatum root extract

antimicrobial activity against S. aureus75

not found

Melia azadirachta leaf extract

anti-biofilm activity

not found

peat moss extract

anti-biofilm activity

not found

Prunus spinosa fruit juice

phenolic components and antioxidant activity76

not found

Simmondsia chinensis (jojoba) seed oil

antimicrobial activity against S. aureus

not found

Juglans regia (walnut) oil extract

anticariogenic77 and anti-Candida albicans activity78

not found

papain

anticariogenic,79 anti-biofilm formation; effectively digests the main actinomyces fimbrial proteins, fimP and fimA80

not found

bromelain

antimicrobial,81 antiplaque and antigingivitis,82 adjuvant in treatment of periodontitis83

not found

Petroselinum sativum oil

antimicrobial agent active on Streptococcus mutans84

not found

Berberis vulgaris extract

antimicrobial agent85; inhibits collagenase activity of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis86

not found

Eucalyptus globulus oil

anti-inflammatory agent

not found

Cinnamomum zeylanicum oil

active against S. mutans, S. aureus and Candida albicans

not found

stevioside

natural sweetener87

not found

Glycyrrhiza glabra (licorice) root extract

anti-inflammatory, antioxidant88

not found

Leptospermum scoparium branch/leaf oil (Manuka oil)

strong antibacterial activity against periodontopathic and cariogenic bacteria (Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, S. mutans, and S. sobrinus)89

not found

Colocasia antiquorum extract

antioxidant, effective in the treatment of aphthous ulcers90

not found

Biological additives

maris sal (dead sea salt)

saliva flow stimulation

not found

propolis cera

mucositis-effective91

not found

Ammonium glycyrrhizate (licorice root)

anti-inflammatory, antioxidant88

not found

Antioxidants

xanthophyll

antioxidant

not found

Styrax benzoin extract

antioxidant92

not found

Vitamins

cyanocobalamin (vitamin B12)

vitamin93

not found

Table 2. Description of inactive ingredients with possible adverse events

Purpose and known adverse events of inactive toothpaste ingredients

Type of ingredient

Ingredient

Purpose

Known adverse event

Sweeteners

sodium saccharin

artificial sweetener1

mixed findings; considered safe for consumption,1 but new research states that it contributes to enamel demineralization2

Stevia rebaudiana (leaf) extract

bio-sweetener,3 antioxidant activity4

not reported

sorbitol

substitute for sugar used as a sweetening agent1

reported to cause abdominal discomfort5

Flavorings

flavoring agent

functions as a flavoring agent6

has been shown to cause allergic reactions,
such as inflammation of the mouth and lips and gingivitis6

menthol

functions as a flavoring and scent for a toothpaste7

no known contamination risks7

Commiphora myrrha resin extract

functions as a flavoring and scent for toothpaste and a natural anti-septic

no known contamination risks8

Natural colorants

CI 75810 (natural green (chlorophyll))

natural green pigment

no known contamination risks9

CI 77268:1 (Carbo vegetabilis)

cosmetic colorant

not reported

CI 75470 (natural red)

cosmetic colorant

not reported

Fragrances

limonene

flavor and fragrance additive,10 derived from Citrus aurantiifolia oil

generally recognized as safe; case reports on irritant effect on eyes, nose, throat and skin; also, found to cause kidney damage in rats, but similar results were not found in humans7

cinnamaldehyde

flavor and fragrance additive

strong evidence: human immune system toxicant or allergen; not suspected to be bio-accumulative11

linalool

flavor and fragrance additive

skin, eye and respiratory tract irritant;
not suspected to be bio-accumulative11

eugenol

flavor and fragrance additive

classified as safe12

citral

derived from Citrusaurantiifolia oil flavor and fragrance additive

no known contamination risks

geraniol

flavor and fragrance additive

dangerous in case of ingestion and inhalation; marginally hazardous in case of skin contact (permeator), skin and eye irritant11

citronella

flavor and fragrance additive

hazardous in case of ingestion; skin and eye irritant

coumarin

flavor and fragrance additive

extremely hazardous in case of ingestion and inhalation;
skin and eye irritant; severe overexposure can result in death; potential chronic carcinogenic effects (classified 2B, possible for humans according to the standard IARC classification)13

Table 3. Classification of ingredients

Ingredients

n

Safe
n (%)

With AEs
n (%)

Active

fluorides

2

1 (50)

1 (50)

emulsifiers

19

12 (63.15)

7 (36.85)

emollients

4

4 (100)

0

buffering agents

4

1 (25)

3 (75)

preserving agents

6

0

6 (100)

thickening agents

3

0

3 (100)

abrasives

4

3 (75)

1 (25)

whitening/plaque removal agents

7

2 (28.6)

5 (72.4)

wetting agents

4

3 (75)

1 (25)

solvents

3

3 (100)

0

absorbents

4

4 (100)

0

antibacterials

5

5 (100)

0

active plant/herbal extracts

74

71 (96)

3 (4)

total

139

109 (78.4)

30 (21.6)

Inactive

sweeteners

3

1 (33.3)

2 (66.7)

natural colorants

3

3 (100)

0

flavorings

3

2 (66.7)

1 (33.3)

fragrances

8

2 (25)

6 (75)

total

17

8 (47)

9 (53)

AEs – adverse events.

References (38)

  1. FDI World Dental Federation. Sustainability in Dentistry. https://www.fdiworlddental.org/sustainability-dentistry. Accessed September 10, 2021.
  2. General Assembly of the United Nations. Resolution Adopted by the General Assembly on 25 September 2015. Agenda items 15 and 116. http://unctad.org/meetings/en/SessionalDocuments/ares70d1_en.pdf. Accessed September 10, 2021.
  3. Sukhdev P, Stone S, Nuttall N. Green Economy: Developing Countries Success Stories. United Nations Environment Programme; 2010:1–15. http://www.indiaenvironmentportal.org.in/files/GreenEconomy_SuccessStories.pdf. Accessed September 10, 2021.
  4. Mazur M, Ndokaj A, Jedlinski M, et al. How dentistry is impacting the environment. Senses Sci. 2019;6(4):922–928. doi:10.14616/sands-2019-6-922928
  5. Lippert F. An introduction to toothpaste – its purpose, history and ingredients. Monogr Oral Sci. 2013;23:1–14. doi:10.1159/000350456
  6. Grand View Research. Organic Personal Care Market Size, Share & Trends Analysis Report by Product (Skin Care, Hair Care, Oral Care, Cosmetics), by Region (North America, Europe, Asia Pacific, CSA, MEA) and Segment Forecast, 2018–2025. https://www.grandviewresearch.com/industry-analysis/organic-personal-care-market. Accessed February 27, 2019.
  7. McKay A. Organic toothpaste. Br Dent J. 2012;212(5):206. doi:10.1038/sj.bdj.2012.180
  8. Basch CH, Kernan WD. Ingredients in children’s fluoridated toothpaste: A literature review. Glob J Health Sci. 2016;9(3):1. doi:10.5539/gjhs.v9n3p1
  9. Joint FAO/WHO Expert Committee on Food Safety. Evaluation of Certain Food Additives and Contaminants. Geneva, Switzerland: WHO; 2011;7:227. https://apps.who.int/iris/handle/10665/44515. Accessed September 6, 2021.
  10. Fruijtier-Pölloth C. Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products. Toxicology. 2005;214(1–2):1–38. doi:10.1016/j.tox.2005.06.001
  11. Brown RS, Smith L, Glascoe AL. Inflammatory reaction of the anterior dorsal tongue presumably to sodium lauryl sulfate within toothpastes: A triple case report. Oral Surg Oral Med Oral Pathol Oral Radiol. 2018;125(2):e17–e21. doi:10.1016/j.oooo.2017.11.017
  12. Zirwas MJ, Otto S. Toothpaste allergy diagnosis and management. J Clin Aesthet Dermatol. 2010;3(5):42–47. PMID:20725569.
  13. Van Baelen A, Kerre S, Goossens A. Allergic contact cheilitis and hand dermatitis caused by a toothpaste. Contact Dermatitis. 2016;74(3):187–189. doi:10.1111/cod.12505
  14. Bruno M, Taddeo F, Medeiros IS, et al. Relationship between toothpastes properties and patient-reported discomfort: Crossover study. Clin Oral Investig. 2016;20(3):485–494. doi:10.1007/s00784-015-1539-8
  15. Green A, Crichard S, Ling-Mountford N, et al. A randomised clinical study comparing the effect of Steareth 30 and SLS containing toothpastes on oral epithelial integrity (desquamation). J Dent. 2019;80 Suppl 1:S33–S39. doi:10.1016/j.jdent.2018.11.005
  16. Tadin A, Gavic L, Zeravica A, Ugrin K, Galic N, Zeljezic D. Assessment of cytotoxic and genotoxic effects of conventional and whitening kinds of toothpaste on oral mucosa cells. Acta Odontol Scand. 2018;76(1):64–70. doi:10.1080/00016357.2017.1384567
  17. Cvikl B, Lussi A, Moritz A, Gruber R. Dentifrices for children differentially affect cell viability in vitro. Clin Oral Investig. 2017;21(1):453–461. doi:10.1007/s00784-016-1813-4
  18. Ghapanchi J, Kamali F, Moattari A, et al. In vitro comparison of cytotoxic and antibacterial effects of 16 commercial toothpastes. J Int Oral Health. 2015;7(3):39–43. PMID:25878477.
  19. Kobylewski, S, Jacobson MF. Food Dyes: A Rainbow of Risks. Washington, USA: Center for Science in the Public Interest; 2010. https://cspinet.org/sites/default/files/attachment/food-dyes-rainbow-of-risks.pdf. Accessed August 27, 2021.
  20. Science Labs. Material safety data sheet. https://esciencelabs.com/educators/msds. Accessed August 27, 2021.
  21. National Institute of Environmental Health Sciences. D&C Red No. 27/D&C Red No. 28. http://ntp.niehs.nih.gov/ntp/htdocs/Chem_Background/ExSumPdf/RedDyes_508.pdf. Accessed August 27, 2021.
  22. Schnuch A, Lessmann H, Geier J, Uter W. Is cocamidopropyl betaine a contact allergen? Analysis of network data and short review of the literature. Contact Dermatitis. 2011;64(4):203–211. doi:10.1111/j.1600-0536.2010.01863.x
  23. Jacob SE, Amini S. Cocamidopropyl betaine. Dermatitis. 2008;19(3):157–160. PMID:18627690.
  24. Fitch C, Keim KS; Academy of Nutrition and Dietetics. Position of the Academy of Nutrition and Dietetics: Use of nutritive and nonnutritive sweeteners. J Acad Nutr Diet. 2012;112(5):739–758. doi:10.1016/j.jand.2012.03.009
  25. Giacaman RA, Campos P, Muñoz-Sandoval C, Castro RJ. Cariogenic potential of commercial sweeteners in an experimental biofilm caries model on enamel. Arch Oral Biol. 2013;58(9):1116–1122. doi:10.1016/j.archoralbio.2013.03.005
  26. Fernández-Bañares F, Esteve M, Viver JM. Fructose-sorbitol malabsorption. Curr Gastroenterol Rep. 2009;11(5):368–374. doi:10.1007/s11894-009-0056-9
  27. de Cock P, Mäkinen K, Honkala E, Saag M, Kennepohl E, Eapen A. Erythritol is more effective than xylitol and sorbitol in managing oral health endpoints. Int J Dent. 2016;2016:9868421. doi:10.1155/2016/9868421
  28. Munro IC, Bernt WO, Borzelleca JF, et al. Erythritol: An interpretive summary of biochemical, metabolic, toxicological and clinical data. Food Chem Toxicol. 1998;36(12):1139–1174. doi:10.1016/s0278-6915(98)00091-x
  29. O’Donnell K, Kearsley M, eds. Sweeteners and Sugar Alternatives in Food Technology. 2nd ed. Oxford, UK: Wiley-Blackwell; 2012.
  30. Ethier AA, Muckle G, Bastien C, et al. Effects of environmental contaminant exposure on visual brain development: A prospective electrophysiological study in school-aged children. Neurotoxicology. 2012;33(5):1075–1085. doi:10.1016/j.neuro.2012.05.010
  31. American Dental Association. Toothpaste. https://www.ada.org/resources/research/science-and-research-institute/oral-health-topics/toothpastes. Accessed September 10, 2021.
  32. Siebert AK, Obeid R, Weder S, et al. Vitamin B-12-fortified toothpaste improves vitamin status in vegans: A 12-wk randomized placebo-controlled study. Am J Clin Nutr. 2017;105(3):618–625. doi:10.3945/ajcn.116.141978
  33. Bijle MNA, Ekambaram M, Lo EC, Yiu CKY. The combined enamel remineralization potential of arginine and fluoride toothpaste. J Dent. 2018;76:75–82. doi:10.1016/j.jdent.2018.06.009
  34. Mazur M, Ndokaj A, Jedlinski M, Ardan R, Bietolini S, Ottolenghi L. Impact of green tea (Camellia Sinensis) on periodontitis and caries: Systematic review and meta-analysis. Jpn Dent Sci Rev. 2021;57:1–11. doi:10.1016/j.jdsr.2020.11.003
  35. Nardi GM, Cesarano F, Papa G, et al. Evaluation of salivary matrix metalloproteinase (MMP-8) in periodontal patients undergoing non-surgical periodontal therapy and mouthwash based on ozonated olive oil: A randomized clinical trial. Int J Environ Res Public Health. 2020;17(18):6619. doi:10.3390/ijerph17186619
  36. Jaroń A, Jedliński M, Grzywacz E, Mazur M, Trybek G. Kinesiology taping as an innovative measure against post-operative complications after third molar extraction – systematic review. J Clin Med. 2020;9(12):3988. doi:10.3390/jcm9123988
  37. Askar H, Krois J, Rohrer C, et al. Detecting white spot lesions on dental photography using deep learning: A pilot study. J Dent. 2021;107:103615. doi:10.1016/j.jdent.2021.103615
  38. Trybek G, Jedliński M, Jaroń A, Preuss O, Mazur M, Grzywacz A. Impact of lactoferrin on bone regenerative processes and its possible implementation in oral surgery – a systematic review of novel studies with metanalysis and metaregression. BMC Oral Health. 2020;20(1):232. doi:10.1186/s12903-020-01211-6