Role of Salvadora persica chewing stick (miswak): A natural toothbrush for holistic oral health.

From an ancient tool to a modern way of improving oral health, miswak (chewing stick) has proven to be an effective tool for oral health. The miswak removes the bacterial plaque by mechanical and chemical actions. It provides a cheap and easily accessible way of improving oral health of the individuals and populations. The use of miswak was promoted centuries ago by Prophet Muhammad (Peace be Upon Him). In the modern era, the beneficial role of using miswak such as antiseptic, antimicrobial, anticariogenic and analgesic effects have been proven scientifically. This article reviews the various oral health benefits of miswak in the light of religious, scientific and social evidences.

INTRODUCTION

Different oral hygiene methods have been used to overcome widely endemic diseases such as dental caries and oral infections. Due to Increasing awareness and expected evolving population; the use of safe, effective and economical products have expanded drastically. Both chemical and mechanical ways are being used in achieving good oral hygiene.[1] However; mechanical cleaning using the toothbrush plays the most vital role. The advancement of the modern tooth brushes can be traced back to chewing sticks used by the Babylonians (the Greek and Romans) 7000 years ago.[2] The use of miswak becomes very popular in the Muslim world including several African and Arab countries. It is widely known as the chewing stick or natural tooth brush and holds great importance for oral hygiene and has also been recommended by the World Health Organization.[3]

Miswak is an Arabic word in origin that describes the chewing stick prepared from the root, stem, twigs or bark of a tree and used for cleaning the oral cavity. Conventionally, it is a 15–20 cm long penciled stick [Figure 1] holding a diameter of 1–1.5 cm.[45] For an affective functioning, it is supposed to be frayed into brush by the act of chewing. In addition to removing the bacterial plaque mechanically, it prevents the growth of oral microbes and dental plaque.[6] Similarly, it possesses the antimicrobial property that ceases the process of tooth decay and inhibiting the growth capability of several cariogenic microorganisms. Considering the therapeutic benefits, miswak is commonly being used by populations of many developing countries. It is also helpful to counteract an increased level of resistance developed by pathogenic microorganisms to commercially available antimicrobial drugs being advised in every community.[7] A number of manufacturers have used the extracts of miswak as an active toothpaste component. A few examples are Sarkan toothpaste (UK), QualiMeswak toothpaste (Switzerland) Epident toothpaste (Egypt), Siwak-F toothpaste (Indonesia) and various herbal mouthwashes. A typical miswak stick is shown in Figure 1.

Figure 1

Types of chewing sticks used as an oral hygiene aids

The most commonly used plant for miswak is Salvadora persica.[891011] Antimicrobial extracts are obtained from different parts of S. persica. It has been proven scientifically that these extracts are equally effective compared to the efficacy of oral disinfectants including chlorohexidine gluconate. Chlorohexidine gluconate has antifungal, antiplasmodial and antibacterial effects when used at an optimal concentration.[1213] S. persica as a root canal irrigant has better antimicrobial properties when compared to chlorhexidine gluconate and sodium hypochlorite.[81011]

RELIGIOUS ASPECTS

The use of miswak dates back to ancient times however its importance was highlighted by Prophet Muhammad (Peace be Upon Him [PBUH]) during the early days of Islam. The religion Islam has stressed on the importance of maintaining good overall body as well as oral hygiene. It has been advised to the followers to keep in practice the use of chewing stick (miswak) for keeping the oral cavity clean and minimizing halitosis. The Prophet Muhammad (PBUH) preached Islam not just by his words but also through his actions by showing and observing practically. The sayings of the Holy Prophet Muhammad PBUH described and stressed on the importance of various plant species amongst which miswak tops the list.[14] Following are some hadiths in which The Prophet Muhammad (PBUH) emphasized on the use of Miswak; Jabbir Bin Abdullah (RA) relates that prophet Muhammad (PBUH) said “The black colored Kapas (fruit of Salvadora) is the finest one.”[15] Hazrat Aaisha (RA) narrates that Muhammad (PBUH) said “Miswak purifies the mouth and is a cause of Allah's pleasure.”[15] Furthermore, Abu-Hizat-us-Sabahi (RA) described that Muhammad (PBUH) gave him a twig of Salvadora and said, “Use it as miswak.”[14]

TYPES OF CHEWING STICKS

There are more than 180 plant species that can be used as a natural toothbrush. These species differ from each other on the basis of appearance, scent, texture and taste. Some of the most commonly practiced species are S. persica (Peelu), Azadirachta indica (Neem), Olea europaea (Zaitoon), Acacia arabica (Kikar), Glycosmis pentaphylla (Ban), Capparis aphylla (Khiran).[16] Most of these sticks are easily available in different parts of Pakistan, Middle East and African countries. Arak (S. persica) is the most commonly used miswak in Saudi Arabia while litmus and orange tree are common in West Africa.[817]S. persica obtained from Arak tree is the most popular having spongy characteristics and stem that can easily be crushed between teeth. The stick is widely accepted by people around the world due to its pleasant flavor, texture and its effectiveness in maintaining oral hygiene.[81819]

HOW TO USE MISWAK EFFECTIVELY?

Miswak has its own unique aspects that must be adapted prior to use for the best results. The functional end of a thin bark piece is striped off followed by chewing. Chewing of miswak separates fibers and giving it a brush like appearance that helps in cleaning the teeth easily. The recommended length for a stick is about 15 cm so that it can easily be grasped along with ease to carry around, whereas, the diameter is preferred to be <1 cm.[6]

There are two methods documented to hold the miswak. One is the three finger grip technique and the other is five finger grip technique [Figure 2a]. The aim of both techniques is to make sure that all surfaces of the teeth are accessible and cleaned with convenience and controlled movements of the stick in the oral cavity. In order to clean the tooth surfaces, the fibers of miswak should be held perpendicular to the tooth surface and gently moved in up and down motions, directed away from the gingival margins on both the buccal and lingual surfaces [Figure 2b][2021]

Figure 2

Manipulation of miswak for oral hygiene maintenance, (a) Palm grip for holding, (b) schematic presentation of various steps for using miswak

THERAPEUTIC EFFECTS OF MISWAK ON ORAL AND GENERAL HEALTH

Chemistry of miswak

Different evidences and researchers have suggested that miswak contains more than 10 natural occurring constituents essential for maintaining good oral and general health [Table 1]. S. persica (miswak) has a number of numerous oral health benefits. Upon chewing, it releases antibacterial extracts and improves primary and secondary dental development.[26]

Table 1

Chemical analysis of various components of miswak (Salvadora persica)

Table 2 demonstrates different therapeutic effects of miswak on the oral cavity. Its antimicrobial action lowers the proportion of oral candidiasis in patients with renal transplant. The antiplasmodial content in miswak is used to treat malaria and the seed oil is used for the treatment of joints and skin diseases.[3839] Use of miswak is also found to regulate peristaltic movements, lowers high-density lipoprotein cholesterol and improves appetite.[2734]

Table 2

Beneficial role of various chemicals present in miswak (Salvadora persica)

TOOTHPASTE AND MOUTHWASH

The utmost and primary method of plaque removal and to maintain good oral hygiene is to remove plaque mechanically using brushing and flossing.[4041] A variety of S. persica toothpastes are readily available in the market, i.e., Dentacare Miswak (Saudi Arabia) and Fluorosiwak (Pakistan) and have proved a high efficacy in bacterial plaque removal. Further, S. persica mouthwashes have found to be effective to inhibit the colonization of Streptococcus mutans bacterial strains on orthodontic rings. Lower plaque formation has been reported on tooth surfaces after using miswak mouthwashes. Unfortunately, no commercial availability of miswak mouth wash exists in the market at present.[4243]

ANALGESIC EFFECTS

Miswak has analgesic, astringent and anti-inflammatory properties, making it an effective treatment for primary periodontal diseases.[2044] Evidences suggested miswak being affective against thermal stimuli compared to chemical ones. Focusing on the physiology, the responses of the thermal stimuli are via skin pain receptors whereas the chemical stimulus has its response via the visceral receptors. Thus it was found that miswak responds to the peripheral pain and not the visceral. Hence, if applied to the oral mucosa it sets a relief in the oral pain.[4546] Experiments on mice in a laboratory proved miswak has a moderate analgesic effect that is related to interaction with the peripheral opiate system.[47] In addition, it has been noted that patients practicing miswak regularly had a low incidence of toothache compared to toothbrush users.[2]

ANTIPLAQUE EFFECTS

The main cause of gingivitis and other periodontal conditions is the accumulation of bacterial plaque; hence it is of great importance to avoid plaque accumulation and maintaining good oral hygiene. Miswak is practiced by rubbing it on the surface of the teeth and thus is an effective mechanical tool for reducing the level of daily plaque accumulation.[48] Numerous studies have identified that silica in miswak possesses plaque inhibiting properties, plays vital role in caries prevention and helps maintaining normal pH after acidogenic attacks chemically.[54950] The presence of calcium and chlorides in miswak inhibit the bacterial attachment on to the enamel surface hence providing a protective medium.[33] In addition, miswak has an ability to remove plaque from the interproximal sites as well. This is due to better mechanical cleaning action of its fibers compared to fibers of conventional synthetic toothbrushes.[63351]

CYTOTOXICITY AND ROOT CANAL IRRIGATION

Irrigation is considered to be of prime importance in root canal therapy as it aids in flushing, debridement, cleaning and dissolution of necrotic tissues in the root canal. Miswak, besides being used in practices such as (mouthwashes and toothpastes), is also used as a root canal irrigant. Recent studies and evidences have suggested that S. persica has good antimicrobial activity with a low level of cytotoxicity and causing no significant damage to the host cells at an optimal therapeutic concentration.[3550]S. persica (15%) exhibited an effective antimicrobial activity against aerobic and an-aerobic organisms. Further, a recent study by Almas compared cytotoxicity of chlorhexidine gluconate and miswak extracts on mouse fibroblasts. The miswak extracts was less cytotoxic and cells viability with miswak extracts was greater than chlorhexidine gluconate.[8] These evidences altogether supported the idea of using miswak extracts as an endodontic irrigation solution.[10] Further research is required to evaluate the cytotoxic effects of miswak extracts and chlorhexidine on macrophages, epithelial cells and osteoblasts

ANTIMICROBIAL ACTIVITY

Miswak has been endowed with the property of ceasing growth potential of bacteria causing periodontal disease and dental caries. The antimicrobial effects of miswak is more pronounced against Enterococcus faecalis, Porphyromonas gingivalis, Actinobacillus, Haemophilus influenza, S. mutans and limited against Lactobacillus.[50] Furthermore, extracts obtained from the root of miswak have better antimicrobial property compared to miswak from other parts of the tree.[47] The incidence of caries is notably low in miswak users owing to the presence of a strong antimicrobial thiocyanate agent, accompanied by other chemicals such as sodium chloride, potassium chloride, saponin, tanins.[1252] The extracts of miswak showed significant reduction in the growth of cariogenic bacteria.[53] The miswak soaked in 0.1–0.5% NaF solutions help to reduce the cariogenic bacterial count and dental decay.[1252] Fluoride is well known for antimicrobial activates in the oral cavity.[5455]

ACCUMULATIVE HEALTH BENEFITS OF MISWAK ON PERIODONTAL TISSUES

The main etiological factor for gingival recession and bone loss is bacterial plaque. The calcified mass deposits are mechanical irritants and act as potential retentive areas for the accumulation of bacterial plaque.[56] The frequent use of miswak helps in reduction of plaque accumulation thus leading to a better oral hygiene. According to a study conducted in Kenya, miswak users (50 or over) had a very low incidence of periodontal diseases.[2] Active miswak users reported better periodontal health, less gingival bleeding and interproximal bone loss compared to toothbrush users. Comparatively reduced gingival bleeding and low gingival indices score were observed in miswak users.[57] Similar results were reported in a randomize control trials conducted by Al-Otaibi et al. A significant reduction in plaque score, gingival inflammation and bleeding of gums was observed in miswak users. Further, less tooth loss cases were reported in subjects who used miswak.[52] Periodontal pathologies such as gingival recession, tooth wear and severe periodontal pockets have been reported in miswak users however, it may be due to excessive use of miswak, faulty technique or due to other etiological factors.[445859]

ANTIFUNGAL EFFECTS

Recent studies have endorsed the fact that S. persica has antifungal properties.[60] Recently, Alili et al. compared antifungal property of solid miswak with grounded miswak particles against different strains of Candida. It was concluded that solid miswak exhibited strong antifungal property while pulverized miswak presented no antifungal property.[6061] Similarly, an in vitro study by Naeini et al. explored that alcoholic extracts of S. persica showed antifungal properties against all strains of Candida except Candida parapsilosis and Candida krusei.[6062] Furthermore, the hexane components in the roots of miswak was found robust against Candida albicans and E. faecalis.[63]

ANTIOXIDANT EFFECTS

Antioxidants are substances that shield the body against free radical induced oxidative stress. Current literature has proved antioxidant properties are present in the miswak. A study by Mohamed and Khan concluded that antioxidant enzymes in miswak (catalase, peroxidase, polyphenols oxidase) attribute to antioxidant property of S. persica. Thus, synergistic effect of antioxidant compounds and enzymes makes miswak a good oral hygiene maintaining tool.[64] Another study by Ibrahim et al.[65] showed that antioxidant property, content of flavonoid and phenolic was more in miswak from southern region compared to the central region of Saudi Arabia. Gupta et al. performed antioxidant and phytochemical study on S. persica and reported that the chloroform extract from miswak showed most antioxidant effect in vitro followed by ethanolic extract.[66] Based on all these findings and evidence it can be positively inferred that S. persica is a potential source of antioxidant compound and can be used in medicinal preparation to tackle oxidative stress related disorders.[6567]

SALVADORA PERSICAAS A POTENTIAL FOOD BIO PRESERVATIVE

In recent years, customers have developed extra awareness regarding processed foods. Synthetic preservatives in canned and processed foods may lead to hazardous health effects.[67] Since the roots of S. persica contain antimicrobial, antifungal and antioxidant properties, it can be used as a potential food preservative with no side effects. A recent study by Zaid et al.[68] concluded that adding aqueous extract of S. persica as a natural food preservative in chicken burgers improved the shelf life. The aqueous extract showed the strongest inhibitory effects against (Streptococcus mitis, Streptococcus salivarius, S. mutans, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhimurium, and C. albicans) after 48 h. Based on these results S. persica can be recommended as a safe and economical natural food and pharmaceutical preservative[68] however further research is needed on this aspect.

MISWAK VERSUS TOOTH BRUSHES FOR DENTAL CARE

Is using miswak as effective as the tooth brush? It is a very common question and discussed frequently among health professionals and general public. Miswak and tooth brush both serve the same function, i.e. maintenance of good oral hygiene but both these oral hygiene tools vary in certain aspects [Table 3].

Table 3

Salient difference between miswak and toothbrush

A recent study by Malik et al. proposed that miswak (S. persica) has comparable or at times greater chemical and mechanical capability in plaque removal.[76] On the basis of the conclusion of this study, advocacy should be planned for miswak promotion as oral hygiene tool replacing nylon filament tooth brushes in developing countries where there exist economic restrains, high unmet needs and restricted dental care for general public.[76]

SALVADORA PERSICAAND CULTURAL IMPLICATIONS IN PROMOTING ORAL HEALTH

Factors such as needs, customs and traditions along with cultural diversity and variations amongst public constrains, dental care professionals have to gain and develop patient trust along with providing dental care with efficacy. Similarly, in case of miswak (S. persica), where dental care providers need to overcome these barriers and must educate along with implication of miswak use amongst patients for better oral health and thus maximizing plaque removal.[77] Farsi et al. assessed the behavior, attitude and knowledge in relation to periodontal health status in school going pupils. It was revealed that private school going pupils were more inclined towards the use of tooth brushes whereas governmental school going students used miswak as a main tool for maintaining oral health.[78] Another study by Wagner and Redford-Badwal identified low cultural knowledge among dental graduates.[79]

To overcome this cultural barrier it is recommended to train dental care providers who are culturally and linguistically competent, well versed in cultural practices, mature and sensitive enough to understand practices, traditions and beliefs of different cultures.[77] Building an instructive framework which is acceptable by dental care professionals based on the expectations of rural communities ingrained in cultural and religious foundations will assist in reducing oral disparities and inequalities. Miswak aids as a model to instruct culturally insensitive dental care providers worldwide.[77]

Limitation of miswak

Although miswak (S. persica) is considered as an inexpensive, cheap and affordable method of maintaining good oral as well as general health, however there are a few limitations. Fibers of miswak are present in long axis making it difficult for the users to access the lingual surfaces of tooth.[20] Hollist and Khoory claimed that excessive scrubbing of miswak on the anterior teeth by permanent miswak users compromised the aesthetic zone and resulted in severe attrition of the anterior teeth.[8081] Eid et al.[58] claimed miswak as one of the etiology of gingival recession[58] as a relatively high incidence of gingival recession has been linked to miswak users compared to toothbrush users.[45] It has been demonstrated that freshly cut miswak has no cytotoxic effect on oral health. But same miswak used after 24 h contained toxins harmful for the oral and general health.[36] All the above mentioned limitations can easily be overcome by understanding and adapting the proper technique and method of use of miswak as it is a technique sensitive oral hygiene tool.[4] A dried out miswak can be extra hard and abrasive to oral tissues that may result in an excessive wear and damage to the teeth. Oral hygiene instructions should be given for using freshly cut miswak that is flexible, easily chewable and full of natural ingredients. Any damages such as gingival recession, tooth wear and severe periodontal pockets in miswak users are mainly linked to aggressive, excessive and improper use of miswak,[445859] hence can be controlled by educating patients for using proper technique carefully.

CONCLUSIONS

Evidence suggests that S. persica is a miraculous stick for oral health care along with being a cost-effective solution to improve and maintain good dental care. In certain developing countries where use of toothbrush is still considered expensive, miswak is an ideal alternative oral hygiene tool. Its recommendation is also dependable with the notion of the primary healthcare approaches that focus on prevention, community participation, and the use of appropriate technology. Due to its enormous medicinal and therapeutic properties, it is highly commended in oral care but being technique sensitive its method of use and handling must first be adapted for best results. It is permitted to use toothbrush in combination with miswak for superior oral hygiene and more possibilities should be explored to use miswak extracts in mouthwash and root canal irrigants.

It is hoped that the review would help general dental and medical professionals to know about the scientific, cultural and religious importance of miswak use in various populations. It would also help to improve not only the quality of oral health but also the quality of life of populace. Further research is needed for unwarranted oral health care products containing miswak extracts or powders, available in markets, claiming clinical efficacy of those products.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest