1. INTRODUCTION
Salvadora persica (SP) is a wild plant that grows in the region extending from north western India to Africa. This plant is also known as natural Arak tree, chewing stick, toothbrush and Meswak [1]. Some other applications have been reported for this plant. SP is used for controlling blood sugar level, splenic disorders, deep wounds, and gingival and gastric problems. The extract of the plant boiled in oil is an appropriate ointment for treatment of crush injuries. Its leaves, branches and roots contain a kind of oil with diuretic effects. Its bark is used against stings of poisonous animals and its branches are used for treatment of cough, asthma, scurvy, rheumatism, leprosy, gonorrhea, headache, hepatic problems and various other disorders. Its boiled extract has shown protective effects against ethanol intoxication and stressrelated peptic ulcer in rats and regulating effects on blood sugar levels as well. This plant contains such chemicals as trimethyl amine, organic sulfur compounds and B-sitosterol and small amounts of saponin and lignane glycosides.
Dental plaques are the leading cause of oral diseases and dental caries; so elimination or reduction of plaques is necessary for prevention of these diseases. This plant has been used in Saudi Arabia as a toothbrush since 1400 years ago [1]. It has anti-microbial, anti-inflammatory and hypoglycemic properties. Toothpastes containing the extract of this plant protect gums and teeth. The plant is also used for various other purposes [2]. Chewing sticks are traditionally used for cleaning the teeth [3,4]. Although new artificial toothbrushes are considerably used in Asian and African countries, chewing sticks are still used for cleaning the teeth [3,5]. The benefits of these sticks are due to their constituents and mechanism of action [6]. Recently WHO has proposed the use of these sticks as an effective tool for oral hygiene and their effect against certain aerobic and anaerobic bacteria has been studied [7].
Primary analysis of SP showed that it contains trimethyl amines, salvadorin, chloride, fluoride, silica, sulfur, mustard oil, vitamin C, resin and small amounts of tannin and saponine. These ingredients have antibacterial and anti-febrile properties and protect gums against irritation. Fluoride has anti-caries properties; Silica is abrasive and removes plaques and stains, and mustard oil and sulfur show anti-bacterial effects. In addition, the resin creates a protective layer on the surface of the enamel and tannin has a contractive effect on the mucous membranes thus inhibits the transfer of glycosyl. Some chewing sticks contain such alkaline compounds as anthraquinones (Acacia Arabica), fagaronine and benzophenathridine with anti-bacterial properties [8,9].
Recent in vitro studies on the microbiological effects of Miswak on oral bacteria have shown that its raw extract has a bacteriostatic effect on Bacteriodes Gingivalis. Other studies regarding its chemical compounds and pharmaceutical effects have proved that the high fluoride content in Miswak is responsible for its strong anti-caries effect [10,11].
Many researchers have paid attention to the mechanical cleaning effect of Miswak stick and the anti-microbial activity of its extract. The mechanical cleaning effects of the chewing sticks have been reported as the mechanism of the reduction of plaques and gum inflammation [12].
Nowadays, although more attention is paid to oral and dental hygiene all over the world, the frequency of dental caries and periodontal diseases is increasing which is probably due to increased consumption of carbohydrates, and deficiency of fluoride and calcium in diet and improper oral hygiene [12,13].
Natural toothbrush that was initially proposed by the Holly Prophet, Hazrat Mohammad (SAW), for cleaning and strengthening of teeth and prevention of dental caries more than 1400 years ago is now used in many countries and the significant effects of brushing for prevention of dental caries and oral diseases have been determined. The anti-bacterial, and anti-fungal effects of this natural product and its effect against caries, and plaque formation have been studied and it is proposed that these effects are due to both mechanical and chemical effects [12,14].
Studies have shown that 90% of rural population of Nigeria and Tanzania (10% of urban children), 50% of Saudi Arabians and Indians (65% rural and 43% urban population) use Miswak [15-17].
These sticks are effective, inexpensive, abundant, and available and have both mechanical and chemical effects. In the study by Khalid Almas, two types of Miswak sticks were studied and their anti-bacterial effect on streptococcus mutans and fecalis was significant [18].
In the present study, the effects of Miswak on oral and dental hygiene, DMF (decayed, missed, filled), and prevention of caries and dental plaque was studied and compared with common toothpastes and toothbrushes.
2. METHODS
This was a semi-experimental clinical trial which was conducted by parallel plan. In a 1 year period (from March 2010 till March 2011) subjects referred to dentistry clinics of health centers in Shahid Sadoughi University of Medical Sciences, Yazd, Iran with following criteria entered the study: Age between 18 and 50 years, living in Yazd, and having at least 20 permanent teeth. Smokers, orthodontic patients, and those with dental anomalies or acute periodontal disease were excluded from the study.
A total of 12 health centers were randomly selected and divided into 3 groups (4 clinics in each group). The groups were randomly assigned to one of the methods of tooth brushing. The methods included: group 1: natural toothbrush (Salvadora persica), group 2: artificial toothbrush and toothpaste, and group 3: both artificial and natural toothbrush.
One hundred and thirty cases in each group were included in the study. Then a questionnaire including name, home address and telephone number for follow up, demographic features, and state of teeth before intervention was filled for each participant. All subjects were similarly trained for oral and dental health and care. Miswak toothbrush (Figure 1) was given to the natural toothbrush group and they were trained for its use. The second group received artificial toothbrush and toothpaste and was trained for its use, while the third group received both natural and artificial toothbrush and toothpaste. All participants were asked to brush their teeth 3 times a day and to refer every three months until 1 year and the state of their oral and dental care was recorded. The subjects in the third group were asked to brush their teeth two times with one method and one time with another and change this arrangement every other day. They were provided by new toothpaste and toothbrushes as necessary in each visit. At the end of one year, the plaque index and number of decayed, filled and extracted teeth (due to caries) was evaluated.
The manager of the dentistry clinic and a dentist in each center attended a 2-day workshop about the method of teaching tooth brushing with SP at the deputy of health
of the university. They were also trained how to determine the plaque index and state of tooth caries. On the basis of standard references of reconstructive dentistry, tooth caries was classified into 6 caries levels (CL):
CL I: Occlusal surface of the posterior teeth, palatal surface of the anterior teeth, and buccal and lingual surfaces of the upper contour of the teeth.
CL II: Mesial and distal surfaces of the posterior teeth.
CL III: Mesial and distal surfaces of the anterior teeth, incisal border not involved.
CL IV: Mesial and distal surfaces of the anterior teeth with involvement of the incisal border.
CL V: Buccal and lingual surfaces in the one third of gingival area.
CL VI: Tip of cusp.
Plaque index was graded 0 - 3 as follows:
0: Plaque not visible and not observed even on rubbing the probe.
1: Plaque not visible but observed after rubbing the probe or using the tablet.
2: Plaque visible and observed after rubbing the probe against the gum margins as well.
3: Plaque visible and covering the dental margins and even extending to the teeth surface.
The data was analyzed by SPSS (ver. 17) using ANOVA, Kruskall Wallis, paired—t-test, chi square, Fisher exact and Mc-Nemar tests. LSD method was used for double comparisons.
No expenses were incurred upon the cases and they were explained in detail about the study at the beginning. After explaining the research protocol, an informed consent was obtained from each subject. The proposal of this study was approved by the ethics committee of Shahid Sadoughi University of Medical Sciences.
3. RESULTS
A total of 390 subjects were divided into 3 groups: natural toothbrush (Salvadora persica), artificial toothbrush and toothpaste and both methods. Ultimately, 35 subjects failed to continue to the end and 355 cases were evaluated.
The mean age of the population under study was 28.98 ± 6.08 years (range: 18 - 50 years). The mean age was not significantly different among 3 groups (ANOVA test, P value = 0.435). Ninety eight (27.6%) and 253 (72.4%) subjects were males and females, respectively. This ratio was not significantly different among three groups (Chi square test, P value = 0.083). On follow-up evaluations, the mean number of tooth brushings increased from 1.11 to 1.54 times per day and the use of dental floss increased from 26.8% at the beginning of the study to 36.6% at the end of the study. The mean decrease in the plaque index was 0.71 degrees in all subjects.
Table 1 compares the educational state of subjects in 3 groups. Educational state was not significantly different among 3 groups (P value = 0.256).