Effectiveness of Salvadora Persica Miswak in Improving Plaque Control and Gingival Health

Dental plaque is a main etiologic agent in periodontal disease. Global of Burden Disease Study 2016 ranked periodontal disease as the 11th most prevalent disease affecting 10.5% population worldwide. Tooth brushing is a reliable mechanical means to control dental plaque accumulation in order to maintain oral health. For decades, studies have demonstrated the efficiency of unprocessed Salvadora persica (miswak) chewing stick practice as an alternative to a standard toothbrush. Recently, a local Malaysian company has invented and successfully mass manufactured a world-first Salvadora persica toothbrush where its nylon bristles are primarily mixed with miswak powder and natural silica. With the benefits of Salvadora persica properties intact, it is also claimed to be effective without the application of toothpaste. However, the claim remains to be fully elucidated. There is also no randomized controlled trial available evaluating the efficacy of Salvadora persica toothbrush to date. Therefore, the aim of this study is to evaluate the effectiveness of the newly invented Salvadora persica toothbrush on oral health, particularly on anti-plaque and anti-gingivitis effects. The patient related-outcomes of Salvadora persica on a short-term use will also be assessed. The hypotheses of this study are that Salvadora persica toothbrush does not contribute to the significant effects on oral health and there is no difference in the use of Salvadora persica chewing stick, Salvadora persica toothbrush as well as the standard toothbrush on anti-plaque and anti-gingivitis in a standardized manner. Additionally, a hypothesis that there is no patient-related outcome of Salvadora persica on a short-term use has also been devised. A randomized, single blind, and parallel clinical study will be conducted over a five-week period involving the healthy non-dental students of the National University of Malaysia. This study consists of three groups of different oral hygiene tools: (i) Salvadora persica toothbrush; (ii) Salvadora persica chewing stick; and (iii) Standard toothbrush and toothpaste as control. The primary outcomes of this study are the clinical parameters that will be recorded at four different appointments. Salvadora persica toothbrush is expected to show positive effects to that of standard toothbrush with respect to plaque and gingivitis control. This study is thus designed to provide an insight on Salvadora persica toothbrush as a good preventive home care therapy.

The specific objectives of this clinical trial are to evaluate and compare the oral health status on gingivitis and plaque control in a standardised manner between Salvadora persica toothbrush and Salvadora persica chewing stick usage, to investigate the clinical efficiency of Salvadora persica toothbrush and Salvadora persica chewing stick on plaque removal in comparison with standard toothbrush, and to assess the patient-related outcome of Salvadora persica on a short-term use. A 20% drop out rate is to be expected.

Convenience sampling will be used in this study involving non-dental students of the National University of Malaysia Kuala Lumpur Campus. They are within the radius of the study site therefore are easy to obtain. Their manual dexterity and attitude towards oral health are the critical basis needed to maintain proper oral cleanliness, hence justified this non-probability sampling method selected.

The sample size calculation formula will be devised from a pilot study, which will primarily be conducted first involving five participants on each arm who are selected by a convenience sampling. The mean and standard deviation of two clinical parameters; Gingival Index and Plaque Index of the three groups assigned will be calculated. A confidence level of 95% with margin of error of 0.5 will be set to calculate the appropriate sample size for this study. The calculated sample size will be raised to the nearest 5 e.g. 23 will be increased to 25, to improve the validity of the study.

Prior to the participants' recruitment, the information sheet and the consent forms will be distributed. Enough time will be given for them to read and understand the study protocol before they agree to participate in this study. Those who give a consent to involve in the study will be enrolled as the participants. The principal investigator must ensure the participants understand the benefits and risks of the study. This information will be conveyed in an objective manner and any queries from the participants will be answered truthfully. The participants will have the right to refuse in participating in this study.

In this study, one principal examiner will be involved for the clinical evaluations. Prior to the initiation of the study, the examiner will be calibrated to measure the clinical parameters of periodontal attachment level, Plaque Index, and Gingival Index against another researcher who will act as a benchmark. For the assessment of intra-examiner reliability, these three clinical parameters will be recorded on five non-dental students who are not participating in this study, under the same circumstances with similar patient positioning, light positioning, and instruments. A weighted kappa score will be used to calculate the strength of agreement for both inter-examiner and intra-examiner reliability. An agreement is achieved when the values are \>0.8.

The clinical protocol will be conducted over a five-week period, with a total of 4 clinical appointments performed throughout the study. In appointment 1 (baseline period), all subjects will be undergoing a clinical examination prior to participating in the study. Subjects will also be interviewed using a structured questionnaire to assess their oral hygiene habits i.e. frequency and methods of toothbrushing, frequency of dental visits, as well as history of adjunct oral hygiene aid e.g. floss, and mouthwash. To ensure that all included subjects received the same standard of care, all participants will receive professional dental cleaning consisting of scaling and polishing during the first visit.

During appointment 2 (pre-intervention period), the proper technique of using the designated standard and the new miswak toothbrushes, as well as miswak chewing sticks will be explained both verbally and visually using models to each participant accordingly by another trained dentist who is blinded to the study protocol. In addition, all subjects received written instructions with coloured pictures demonstrating the modified bass technique for tooth brushing. Subjects who are selected to use miswak chewing stick will be given a sheet of written instructions demonstrating the proper preparation and preservation techniques of miswak chewing stick. It is very crucial that the participants are reminded to avoid using other means of cleaning devices, dentifrices, or adjuncts for the following three weeks of the study. Participants are also encouraged to seek for oral hygiene reinforcement wherever they feel the need to do so throughout the study period. At this visit, participants will also be asked to answer the pre-intervention S-OHIP questionnaires in front of an interviewer, which has also been validated both in English and Malay versions.

Appointment 3 is one-week post-intervention while appointment 4 will be three weeks post-intervention. In these visits, clinical examination will be carried out and assessment of any adverse effects of oral hygiene tools used will be taken. At final visit (appointment 4), participants will be asked to answer the post-intervention S-OHIP questionnaires in front of an interviewer.

Statistical analysis will be performed using the Statistical Package for Social Sciences (SPSS) version 26 (SPSS Inc., Chicago, IL, USA). For the primary outcomes measure, the values for Plaque Index and Gingival Index will be expressed as mean ± standard deviation. These parametric variables will be analysed using Kruskal-Wallis test to determine whether significant differences exist between the three independent groups from baseline to pre-intervention, and from pre-intervention to first and third week of analysis of post-intervention. Statistical significance will be set at the 95% confidence level (α=0.05) for hypothesis testing. Post-hoc tests for multiple comparison of significant mean differences between groups at specific time intervals will be performed with either Dunn-Bonferroni Test (less statistical powerful and conservative) or several Mann-Whitney U Test (inflation of Type I error), with the understanding of both test limitations. For the secondary outcome measures, frequencies and percentages will be used to describe the distribution of responses for each question in OHIP-14 questionnaires. Depending on the distribution the data later, independent sample t-test/ANOVA or the Mann-Whitney/Kruskal-Wallis tests will be used to assess the median OHIP-14 scores based on sample characteristics, oral hygiene habits/practices and oral status. Meanwhile, the comparisons of all groups for the presence and frequency of both objective and subjective adverse reactions (nominal values) will be tested with Chi-Square or Fisher's exact test where appropriate. Analysis of the subjective and objectives adverse events sessions will be done using McNemar test.

Eligibility Criteria:
Inclusion Criteria:

1. Individuals who are systemically healthy
2. Individuals who have ≥ 24 teeth
3. Individuals who have Basic Periodontal Examination score 0, 1 and 2 only with no periodontal deep pocket more than 5.5mm (gum disease)
4. Individuals who have never smoke cigarettes or other tobacco products

Exclusion Criteria:

1. Individuals who are the habitual users of miswak chewing sticks, or have experienced in using them
2. Individuals who wear orthodontic appliances (braces)
3. Individuals who have grossly decayed teeth, gross overhanging restorations, severe malpositioned teeth (crowded teeth) and/or gingival recession (receding gum), have crowns placed, and wear partial dentures
4. Individuals who have current or previous history of periodontal treatment (gum treatment) including root surface debridement/periodontal surgery
5. Individuals who are poor in manual dexterity
6. Individuals who are pregnant or lactating mothers
7. Individuals who have taken antibiotics in the previous 3 months