The effectiveness of miswak (Salvadora persica L. and Azadirachta indica A. Juss.) practices in reducing plaque and gingivitis among adults: A systematic review and meta-analysis

Ethnopharmacological relevance:
Salvadora persica L. and Azadirachtaindica A.Juss. are listed within the most common sources of miswak or chewing stick that widely used among Western Asia and Muslim populations worldwide. Miswak use in conjunction with toothbrush (adjunctive) has become apparent among the adults. Furthermore, miswak has been reported to have mechanical and pharmacological activities, and benefits to the oral health, by many studies.

Aim of the study:
To assess the effectiveness of miswak in maintaining periodontal health among adults.

Materials and methods:
We searched for randomised controlled trials (RCTs) investigating the effect of miswak published in PubMed, EBSCOHOST (Dentistry & Oral Sciences), SCOPUS, and Cochrane Database for Systematic Review (CDSR) from inception to May 08, 2022. The primary outcomes of interest were changes in the periodontal health measured with plaque and gingivitis scores as well as subgingival bacteria load. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach while the estimates of effect were pooled using a random-effects model.

Results:
Ten eligible articles were identified, of which 9 could be analysed quantitatively. The remaining report was included as part of the qualitative analysis. The meta-analysis showed that miswak was comparable with the toothbrush in reducing the mean plaque score (p= 0.08, SMD: 0.39, and 95% CI: −0.05 to 0.83) and mean gingivitis score (p= 0.37, SMD: 0.13, and 95% CI: −0.16 to 0.43). Even higher certainty of evidence for the effect of miswak on mean plaque reduction on labial surface of anterior teeth. However, the adjunctive effect of miswak was significantly more superior for reducing plaque (p= 0.01, SMD: 0.68, and 95% CI: 0.14 to 1.22) and gingivitis score (p= 0.04, SMD: 0.66, and 95% CI: 0.03 to 1.29).

Conclusions:
Miswak effectively reduced plaque and gingivitis scores to a level comparable to toothbrush when used exclusively. Adjunctive miswak use was particularly effective in improving periodontal health. However, the included studies inadequately reported on the method of toothbrushing using miswak and the frequency of miswak use. Therefore, further clinical studies are recommended to explore on the advantages and proper method of miswak practice for optima outcome and safety.