Table 5.

Antibacterial effect of siwak

References	Study type	Siwak application	Sample collection	Microbiological assessment	Finding
Darout et al. [44] and Darout and Skaug [42]	Cross sectional	Exclusive	Subgingival plaque	Whole DNA probe and checkboard DNA-DNA hybridisation	Significantly higher prevalence of Aggregatibacter actinomycetemcomitans, Veillonella parvula, Actinomyces israelii, Capnocytophaga gingivalis and Streptococcus intermedius
Al-Otaibi et al. [34]	RCT	Exclusive	Subgingival plaque	Whole DNA probe and checkboard DNA-DNA hybridisation	Reduced number of A. actinomyctemcomitans
Rifaey et al. [39]	RCT	Adjunctive	Supragingival plaque	Quantitative real-time PCR	No significant difference of A. actinomycetemcomitans and Streptococcus Mutan

RCT, randomised controlled trial; DNA, deoxyribonucleic acid