Author(s): Shatha AlHarthi, Manal AlTamimi, Haya AlDreib, Lamia AlAgeel, Munerah Binshabaib and Ishrat Rahman

Abstract: Chlorhexidine (CX) mouthwash is effective against Porphyromonas gingivalis, a periodontal pathogen, but has unwanted side effects. We developed a prototype Nigella Sativa mouthwash (NSM), and measured its anti-microbial effects against P. gingivalis in vitro, as well as assessed its shelf life. We used the agar disc diffusion method and compared inhibition zones with antibiotics as positive controls, and to study acidity, mold, and microbial growth, we used the streaking plate method, and stored the plates in both light and dark conditions, as well as cold (4º C) and room temperature. Data were collected at zero days, seven days, and 14 days. NSM showed the same anti-microbial inhibition level as the strongest positive control. While acidity did not fluctuate measurably, mold and pellet formation were documented in all samples by 14 days, regardless of temperature or light condition. The NSM was an effective anti-microbial against P. gingivalis, but will need to be reformulated to suppress microbial growth in order to serve as a natural alternative to CX.