Abbas N. Al-Shamary - Department of Basic Science, College of Dentistry, University of Baghdad, Baghdad, Iraq
Abbas S. Al-Mizraqchi - Medical Microbiology, Department of Basic science, College of Dentistry, University of Baghdad, Baghdad, Iraq

Honey is one of the most products has been used as an antimicrobial agent since the ancient times, nicotine is an important cause of dental caries and oral diseases, the purpose of this research is to study the effectiveness of honey and nicotine on the growth, acid production and biofilm formation of salivary mutans streptococci (M.S.).Materials and methods: Saliva samples from dentistry students were used to isolate M.S. In this investigation (age range between ۲۱-۲۳ years old). The morphological characteristics and biochemical tests were used to isolate, purify, and identify these microorganisms. The diameter of inhibition zone of honey and nicotine was determined by agar diffusion method and the pH measured by pH meter.Results: Results from an agar diffusion experiment showed that both honey and nicotine inhibited the growth of Mutans streptococci, with the diameter of the inhibition zone growing larger with increasing concentrations of both substances. However, the nicotine effect was significantly weaker than that of honey. Honey had a bactericidal concentration of ۹۰%, whereas nicotine's was ۴۵ mg/ml. Likewise, the honey and nicotine was high significant inhibit (P<۰.۰۱) the growth of M.S in vitro. Furthermore, the nicotine have a negative effect on honey activity on inhibition the acid product.Conclusion: In our study, we concluded that honey have indicated strong effects in inhibit M.S acid production. On the other hand, nicotine increased acidity and metabolic activity of M.S in the presence of honey. Therefore, smokers with a high consumption of nicotine should consider to the honey to minimize their chance of developing dental caries by reducing acid production from M.S streptococci.

Acid Production, honey, Mutans streptococcus, Nicotine, Inhibition zone