Antibacterial activity of plant extracts against periodontal pathogens: A systematic review

Objective: This review intended to evaluate the in vitro antibacterial effect of natural plant extracts against periodontal pathogens responsible for periodontal disease. Methods: The research was conducted in five English databases (PubMed, Cochrane Library, Scopus, EBSCO, web of science) from January 2000 to June 2019. Only articles in English and French were retrieved. The inclusion criteria concerned all in vitro studies of the antibacterial activity of plant extracts on periodontal bacteria. The Reports on in vivo trials, essential oils, pure compounds have been excluded. The risk of bias was assessed using a standard approach. Results: 51 studies were selected in this review. The outcomes of selected studies expressed by the diameter of the zone of inhibition, the values of the minimum inhibitory concentration and the minimum bactericidal concentration were included. Out of the 51 studies, 25 have shown the antibacterial effect of plant extracts against Aggregatibacter actinomycetemcomitans; 33 out of the 51 studies reported on the effects against Porphyromanas gingivalis; 17 studies against Prevotella intermedia names; 13 studies on Fusobacterium nucleatum; three studies on Tannerella forsythia; and only one study against Treponema denticola. Conclusion: Although there is a high heterogeneity in the results of the minimum inhibitory concentration from one study to another, the results showed that plant extracts had an antimicrobial activity on the major periodontal pathogens. Thus, they can serve as alternatives to chemical antiseptic agents for the prevention and treatment of periodontal diseases.