Onions are botanically known as Allium cepa, which is a bulbous plant belonging to allium family having characteristic pungent flavour. This vegetable has been used since ancient times for cooking purpose and also for its medicinal benefits. They are rich in flavonoids and phytochemicals. They also contain an antibacterial sulphur compound which can act against certain microbes causing gum/teeth infection. Apart from their antibacterial property, they are also known for their antiviral, antiparasitic, antihypertensive, antihyperlipidemic and antioxidant property.
Studies have shown that, onion extracts have got potential bactericidal effect against gram positive organisms. Among the oral pathogenic flora, Allium cepa extracts showed bactericidal effect against S.mutans, S.sorbinus, P.gingivalis and P.intermedia, which are the key organisms for causation of dental caries and periodontal diseases. Other scientific observations revealed that, red type of onions have more effect on oral streptococcus strains as compared to other variants of onion (white, yellow and green onion). Further, antimicrobial efficacy increased with increasing concentration of onion extract. Some in vitro studies also showed that, fresh onions has got better antimicrobial property as compared to old and stored onions i.e., age of the onions.
It is also noticed that, onions are used in folk medicine for the multiple health benefits. One among the way is to chew the raw onion or lightly cooked onions for at least 2-3minutes which can alleviate teeth pain and gum infections. This was assumed due to the action of sulphur compounds of onion in the improvement of gum circulation. More specifically, onions are used as home remedy for pyorrhea. Hence, it can be recommended to consume onions on regular basis as it can contribute in the prevention of the oral diseases to a certain extent if good oral hygiene practises are followed. Onions are also known for their easy availability and daily food flavour enhancing agent.