Guava (Psidium guajava) has a long history of use in traditional medicine for oral health, but there is also emerging scientific evidence supporting its potential for treating gingivitis. Several studies have investigated guava leaf extracts for their antimicrobial, anti-inflammatory, and antioxidant properties, which are relevant in the management of gingivitis—a common inflammatory condition of the gums caused by plaque accumulation.

Randomized controlled trials and in vitro studies have shown that guava leaf extracts can inhibit the growth of key oral pathogens such as Streptococcus mutans and Porphyromonas gingivalis. Additionally, guava contains flavonoids (such as quercetin), tannins, and other polyphenols that exhibit anti-inflammatory activity, which may help reduce gum inflammation and bleeding. A 2017 randomized clinical trial found that mouthwashes containing guava leaf extract significantly reduced gingival bleeding and plaque indices compared to placebo.

While the evidence is promising and suggests a scientific basis for the use of guava in gingivitis, most studies are preliminary, with small sample sizes and short durations. More large-scale, long-term clinical trials are needed to firmly establish efficacy and safety. Overall, guava's use in gingivitis is supported by moderate-quality scientific evidence, justifying further research and cautious clinical consideration.