Melaleuca alternifolia, commonly known as tea tree, has a long history of traditional use for oral health, including gum support. More recently, scientific studies have investigated its potential benefits for periodontal (gum) health, primarily due to its antimicrobial properties attributed to components such as terpinen-4-ol. Several in vitro studies have demonstrated that tea tree oil exhibits significant activity against oral pathogens implicated in gum disease, including Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans.

Clinical trials are limited but promising. For example, a 2004 randomized controlled trial published in the journal Australian Dental Journal found that tea tree oil gel applied to the gums reduced gingival bleeding and inflammation compared to placebo. Other small clinical studies have found similar results, though with some variability in effect size and concerns regarding irritation or allergic response in sensitive individuals.

Major dental associations do not currently recommend tea tree oil as a first-line treatment for periodontal disease, but acknowledge its antimicrobial effects. Overall, the evidence supporting Melaleuca alternifolia for gum health is stronger than tradition alone, but not as robust as that supporting conventional treatments like chlorhexidine. Thus, its use to support the gums is justified by both traditional use and emerging scientific evidence, meriting a moderate evidence rating.