Background: Periodontitis is a problem in dental and oral health with a high prevalence in Indonesia of 74.1%. Porphyromonas gingivalis was found in 85.75% of the subgingival plaque of periodontitis patients. Metronidazole is often used as adjunctive therapy to provide maximum results in the treatment of periodontitis but is contraindicated in certain patients. The wuluh starfruit has been shown to have active compounds including tannins, saponins, alkaloids, and flavonoids as well as vitamins that are antibacterial. This study aimed to analyze the antibacterial power of wuluh starfruit extract on the growth of P. gingivalis at concentrations of 6.25%, 12.5%, 25%, 50%, and 100%.

Methods: This type of research is an experimental laboratory with the post-test only control group design. Antibacterial test using disc diffusion method. This study consisted of 5 treatment groups (concentration of wuluh starfruit extract 6.25%, 12.5%, 25%, 50%, and 100%) and 2 control groups (negative control group and positive control group).

Results: The research data in the form of the diameter of the inhibition zone were analyzed by the Kruskal Wallis test followed by the Mann-Whitney test with the results that there were significant differences.

Conclusions: Based on the research, it can be concluded that the extract of wuluh starfruit (Averrhoa bilimbi L.) at concentrations of 6.25%, 12.5%, 25%, 50%, and 100% had antibacterial activity against the growth of P. gingivalis, the smallest at a concentration of 6.25% and the largest at a concentration of 100%.