ObjectivesPorphyromonas gingivalis, as the main etiology of periodontitis, causes inflammation in the periodontal tissue, which triggers the immune response, fibroblast decline, and collagen destruction, generating attachment loss. Fibroblasts and collagen perform a fundamental role in the repair process of periodontal tissue. This study examined the potential of cassava leaf extract in increasing the quantity of fibroblasts and collagen density in the gingiva of rats with periodontitis.MethodsA posttest-only control group was used in this study. The experiment involved 24 male Wistar rats divided into four different groups: control group, group induced byP. gingivalisand given aquadest, group induced byP. gingivalisand given metronidazole, and group induced byP. gingivalisand given cassava leaf extract. Gingival tissue was taken after euthanasia, after which histological preparations were made, and fibroblasts and collagen were observed.ResultsOne-way analysis of variance revealed that the collagen density and fibroblasts quantity showed a notable difference between each group (p < 0.05), and interestingly, there was no significant difference between metronidazole and cassava leaf extract in the least significant difference test results (p > 0.05).ConclusionCassava leaf extract has the potential to increase fibroblast quantity and collagen density in the gingiva of periodontitis rat models.