AbstractHyptis pectinata (L.) Poit., Lamiaceae, is an aromatic, abundant and broadly used plant species in Sergipe to treat oral and gastrointestinal pain and inflammation. The aim of the present study was to analyze the relation between periodontitis and changes in the corporal mass and alveolar bone structure after induction of experimental periodontal disease in rat treated or not treated with H. pectinata gel at 5% (GS5%) and 10% (GS10%), comparing their effects with doxycycline gel at 10% (D10%, positive control), vehicle gel (negative control) and a group with experimental periodontal disease, but non-treated. The gels were locally applied in the gingival region immediately after the experimental periodontal disease induction by ligature (3×/day, 11 days). Bone destruction was determined through clinical exam, histopathological analysis and cone beam computed tomography of the experimental animals (n=36). After 11 days of periodontitis induction, all groups that received ligature presented a decrease in the corporal mass, except to the naïve group (without experimental periodontal disease) (p<0.05). Computed tomography results have shown healthy bone structure in the group I and bone resorption for the test groups. Histopathological analysis confirmed the healthy bone structure for naïve group animals, while the test groups exhibited bone loss in several degrees. In particular, the non-treated group animals had an intense inflammatory process. When the periodontium of the animals treated with GS10% was histopathologically analyzed, insertion periodontium was preserved. The results for these groups were significantly different of the vehicle group (p<0.05). According to the results, the gel based in the aqueous extract of H. pectinata at 10% can prevent bone loss in experimental periodontal disease similarly to doxycycline 10%.