Periodontal diseases are oral inflammatory diseases ranging from gingivitis to chronic periodontitis.Porphyromonas gingivalisis one of the major pathogens responsible for severe and chronic periodontitis. Plant extracts with antimicrobial activity could be considered possible alternatives to chlorhexidine, an antiseptic substance used in oral hygiene thatcan cause bacteria resistance. Here, two commercial extracts obtained fromCistus×incanusL. andScutellaria laterifloraL. were chemically characterized usingUltra-High-Performance Liquid Chromatography (UHPLC) coupled with a Q-Exactive Hybrid Quadrupole Orbitrap Mass Spectrometer. The extracts were studied for their bioaccessibility after simulated in vitro oral digestion, their antimicrobial activity againstP. gingivalis, their protective effects against cellular invasion byP. gingivalis, and their antibiofilm activity. The extracts were found to contain very complex mixtures of polyphenols, which were quite stable after in vitro simulated oral digestion and demonstrated mild, dose-dependent inhibitory activity againstP. gingivalisgrowth. This activity increased with the combination of the two extracts. Moreover, the combination of the extracts induced a reduction inP. gingivalisHaCaT invasiveness, and the reduction in biofilm came to around 80%. In conclusion, a combination ofC. incanusandS. lateriflorashowed promising effects useful in the treatment of gingivitis.