Dental plaque is a complex environment that maintains a balance with certain microbial communities; however, this microhabitat can be disturbed by some endogenous species causing disease. An exploratory systematic review was carried out using the PubMed, Scopus, Lilacs, and Science Direct databases, identifying that the thymol, menthol, and eucalyptol compounds present varying antimicrobial activity, intra- and interspecies discordance, and a strong antimicrobial intensity on Aggregatibacter actinomycetemcomitans, Candida albicans, Candida dubliniensis, Enterococcus faecalis, Escherichia coli, Lactobacillus plantarum, and Streptococcus mutans, indicating that these phytochemicals can be considered broad-spectrum antimicrobial substances, with an effect on microorganisms linked to oral diseases.