A bstract Introduction Among the various plants studied, cinnamon has emerged as a potential herbal antimicrobial agent. Besides the medicinal plants, recently probiotics have also been recognized to affect cinnamon bark oil Streptococcus mutans (S. mutans) and other harmful oral and gut microflora. Aim and objective This placebo-controlled study aims to compare the antimicrobial potential of cinnamon bark oil incorporated and probiotic blend [ Lactobacillus plantarum (TSP-Lp1), and Lactobacillus rhamnosus (TSP-Lrh1)] incorporated mucoadhesive patch against salivary S. mutans in caries active 7–10-year-old children. Design It was a double-blinded placebo-controlled study with n = 60. They were randomly allotted into three groups—Group I: Cinnamon patch, group II: probiotic patch, and group III: control patch (placebo) with n = 20 in each group. Materials and methods The study was carried out in three phases. In the first phase, the minimal inhibitory concentration (MIC) of cinnamon bark oil was determined against S. mutans followed by the formulation of cinnamon and probiotic patches. After a washout period of 2 weeks and a collection of baseline saliva samples, these patches were tested on the subjects from respective groups for 14 days with twice a day placement protocol. On the 15th day, saliva samples were collected and cultured, CFU/mL of the saliva of S. mutans for each subject was recorded and compared with baseline samples. Feedback in the form of a questionnaire was obtained from the patients. Statistical analysis Descriptive statistics, paired t -test for intragroup comparison, unpaired t -test for intergroup comparison, analysis of variance (ANOVA) for intergroup comparison, and post hoc Scheffe's. Results The results showed that both cinnamon patch and probiotic patch were comparable to each other in terms of their anti- S. mutans activity. The intragroup comparison of the CFU/mL count showed a highly significant reduction from baseline to post-intervention for both the groups ( p = 0.001). Conclusion Both cinnamon and probiotic blend have a strong antimicrobial property owing to their ability to cause significant reduction in salivary S. mutans and both the patches showed good patient acceptance. How to cite this article Gandhi HA, Srilatha KT, Deshmukh S, et al. Comparison of Antimicrobial Efficacy of Cinnamon Bark Oil Incorporated and Probiotic Blend Incorporated ...