Objective: The objective of this review was to systematically analyse available literature on the effects of titanium dioxide nanoparticles (TiO₂ NPs) in improving the antimicrobial activity and shear bond strength when incorporated in orthodontic adhesives. Methods: All invitro studies that have evaluated the shear bond strength and the antimicrobial activity of TiO2 NPs infiltrated orthodontic adhesive were included in this review. A comprehensive search in 5 electronic databases namely, Google scholar, PUBMED, EMBASE, Cochrane and Web of science were done up to January 2023. Using the reference method for invitro studies, the Risk of bias ROB was evaluated. Meta-analysis using Random Effects Model was performed for assessing the antimicrobial activity against S. mutans, C. albicans and L. Acidophilus. Results: All the included studies had a moderate risk of bias. On qualitative analysis, a significant antimicrobial effect against Streptococcus mutans and Lactobacillus acidophilus and a non-significant shear bond strength of TiO2 infiltrated orthodontic adhesive was reported. The meta-analysis revealed a significant overall antimicrobial effect and nonsignificant shear bond strength values with a high heterogeneity. Conclusion: An overall significant antimicrobial effect of TiO₂ infiltrated orthodontic adhesive against S. mutans and L. Acidophilus was noted but with a high heterogeneity and a moderate risk of bias. An overall non-significant shear bond strength of TiO₂ infiltrated orthodontic adhesive was noted but with a high heterogeneity and a moderate risk of bias.